| # | 
 | # (C) Copyright 2000 - 2005 | 
 | # Wolfgang Denk, DENX Software Engineering, wd@denx.de. | 
 | # | 
 | # See file CREDITS for list of people who contributed to this | 
 | # project. | 
 | # | 
 | # This program is free software; you can redistribute it and/or | 
 | # modify it under the terms of the GNU General Public License as | 
 | # published by the Free Software Foundation; either version 2 of | 
 | # the License, or (at your option) any later version. | 
 | # | 
 | # This program is distributed in the hope that it will be useful, | 
 | # but WITHOUT ANY WARRANTY; without even the implied warranty of | 
 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the | 
 | # GNU General Public License for more details. | 
 | # | 
 | # You should have received a copy of the GNU General Public License | 
 | # along with this program; if not, write to the Free Software | 
 | # Foundation, Inc., 59 Temple Place, Suite 330, Boston, | 
 | # MA 02111-1307 USA | 
 | # | 
 |  | 
 | Summary: | 
 | ======== | 
 |  | 
 | This directory contains the source code for U-Boot, a boot loader for | 
 | Embedded boards based on PowerPC, ARM, MIPS and several other | 
 | processors, which can be installed in a boot ROM and used to | 
 | initialize and test the hardware or to download and run application | 
 | code. | 
 |  | 
 | The development of U-Boot is closely related to Linux: some parts of | 
 | the source code originate in the Linux source tree, we have some | 
 | header files in common, and special provision has been made to | 
 | support booting of Linux images. | 
 |  | 
 | Some attention has been paid to make this software easily | 
 | configurable and extendable. For instance, all monitor commands are | 
 | implemented with the same call interface, so that it's very easy to | 
 | add new commands. Also, instead of permanently adding rarely used | 
 | code (for instance hardware test utilities) to the monitor, you can | 
 | load and run it dynamically. | 
 |  | 
 |  | 
 | Status: | 
 | ======= | 
 |  | 
 | In general, all boards for which a configuration option exists in the | 
 | Makefile have been tested to some extent and can be considered | 
 | "working". In fact, many of them are used in production systems. | 
 |  | 
 | In case of problems see the CHANGELOG and CREDITS files to find out | 
 | who contributed the specific port. | 
 |  | 
 |  | 
 | Where to get help: | 
 | ================== | 
 |  | 
 | In case you have questions about, problems with or contributions for | 
 | U-Boot you should send a message to the U-Boot mailing list at | 
 | <u-boot-users@lists.sourceforge.net>. There is also an archive of | 
 | previous traffic on the mailing list - please search the archive | 
 | before asking FAQ's. Please see | 
 | http://lists.sourceforge.net/lists/listinfo/u-boot-users/ | 
 |  | 
 |  | 
 | Where we come from: | 
 | =================== | 
 |  | 
 | - start from 8xxrom sources | 
 | - create PPCBoot project (http://sourceforge.net/projects/ppcboot) | 
 | - clean up code | 
 | - make it easier to add custom boards | 
 | - make it possible to add other [PowerPC] CPUs | 
 | - extend functions, especially: | 
 |   * Provide extended interface to Linux boot loader | 
 |   * S-Record download | 
 |   * network boot | 
 |   * PCMCIA / CompactFLash / ATA disk / SCSI ... boot | 
 | - create ARMBoot project (http://sourceforge.net/projects/armboot) | 
 | - add other CPU families (starting with ARM) | 
 | - create U-Boot project (http://sourceforge.net/projects/u-boot) | 
 |  | 
 |  | 
 | Names and Spelling: | 
 | =================== | 
 |  | 
 | The "official" name of this project is "Das U-Boot". The spelling | 
 | "U-Boot" shall be used in all written text (documentation, comments | 
 | in source files etc.). Example: | 
 |  | 
 | 	This is the README file for the U-Boot project. | 
 |  | 
 | File names etc. shall be based on the string "u-boot". Examples: | 
 |  | 
 | 	include/asm-ppc/u-boot.h | 
 |  | 
 | 	#include <asm/u-boot.h> | 
 |  | 
 | Variable names, preprocessor constants etc. shall be either based on | 
 | the string "u_boot" or on "U_BOOT". Example: | 
 |  | 
 | 	U_BOOT_VERSION		u_boot_logo | 
 | 	IH_OS_U_BOOT		u_boot_hush_start | 
 |  | 
 |  | 
 | Versioning: | 
 | =========== | 
 |  | 
 | U-Boot uses a 3 level version number containing a version, a | 
 | sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", | 
 | sub-version "34", and patchlevel "4". | 
 |  | 
 | The patchlevel is used to indicate certain stages of development | 
 | between released versions, i. e. officially released versions of | 
 | U-Boot will always have a patchlevel of "0". | 
 |  | 
 |  | 
 | Directory Hierarchy: | 
 | ==================== | 
 |  | 
 | - board		Board dependent files | 
 | - common	Misc architecture independent functions | 
 | - cpu		CPU specific files | 
 |   - 74xx_7xx	Files specific to Freescale MPC74xx and 7xx CPUs | 
 |   - arm720t	Files specific to ARM 720 CPUs | 
 |   - arm920t	Files specific to ARM 920 CPUs | 
 |     - at91rm9200 Files specific to Atmel AT91RM9200 CPU | 
 |     - imx	Files specific to Freescale MC9328 i.MX CPUs | 
 |     - s3c24x0	Files specific to Samsung S3C24X0 CPUs | 
 |   - arm925t	Files specific to ARM 925 CPUs | 
 |   - arm926ejs	Files specific to ARM 926 CPUs | 
 |   - arm1136	Files specific to ARM 1136 CPUs | 
 |   - i386	Files specific to i386 CPUs | 
 |   - ixp		Files specific to Intel XScale IXP CPUs | 
 |   - mcf52x2	Files specific to Freescale ColdFire MCF52x2 CPUs | 
 |   - mips	Files specific to MIPS CPUs | 
 |   - mpc5xx	Files specific to Freescale MPC5xx  CPUs | 
 |   - mpc5xxx	Files specific to Freescale MPC5xxx CPUs | 
 |   - mpc8xx	Files specific to Freescale MPC8xx  CPUs | 
 |   - mpc8220	Files specific to Freescale MPC8220 CPUs | 
 |   - mpc824x	Files specific to Freescale MPC824x CPUs | 
 |   - mpc8260	Files specific to Freescale MPC8260 CPUs | 
 |   - mpc85xx	Files specific to Freescale MPC85xx CPUs | 
 |   - nios	Files specific to Altera NIOS CPUs | 
 |   - nios2	Files specific to Altera Nios-II CPUs | 
 |   - ppc4xx	Files specific to AMCC PowerPC 4xx CPUs | 
 |   - pxa		Files specific to Intel XScale PXA CPUs | 
 |   - s3c44b0	Files specific to Samsung S3C44B0 CPUs | 
 |   - sa1100	Files specific to Intel StrongARM SA1100 CPUs | 
 | - disk		Code for disk drive partition handling | 
 | - doc		Documentation (don't expect too much) | 
 | - drivers	Commonly used device drivers | 
 | - dtt		Digital Thermometer and Thermostat drivers | 
 | - examples	Example code for standalone applications, etc. | 
 | - include	Header Files | 
 | - lib_arm	Files generic to ARM	 architecture | 
 | - lib_generic	Files generic to all	 architectures | 
 | - lib_i386	Files generic to i386	 architecture | 
 | - lib_m68k	Files generic to m68k	 architecture | 
 | - lib_mips	Files generic to MIPS	 architecture | 
 | - lib_nios	Files generic to NIOS	 architecture | 
 | - lib_ppc	Files generic to PowerPC architecture | 
 | - net		Networking code | 
 | - post		Power On Self Test | 
 | - rtc		Real Time Clock drivers | 
 | - tools		Tools to build S-Record or U-Boot images, etc. | 
 |  | 
 | Software Configuration: | 
 | ======================= | 
 |  | 
 | Configuration is usually done using C preprocessor defines; the | 
 | rationale behind that is to avoid dead code whenever possible. | 
 |  | 
 | There are two classes of configuration variables: | 
 |  | 
 | * Configuration _OPTIONS_: | 
 |   These are selectable by the user and have names beginning with | 
 |   "CONFIG_". | 
 |  | 
 | * Configuration _SETTINGS_: | 
 |   These depend on the hardware etc. and should not be meddled with if | 
 |   you don't know what you're doing; they have names beginning with | 
 |   "CFG_". | 
 |  | 
 | Later we will add a configuration tool - probably similar to or even | 
 | identical to what's used for the Linux kernel. Right now, we have to | 
 | do the configuration by hand, which means creating some symbolic | 
 | links and editing some configuration files. We use the TQM8xxL boards | 
 | as an example here. | 
 |  | 
 |  | 
 | Selection of Processor Architecture and Board Type: | 
 | --------------------------------------------------- | 
 |  | 
 | For all supported boards there are ready-to-use default | 
 | configurations available; just type "make <board_name>_config". | 
 |  | 
 | Example: For a TQM823L module type: | 
 |  | 
 | 	cd u-boot | 
 | 	make TQM823L_config | 
 |  | 
 | For the Cogent platform, you need to specify the cpu type as well; | 
 | e.g. "make cogent_mpc8xx_config". And also configure the cogent | 
 | directory according to the instructions in cogent/README. | 
 |  | 
 |  | 
 | Configuration Options: | 
 | ---------------------- | 
 |  | 
 | Configuration depends on the combination of board and CPU type; all | 
 | such information is kept in a configuration file | 
 | "include/configs/<board_name>.h". | 
 |  | 
 | Example: For a TQM823L module, all configuration settings are in | 
 | "include/configs/TQM823L.h". | 
 |  | 
 |  | 
 | Many of the options are named exactly as the corresponding Linux | 
 | kernel configuration options. The intention is to make it easier to | 
 | build a config tool - later. | 
 |  | 
 |  | 
 | The following options need to be configured: | 
 |  | 
 | - CPU Type:	Define exactly one of | 
 |  | 
 | 		PowerPC based CPUs: | 
 | 		------------------- | 
 | 		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860 | 
 | 	or	CONFIG_MPC5xx | 
 | 	or	CONFIG_MPC8220 | 
 | 	or	CONFIG_MPC824X, CONFIG_MPC8260 | 
 | 	or	CONFIG_MPC85xx | 
 | 	or	CONFIG_IOP480 | 
 | 	or	CONFIG_405GP | 
 | 	or	CONFIG_405EP | 
 | 	or	CONFIG_440 | 
 | 	or	CONFIG_MPC74xx | 
 | 	or	CONFIG_750FX | 
 |  | 
 | 		ARM based CPUs: | 
 | 		--------------- | 
 | 		CONFIG_SA1110 | 
 | 		CONFIG_ARM7 | 
 | 		CONFIG_PXA250 | 
 | 		CONFIG_CPU_MONAHANS | 
 |  | 
 | 		MicroBlaze based CPUs: | 
 | 		---------------------- | 
 | 		CONFIG_MICROBLAZE | 
 |  | 
 | 		Nios-2 based CPUs: | 
 | 		---------------------- | 
 | 		CONFIG_NIOS2 | 
 |  | 
 |  | 
 | - Board Type:	Define exactly one of | 
 |  | 
 | 		PowerPC based boards: | 
 | 		--------------------- | 
 |  | 
 | 		CONFIG_ADCIOP		CONFIG_FPS860L		CONFIG_OXC | 
 | 		CONFIG_ADS860		CONFIG_GEN860T		CONFIG_PCI405 | 
 | 		CONFIG_AMX860		CONFIG_GENIETV		CONFIG_PCIPPC2 | 
 | 		CONFIG_AP1000		CONFIG_GTH		CONFIG_PCIPPC6 | 
 | 		CONFIG_AR405		CONFIG_gw8260		CONFIG_pcu_e | 
 | 		CONFIG_BAB7xx		CONFIG_hermes		CONFIG_PIP405 | 
 | 		CONFIG_BC3450		CONFIG_hymod		CONFIG_PM826 | 
 | 		CONFIG_c2mon		CONFIG_IAD210		CONFIG_ppmc8260 | 
 | 		CONFIG_CANBT		CONFIG_ICU862		CONFIG_QS823 | 
 | 		CONFIG_CCM		CONFIG_IP860		CONFIG_QS850 | 
 | 		CONFIG_CMI		CONFIG_IPHASE4539	CONFIG_QS860T | 
 | 		CONFIG_cogent_mpc8260	CONFIG_IVML24		CONFIG_RBC823 | 
 | 		CONFIG_cogent_mpc8xx	CONFIG_IVML24_128	CONFIG_RPXClassic | 
 | 		CONFIG_CPCI405		CONFIG_IVML24_256	CONFIG_RPXlite | 
 | 		CONFIG_CPCI4052		CONFIG_IVMS8		CONFIG_RPXsuper | 
 | 		CONFIG_CPCIISER4	CONFIG_IVMS8_128	CONFIG_rsdproto | 
 | 		CONFIG_CPU86		CONFIG_IVMS8_256	CONFIG_sacsng | 
 | 		CONFIG_CRAYL1		CONFIG_JSE		CONFIG_Sandpoint8240 | 
 | 		CONFIG_CSB272		CONFIG_LANTEC		CONFIG_Sandpoint8245 | 
 | 		CONFIG_CU824		CONFIG_LITE5200B	CONFIG_sbc8260 | 
 | 		CONFIG_DASA_SIM		CONFIG_lwmon		CONFIG_sbc8560 | 
 | 		CONFIG_DB64360		CONFIG_MBX		CONFIG_SM850 | 
 | 		CONFIG_DB64460		CONFIG_MBX860T		CONFIG_SPD823TS | 
 | 		CONFIG_DU405		CONFIG_MHPC		CONFIG_STXGP3 | 
 | 		CONFIG_DUET_ADS		CONFIG_MIP405		CONFIG_SXNI855T | 
 | 		CONFIG_EBONY		CONFIG_MOUSSE		CONFIG_TQM823L | 
 | 		CONFIG_ELPPC		CONFIG_MPC8260ADS	CONFIG_TQM8260 | 
 | 		CONFIG_ELPT860		CONFIG_MPC8540ADS	CONFIG_TQM850L | 
 | 		CONFIG_ep8260		CONFIG_MPC8540EVAL	CONFIG_TQM855L | 
 | 		CONFIG_ERIC		CONFIG_MPC8560ADS	CONFIG_TQM860L | 
 | 		CONFIG_ESTEEM192E	CONFIG_MUSENKI		CONFIG_TTTech | 
 | 		CONFIG_ETX094		CONFIG_MVS1		CONFIG_UTX8245 | 
 | 		CONFIG_EVB64260		CONFIG_NETPHONE		CONFIG_V37 | 
 | 		CONFIG_FADS823		CONFIG_NETTA		CONFIG_W7OLMC | 
 | 		CONFIG_FADS850SAR	CONFIG_NETVIA		CONFIG_W7OLMG | 
 | 		CONFIG_FADS860T		CONFIG_NX823		CONFIG_WALNUT | 
 | 		CONFIG_FLAGADM		CONFIG_OCRTC		CONFIG_ZPC1900 | 
 | 		CONFIG_FPS850L		CONFIG_ORSG		CONFIG_ZUMA | 
 |  | 
 | 		ARM based boards: | 
 | 		----------------- | 
 |  | 
 | 		CONFIG_ARMADILLO,	CONFIG_AT91RM9200DK,	CONFIG_CERF250, | 
 | 		CONFIG_CSB637,		CONFIG_DELTA,		CONFIG_DNP1110, | 
 | 	 	CONFIG_EP7312,		CONFIG_H2_OMAP1610,	CONFIG_HHP_CRADLE, | 
 | 		CONFIG_IMPA7,	    CONFIG_INNOVATOROMAP1510,	CONFIG_INNOVATOROMAP1610, | 
 | 		CONFIG_KB9202,		CONFIG_LART,		CONFIG_LPD7A400, | 
 | 		CONFIG_LUBBOCK,		CONFIG_OSK_OMAP5912,	CONFIG_OMAP2420H4, | 
 | 		CONFIG_SHANNON,		CONFIG_P2_OMAP730,	CONFIG_SMDK2400, | 
 | 		CONFIG_SMDK2410,	CONFIG_TRAB,		CONFIG_VCMA9 | 
 |  | 
 | 		MicroBlaze based boards: | 
 | 		------------------------ | 
 |  | 
 | 		CONFIG_SUZAKU | 
 |  | 
 | 		Nios-2 based boards: | 
 | 		------------------------ | 
 |  | 
 | 		CONFIG_PCI5441 CONFIG_PK1C20 | 
 |  | 
 |  | 
 | - CPU Module Type: (if CONFIG_COGENT is defined) | 
 | 		Define exactly one of | 
 | 		CONFIG_CMA286_60_OLD | 
 | --- FIXME --- not tested yet: | 
 | 		CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, | 
 | 		CONFIG_CMA287_23, CONFIG_CMA287_50 | 
 |  | 
 | - Motherboard Type: (if CONFIG_COGENT is defined) | 
 | 		Define exactly one of | 
 | 		CONFIG_CMA101, CONFIG_CMA102 | 
 |  | 
 | - Motherboard I/O Modules: (if CONFIG_COGENT is defined) | 
 | 		Define one or more of | 
 | 		CONFIG_CMA302 | 
 |  | 
 | - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) | 
 | 		Define one or more of | 
 | 		CONFIG_LCD_HEARTBEAT	- update a character position on | 
 | 					  the lcd display every second with | 
 | 					  a "rotator" |\-/|\-/ | 
 |  | 
 | - Board flavour: (if CONFIG_MPC8260ADS is defined) | 
 | 		CONFIG_ADSTYPE | 
 | 		Possible values are: | 
 | 			CFG_8260ADS	- original MPC8260ADS | 
 | 			CFG_8266ADS	- MPC8266ADS | 
 | 			CFG_PQ2FADS	- PQ2FADS-ZU or PQ2FADS-VR | 
 | 			CFG_8272ADS	- MPC8272ADS | 
 |  | 
 | - MPC824X Family Member (if CONFIG_MPC824X is defined) | 
 | 		Define exactly one of | 
 | 		CONFIG_MPC8240, CONFIG_MPC8245 | 
 |  | 
 | - 8xx CPU Options: (if using an MPC8xx cpu) | 
 | 		CONFIG_8xx_GCLK_FREQ	- deprecated: CPU clock if | 
 | 					  get_gclk_freq() cannot work | 
 | 					  e.g. if there is no 32KHz | 
 | 					  reference PIT/RTC clock | 
 | 		CONFIG_8xx_OSCLK	- PLL input clock (either EXTCLK | 
 | 					  or XTAL/EXTAL) | 
 |  | 
 | - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): | 
 | 		CFG_8xx_CPUCLK_MIN | 
 | 		CFG_8xx_CPUCLK_MAX | 
 | 		CONFIG_8xx_CPUCLK_DEFAULT | 
 | 			See doc/README.MPC866 | 
 |  | 
 | 		CFG_MEASURE_CPUCLK | 
 |  | 
 | 		Define this to measure the actual CPU clock instead | 
 | 		of relying on the correctness of the configured | 
 | 		values. Mostly useful for board bringup to make sure | 
 | 		the PLL is locked at the intended frequency. Note | 
 | 		that this requires a (stable) reference clock (32 kHz | 
 | 		RTC clock or CFG_8XX_XIN) | 
 |  | 
 | - Intel Monahans options: | 
 | 		CFG_MONAHANS_RUN_MODE_OSC_RATIO | 
 |  | 
 | 		Defines the Monahans run mode to oscillator | 
 | 		ratio. Valid values are 8, 16, 24, 31. The core | 
 | 		frequency is this value multiplied by 13 MHz. | 
 |  | 
 | 		CFG_MONAHANS_TURBO_RUN_MODE_RATIO | 
 |  | 
 | 		Defines the Monahans turbo mode to oscillator | 
 | 		ratio. Valid values are 1 (default if undefined) and | 
 | 		2. The core frequency as calculated above is multiplied | 
 | 		by this value. | 
 |  | 
 | - Linux Kernel Interface: | 
 | 		CONFIG_CLOCKS_IN_MHZ | 
 |  | 
 | 		U-Boot stores all clock information in Hz | 
 | 		internally. For binary compatibility with older Linux | 
 | 		kernels (which expect the clocks passed in the | 
 | 		bd_info data to be in MHz) the environment variable | 
 | 		"clocks_in_mhz" can be defined so that U-Boot | 
 | 		converts clock data to MHZ before passing it to the | 
 | 		Linux kernel. | 
 | 		When CONFIG_CLOCKS_IN_MHZ is defined, a definition of | 
 | 		"clocks_in_mhz=1" is  automatically  included  in  the | 
 | 		default environment. | 
 |  | 
 | 		CONFIG_MEMSIZE_IN_BYTES		[relevant for MIPS only] | 
 |  | 
 | 		When transfering memsize parameter to linux, some versions | 
 | 		expect it to be in bytes, others in MB. | 
 | 		Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. | 
 |  | 
 | 		CONFIG_OF_FLAT_TREE | 
 |  | 
 | 		New kernel versions are expecting firmware settings to be | 
 | 		passed using flat open firmware trees. | 
 | 		The environment variable "disable_of", when set, disables this | 
 | 		functionality. | 
 |  | 
 | 		CONFIG_OF_FLAT_TREE_MAX_SIZE | 
 |  | 
 | 		The maximum size of the constructed OF tree. | 
 |  | 
 | 		OF_CPU - The proper name of the cpus node. | 
 | 		OF_SOC - The proper name of the soc node. | 
 | 		OF_TBCLK - The timebase frequency. | 
 | 		OF_STDOUT_PATH - The path to the console device | 
 |  | 
 | 		CONFIG_OF_HAS_BD_T | 
 |  | 
 | 		The resulting flat device tree will have a copy of the bd_t. | 
 | 		Space should be pre-allocated in the dts for the bd_t. | 
 |  | 
 | 		CONFIG_OF_HAS_UBOOT_ENV | 
 |  | 
 | 		The resulting flat device tree will have a copy of u-boot's | 
 | 		environment variables | 
 |  | 
 | 		CONFIG_OF_BOARD_SETUP | 
 |  | 
 | 		Board code has addition modification that it wants to make | 
 | 		to the flat device tree before handing it off to the kernel | 
 |  | 
 | - Serial Ports: | 
 | 		CFG_PL010_SERIAL | 
 |  | 
 | 		Define this if you want support for Amba PrimeCell PL010 UARTs. | 
 |  | 
 | 		CFG_PL011_SERIAL | 
 |  | 
 | 		Define this if you want support for Amba PrimeCell PL011 UARTs. | 
 |  | 
 | 		CONFIG_PL011_CLOCK | 
 |  | 
 | 		If you have Amba PrimeCell PL011 UARTs, set this variable to | 
 | 		the clock speed of the UARTs. | 
 |  | 
 | 		CONFIG_PL01x_PORTS | 
 |  | 
 | 		If you have Amba PrimeCell PL010 or PL011 UARTs on your board, | 
 | 		define this to a list of base addresses for each (supported) | 
 | 		port. See e.g. include/configs/versatile.h | 
 |  | 
 |  | 
 | - Console Interface: | 
 | 		Depending on board, define exactly one serial port | 
 | 		(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, | 
 | 		CONFIG_8xx_CONS_SCC1, ...), or switch off the serial | 
 | 		console by defining CONFIG_8xx_CONS_NONE | 
 |  | 
 | 		Note: if CONFIG_8xx_CONS_NONE is defined, the serial | 
 | 		port routines must be defined elsewhere | 
 | 		(i.e. serial_init(), serial_getc(), ...) | 
 |  | 
 | 		CONFIG_CFB_CONSOLE | 
 | 		Enables console device for a color framebuffer. Needs following | 
 | 		defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) | 
 | 			VIDEO_FB_LITTLE_ENDIAN	graphic memory organisation | 
 | 						(default big endian) | 
 | 			VIDEO_HW_RECTFILL	graphic chip supports | 
 | 						rectangle fill | 
 | 						(cf. smiLynxEM) | 
 | 			VIDEO_HW_BITBLT		graphic chip supports | 
 | 						bit-blit (cf. smiLynxEM) | 
 | 			VIDEO_VISIBLE_COLS	visible pixel columns | 
 | 						(cols=pitch) | 
 | 			VIDEO_VISIBLE_ROWS	visible pixel rows | 
 | 			VIDEO_PIXEL_SIZE	bytes per pixel | 
 | 			VIDEO_DATA_FORMAT	graphic data format | 
 | 						(0-5, cf. cfb_console.c) | 
 | 			VIDEO_FB_ADRS		framebuffer address | 
 | 			VIDEO_KBD_INIT_FCT	keyboard int fct | 
 | 						(i.e. i8042_kbd_init()) | 
 | 			VIDEO_TSTC_FCT		test char fct | 
 | 						(i.e. i8042_tstc) | 
 | 			VIDEO_GETC_FCT		get char fct | 
 | 						(i.e. i8042_getc) | 
 | 			CONFIG_CONSOLE_CURSOR	cursor drawing on/off | 
 | 						(requires blink timer | 
 | 						cf. i8042.c) | 
 | 			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) | 
 | 			CONFIG_CONSOLE_TIME	display time/date info in | 
 | 						upper right corner | 
 | 						(requires CFG_CMD_DATE) | 
 | 			CONFIG_VIDEO_LOGO	display Linux logo in | 
 | 						upper left corner | 
 | 			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of | 
 | 						linux_logo.h for logo. | 
 | 						Requires CONFIG_VIDEO_LOGO | 
 | 			CONFIG_CONSOLE_EXTRA_INFO | 
 | 						addional board info beside | 
 | 						the logo | 
 |  | 
 | 		When CONFIG_CFB_CONSOLE is defined, video console is | 
 | 		default i/o. Serial console can be forced with | 
 | 		environment 'console=serial'. | 
 |  | 
 | 		When CONFIG_SILENT_CONSOLE is defined, all console | 
 | 		messages (by U-Boot and Linux!) can be silenced with | 
 | 		the "silent" environment variable. See | 
 | 		doc/README.silent for more information. | 
 |  | 
 | - Console Baudrate: | 
 | 		CONFIG_BAUDRATE - in bps | 
 | 		Select one of the baudrates listed in | 
 | 		CFG_BAUDRATE_TABLE, see below. | 
 | 		CFG_BRGCLK_PRESCALE, baudrate prescale | 
 |  | 
 | - Interrupt driven serial port input: | 
 | 		CONFIG_SERIAL_SOFTWARE_FIFO | 
 |  | 
 | 		PPC405GP only. | 
 | 		Use an interrupt handler for receiving data on the | 
 | 		serial port. It also enables using hardware handshake | 
 | 		(RTS/CTS) and UART's built-in FIFO. Set the number of | 
 | 		bytes the interrupt driven input buffer should have. | 
 |  | 
 | 		Leave undefined to disable this feature, including | 
 | 		disable the buffer and hardware handshake. | 
 |  | 
 | - Console UART Number: | 
 | 		CONFIG_UART1_CONSOLE | 
 |  | 
 | 		AMCC PPC4xx only. | 
 | 		If defined internal UART1 (and not UART0) is used | 
 | 		as default U-Boot console. | 
 |  | 
 | - Boot Delay:	CONFIG_BOOTDELAY - in seconds | 
 | 		Delay before automatically booting the default image; | 
 | 		set to -1 to disable autoboot. | 
 |  | 
 | 		See doc/README.autoboot for these options that | 
 | 		work with CONFIG_BOOTDELAY. None are required. | 
 | 		CONFIG_BOOT_RETRY_TIME | 
 | 		CONFIG_BOOT_RETRY_MIN | 
 | 		CONFIG_AUTOBOOT_KEYED | 
 | 		CONFIG_AUTOBOOT_PROMPT | 
 | 		CONFIG_AUTOBOOT_DELAY_STR | 
 | 		CONFIG_AUTOBOOT_STOP_STR | 
 | 		CONFIG_AUTOBOOT_DELAY_STR2 | 
 | 		CONFIG_AUTOBOOT_STOP_STR2 | 
 | 		CONFIG_ZERO_BOOTDELAY_CHECK | 
 | 		CONFIG_RESET_TO_RETRY | 
 |  | 
 | - Autoboot Command: | 
 | 		CONFIG_BOOTCOMMAND | 
 | 		Only needed when CONFIG_BOOTDELAY is enabled; | 
 | 		define a command string that is automatically executed | 
 | 		when no character is read on the console interface | 
 | 		within "Boot Delay" after reset. | 
 |  | 
 | 		CONFIG_BOOTARGS | 
 | 		This can be used to pass arguments to the bootm | 
 | 		command. The value of CONFIG_BOOTARGS goes into the | 
 | 		environment value "bootargs". | 
 |  | 
 | 		CONFIG_RAMBOOT and CONFIG_NFSBOOT | 
 | 		The value of these goes into the environment as | 
 | 		"ramboot" and "nfsboot" respectively, and can be used | 
 | 		as a convenience, when switching between booting from | 
 | 		ram and nfs. | 
 |  | 
 | - Pre-Boot Commands: | 
 | 		CONFIG_PREBOOT | 
 |  | 
 | 		When this option is #defined, the existence of the | 
 | 		environment variable "preboot" will be checked | 
 | 		immediately before starting the CONFIG_BOOTDELAY | 
 | 		countdown and/or running the auto-boot command resp. | 
 | 		entering interactive mode. | 
 |  | 
 | 		This feature is especially useful when "preboot" is | 
 | 		automatically generated or modified. For an example | 
 | 		see the LWMON board specific code: here "preboot" is | 
 | 		modified when the user holds down a certain | 
 | 		combination of keys on the (special) keyboard when | 
 | 		booting the systems | 
 |  | 
 | - Serial Download Echo Mode: | 
 | 		CONFIG_LOADS_ECHO | 
 | 		If defined to 1, all characters received during a | 
 | 		serial download (using the "loads" command) are | 
 | 		echoed back. This might be needed by some terminal | 
 | 		emulations (like "cu"), but may as well just take | 
 | 		time on others. This setting #define's the initial | 
 | 		value of the "loads_echo" environment variable. | 
 |  | 
 | - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) | 
 | 		CONFIG_KGDB_BAUDRATE | 
 | 		Select one of the baudrates listed in | 
 | 		CFG_BAUDRATE_TABLE, see below. | 
 |  | 
 | - Monitor Functions: | 
 | 		CONFIG_COMMANDS | 
 | 		Most monitor functions can be selected (or | 
 | 		de-selected) by adjusting the definition of | 
 | 		CONFIG_COMMANDS; to select individual functions, | 
 | 		#define CONFIG_COMMANDS by "OR"ing any of the | 
 | 		following values: | 
 |  | 
 | 		#define enables commands: | 
 | 		------------------------- | 
 | 		CFG_CMD_ASKENV	* ask for env variable | 
 | 		CFG_CMD_AUTOSCRIPT Autoscript Support | 
 | 		CFG_CMD_BDI	  bdinfo | 
 | 		CFG_CMD_BEDBUG	* Include BedBug Debugger | 
 | 		CFG_CMD_BMP	* BMP support | 
 | 		CFG_CMD_BSP	* Board specific commands | 
 | 		CFG_CMD_BOOTD	  bootd | 
 | 		CFG_CMD_CACHE	* icache, dcache | 
 | 		CFG_CMD_CONSOLE	  coninfo | 
 | 		CFG_CMD_DATE	* support for RTC, date/time... | 
 | 		CFG_CMD_DHCP	* DHCP support | 
 | 		CFG_CMD_DIAG	* Diagnostics | 
 | 		CFG_CMD_DOC	* Disk-On-Chip Support | 
 | 		CFG_CMD_DTT	* Digital Therm and Thermostat | 
 | 		CFG_CMD_ECHO	  echo arguments | 
 | 		CFG_CMD_EEPROM	* EEPROM read/write support | 
 | 		CFG_CMD_ELF	* bootelf, bootvx | 
 | 		CFG_CMD_ENV	  saveenv | 
 | 		CFG_CMD_FDC	* Floppy Disk Support | 
 | 		CFG_CMD_FAT	* FAT partition support | 
 | 		CFG_CMD_FDOS	* Dos diskette Support | 
 | 		CFG_CMD_FLASH	  flinfo, erase, protect | 
 | 		CFG_CMD_FPGA	  FPGA device initialization support | 
 | 		CFG_CMD_HWFLOW	* RTS/CTS hw flow control | 
 | 		CFG_CMD_I2C	* I2C serial bus support | 
 | 		CFG_CMD_IDE	* IDE harddisk support | 
 | 		CFG_CMD_IMI	  iminfo | 
 | 		CFG_CMD_IMLS	  List all found images | 
 | 		CFG_CMD_IMMAP	* IMMR dump support | 
 | 		CFG_CMD_IRQ	* irqinfo | 
 | 		CFG_CMD_ITEST	  Integer/string test of 2 values | 
 | 		CFG_CMD_JFFS2	* JFFS2 Support | 
 | 		CFG_CMD_KGDB	* kgdb | 
 | 		CFG_CMD_LOADB	  loadb | 
 | 		CFG_CMD_LOADS	  loads | 
 | 		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base, | 
 | 				  loop, loopw, mtest | 
 | 		CFG_CMD_MISC	  Misc functions like sleep etc | 
 | 		CFG_CMD_MMC	* MMC memory mapped support | 
 | 		CFG_CMD_MII	* MII utility commands | 
 | 		CFG_CMD_NAND	* NAND support | 
 | 		CFG_CMD_NET	  bootp, tftpboot, rarpboot | 
 | 		CFG_CMD_PCI	* pciinfo | 
 | 		CFG_CMD_PCMCIA	* PCMCIA support | 
 | 		CFG_CMD_PING	* send ICMP ECHO_REQUEST to network host | 
 | 		CFG_CMD_PORTIO	* Port I/O | 
 | 		CFG_CMD_REGINFO * Register dump | 
 | 		CFG_CMD_RUN	  run command in env variable | 
 | 		CFG_CMD_SAVES	* save S record dump | 
 | 		CFG_CMD_SCSI	* SCSI Support | 
 | 		CFG_CMD_SDRAM	* print SDRAM configuration information | 
 | 				  (requires CFG_CMD_I2C) | 
 | 		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) | 
 | 		CFG_CMD_SPI	* SPI serial bus support | 
 | 		CFG_CMD_USB	* USB support | 
 | 		CFG_CMD_VFD	* VFD support (TRAB) | 
 | 		CFG_CMD_BSP	* Board SPecific functions | 
 | 		CFG_CMD_CDP	* Cisco Discover Protocol support | 
 | 		----------------------------------------------- | 
 | 		CFG_CMD_ALL	all | 
 |  | 
 | 		CONFIG_CMD_DFL	Default configuration; at the moment | 
 | 				this is includes all commands, except | 
 | 				the ones marked with "*" in the list | 
 | 				above. | 
 |  | 
 | 		If you don't define CONFIG_COMMANDS it defaults to | 
 | 		CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can | 
 | 		override the default settings in the respective | 
 | 		include file. | 
 |  | 
 | 		EXAMPLE: If you want all functions except of network | 
 | 		support you can write: | 
 |  | 
 | 		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) | 
 |  | 
 |  | 
 | 	Note:	Don't enable the "icache" and "dcache" commands | 
 | 		(configuration option CFG_CMD_CACHE) unless you know | 
 | 		what you (and your U-Boot users) are doing. Data | 
 | 		cache cannot be enabled on systems like the 8xx or | 
 | 		8260 (where accesses to the IMMR region must be | 
 | 		uncached), and it cannot be disabled on all other | 
 | 		systems where we (mis-) use the data cache to hold an | 
 | 		initial stack and some data. | 
 |  | 
 |  | 
 | 		XXX - this list needs to get updated! | 
 |  | 
 | - Watchdog: | 
 | 		CONFIG_WATCHDOG | 
 | 		If this variable is defined, it enables watchdog | 
 | 		support. There must be support in the platform specific | 
 | 		code for a watchdog. For the 8xx and 8260 CPUs, the | 
 | 		SIU Watchdog feature is enabled in the SYPCR | 
 | 		register. | 
 |  | 
 | - U-Boot Version: | 
 | 		CONFIG_VERSION_VARIABLE | 
 | 		If this variable is defined, an environment variable | 
 | 		named "ver" is created by U-Boot showing the U-Boot | 
 | 		version as printed by the "version" command. | 
 | 		This variable is readonly. | 
 |  | 
 | - Real-Time Clock: | 
 |  | 
 | 		When CFG_CMD_DATE is selected, the type of the RTC | 
 | 		has to be selected, too. Define exactly one of the | 
 | 		following options: | 
 |  | 
 | 		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx | 
 | 		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC | 
 | 		CONFIG_RTC_MC146818	- use MC146818 RTC | 
 | 		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC | 
 | 		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC | 
 | 		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC | 
 | 		CONFIG_RTC_DS164x	- use Dallas DS164x RTC | 
 | 		CONFIG_RTC_MAX6900	- use Maxim, Inc. MAX6900 RTC | 
 |  | 
 | 		Note that if the RTC uses I2C, then the I2C interface | 
 | 		must also be configured. See I2C Support, below. | 
 |  | 
 | - Timestamp Support: | 
 |  | 
 | 		When CONFIG_TIMESTAMP is selected, the timestamp | 
 | 		(date and time) of an image is printed by image | 
 | 		commands like bootm or iminfo. This option is | 
 | 		automatically enabled when you select CFG_CMD_DATE . | 
 |  | 
 | - Partition Support: | 
 | 		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION | 
 | 		and/or CONFIG_ISO_PARTITION | 
 |  | 
 | 		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or | 
 | 		CFG_CMD_SCSI) you must configure support for at least | 
 | 		one partition type as well. | 
 |  | 
 | - IDE Reset method: | 
 | 		CONFIG_IDE_RESET_ROUTINE - this is defined in several | 
 | 		board configurations files but used nowhere! | 
 |  | 
 | 		CONFIG_IDE_RESET - is this is defined, IDE Reset will | 
 | 		be performed by calling the function | 
 | 			ide_set_reset(int reset) | 
 | 		which has to be defined in a board specific file | 
 |  | 
 | - ATAPI Support: | 
 | 		CONFIG_ATAPI | 
 |  | 
 | 		Set this to enable ATAPI support. | 
 |  | 
 | - LBA48 Support | 
 | 		CONFIG_LBA48 | 
 |  | 
 | 		Set this to enable support for disks larger than 137GB | 
 | 		Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL | 
 | 		Whithout these , LBA48 support uses 32bit variables and will 'only' | 
 | 		support disks up to 2.1TB. | 
 |  | 
 | 		CFG_64BIT_LBA: | 
 | 			When enabled, makes the IDE subsystem use 64bit sector addresses. | 
 | 			Default is 32bit. | 
 |  | 
 | - SCSI Support: | 
 | 		At the moment only there is only support for the | 
 | 		SYM53C8XX SCSI controller; define | 
 | 		CONFIG_SCSI_SYM53C8XX to enable it. | 
 |  | 
 | 		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and | 
 | 		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * | 
 | 		CFG_SCSI_MAX_LUN] can be adjusted to define the | 
 | 		maximum numbers of LUNs, SCSI ID's and target | 
 | 		devices. | 
 | 		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) | 
 |  | 
 | - NETWORK Support (PCI): | 
 | 		CONFIG_E1000 | 
 | 		Support for Intel 8254x gigabit chips. | 
 |  | 
 | 		CONFIG_EEPRO100 | 
 | 		Support for Intel 82557/82559/82559ER chips. | 
 | 		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom | 
 | 		write routine for first time initialisation. | 
 |  | 
 | 		CONFIG_TULIP | 
 | 		Support for Digital 2114x chips. | 
 | 		Optional CONFIG_TULIP_SELECT_MEDIA for board specific | 
 | 		modem chip initialisation (KS8761/QS6611). | 
 |  | 
 | 		CONFIG_NATSEMI | 
 | 		Support for National dp83815 chips. | 
 |  | 
 | 		CONFIG_NS8382X | 
 | 		Support for National dp8382[01] gigabit chips. | 
 |  | 
 | - NETWORK Support (other): | 
 |  | 
 | 		CONFIG_DRIVER_LAN91C96 | 
 | 		Support for SMSC's LAN91C96 chips. | 
 |  | 
 | 			CONFIG_LAN91C96_BASE | 
 | 			Define this to hold the physical address | 
 | 			of the LAN91C96's I/O space | 
 |  | 
 | 			CONFIG_LAN91C96_USE_32_BIT | 
 | 			Define this to enable 32 bit addressing | 
 |  | 
 | 		CONFIG_DRIVER_SMC91111 | 
 | 		Support for SMSC's LAN91C111 chip | 
 |  | 
 | 			CONFIG_SMC91111_BASE | 
 | 			Define this to hold the physical address | 
 | 			of the device (I/O space) | 
 |  | 
 | 			CONFIG_SMC_USE_32_BIT | 
 | 			Define this if data bus is 32 bits | 
 |  | 
 | 			CONFIG_SMC_USE_IOFUNCS | 
 | 			Define this to use i/o functions instead of macros | 
 | 			(some hardware wont work with macros) | 
 |  | 
 | - USB Support: | 
 | 		At the moment only the UHCI host controller is | 
 | 		supported (PIP405, MIP405, MPC5200); define | 
 | 		CONFIG_USB_UHCI to enable it. | 
 | 		define CONFIG_USB_KEYBOARD to enable the USB Keyboard | 
 | 		and define CONFIG_USB_STORAGE to enable the USB | 
 | 		storage devices. | 
 | 		Note: | 
 | 		Supported are USB Keyboards and USB Floppy drives | 
 | 		(TEAC FD-05PUB). | 
 | 		MPC5200 USB requires additional defines: | 
 | 			CONFIG_USB_CLOCK | 
 | 				for 528 MHz Clock: 0x0001bbbb | 
 | 			CONFIG_USB_CONFIG | 
 | 				for differential drivers: 0x00001000 | 
 | 				for single ended drivers: 0x00005000 | 
 |  | 
 |  | 
 | - MMC Support: | 
 | 		The MMC controller on the Intel PXA is supported. To | 
 | 		enable this define CONFIG_MMC. The MMC can be | 
 | 		accessed from the boot prompt by mapping the device | 
 | 		to physical memory similar to flash. Command line is | 
 | 		enabled with CFG_CMD_MMC. The MMC driver also works with | 
 | 		the FAT fs. This is enabled with CFG_CMD_FAT. | 
 |  | 
 | - Journaling Flash filesystem support: | 
 | 		CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, | 
 | 		CONFIG_JFFS2_NAND_DEV | 
 | 		Define these for a default partition on a NAND device | 
 |  | 
 | 		CFG_JFFS2_FIRST_SECTOR, | 
 | 		CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS | 
 | 		Define these for a default partition on a NOR device | 
 |  | 
 | 		CFG_JFFS_CUSTOM_PART | 
 | 		Define this to create an own partition. You have to provide a | 
 | 		function struct part_info* jffs2_part_info(int part_num) | 
 |  | 
 | 		If you define only one JFFS2 partition you may also want to | 
 | 		#define CFG_JFFS_SINGLE_PART	1 | 
 | 		to disable the command chpart. This is the default when you | 
 | 		have not defined a custom partition | 
 |  | 
 | - Keyboard Support: | 
 | 		CONFIG_ISA_KEYBOARD | 
 |  | 
 | 		Define this to enable standard (PC-Style) keyboard | 
 | 		support | 
 |  | 
 | 		CONFIG_I8042_KBD | 
 | 		Standard PC keyboard driver with US (is default) and | 
 | 		GERMAN key layout (switch via environment 'keymap=de') support. | 
 | 		Export function i8042_kbd_init, i8042_tstc and i8042_getc | 
 | 		for cfb_console. Supports cursor blinking. | 
 |  | 
 | - Video support: | 
 | 		CONFIG_VIDEO | 
 |  | 
 | 		Define this to enable video support (for output to | 
 | 		video). | 
 |  | 
 | 		CONFIG_VIDEO_CT69000 | 
 |  | 
 | 		Enable Chips & Technologies 69000 Video chip | 
 |  | 
 | 		CONFIG_VIDEO_SMI_LYNXEM | 
 | 		Enable Silicon Motion SMI 712/710/810 Video chip. The | 
 | 		video output is selected via environment 'videoout' | 
 | 		(1 = LCD and 2 = CRT). If videoout is undefined, CRT is | 
 | 		assumed. | 
 |  | 
 | 		For the CT69000 and SMI_LYNXEM drivers, videomode is | 
 | 		selected via environment 'videomode'. Two diferent ways | 
 | 		are possible: | 
 | 		- "videomode=num"   'num' is a standard LiLo mode numbers. | 
 | 		Following standard modes are supported	(* is default): | 
 |  | 
 | 		      Colors	640x480 800x600 1024x768 1152x864 1280x1024 | 
 | 		-------------+--------------------------------------------- | 
 | 		      8 bits |	0x301*	0x303	 0x305	  0x161	    0x307 | 
 | 		     15 bits |	0x310	0x313	 0x316	  0x162	    0x319 | 
 | 		     16 bits |	0x311	0x314	 0x317	  0x163	    0x31A | 
 | 		     24 bits |	0x312	0x315	 0x318	    ?	    0x31B | 
 | 		-------------+--------------------------------------------- | 
 | 		(i.e. setenv videomode 317; saveenv; reset;) | 
 |  | 
 | 		- "videomode=bootargs" all the video parameters are parsed | 
 | 		from the bootargs. (See drivers/videomodes.c) | 
 |  | 
 |  | 
 | 		CONFIG_VIDEO_SED13806 | 
 | 		Enable Epson SED13806 driver. This driver supports 8bpp | 
 | 		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP | 
 | 		or CONFIG_VIDEO_SED13806_16BPP | 
 |  | 
 | - Keyboard Support: | 
 | 		CONFIG_KEYBOARD | 
 |  | 
 | 		Define this to enable a custom keyboard support. | 
 | 		This simply calls drv_keyboard_init() which must be | 
 | 		defined in your board-specific files. | 
 | 		The only board using this so far is RBC823. | 
 |  | 
 | - LCD Support:	CONFIG_LCD | 
 |  | 
 | 		Define this to enable LCD support (for output to LCD | 
 | 		display); also select one of the supported displays | 
 | 		by defining one of these: | 
 |  | 
 | 		CONFIG_NEC_NL6448AC33: | 
 |  | 
 | 			NEC NL6448AC33-18. Active, color, single scan. | 
 |  | 
 | 		CONFIG_NEC_NL6448BC20 | 
 |  | 
 | 			NEC NL6448BC20-08. 6.5", 640x480. | 
 | 			Active, color, single scan. | 
 |  | 
 | 		CONFIG_NEC_NL6448BC33_54 | 
 |  | 
 | 			NEC NL6448BC33-54. 10.4", 640x480. | 
 | 			Active, color, single scan. | 
 |  | 
 | 		CONFIG_SHARP_16x9 | 
 |  | 
 | 			Sharp 320x240. Active, color, single scan. | 
 | 			It isn't 16x9, and I am not sure what it is. | 
 |  | 
 | 		CONFIG_SHARP_LQ64D341 | 
 |  | 
 | 			Sharp LQ64D341 display, 640x480. | 
 | 			Active, color, single scan. | 
 |  | 
 | 		CONFIG_HLD1045 | 
 |  | 
 | 			HLD1045 display, 640x480. | 
 | 			Active, color, single scan. | 
 |  | 
 | 		CONFIG_OPTREX_BW | 
 |  | 
 | 			Optrex	 CBL50840-2 NF-FW 99 22 M5 | 
 | 			or | 
 | 			Hitachi	 LMG6912RPFC-00T | 
 | 			or | 
 | 			Hitachi	 SP14Q002 | 
 |  | 
 | 			320x240. Black & white. | 
 |  | 
 | 		Normally display is black on white background; define | 
 | 		CFG_WHITE_ON_BLACK to get it inverted. | 
 |  | 
 | - Splash Screen Support: CONFIG_SPLASH_SCREEN | 
 |  | 
 | 		If this option is set, the environment is checked for | 
 | 		a variable "splashimage". If found, the usual display | 
 | 		of logo, copyright and system information on the LCD | 
 | 		is suppressed and the BMP image at the address | 
 | 		specified in "splashimage" is loaded instead. The | 
 | 		console is redirected to the "nulldev", too. This | 
 | 		allows for a "silent" boot where a splash screen is | 
 | 		loaded very quickly after power-on. | 
 |  | 
 | - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP | 
 |  | 
 | 		If this option is set, additionally to standard BMP | 
 | 		images, gzipped BMP images can be displayed via the | 
 | 		splashscreen support or the bmp command. | 
 |  | 
 | - Compression support: | 
 | 		CONFIG_BZIP2 | 
 |  | 
 | 		If this option is set, support for bzip2 compressed | 
 | 		images is included. If not, only uncompressed and gzip | 
 | 		compressed images are supported. | 
 |  | 
 | 		NOTE: the bzip2 algorithm requires a lot of RAM, so | 
 | 		the malloc area (as defined by CFG_MALLOC_LEN) should | 
 | 		be at least 4MB. | 
 |  | 
 | - MII/PHY support: | 
 | 		CONFIG_PHY_ADDR | 
 |  | 
 | 		The address of PHY on MII bus. | 
 |  | 
 | 		CONFIG_PHY_CLOCK_FREQ (ppc4xx) | 
 |  | 
 | 		The clock frequency of the MII bus | 
 |  | 
 | 		CONFIG_PHY_GIGE | 
 |  | 
 | 		If this option is set, support for speed/duplex | 
 | 		detection of Gigabit PHY is included. | 
 |  | 
 | 		CONFIG_PHY_RESET_DELAY | 
 |  | 
 | 		Some PHY like Intel LXT971A need extra delay after | 
 | 		reset before any MII register access is possible. | 
 | 		For such PHY, set this option to the usec delay | 
 | 		required. (minimum 300usec for LXT971A) | 
 |  | 
 | 		CONFIG_PHY_CMD_DELAY (ppc4xx) | 
 |  | 
 | 		Some PHY like Intel LXT971A need extra delay after | 
 | 		command issued before MII status register can be read | 
 |  | 
 | - Ethernet address: | 
 | 		CONFIG_ETHADDR | 
 | 		CONFIG_ETH2ADDR | 
 | 		CONFIG_ETH3ADDR | 
 |  | 
 | 		Define a default value for ethernet address to use | 
 | 		for the respective ethernet interface, in case this | 
 | 		is not determined automatically. | 
 |  | 
 | - IP address: | 
 | 		CONFIG_IPADDR | 
 |  | 
 | 		Define a default value for the IP address to use for | 
 | 		the default ethernet interface, in case this is not | 
 | 		determined through e.g. bootp. | 
 |  | 
 | - Server IP address: | 
 | 		CONFIG_SERVERIP | 
 |  | 
 | 		Defines a default value for theIP address of a TFTP | 
 | 		server to contact when using the "tftboot" command. | 
 |  | 
 | - BOOTP Recovery Mode: | 
 | 		CONFIG_BOOTP_RANDOM_DELAY | 
 |  | 
 | 		If you have many targets in a network that try to | 
 | 		boot using BOOTP, you may want to avoid that all | 
 | 		systems send out BOOTP requests at precisely the same | 
 | 		moment (which would happen for instance at recovery | 
 | 		from a power failure, when all systems will try to | 
 | 		boot, thus flooding the BOOTP server. Defining | 
 | 		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be | 
 | 		inserted before sending out BOOTP requests. The | 
 | 		following delays are insterted then: | 
 |  | 
 | 		1st BOOTP request:	delay 0 ... 1 sec | 
 | 		2nd BOOTP request:	delay 0 ... 2 sec | 
 | 		3rd BOOTP request:	delay 0 ... 4 sec | 
 | 		4th and following | 
 | 		BOOTP requests:		delay 0 ... 8 sec | 
 |  | 
 | - DHCP Advanced Options: | 
 | 		CONFIG_BOOTP_MASK | 
 |  | 
 | 		You can fine tune the DHCP functionality by adding | 
 | 		these flags to the CONFIG_BOOTP_MASK define: | 
 |  | 
 | 		CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS | 
 | 		serverip from a DHCP server, it is possible that more | 
 | 		than one DNS serverip is offered to the client. | 
 | 		If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS | 
 | 		serverip will be stored in the additional environment | 
 | 		variable "dnsip2". The first DNS serverip is always | 
 | 		stored in the variable "dnsip", when CONFIG_BOOTP_DNS | 
 | 		is added to the CONFIG_BOOTP_MASK. | 
 |  | 
 | 		CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable | 
 | 		to do a dynamic update of a DNS server. To do this, they | 
 | 		need the hostname of the DHCP requester. | 
 | 		If CONFIG_BOOP_SEND_HOSTNAME is added to the | 
 | 		CONFIG_BOOTP_MASK, the content of the "hostname" | 
 | 		environment variable is passed as option 12 to | 
 | 		the DHCP server. | 
 |  | 
 |  - CDP Options: | 
 | 		CONFIG_CDP_DEVICE_ID | 
 |  | 
 | 		The device id used in CDP trigger frames. | 
 |  | 
 | 		CONFIG_CDP_DEVICE_ID_PREFIX | 
 |  | 
 | 		A two character string which is prefixed to the MAC address | 
 | 		of the device. | 
 |  | 
 | 		CONFIG_CDP_PORT_ID | 
 |  | 
 | 		A printf format string which contains the ascii name of | 
 | 		the port. Normally is set to "eth%d" which sets | 
 | 		eth0 for the first ethernet, eth1 for the second etc. | 
 |  | 
 | 		CONFIG_CDP_CAPABILITIES | 
 |  | 
 | 		A 32bit integer which indicates the device capabilities; | 
 | 		0x00000010 for a normal host which does not forwards. | 
 |  | 
 | 		CONFIG_CDP_VERSION | 
 |  | 
 | 		An ascii string containing the version of the software. | 
 |  | 
 | 		CONFIG_CDP_PLATFORM | 
 |  | 
 | 		An ascii string containing the name of the platform. | 
 |  | 
 | 		CONFIG_CDP_TRIGGER | 
 |  | 
 | 		A 32bit integer sent on the trigger. | 
 |  | 
 | 		CONFIG_CDP_POWER_CONSUMPTION | 
 |  | 
 | 		A 16bit integer containing the power consumption of the | 
 | 		device in .1 of milliwatts. | 
 |  | 
 | 		CONFIG_CDP_APPLIANCE_VLAN_TYPE | 
 |  | 
 | 		A byte containing the id of the VLAN. | 
 |  | 
 | - Status LED:	CONFIG_STATUS_LED | 
 |  | 
 | 		Several configurations allow to display the current | 
 | 		status using a LED. For instance, the LED will blink | 
 | 		fast while running U-Boot code, stop blinking as | 
 | 		soon as a reply to a BOOTP request was received, and | 
 | 		start blinking slow once the Linux kernel is running | 
 | 		(supported by a status LED driver in the Linux | 
 | 		kernel). Defining CONFIG_STATUS_LED enables this | 
 | 		feature in U-Boot. | 
 |  | 
 | - CAN Support:	CONFIG_CAN_DRIVER | 
 |  | 
 | 		Defining CONFIG_CAN_DRIVER enables CAN driver support | 
 | 		on those systems that support this (optional) | 
 | 		feature, like the TQM8xxL modules. | 
 |  | 
 | - I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C | 
 |  | 
 | 		These enable I2C serial bus commands. Defining either of | 
 | 		(but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will | 
 | 		include the appropriate I2C driver for the selected cpu. | 
 |  | 
 | 		This will allow you to use i2c commands at the u-boot | 
 | 		command line (as long as you set CFG_CMD_I2C in | 
 | 		CONFIG_COMMANDS) and communicate with i2c based realtime | 
 | 		clock chips. See common/cmd_i2c.c for a description of the | 
 | 		command line interface. | 
 |  | 
 | 		CONFIG_HARD_I2C selects the CPM hardware driver for I2C. | 
 |  | 
 | 		CONFIG_SOFT_I2C configures u-boot to use a software (aka | 
 | 		bit-banging) driver instead of CPM or similar hardware | 
 | 		support for I2C. | 
 |  | 
 | 		There are several other quantities that must also be | 
 | 		defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. | 
 |  | 
 | 		In both cases you will need to define CFG_I2C_SPEED | 
 | 		to be the frequency (in Hz) at which you wish your i2c bus | 
 | 		to run and CFG_I2C_SLAVE to be the address of this node (ie | 
 | 		the cpu's i2c node address). | 
 |  | 
 | 		Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) | 
 | 		sets the cpu up as a master node and so its address should | 
 | 		therefore be cleared to 0 (See, eg, MPC823e User's Manual | 
 | 		p.16-473). So, set CFG_I2C_SLAVE to 0. | 
 |  | 
 | 		That's all that's required for CONFIG_HARD_I2C. | 
 |  | 
 | 		If you use the software i2c interface (CONFIG_SOFT_I2C) | 
 | 		then the following macros need to be defined (examples are | 
 | 		from include/configs/lwmon.h): | 
 |  | 
 | 		I2C_INIT | 
 |  | 
 | 		(Optional). Any commands necessary to enable the I2C | 
 | 		controller or configure ports. | 
 |  | 
 | 		eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |=	PB_SCL) | 
 |  | 
 | 		I2C_PORT | 
 |  | 
 | 		(Only for MPC8260 CPU). The I/O port to use (the code | 
 | 		assumes both bits are on the same port). Valid values | 
 | 		are 0..3 for ports A..D. | 
 |  | 
 | 		I2C_ACTIVE | 
 |  | 
 | 		The code necessary to make the I2C data line active | 
 | 		(driven).  If the data line is open collector, this | 
 | 		define can be null. | 
 |  | 
 | 		eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |=  PB_SDA) | 
 |  | 
 | 		I2C_TRISTATE | 
 |  | 
 | 		The code necessary to make the I2C data line tri-stated | 
 | 		(inactive).  If the data line is open collector, this | 
 | 		define can be null. | 
 |  | 
 | 		eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) | 
 |  | 
 | 		I2C_READ | 
 |  | 
 | 		Code that returns TRUE if the I2C data line is high, | 
 | 		FALSE if it is low. | 
 |  | 
 | 		eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) | 
 |  | 
 | 		I2C_SDA(bit) | 
 |  | 
 | 		If <bit> is TRUE, sets the I2C data line high. If it | 
 | 		is FALSE, it clears it (low). | 
 |  | 
 | 		eg: #define I2C_SDA(bit) \ | 
 | 			if(bit) immr->im_cpm.cp_pbdat |=  PB_SDA; \ | 
 | 			else	immr->im_cpm.cp_pbdat &= ~PB_SDA | 
 |  | 
 | 		I2C_SCL(bit) | 
 |  | 
 | 		If <bit> is TRUE, sets the I2C clock line high. If it | 
 | 		is FALSE, it clears it (low). | 
 |  | 
 | 		eg: #define I2C_SCL(bit) \ | 
 | 			if(bit) immr->im_cpm.cp_pbdat |=  PB_SCL; \ | 
 | 			else	immr->im_cpm.cp_pbdat &= ~PB_SCL | 
 |  | 
 | 		I2C_DELAY | 
 |  | 
 | 		This delay is invoked four times per clock cycle so this | 
 | 		controls the rate of data transfer.  The data rate thus | 
 | 		is 1 / (I2C_DELAY * 4). Often defined to be something | 
 | 		like: | 
 |  | 
 | 		#define I2C_DELAY  udelay(2) | 
 |  | 
 | 		CFG_I2C_INIT_BOARD | 
 |  | 
 | 		When a board is reset during an i2c bus transfer | 
 | 		chips might think that the current transfer is still | 
 | 		in progress. On some boards it is possible to access | 
 | 		the i2c SCLK line directly, either by using the | 
 | 		processor pin as a GPIO or by having a second pin | 
 | 		connected to the bus. If this option is defined a | 
 | 		custom i2c_init_board() routine in boards/xxx/board.c | 
 | 		is run early in the boot sequence. | 
 |  | 
 | 		CONFIG_I2CFAST (PPC405GP|PPC405EP only) | 
 |  | 
 | 		This option enables configuration of bi_iic_fast[] flags | 
 | 		in u-boot bd_info structure based on u-boot environment | 
 | 		variable "i2cfast". (see also i2cfast) | 
 |  | 
 | - SPI Support:	CONFIG_SPI | 
 |  | 
 | 		Enables SPI driver (so far only tested with | 
 | 		SPI EEPROM, also an instance works with Crystal A/D and | 
 | 		D/As on the SACSng board) | 
 |  | 
 | 		CONFIG_SPI_X | 
 |  | 
 | 		Enables extended (16-bit) SPI EEPROM addressing. | 
 | 		(symmetrical to CONFIG_I2C_X) | 
 |  | 
 | 		CONFIG_SOFT_SPI | 
 |  | 
 | 		Enables a software (bit-bang) SPI driver rather than | 
 | 		using hardware support. This is a general purpose | 
 | 		driver that only requires three general I/O port pins | 
 | 		(two outputs, one input) to function. If this is | 
 | 		defined, the board configuration must define several | 
 | 		SPI configuration items (port pins to use, etc). For | 
 | 		an example, see include/configs/sacsng.h. | 
 |  | 
 | - FPGA Support: CONFIG_FPGA_COUNT | 
 |  | 
 | 		Specify the number of FPGA devices to support. | 
 |  | 
 | 		CONFIG_FPGA | 
 |  | 
 | 		Used to specify the types of FPGA devices.  For example, | 
 | 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2 | 
 |  | 
 | 		CFG_FPGA_PROG_FEEDBACK | 
 |  | 
 | 		Enable printing of hash marks during FPGA configuration. | 
 |  | 
 | 		CFG_FPGA_CHECK_BUSY | 
 |  | 
 | 		Enable checks on FPGA configuration interface busy | 
 | 		status by the configuration function. This option | 
 | 		will require a board or device specific function to | 
 | 		be written. | 
 |  | 
 | 		CONFIG_FPGA_DELAY | 
 |  | 
 | 		If defined, a function that provides delays in the FPGA | 
 | 		configuration driver. | 
 |  | 
 | 		CFG_FPGA_CHECK_CTRLC | 
 | 		Allow Control-C to interrupt FPGA configuration | 
 |  | 
 | 		CFG_FPGA_CHECK_ERROR | 
 |  | 
 | 		Check for configuration errors during FPGA bitfile | 
 | 		loading. For example, abort during Virtex II | 
 | 		configuration if the INIT_B line goes low (which | 
 | 		indicated a CRC error). | 
 |  | 
 | 		CFG_FPGA_WAIT_INIT | 
 |  | 
 | 		Maximum time to wait for the INIT_B line to deassert | 
 | 		after PROB_B has been deasserted during a Virtex II | 
 | 		FPGA configuration sequence. The default time is 500 | 
 | 		mS. | 
 |  | 
 | 		CFG_FPGA_WAIT_BUSY | 
 |  | 
 | 		Maximum time to wait for BUSY to deassert during | 
 | 		Virtex II FPGA configuration. The default is 5 mS. | 
 |  | 
 | 		CFG_FPGA_WAIT_CONFIG | 
 |  | 
 | 		Time to wait after FPGA configuration. The default is | 
 | 		200 mS. | 
 |  | 
 | - Configuration Management: | 
 | 		CONFIG_IDENT_STRING | 
 |  | 
 | 		If defined, this string will be added to the U-Boot | 
 | 		version information (U_BOOT_VERSION) | 
 |  | 
 | - Vendor Parameter Protection: | 
 |  | 
 | 		U-Boot considers the values of the environment | 
 | 		variables "serial#" (Board Serial Number) and | 
 | 		"ethaddr" (Ethernet Address) to be parameters that | 
 | 		are set once by the board vendor / manufacturer, and | 
 | 		protects these variables from casual modification by | 
 | 		the user. Once set, these variables are read-only, | 
 | 		and write or delete attempts are rejected. You can | 
 | 		change this behviour: | 
 |  | 
 | 		If CONFIG_ENV_OVERWRITE is #defined in your config | 
 | 		file, the write protection for vendor parameters is | 
 | 		completely disabled. Anybody can change or delete | 
 | 		these parameters. | 
 |  | 
 | 		Alternatively, if you #define _both_ CONFIG_ETHADDR | 
 | 		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default | 
 | 		ethernet address is installed in the environment, | 
 | 		which can be changed exactly ONCE by the user. [The | 
 | 		serial# is unaffected by this, i. e. it remains | 
 | 		read-only.] | 
 |  | 
 | - Protected RAM: | 
 | 		CONFIG_PRAM | 
 |  | 
 | 		Define this variable to enable the reservation of | 
 | 		"protected RAM", i. e. RAM which is not overwritten | 
 | 		by U-Boot. Define CONFIG_PRAM to hold the number of | 
 | 		kB you want to reserve for pRAM. You can overwrite | 
 | 		this default value by defining an environment | 
 | 		variable "pram" to the number of kB you want to | 
 | 		reserve. Note that the board info structure will | 
 | 		still show the full amount of RAM. If pRAM is | 
 | 		reserved, a new environment variable "mem" will | 
 | 		automatically be defined to hold the amount of | 
 | 		remaining RAM in a form that can be passed as boot | 
 | 		argument to Linux, for instance like that: | 
 |  | 
 | 			setenv bootargs ... mem=\${mem} | 
 | 			saveenv | 
 |  | 
 | 		This way you can tell Linux not to use this memory, | 
 | 		either, which results in a memory region that will | 
 | 		not be affected by reboots. | 
 |  | 
 | 		*WARNING* If your board configuration uses automatic | 
 | 		detection of the RAM size, you must make sure that | 
 | 		this memory test is non-destructive. So far, the | 
 | 		following board configurations are known to be | 
 | 		"pRAM-clean": | 
 |  | 
 | 			ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, | 
 | 			HERMES, IP860, RPXlite, LWMON, LANTEC, | 
 | 			PCU_E, FLAGADM, TQM8260 | 
 |  | 
 | - Error Recovery: | 
 | 		CONFIG_PANIC_HANG | 
 |  | 
 | 		Define this variable to stop the system in case of a | 
 | 		fatal error, so that you have to reset it manually. | 
 | 		This is probably NOT a good idea for an embedded | 
 | 		system where you want to system to reboot | 
 | 		automatically as fast as possible, but it may be | 
 | 		useful during development since you can try to debug | 
 | 		the conditions that lead to the situation. | 
 |  | 
 | 		CONFIG_NET_RETRY_COUNT | 
 |  | 
 | 		This variable defines the number of retries for | 
 | 		network operations like ARP, RARP, TFTP, or BOOTP | 
 | 		before giving up the operation. If not defined, a | 
 | 		default value of 5 is used. | 
 |  | 
 | - Command Interpreter: | 
 | 		CFG_AUTO_COMPLETE | 
 |  | 
 | 		Enable auto completion of commands using TAB. | 
 |  | 
 | 		CFG_HUSH_PARSER | 
 |  | 
 | 		Define this variable to enable the "hush" shell (from | 
 | 		Busybox) as command line interpreter, thus enabling | 
 | 		powerful command line syntax like | 
 | 		if...then...else...fi conditionals or `&&' and '||' | 
 | 		constructs ("shell scripts"). | 
 |  | 
 | 		If undefined, you get the old, much simpler behaviour | 
 | 		with a somewhat smaller memory footprint. | 
 |  | 
 |  | 
 | 		CFG_PROMPT_HUSH_PS2 | 
 |  | 
 | 		This defines the secondary prompt string, which is | 
 | 		printed when the command interpreter needs more input | 
 | 		to complete a command. Usually "> ". | 
 |  | 
 | 	Note: | 
 |  | 
 | 		In the current implementation, the local variables | 
 | 		space and global environment variables space are | 
 | 		separated. Local variables are those you define by | 
 | 		simply typing `name=value'. To access a local | 
 | 		variable later on, you have write `$name' or | 
 | 		`${name}'; to execute the contents of a variable | 
 | 		directly type `$name' at the command prompt. | 
 |  | 
 | 		Global environment variables are those you use | 
 | 		setenv/printenv to work with. To run a command stored | 
 | 		in such a variable, you need to use the run command, | 
 | 		and you must not use the '$' sign to access them. | 
 |  | 
 | 		To store commands and special characters in a | 
 | 		variable, please use double quotation marks | 
 | 		surrounding the whole text of the variable, instead | 
 | 		of the backslashes before semicolons and special | 
 | 		symbols. | 
 |  | 
 | - Default Environment: | 
 | 		CONFIG_EXTRA_ENV_SETTINGS | 
 |  | 
 | 		Define this to contain any number of null terminated | 
 | 		strings (variable = value pairs) that will be part of | 
 | 		the default environment compiled into the boot image. | 
 |  | 
 | 		For example, place something like this in your | 
 | 		board's config file: | 
 |  | 
 | 		#define CONFIG_EXTRA_ENV_SETTINGS \ | 
 | 			"myvar1=value1\0" \ | 
 | 			"myvar2=value2\0" | 
 |  | 
 | 		Warning: This method is based on knowledge about the | 
 | 		internal format how the environment is stored by the | 
 | 		U-Boot code. This is NOT an official, exported | 
 | 		interface! Although it is unlikely that this format | 
 | 		will change soon, there is no guarantee either. | 
 | 		You better know what you are doing here. | 
 |  | 
 | 		Note: overly (ab)use of the default environment is | 
 | 		discouraged. Make sure to check other ways to preset | 
 | 		the environment like the autoscript function or the | 
 | 		boot command first. | 
 |  | 
 | - DataFlash Support: | 
 | 		CONFIG_HAS_DATAFLASH | 
 |  | 
 | 		Defining this option enables DataFlash features and | 
 | 		allows to read/write in Dataflash via the standard | 
 | 		commands cp, md... | 
 |  | 
 | - SystemACE Support: | 
 | 		CONFIG_SYSTEMACE | 
 |  | 
 | 		Adding this option adds support for Xilinx SystemACE | 
 | 		chips attached via some sort of local bus. The address | 
 | 		of the chip must alsh be defined in the | 
 | 		CFG_SYSTEMACE_BASE macro. For example: | 
 |  | 
 | 		#define CONFIG_SYSTEMACE | 
 | 		#define CFG_SYSTEMACE_BASE 0xf0000000 | 
 |  | 
 | 		When SystemACE support is added, the "ace" device type | 
 | 		becomes available to the fat commands, i.e. fatls. | 
 |  | 
 | - TFTP Fixed UDP Port: | 
 | 		CONFIG_TFTP_PORT | 
 |  | 
 | 		If this is defined, the environment variable tftpsrcp | 
 | 		is used to supply the TFTP UDP source port value. | 
 | 		If tftpsrcp isn't defined, the normal pseudo-random port | 
 | 		number generator is used. | 
 |  | 
 | 		Also, the environment variable tftpdstp is used to supply | 
 | 		the TFTP UDP destination port value.  If tftpdstp isn't | 
 | 		defined, the normal port 69 is used. | 
 |  | 
 | 		The purpose for tftpsrcp is to allow a TFTP server to | 
 | 		blindly start the TFTP transfer using the pre-configured | 
 | 		target IP address and UDP port. This has the effect of | 
 | 		"punching through" the (Windows XP) firewall, allowing | 
 | 		the remainder of the TFTP transfer to proceed normally. | 
 | 		A better solution is to properly configure the firewall, | 
 | 		but sometimes that is not allowed. | 
 |  | 
 | - Show boot progress: | 
 | 		CONFIG_SHOW_BOOT_PROGRESS | 
 |  | 
 | 		Defining this option allows to add some board- | 
 | 		specific code (calling a user-provided function | 
 | 		"show_boot_progress(int)") that enables you to show | 
 | 		the system's boot progress on some display (for | 
 | 		example, some LED's) on your board. At the moment, | 
 | 		the following checkpoints are implemented: | 
 |  | 
 |   Arg	Where			When | 
 |     1	common/cmd_bootm.c	before attempting to boot an image | 
 |    -1	common/cmd_bootm.c	Image header has bad	 magic number | 
 |     2	common/cmd_bootm.c	Image header has correct magic number | 
 |    -2	common/cmd_bootm.c	Image header has bad	 checksum | 
 |     3	common/cmd_bootm.c	Image header has correct checksum | 
 |    -3	common/cmd_bootm.c	Image data   has bad	 checksum | 
 |     4	common/cmd_bootm.c	Image data   has correct checksum | 
 |    -4	common/cmd_bootm.c	Image is for unsupported architecture | 
 |     5	common/cmd_bootm.c	Architecture check OK | 
 |    -5	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone) | 
 |     6	common/cmd_bootm.c	Image Type check OK | 
 |    -6	common/cmd_bootm.c	gunzip uncompression error | 
 |    -7	common/cmd_bootm.c	Unimplemented compression type | 
 |     7	common/cmd_bootm.c	Uncompression OK | 
 |    -8	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone) | 
 |     8	common/cmd_bootm.c	Image Type check OK | 
 |    -9	common/cmd_bootm.c	Unsupported OS (not Linux, BSD, VxWorks, QNX) | 
 |     9	common/cmd_bootm.c	Start initial ramdisk verification | 
 |   -10	common/cmd_bootm.c	Ramdisk header has bad	   magic number | 
 |   -11	common/cmd_bootm.c	Ramdisk header has bad	   checksum | 
 |    10	common/cmd_bootm.c	Ramdisk header is OK | 
 |   -12	common/cmd_bootm.c	Ramdisk data   has bad	   checksum | 
 |    11	common/cmd_bootm.c	Ramdisk data   has correct checksum | 
 |    12	common/cmd_bootm.c	Ramdisk verification complete, start loading | 
 |   -13	common/cmd_bootm.c	Wrong Image Type (not PPC Linux Ramdisk) | 
 |    13	common/cmd_bootm.c	Start multifile image verification | 
 |    14	common/cmd_bootm.c	No initial ramdisk, no multifile, continue. | 
 |    15	common/cmd_bootm.c	All preparation done, transferring control to OS | 
 |  | 
 |   -30	lib_ppc/board.c		Fatal error, hang the system | 
 |   -31	post/post.c		POST test failed, detected by post_output_backlog() | 
 |   -32	post/post.c		POST test failed, detected by post_run_single() | 
 |  | 
 |    -1	common/cmd_doc.c	Bad usage of "doc" command | 
 |    -1	common/cmd_doc.c	No boot device | 
 |    -1	common/cmd_doc.c	Unknown Chip ID on boot device | 
 |    -1	common/cmd_doc.c	Read Error on boot device | 
 |    -1	common/cmd_doc.c	Image header has bad magic number | 
 |  | 
 |    -1	common/cmd_ide.c	Bad usage of "ide" command | 
 |    -1	common/cmd_ide.c	No boot device | 
 |    -1	common/cmd_ide.c	Unknown boot device | 
 |    -1	common/cmd_ide.c	Unknown partition table | 
 |    -1	common/cmd_ide.c	Invalid partition type | 
 |    -1	common/cmd_ide.c	Read Error on boot device | 
 |    -1	common/cmd_ide.c	Image header has bad magic number | 
 |  | 
 |    -1	common/cmd_nand.c	Bad usage of "nand" command | 
 |    -1	common/cmd_nand.c	No boot device | 
 |    -1	common/cmd_nand.c	Unknown Chip ID on boot device | 
 |    -1	common/cmd_nand.c	Read Error on boot device | 
 |    -1	common/cmd_nand.c	Image header has bad magic number | 
 |  | 
 |    -1	common/env_common.c	Environment has a bad CRC, using default | 
 |  | 
 |  | 
 | Modem Support: | 
 | -------------- | 
 |  | 
 | [so far only for SMDK2400 and TRAB boards] | 
 |  | 
 | - Modem support endable: | 
 | 		CONFIG_MODEM_SUPPORT | 
 |  | 
 | - RTS/CTS Flow control enable: | 
 | 		CONFIG_HWFLOW | 
 |  | 
 | - Modem debug support: | 
 | 		CONFIG_MODEM_SUPPORT_DEBUG | 
 |  | 
 | 		Enables debugging stuff (char screen[1024], dbg()) | 
 | 		for modem support. Useful only with BDI2000. | 
 |  | 
 | - Interrupt support (PPC): | 
 |  | 
 | 		There are common interrupt_init() and timer_interrupt() | 
 | 		for all PPC archs. interrupt_init() calls interrupt_init_cpu() | 
 | 		for cpu specific initialization. interrupt_init_cpu() | 
 | 		should set decrementer_count to appropriate value. If | 
 | 		cpu resets decrementer automatically after interrupt | 
 | 		(ppc4xx) it should set decrementer_count to zero. | 
 | 		timer_interrupt() calls timer_interrupt_cpu() for cpu | 
 | 		specific handling. If board has watchdog / status_led | 
 | 		/ other_activity_monitor it works automatically from | 
 | 		general timer_interrupt(). | 
 |  | 
 | - General: | 
 |  | 
 | 		In the target system modem support is enabled when a | 
 | 		specific key (key combination) is pressed during | 
 | 		power-on. Otherwise U-Boot will boot normally | 
 | 		(autoboot). The key_pressed() fuction is called from | 
 | 		board_init(). Currently key_pressed() is a dummy | 
 | 		function, returning 1 and thus enabling modem | 
 | 		initialization. | 
 |  | 
 | 		If there are no modem init strings in the | 
 | 		environment, U-Boot proceed to autoboot; the | 
 | 		previous output (banner, info printfs) will be | 
 | 		supressed, though. | 
 |  | 
 | 		See also: doc/README.Modem | 
 |  | 
 |  | 
 | Configuration Settings: | 
 | ----------------------- | 
 |  | 
 | - CFG_LONGHELP: Defined when you want long help messages included; | 
 | 		undefine this when you're short of memory. | 
 |  | 
 | - CFG_PROMPT:	This is what U-Boot prints on the console to | 
 | 		prompt for user input. | 
 |  | 
 | - CFG_CBSIZE:	Buffer size for input from the Console | 
 |  | 
 | - CFG_PBSIZE:	Buffer size for Console output | 
 |  | 
 | - CFG_MAXARGS:	max. Number of arguments accepted for monitor commands | 
 |  | 
 | - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to | 
 | 		the application (usually a Linux kernel) when it is | 
 | 		booted | 
 |  | 
 | - CFG_BAUDRATE_TABLE: | 
 | 		List of legal baudrate settings for this board. | 
 |  | 
 | - CFG_CONSOLE_INFO_QUIET | 
 | 		Suppress display of console information at boot. | 
 |  | 
 | - CFG_CONSOLE_IS_IN_ENV | 
 | 		If the board specific function | 
 | 			extern int overwrite_console (void); | 
 | 		returns 1, the stdin, stderr and stdout are switched to the | 
 | 		serial port, else the settings in the environment are used. | 
 |  | 
 | - CFG_CONSOLE_OVERWRITE_ROUTINE | 
 | 		Enable the call to overwrite_console(). | 
 |  | 
 | - CFG_CONSOLE_ENV_OVERWRITE | 
 | 		Enable overwrite of previous console environment settings. | 
 |  | 
 | - CFG_MEMTEST_START, CFG_MEMTEST_END: | 
 | 		Begin and End addresses of the area used by the | 
 | 		simple memory test. | 
 |  | 
 | - CFG_ALT_MEMTEST: | 
 | 		Enable an alternate, more extensive memory test. | 
 |  | 
 | - CFG_MEMTEST_SCRATCH: | 
 | 		Scratch address used by the alternate memory test | 
 | 		You only need to set this if address zero isn't writeable | 
 |  | 
 | - CFG_TFTP_LOADADDR: | 
 | 		Default load address for network file downloads | 
 |  | 
 | - CFG_LOADS_BAUD_CHANGE: | 
 | 		Enable temporary baudrate change while serial download | 
 |  | 
 | - CFG_SDRAM_BASE: | 
 | 		Physical start address of SDRAM. _Must_ be 0 here. | 
 |  | 
 | - CFG_MBIO_BASE: | 
 | 		Physical start address of Motherboard I/O (if using a | 
 | 		Cogent motherboard) | 
 |  | 
 | - CFG_FLASH_BASE: | 
 | 		Physical start address of Flash memory. | 
 |  | 
 | - CFG_MONITOR_BASE: | 
 | 		Physical start address of boot monitor code (set by | 
 | 		make config files to be same as the text base address | 
 | 		(TEXT_BASE) used when linking) - same as | 
 | 		CFG_FLASH_BASE when booting from flash. | 
 |  | 
 | - CFG_MONITOR_LEN: | 
 | 		Size of memory reserved for monitor code, used to | 
 | 		determine _at_compile_time_ (!) if the environment is | 
 | 		embedded within the U-Boot image, or in a separate | 
 | 		flash sector. | 
 |  | 
 | - CFG_MALLOC_LEN: | 
 | 		Size of DRAM reserved for malloc() use. | 
 |  | 
 | - CFG_BOOTM_LEN: | 
 | 		Normally compressed uImages are limited to an | 
 | 		uncompressed size of 8 MBytes. If this is not enough, | 
 | 		you can define CFG_BOOTM_LEN in your board config file | 
 | 		to adjust this setting to your needs. | 
 |  | 
 | - CFG_BOOTMAPSZ: | 
 | 		Maximum size of memory mapped by the startup code of | 
 | 		the Linux kernel; all data that must be processed by | 
 | 		the Linux kernel (bd_info, boot arguments, eventually | 
 | 		initrd image) must be put below this limit. | 
 |  | 
 | - CFG_MAX_FLASH_BANKS: | 
 | 		Max number of Flash memory banks | 
 |  | 
 | - CFG_MAX_FLASH_SECT: | 
 | 		Max number of sectors on a Flash chip | 
 |  | 
 | - CFG_FLASH_ERASE_TOUT: | 
 | 		Timeout for Flash erase operations (in ms) | 
 |  | 
 | - CFG_FLASH_WRITE_TOUT: | 
 | 		Timeout for Flash write operations (in ms) | 
 |  | 
 | - CFG_FLASH_LOCK_TOUT | 
 | 		Timeout for Flash set sector lock bit operation (in ms) | 
 |  | 
 | - CFG_FLASH_UNLOCK_TOUT | 
 | 		Timeout for Flash clear lock bits operation (in ms) | 
 |  | 
 | - CFG_FLASH_PROTECTION | 
 | 		If defined, hardware flash sectors protection is used | 
 | 		instead of U-Boot software protection. | 
 |  | 
 | - CFG_DIRECT_FLASH_TFTP: | 
 |  | 
 | 		Enable TFTP transfers directly to flash memory; | 
 | 		without this option such a download has to be | 
 | 		performed in two steps: (1) download to RAM, and (2) | 
 | 		copy from RAM to flash. | 
 |  | 
 | 		The two-step approach is usually more reliable, since | 
 | 		you can check if the download worked before you erase | 
 | 		the flash, but in some situations (when sytem RAM is | 
 | 		too limited to allow for a tempory copy of the | 
 | 		downloaded image) this option may be very useful. | 
 |  | 
 | - CFG_FLASH_CFI: | 
 | 		Define if the flash driver uses extra elements in the | 
 | 		common flash structure for storing flash geometry. | 
 |  | 
 | - CFG_FLASH_CFI_DRIVER | 
 | 		This option also enables the building of the cfi_flash driver | 
 | 		in the drivers directory | 
 |  | 
 | - CFG_FLASH_QUIET_TEST | 
 | 		If this option is defined, the common CFI flash doesn't | 
 | 		print it's warning upon not recognized FLASH banks. This | 
 | 		is useful, if some of the configured banks are only | 
 | 		optionally available. | 
 |  | 
 | - CFG_RX_ETH_BUFFER: | 
 | 		Defines the number of ethernet receive buffers. On some | 
 | 		ethernet controllers it is recommended to set this value | 
 | 		to 8 or even higher (EEPRO100 or 405 EMAC), since all | 
 | 		buffers can be full shortly after enabling the interface | 
 | 		on high ethernet traffic. | 
 | 		Defaults to 4 if not defined. | 
 |  | 
 | The following definitions that deal with the placement and management | 
 | of environment data (variable area); in general, we support the | 
 | following configurations: | 
 |  | 
 | - CFG_ENV_IS_IN_FLASH: | 
 |  | 
 | 	Define this if the environment is in flash memory. | 
 |  | 
 | 	a) The environment occupies one whole flash sector, which is | 
 | 	   "embedded" in the text segment with the U-Boot code. This | 
 | 	   happens usually with "bottom boot sector" or "top boot | 
 | 	   sector" type flash chips, which have several smaller | 
 | 	   sectors at the start or the end. For instance, such a | 
 | 	   layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In | 
 | 	   such a case you would place the environment in one of the | 
 | 	   4 kB sectors - with U-Boot code before and after it. With | 
 | 	   "top boot sector" type flash chips, you would put the | 
 | 	   environment in one of the last sectors, leaving a gap | 
 | 	   between U-Boot and the environment. | 
 |  | 
 | 	- CFG_ENV_OFFSET: | 
 |  | 
 | 	   Offset of environment data (variable area) to the | 
 | 	   beginning of flash memory; for instance, with bottom boot | 
 | 	   type flash chips the second sector can be used: the offset | 
 | 	   for this sector is given here. | 
 |  | 
 | 	   CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. | 
 |  | 
 | 	- CFG_ENV_ADDR: | 
 |  | 
 | 	   This is just another way to specify the start address of | 
 | 	   the flash sector containing the environment (instead of | 
 | 	   CFG_ENV_OFFSET). | 
 |  | 
 | 	- CFG_ENV_SECT_SIZE: | 
 |  | 
 | 	   Size of the sector containing the environment. | 
 |  | 
 |  | 
 | 	b) Sometimes flash chips have few, equal sized, BIG sectors. | 
 | 	   In such a case you don't want to spend a whole sector for | 
 | 	   the environment. | 
 |  | 
 | 	- CFG_ENV_SIZE: | 
 |  | 
 | 	   If you use this in combination with CFG_ENV_IS_IN_FLASH | 
 | 	   and CFG_ENV_SECT_SIZE, you can specify to use only a part | 
 | 	   of this flash sector for the environment. This saves | 
 | 	   memory for the RAM copy of the environment. | 
 |  | 
 | 	   It may also save flash memory if you decide to use this | 
 | 	   when your environment is "embedded" within U-Boot code, | 
 | 	   since then the remainder of the flash sector could be used | 
 | 	   for U-Boot code. It should be pointed out that this is | 
 | 	   STRONGLY DISCOURAGED from a robustness point of view: | 
 | 	   updating the environment in flash makes it always | 
 | 	   necessary to erase the WHOLE sector. If something goes | 
 | 	   wrong before the contents has been restored from a copy in | 
 | 	   RAM, your target system will be dead. | 
 |  | 
 | 	- CFG_ENV_ADDR_REDUND | 
 | 	  CFG_ENV_SIZE_REDUND | 
 |  | 
 | 	   These settings describe a second storage area used to hold | 
 | 	   a redundand copy of the environment data, so that there is | 
 | 	   a valid backup copy in case there is a power failure during | 
 | 	   a "saveenv" operation. | 
 |  | 
 | BE CAREFUL! Any changes to the flash layout, and some changes to the | 
 | source code will make it necessary to adapt <board>/u-boot.lds* | 
 | accordingly! | 
 |  | 
 |  | 
 | - CFG_ENV_IS_IN_NVRAM: | 
 |  | 
 | 	Define this if you have some non-volatile memory device | 
 | 	(NVRAM, battery buffered SRAM) which you want to use for the | 
 | 	environment. | 
 |  | 
 | 	- CFG_ENV_ADDR: | 
 | 	- CFG_ENV_SIZE: | 
 |  | 
 | 	  These two #defines are used to determin the memory area you | 
 | 	  want to use for environment. It is assumed that this memory | 
 | 	  can just be read and written to, without any special | 
 | 	  provision. | 
 |  | 
 | BE CAREFUL! The first access to the environment happens quite early | 
 | in U-Boot initalization (when we try to get the setting of for the | 
 | console baudrate). You *MUST* have mappend your NVRAM area then, or | 
 | U-Boot will hang. | 
 |  | 
 | Please note that even with NVRAM we still use a copy of the | 
 | environment in RAM: we could work on NVRAM directly, but we want to | 
 | keep settings there always unmodified except somebody uses "saveenv" | 
 | to save the current settings. | 
 |  | 
 |  | 
 | - CFG_ENV_IS_IN_EEPROM: | 
 |  | 
 | 	Use this if you have an EEPROM or similar serial access | 
 | 	device and a driver for it. | 
 |  | 
 | 	- CFG_ENV_OFFSET: | 
 | 	- CFG_ENV_SIZE: | 
 |  | 
 | 	  These two #defines specify the offset and size of the | 
 | 	  environment area within the total memory of your EEPROM. | 
 |  | 
 | 	- CFG_I2C_EEPROM_ADDR: | 
 | 	  If defined, specified the chip address of the EEPROM device. | 
 | 	  The default address is zero. | 
 |  | 
 | 	- CFG_EEPROM_PAGE_WRITE_BITS: | 
 | 	  If defined, the number of bits used to address bytes in a | 
 | 	  single page in the EEPROM device.  A 64 byte page, for example | 
 | 	  would require six bits. | 
 |  | 
 | 	- CFG_EEPROM_PAGE_WRITE_DELAY_MS: | 
 | 	  If defined, the number of milliseconds to delay between | 
 | 	  page writes.	The default is zero milliseconds. | 
 |  | 
 | 	- CFG_I2C_EEPROM_ADDR_LEN: | 
 | 	  The length in bytes of the EEPROM memory array address.  Note | 
 | 	  that this is NOT the chip address length! | 
 |  | 
 | 	- CFG_I2C_EEPROM_ADDR_OVERFLOW: | 
 | 	  EEPROM chips that implement "address overflow" are ones | 
 | 	  like Catalyst 24WC04/08/16 which has 9/10/11 bits of | 
 | 	  address and the extra bits end up in the "chip address" bit | 
 | 	  slots. This makes a 24WC08 (1Kbyte) chip look like four 256 | 
 | 	  byte chips. | 
 |  | 
 | 	  Note that we consider the length of the address field to | 
 | 	  still be one byte because the extra address bits are hidden | 
 | 	  in the chip address. | 
 |  | 
 | 	- CFG_EEPROM_SIZE: | 
 | 	  The size in bytes of the EEPROM device. | 
 |  | 
 |  | 
 | - CFG_ENV_IS_IN_DATAFLASH: | 
 |  | 
 | 	Define this if you have a DataFlash memory device which you | 
 | 	want to use for the environment. | 
 |  | 
 | 	- CFG_ENV_OFFSET: | 
 | 	- CFG_ENV_ADDR: | 
 | 	- CFG_ENV_SIZE: | 
 |  | 
 | 	  These three #defines specify the offset and size of the | 
 | 	  environment area within the total memory of your DataFlash placed | 
 | 	  at the specified address. | 
 |  | 
 | - CFG_ENV_IS_IN_NAND: | 
 |  | 
 | 	Define this if you have a NAND device which you want to use | 
 | 	for the environment. | 
 |  | 
 | 	- CFG_ENV_OFFSET: | 
 | 	- CFG_ENV_SIZE: | 
 |  | 
 | 	  These two #defines specify the offset and size of the environment | 
 | 	  area within the first NAND device. | 
 |  | 
 | 	- CFG_ENV_OFFSET_REDUND | 
 |  | 
 | 	  This setting describes a second storage area of CFG_ENV_SIZE | 
 | 	  size used to hold a redundant copy of the environment data, | 
 | 	  so that there is a valid backup copy in case there is a | 
 | 	  power failure during a "saveenv" operation. | 
 |  | 
 | 	Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned | 
 | 	to a block boundary, and CFG_ENV_SIZE must be a multiple of | 
 | 	the NAND devices block size. | 
 |  | 
 | - CFG_SPI_INIT_OFFSET | 
 |  | 
 | 	Defines offset to the initial SPI buffer area in DPRAM. The | 
 | 	area is used at an early stage (ROM part) if the environment | 
 | 	is configured to reside in the SPI EEPROM: We need a 520 byte | 
 | 	scratch DPRAM area. It is used between the two initialization | 
 | 	calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems | 
 | 	to be a good choice since it makes it far enough from the | 
 | 	start of the data area as well as from the stack pointer. | 
 |  | 
 | Please note that the environment is read-only as long as the monitor | 
 | has been relocated to RAM and a RAM copy of the environment has been | 
 | created; also, when using EEPROM you will have to use getenv_r() | 
 | until then to read environment variables. | 
 |  | 
 | The environment is protected by a CRC32 checksum. Before the monitor | 
 | is relocated into RAM, as a result of a bad CRC you will be working | 
 | with the compiled-in default environment - *silently*!!! [This is | 
 | necessary, because the first environment variable we need is the | 
 | "baudrate" setting for the console - if we have a bad CRC, we don't | 
 | have any device yet where we could complain.] | 
 |  | 
 | Note: once the monitor has been relocated, then it will complain if | 
 | the default environment is used; a new CRC is computed as soon as you | 
 | use the "saveenv" command to store a valid environment. | 
 |  | 
 | - CFG_FAULT_ECHO_LINK_DOWN: | 
 | 		Echo the inverted Ethernet link state to the fault LED. | 
 |  | 
 | 		Note: If this option is active, then CFG_FAULT_MII_ADDR | 
 | 		      also needs to be defined. | 
 |  | 
 | - CFG_FAULT_MII_ADDR: | 
 | 		MII address of the PHY to check for the Ethernet link state. | 
 |  | 
 | - CFG_64BIT_VSPRINTF: | 
 | 		Makes vsprintf (and all *printf functions) support printing | 
 | 		of 64bit values by using the L quantifier | 
 |  | 
 | - CFG_64BIT_STRTOUL: | 
 | 		Adds simple_strtoull that returns a 64bit value | 
 |  | 
 | Low Level (hardware related) configuration options: | 
 | --------------------------------------------------- | 
 |  | 
 | - CFG_CACHELINE_SIZE: | 
 | 		Cache Line Size of the CPU. | 
 |  | 
 | - CFG_DEFAULT_IMMR: | 
 | 		Default address of the IMMR after system reset. | 
 |  | 
 | 		Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, | 
 | 		and RPXsuper) to be able to adjust the position of | 
 | 		the IMMR register after a reset. | 
 |  | 
 | - Floppy Disk Support: | 
 | 		CFG_FDC_DRIVE_NUMBER | 
 |  | 
 | 		the default drive number (default value 0) | 
 |  | 
 | 		CFG_ISA_IO_STRIDE | 
 |  | 
 | 		defines the spacing between fdc chipset registers | 
 | 		(default value 1) | 
 |  | 
 | 		CFG_ISA_IO_OFFSET | 
 |  | 
 | 		defines the offset of register from address. It | 
 | 		depends on which part of the data bus is connected to | 
 | 		the fdc chipset. (default value 0) | 
 |  | 
 | 		If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and | 
 | 		CFG_FDC_DRIVE_NUMBER are undefined, they take their | 
 | 		default value. | 
 |  | 
 | 		if CFG_FDC_HW_INIT is defined, then the function | 
 | 		fdc_hw_init() is called at the beginning of the FDC | 
 | 		setup. fdc_hw_init() must be provided by the board | 
 | 		source code. It is used to make hardware dependant | 
 | 		initializations. | 
 |  | 
 | - CFG_IMMR:	Physical address of the Internal Memory. | 
 | 		DO NOT CHANGE unless you know exactly what you're | 
 | 		doing! (11-4) [MPC8xx/82xx systems only] | 
 |  | 
 | - CFG_INIT_RAM_ADDR: | 
 |  | 
 | 		Start address of memory area that can be used for | 
 | 		initial data and stack; please note that this must be | 
 | 		writable memory that is working WITHOUT special | 
 | 		initialization, i. e. you CANNOT use normal RAM which | 
 | 		will become available only after programming the | 
 | 		memory controller and running certain initialization | 
 | 		sequences. | 
 |  | 
 | 		U-Boot uses the following memory types: | 
 | 		- MPC8xx and MPC8260: IMMR (internal memory of the CPU) | 
 | 		- MPC824X: data cache | 
 | 		- PPC4xx:  data cache | 
 |  | 
 | - CFG_GBL_DATA_OFFSET: | 
 |  | 
 | 		Offset of the initial data structure in the memory | 
 | 		area defined by CFG_INIT_RAM_ADDR. Usually | 
 | 		CFG_GBL_DATA_OFFSET is chosen such that the initial | 
 | 		data is located at the end of the available space | 
 | 		(sometimes written as (CFG_INIT_RAM_END - | 
 | 		CFG_INIT_DATA_SIZE), and the initial stack is just | 
 | 		below that area (growing from (CFG_INIT_RAM_ADDR + | 
 | 		CFG_GBL_DATA_OFFSET) downward. | 
 |  | 
 | 	Note: | 
 | 		On the MPC824X (or other systems that use the data | 
 | 		cache for initial memory) the address chosen for | 
 | 		CFG_INIT_RAM_ADDR is basically arbitrary - it must | 
 | 		point to an otherwise UNUSED address space between | 
 | 		the top of RAM and the start of the PCI space. | 
 |  | 
 | - CFG_SIUMCR:	SIU Module Configuration (11-6) | 
 |  | 
 | - CFG_SYPCR:	System Protection Control (11-9) | 
 |  | 
 | - CFG_TBSCR:	Time Base Status and Control (11-26) | 
 |  | 
 | - CFG_PISCR:	Periodic Interrupt Status and Control (11-31) | 
 |  | 
 | - CFG_PLPRCR:	PLL, Low-Power, and Reset Control Register (15-30) | 
 |  | 
 | - CFG_SCCR:	System Clock and reset Control Register (15-27) | 
 |  | 
 | - CFG_OR_TIMING_SDRAM: | 
 | 		SDRAM timing | 
 |  | 
 | - CFG_MAMR_PTA: | 
 | 		periodic timer for refresh | 
 |  | 
 | - CFG_DER:	Debug Event Register (37-47) | 
 |  | 
 | - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, | 
 |   CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, | 
 |   CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, | 
 |   CFG_BR1_PRELIM: | 
 | 		Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) | 
 |  | 
 | - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, | 
 |   CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, | 
 |   CFG_OR3_PRELIM, CFG_BR3_PRELIM: | 
 | 		Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) | 
 |  | 
 | - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, | 
 |   CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: | 
 | 		Machine Mode Register and Memory Periodic Timer | 
 | 		Prescaler definitions (SDRAM timing) | 
 |  | 
 | - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: | 
 | 		enable I2C microcode relocation patch (MPC8xx); | 
 | 		define relocation offset in DPRAM [DSP2] | 
 |  | 
 | - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: | 
 | 		enable SPI microcode relocation patch (MPC8xx); | 
 | 		define relocation offset in DPRAM [SCC4] | 
 |  | 
 | - CFG_USE_OSCCLK: | 
 | 		Use OSCM clock mode on MBX8xx board. Be careful, | 
 | 		wrong setting might damage your board. Read | 
 | 		doc/README.MBX before setting this variable! | 
 |  | 
 | - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) | 
 | 		Offset of the bootmode word in DPRAM used by post | 
 | 		(Power On Self Tests). This definition overrides | 
 | 		#define'd default value in commproc.h resp. | 
 | 		cpm_8260.h. | 
 |  | 
 | - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, | 
 |   CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, | 
 |   CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, | 
 |   CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, | 
 |   CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, | 
 |   CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, | 
 |   CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, | 
 |   CFG_POCMR2_MASK_ATTRIB: (MPC826x only) | 
 | 		Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. | 
 |  | 
 | - CONFIG_ETHER_ON_FEC[12] | 
 | 		Define to enable FEC[12] on a 8xx series processor. | 
 |  | 
 | - CONFIG_FEC[12]_PHY | 
 | 		Define to the hardcoded PHY address which corresponds | 
 | 		to the given FEC; i. e. | 
 | 			#define CONFIG_FEC1_PHY 4 | 
 | 		means that the PHY with address 4 is connected to FEC1 | 
 |  | 
 | 		When set to -1, means to probe for first available. | 
 |  | 
 | - CONFIG_FEC[12]_PHY_NORXERR | 
 | 		The PHY does not have a RXERR line (RMII only). | 
 | 		(so program the FEC to ignore it). | 
 |  | 
 | - CONFIG_RMII | 
 | 		Enable RMII mode for all FECs. | 
 | 		Note that this is a global option, we can't | 
 | 		have one FEC in standard MII mode and another in RMII mode. | 
 |  | 
 | - CONFIG_CRC32_VERIFY | 
 | 		Add a verify option to the crc32 command. | 
 | 		The syntax is: | 
 |  | 
 | 		=> crc32 -v <address> <count> <crc32> | 
 |  | 
 | 		Where address/count indicate a memory area | 
 | 		and crc32 is the correct crc32 which the | 
 | 		area should have. | 
 |  | 
 | - CONFIG_LOOPW | 
 | 		Add the "loopw" memory command. This only takes effect if | 
 | 		the memory commands are activated globally (CFG_CMD_MEM). | 
 |  | 
 | - CONFIG_MX_CYCLIC | 
 | 		Add the "mdc" and "mwc" memory commands. These are cyclic | 
 | 		"md/mw" commands. | 
 | 		Examples: | 
 |  | 
 | 		=> mdc.b 10 4 500 | 
 | 		This command will print 4 bytes (10,11,12,13) each 500 ms. | 
 |  | 
 | 		=> mwc.l 100 12345678 10 | 
 | 		This command will write 12345678 to address 100 all 10 ms. | 
 |  | 
 | 		This only takes effect if the memory commands are activated | 
 | 		globally (CFG_CMD_MEM). | 
 |  | 
 | - CONFIG_SKIP_LOWLEVEL_INIT | 
 | - CONFIG_SKIP_RELOCATE_UBOOT | 
 |  | 
 | 		[ARM only] If these variables are defined, then | 
 | 		certain low level initializations (like setting up | 
 | 		the memory controller) are omitted and/or U-Boot does | 
 | 		not relocate itself into RAM. | 
 | 		Normally these variables MUST NOT be defined. The | 
 | 		only exception is when U-Boot is loaded (to RAM) by | 
 | 		some other boot loader or by a debugger which | 
 | 		performs these intializations itself. | 
 |  | 
 |  | 
 | Building the Software: | 
 | ====================== | 
 |  | 
 | Building U-Boot has been tested in native PPC environments (on a | 
 | PowerBook G3 running LinuxPPC 2000) and in cross environments | 
 | (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and | 
 | NetBSD 1.5 on x86). | 
 |  | 
 | If you are not using a native PPC environment, it is assumed that you | 
 | have the GNU cross compiling tools available in your path and named | 
 | with a prefix of "powerpc-linux-". If this is not the case, (e.g. if | 
 | you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change | 
 | the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, | 
 | change it to: | 
 |  | 
 | 	CROSS_COMPILE = ppc_4xx- | 
 |  | 
 |  | 
 | U-Boot is intended to be  simple  to  build.  After  installing	 the | 
 | sources	 you must configure U-Boot for one specific board type. This | 
 | is done by typing: | 
 |  | 
 | 	make NAME_config | 
 |  | 
 | where "NAME_config" is the name of one of the existing | 
 | configurations; the following names are supported: | 
 |  | 
 | 	ADCIOP_config		FPS860L_config		omap730p2_config | 
 | 	ADS860_config		GEN860T_config		pcu_e_config | 
 | 	Alaska8220_config | 
 | 	AR405_config		GENIETV_config		PIP405_config | 
 | 	at91rm9200dk_config	GTH_config		QS823_config | 
 | 	CANBT_config		hermes_config		QS850_config | 
 | 	cmi_mpc5xx_config	hymod_config		QS860T_config | 
 | 	cogent_common_config	IP860_config		RPXlite_config | 
 | 	cogent_mpc8260_config	IVML24_config		RPXlite_DW_config | 
 | 	cogent_mpc8xx_config	IVMS8_config		RPXsuper_config | 
 | 	CPCI405_config		JSE_config		rsdproto_config | 
 | 	CPCIISER4_config	LANTEC_config		Sandpoint8240_config | 
 | 	csb272_config		lwmon_config		sbc8260_config | 
 | 	CU824_config		MBX860T_config		sbc8560_33_config | 
 | 	DUET_ADS_config		MBX_config		sbc8560_66_config | 
 | 	EBONY_config		MPC8260ADS_config	SM850_config | 
 | 	ELPT860_config		MPC8540ADS_config	SPD823TS_config | 
 | 	ESTEEM192E_config	MPC8540EVAL_config	stxgp3_config | 
 | 	ETX094_config		MPC8560ADS_config	SXNI855T_config | 
 | 	FADS823_config		NETVIA_config		TQM823L_config | 
 | 	FADS850SAR_config	omap1510inn_config	TQM850L_config | 
 | 	FADS860T_config		omap1610h2_config	TQM855L_config | 
 | 	FPS850L_config		omap1610inn_config	TQM860L_config | 
 | 				omap5912osk_config	walnut_config | 
 | 				omap2420h4_config	Yukon8220_config | 
 | 							ZPC1900_config | 
 |  | 
 | Note: for some board special configuration names may exist; check if | 
 |       additional information is available from the board vendor; for | 
 |       instance, the TQM823L systems are available without (standard) | 
 |       or with LCD support. You can select such additional "features" | 
 |       when chosing the configuration, i. e. | 
 |  | 
 |       make TQM823L_config | 
 | 	- will configure for a plain TQM823L, i. e. no LCD support | 
 |  | 
 |       make TQM823L_LCD_config | 
 | 	- will configure for a TQM823L with U-Boot console on LCD | 
 |  | 
 |       etc. | 
 |  | 
 |  | 
 | Finally, type "make all", and you should get some working U-Boot | 
 | images ready for download to / installation on your system: | 
 |  | 
 | - "u-boot.bin" is a raw binary image | 
 | - "u-boot" is an image in ELF binary format | 
 | - "u-boot.srec" is in Motorola S-Record format | 
 |  | 
 |  | 
 | Please be aware that the Makefiles assume you are using GNU make, so | 
 | for instance on NetBSD you might need to use "gmake" instead of | 
 | native "make". | 
 |  | 
 |  | 
 | If the system board that you have is not listed, then you will need | 
 | to port U-Boot to your hardware platform. To do this, follow these | 
 | steps: | 
 |  | 
 | 1.  Add a new configuration option for your board to the toplevel | 
 |     "Makefile" and to the "MAKEALL" script, using the existing | 
 |     entries as examples. Note that here and at many other places | 
 |     boards and other names are listed in alphabetical sort order. Please | 
 |     keep this order. | 
 | 2.  Create a new directory to hold your board specific code. Add any | 
 |     files you need. In your board directory, you will need at least | 
 |     the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". | 
 | 3.  Create a new configuration file "include/configs/<board>.h" for | 
 |     your board | 
 | 3.  If you're porting U-Boot to a new CPU, then also create a new | 
 |     directory to hold your CPU specific code. Add any files you need. | 
 | 4.  Run "make <board>_config" with your new name. | 
 | 5.  Type "make", and you should get a working "u-boot.srec" file | 
 |     to be installed on your target system. | 
 | 6.  Debug and solve any problems that might arise. | 
 |     [Of course, this last step is much harder than it sounds.] | 
 |  | 
 |  | 
 | Testing of U-Boot Modifications, Ports to New Hardware, etc.: | 
 | ============================================================== | 
 |  | 
 | If you have modified U-Boot sources (for instance added a new	board | 
 | or  support  for  new  devices,	 a new CPU, etc.) you are expected to | 
 | provide feedback to the other developers. The feedback normally takes | 
 | the form of a "patch", i. e. a context diff against a certain (latest | 
 | official or latest in CVS) version of U-Boot sources. | 
 |  | 
 | But before you submit such a patch, please verify that	your  modifi- | 
 | cation	did not break existing code. At least make sure that *ALL* of | 
 | the supported boards compile WITHOUT ANY compiler warnings. To do so, | 
 | just run the "MAKEALL" script, which will configure and build U-Boot | 
 | for ALL supported system. Be warned, this will take a while. You  can | 
 | select	which  (cross)	compiler  to use by passing a `CROSS_COMPILE' | 
 | environment variable to the script, i. e. to use the cross tools from | 
 | MontaVista's Hard Hat Linux you can type | 
 |  | 
 | 	CROSS_COMPILE=ppc_8xx- MAKEALL | 
 |  | 
 | or to build on a native PowerPC system you can type | 
 |  | 
 | 	CROSS_COMPILE=' ' MAKEALL | 
 |  | 
 | See also "U-Boot Porting Guide" below. | 
 |  | 
 |  | 
 | Monitor Commands - Overview: | 
 | ============================ | 
 |  | 
 | go	- start application at address 'addr' | 
 | run	- run commands in an environment variable | 
 | bootm	- boot application image from memory | 
 | bootp	- boot image via network using BootP/TFTP protocol | 
 | tftpboot- boot image via network using TFTP protocol | 
 | 	       and env variables "ipaddr" and "serverip" | 
 | 	       (and eventually "gatewayip") | 
 | rarpboot- boot image via network using RARP/TFTP protocol | 
 | diskboot- boot from IDE devicebootd   - boot default, i.e., run 'bootcmd' | 
 | loads	- load S-Record file over serial line | 
 | loadb	- load binary file over serial line (kermit mode) | 
 | md	- memory display | 
 | mm	- memory modify (auto-incrementing) | 
 | nm	- memory modify (constant address) | 
 | mw	- memory write (fill) | 
 | cp	- memory copy | 
 | cmp	- memory compare | 
 | crc32	- checksum calculation | 
 | imd	- i2c memory display | 
 | imm	- i2c memory modify (auto-incrementing) | 
 | inm	- i2c memory modify (constant address) | 
 | imw	- i2c memory write (fill) | 
 | icrc32	- i2c checksum calculation | 
 | iprobe	- probe to discover valid I2C chip addresses | 
 | iloop	- infinite loop on address range | 
 | isdram	- print SDRAM configuration information | 
 | sspi	- SPI utility commands | 
 | base	- print or set address offset | 
 | printenv- print environment variables | 
 | setenv	- set environment variables | 
 | saveenv - save environment variables to persistent storage | 
 | protect - enable or disable FLASH write protection | 
 | erase	- erase FLASH memory | 
 | flinfo	- print FLASH memory information | 
 | bdinfo	- print Board Info structure | 
 | iminfo	- print header information for application image | 
 | coninfo - print console devices and informations | 
 | ide	- IDE sub-system | 
 | loop	- infinite loop on address range | 
 | loopw	- infinite write loop on address range | 
 | mtest	- simple RAM test | 
 | icache	- enable or disable instruction cache | 
 | dcache	- enable or disable data cache | 
 | reset	- Perform RESET of the CPU | 
 | echo	- echo args to console | 
 | version - print monitor version | 
 | help	- print online help | 
 | ?	- alias for 'help' | 
 |  | 
 |  | 
 | Monitor Commands - Detailed Description: | 
 | ======================================== | 
 |  | 
 | TODO. | 
 |  | 
 | For now: just type "help <command>". | 
 |  | 
 |  | 
 | Environment Variables: | 
 | ====================== | 
 |  | 
 | U-Boot supports user configuration using Environment Variables which | 
 | can be made persistent by saving to Flash memory. | 
 |  | 
 | Environment Variables are set using "setenv", printed using | 
 | "printenv", and saved to Flash using "saveenv". Using "setenv" | 
 | without a value can be used to delete a variable from the | 
 | environment. As long as you don't save the environment you are | 
 | working with an in-memory copy. In case the Flash area containing the | 
 | environment is erased by accident, a default environment is provided. | 
 |  | 
 | Some configuration options can be set using Environment Variables: | 
 |  | 
 |   baudrate	- see CONFIG_BAUDRATE | 
 |  | 
 |   bootdelay	- see CONFIG_BOOTDELAY | 
 |  | 
 |   bootcmd	- see CONFIG_BOOTCOMMAND | 
 |  | 
 |   bootargs	- Boot arguments when booting an RTOS image | 
 |  | 
 |   bootfile	- Name of the image to load with TFTP | 
 |  | 
 |   autoload	- if set to "no" (any string beginning with 'n'), | 
 | 		  "bootp" will just load perform a lookup of the | 
 | 		  configuration from the BOOTP server, but not try to | 
 | 		  load any image using TFTP | 
 |  | 
 |   autostart	- if set to "yes", an image loaded using the "bootp", | 
 | 		  "rarpboot", "tftpboot" or "diskboot" commands will | 
 | 		  be automatically started (by internally calling | 
 | 		  "bootm") | 
 |  | 
 | 		  If set to "no", a standalone image passed to the | 
 | 		  "bootm" command will be copied to the load address | 
 | 		  (and eventually uncompressed), but NOT be started. | 
 | 		  This can be used to load and uncompress arbitrary | 
 | 		  data. | 
 |  | 
 |   i2cfast	- (PPC405GP|PPC405EP only) | 
 | 		  if set to 'y' configures Linux I2C driver for fast | 
 | 		  mode (400kHZ). This environment variable is used in | 
 | 		  initialization code. So, for changes to be effective | 
 | 		  it must be saved and board must be reset. | 
 |  | 
 |   initrd_high	- restrict positioning of initrd images: | 
 | 		  If this variable is not set, initrd images will be | 
 | 		  copied to the highest possible address in RAM; this | 
 | 		  is usually what you want since it allows for | 
 | 		  maximum initrd size. If for some reason you want to | 
 | 		  make sure that the initrd image is loaded below the | 
 | 		  CFG_BOOTMAPSZ limit, you can set this environment | 
 | 		  variable to a value of "no" or "off" or "0". | 
 | 		  Alternatively, you can set it to a maximum upper | 
 | 		  address to use (U-Boot will still check that it | 
 | 		  does not overwrite the U-Boot stack and data). | 
 |  | 
 | 		  For instance, when you have a system with 16 MB | 
 | 		  RAM, and want to reserve 4 MB from use by Linux, | 
 | 		  you can do this by adding "mem=12M" to the value of | 
 | 		  the "bootargs" variable. However, now you must make | 
 | 		  sure that the initrd image is placed in the first | 
 | 		  12 MB as well - this can be done with | 
 |  | 
 | 		  setenv initrd_high 00c00000 | 
 |  | 
 | 		  If you set initrd_high to 0xFFFFFFFF, this is an | 
 | 		  indication to U-Boot that all addresses are legal | 
 | 		  for the Linux kernel, including addresses in flash | 
 | 		  memory. In this case U-Boot will NOT COPY the | 
 | 		  ramdisk at all. This may be useful to reduce the | 
 | 		  boot time on your system, but requires that this | 
 | 		  feature is supported by your Linux kernel. | 
 |  | 
 |   ipaddr	- IP address; needed for tftpboot command | 
 |  | 
 |   loadaddr	- Default load address for commands like "bootp", | 
 | 		  "rarpboot", "tftpboot", "loadb" or "diskboot" | 
 |  | 
 |   loads_echo	- see CONFIG_LOADS_ECHO | 
 |  | 
 |   serverip	- TFTP server IP address; needed for tftpboot command | 
 |  | 
 |   bootretry	- see CONFIG_BOOT_RETRY_TIME | 
 |  | 
 |   bootdelaykey	- see CONFIG_AUTOBOOT_DELAY_STR | 
 |  | 
 |   bootstopkey	- see CONFIG_AUTOBOOT_STOP_STR | 
 |  | 
 |   ethprime	- When CONFIG_NET_MULTI is enabled controls which | 
 | 		  interface is used first. | 
 |  | 
 |   ethact	- When CONFIG_NET_MULTI is enabled controls which | 
 | 		  interface is currently active. For example you | 
 | 		  can do the following | 
 |  | 
 | 		  => setenv ethact FEC ETHERNET | 
 | 		  => ping 192.168.0.1 # traffic sent on FEC ETHERNET | 
 | 		  => setenv ethact SCC ETHERNET | 
 | 		  => ping 10.0.0.1 # traffic sent on SCC ETHERNET | 
 |  | 
 |    netretry	- When set to "no" each network operation will | 
 | 		  either succeed or fail without retrying. | 
 | 		  When set to "once" the network operation will | 
 | 		  fail when all the available network interfaces | 
 | 		  are tried once without success. | 
 | 		  Useful on scripts which control the retry operation | 
 | 		  themselves. | 
 |  | 
 |   tftpsrcport	- If this is set, the value is used for TFTP's | 
 | 		  UDP source port. | 
 |  | 
 |   tftpdstport	- If this is set, the value is used for TFTP's UDP | 
 | 		  destination port instead of the Well Know Port 69. | 
 |  | 
 |    vlan		- When set to a value < 4095 the traffic over | 
 | 		  ethernet is encapsulated/received over 802.1q | 
 | 		  VLAN tagged frames. | 
 |  | 
 | The following environment variables may be used and automatically | 
 | updated by the network boot commands ("bootp" and "rarpboot"), | 
 | depending the information provided by your boot server: | 
 |  | 
 |   bootfile	- see above | 
 |   dnsip		- IP address of your Domain Name Server | 
 |   dnsip2	- IP address of your secondary Domain Name Server | 
 |   gatewayip	- IP address of the Gateway (Router) to use | 
 |   hostname	- Target hostname | 
 |   ipaddr	- see above | 
 |   netmask	- Subnet Mask | 
 |   rootpath	- Pathname of the root filesystem on the NFS server | 
 |   serverip	- see above | 
 |  | 
 |  | 
 | There are two special Environment Variables: | 
 |  | 
 |   serial#	- contains hardware identification information such | 
 | 		  as type string and/or serial number | 
 |   ethaddr	- Ethernet address | 
 |  | 
 | These variables can be set only once (usually during manufacturing of | 
 | the board). U-Boot refuses to delete or overwrite these variables | 
 | once they have been set once. | 
 |  | 
 |  | 
 | Further special Environment Variables: | 
 |  | 
 |   ver		- Contains the U-Boot version string as printed | 
 | 		  with the "version" command. This variable is | 
 | 		  readonly (see CONFIG_VERSION_VARIABLE). | 
 |  | 
 |  | 
 | Please note that changes to some configuration parameters may take | 
 | only effect after the next boot (yes, that's just like Windoze :-). | 
 |  | 
 |  | 
 | Command Line Parsing: | 
 | ===================== | 
 |  | 
 | There are two different command line parsers available with U-Boot: | 
 | the old "simple" one, and the much more powerful "hush" shell: | 
 |  | 
 | Old, simple command line parser: | 
 | -------------------------------- | 
 |  | 
 | - supports environment variables (through setenv / saveenv commands) | 
 | - several commands on one line, separated by ';' | 
 | - variable substitution using "... ${name} ..." syntax | 
 | - special characters ('$', ';') can be escaped by prefixing with '\', | 
 |   for example: | 
 | 	setenv bootcmd bootm \${address} | 
 | - You can also escape text by enclosing in single apostrophes, for example: | 
 | 	setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' | 
 |  | 
 | Hush shell: | 
 | ----------- | 
 |  | 
 | - similar to Bourne shell, with control structures like | 
 |   if...then...else...fi, for...do...done; while...do...done, | 
 |   until...do...done, ... | 
 | - supports environment ("global") variables (through setenv / saveenv | 
 |   commands) and local shell variables (through standard shell syntax | 
 |   "name=value"); only environment variables can be used with "run" | 
 |   command | 
 |  | 
 | General rules: | 
 | -------------- | 
 |  | 
 | (1) If a command line (or an environment variable executed by a "run" | 
 |     command) contains several commands separated by semicolon, and | 
 |     one of these commands fails, then the remaining commands will be | 
 |     executed anyway. | 
 |  | 
 | (2) If you execute several variables with one call to run (i. e. | 
 |     calling run with a list af variables as arguments), any failing | 
 |     command will cause "run" to terminate, i. e. the remaining | 
 |     variables are not executed. | 
 |  | 
 | Note for Redundant Ethernet Interfaces: | 
 | ======================================= | 
 |  | 
 | Some boards come with redundant ethernet interfaces; U-Boot supports | 
 | such configurations and is capable of automatic selection of a | 
 | "working" interface when needed. MAC assignment works as follows: | 
 |  | 
 | Network interfaces are numbered eth0, eth1, eth2, ... Corresponding | 
 | MAC addresses can be stored in the environment as "ethaddr" (=>eth0), | 
 | "eth1addr" (=>eth1), "eth2addr", ... | 
 |  | 
 | If the network interface stores some valid MAC address (for instance | 
 | in SROM), this is used as default address if there is NO correspon- | 
 | ding setting in the environment; if the corresponding environment | 
 | variable is set, this overrides the settings in the card; that means: | 
 |  | 
 | o If the SROM has a valid MAC address, and there is no address in the | 
 |   environment, the SROM's address is used. | 
 |  | 
 | o If there is no valid address in the SROM, and a definition in the | 
 |   environment exists, then the value from the environment variable is | 
 |   used. | 
 |  | 
 | o If both the SROM and the environment contain a MAC address, and | 
 |   both addresses are the same, this MAC address is used. | 
 |  | 
 | o If both the SROM and the environment contain a MAC address, and the | 
 |   addresses differ, the value from the environment is used and a | 
 |   warning is printed. | 
 |  | 
 | o If neither SROM nor the environment contain a MAC address, an error | 
 |   is raised. | 
 |  | 
 |  | 
 | Image Formats: | 
 | ============== | 
 |  | 
 | The "boot" commands of this monitor operate on "image" files which | 
 | can be basicly anything, preceeded by a special header; see the | 
 | definitions in include/image.h for details; basicly, the header | 
 | defines the following image properties: | 
 |  | 
 | * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, | 
 |   4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, | 
 |   LynxOS, pSOS, QNX, RTEMS, ARTOS; | 
 |   Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). | 
 | * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, | 
 |   IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; | 
 |   Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). | 
 | * Compression Type (uncompressed, gzip, bzip2) | 
 | * Load Address | 
 | * Entry Point | 
 | * Image Name | 
 | * Image Timestamp | 
 |  | 
 | The header is marked by a special Magic Number, and both the header | 
 | and the data portions of the image are secured against corruption by | 
 | CRC32 checksums. | 
 |  | 
 |  | 
 | Linux Support: | 
 | ============== | 
 |  | 
 | Although U-Boot should support any OS or standalone application | 
 | easily, the main focus has always been on Linux during the design of | 
 | U-Boot. | 
 |  | 
 | U-Boot includes many features that so far have been part of some | 
 | special "boot loader" code within the Linux kernel. Also, any | 
 | "initrd" images to be used are no longer part of one big Linux image; | 
 | instead, kernel and "initrd" are separate images. This implementation | 
 | serves several purposes: | 
 |  | 
 | - the same features can be used for other OS or standalone | 
 |   applications (for instance: using compressed images to reduce the | 
 |   Flash memory footprint) | 
 |  | 
 | - it becomes much easier to port new Linux kernel versions because | 
 |   lots of low-level, hardware dependent stuff are done by U-Boot | 
 |  | 
 | - the same Linux kernel image can now be used with different "initrd" | 
 |   images; of course this also means that different kernel images can | 
 |   be run with the same "initrd". This makes testing easier (you don't | 
 |   have to build a new "zImage.initrd" Linux image when you just | 
 |   change a file in your "initrd"). Also, a field-upgrade of the | 
 |   software is easier now. | 
 |  | 
 |  | 
 | Linux HOWTO: | 
 | ============ | 
 |  | 
 | Porting Linux to U-Boot based systems: | 
 | --------------------------------------- | 
 |  | 
 | U-Boot cannot save you from doing all the necessary modifications to | 
 | configure the Linux device drivers for use with your target hardware | 
 | (no, we don't intend to provide a full virtual machine interface to | 
 | Linux :-). | 
 |  | 
 | But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). | 
 |  | 
 | Just make sure your machine specific header file (for instance | 
 | include/asm-ppc/tqm8xx.h) includes the same definition of the Board | 
 | Information structure as we define in include/u-boot.h, and make | 
 | sure that your definition of IMAP_ADDR uses the same value as your | 
 | U-Boot configuration in CFG_IMMR. | 
 |  | 
 |  | 
 | Configuring the Linux kernel: | 
 | ----------------------------- | 
 |  | 
 | No specific requirements for U-Boot. Make sure you have some root | 
 | device (initial ramdisk, NFS) for your target system. | 
 |  | 
 |  | 
 | Building a Linux Image: | 
 | ----------------------- | 
 |  | 
 | With U-Boot, "normal" build targets like "zImage" or "bzImage" are | 
 | not used. If you use recent kernel source, a new build target | 
 | "uImage" will exist which automatically builds an image usable by | 
 | U-Boot. Most older kernels also have support for a "pImage" target, | 
 | which was introduced for our predecessor project PPCBoot and uses a | 
 | 100% compatible format. | 
 |  | 
 | Example: | 
 |  | 
 | 	make TQM850L_config | 
 | 	make oldconfig | 
 | 	make dep | 
 | 	make uImage | 
 |  | 
 | The "uImage" build target uses a special tool (in 'tools/mkimage') to | 
 | encapsulate a compressed Linux kernel image with header	 information, | 
 | CRC32 checksum etc. for use with U-Boot. This is what we are doing: | 
 |  | 
 | * build a standard "vmlinux" kernel image (in ELF binary format): | 
 |  | 
 | * convert the kernel into a raw binary image: | 
 |  | 
 | 	${CROSS_COMPILE}-objcopy -O binary \ | 
 | 				 -R .note -R .comment \ | 
 | 				 -S vmlinux linux.bin | 
 |  | 
 | * compress the binary image: | 
 |  | 
 | 	gzip -9 linux.bin | 
 |  | 
 | * package compressed binary image for U-Boot: | 
 |  | 
 | 	mkimage -A ppc -O linux -T kernel -C gzip \ | 
 | 		-a 0 -e 0 -n "Linux Kernel Image" \ | 
 | 		-d linux.bin.gz uImage | 
 |  | 
 |  | 
 | The "mkimage" tool can also be used to create ramdisk images for use | 
 | with U-Boot, either separated from the Linux kernel image, or | 
 | combined into one file. "mkimage" encapsulates the images with a 64 | 
 | byte header containing information about target architecture, | 
 | operating system, image type, compression method, entry points, time | 
 | stamp, CRC32 checksums, etc. | 
 |  | 
 | "mkimage" can be called in two ways: to verify existing images and | 
 | print the header information, or to build new images. | 
 |  | 
 | In the first form (with "-l" option) mkimage lists the information | 
 | contained in the header of an existing U-Boot image; this includes | 
 | checksum verification: | 
 |  | 
 | 	tools/mkimage -l image | 
 | 	  -l ==> list image header information | 
 |  | 
 | The second form (with "-d" option) is used to build a U-Boot image | 
 | from a "data file" which is used as image payload: | 
 |  | 
 | 	tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ | 
 | 		      -n name -d data_file image | 
 | 	  -A ==> set architecture to 'arch' | 
 | 	  -O ==> set operating system to 'os' | 
 | 	  -T ==> set image type to 'type' | 
 | 	  -C ==> set compression type 'comp' | 
 | 	  -a ==> set load address to 'addr' (hex) | 
 | 	  -e ==> set entry point to 'ep' (hex) | 
 | 	  -n ==> set image name to 'name' | 
 | 	  -d ==> use image data from 'datafile' | 
 |  | 
 | Right now, all Linux kernels for PowerPC systems use the same load | 
 | address (0x00000000), but the entry point address depends on the | 
 | kernel version: | 
 |  | 
 | - 2.2.x kernels have the entry point at 0x0000000C, | 
 | - 2.3.x and later kernels have the entry point at 0x00000000. | 
 |  | 
 | So a typical call to build a U-Boot image would read: | 
 |  | 
 | 	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \ | 
 | 	> -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ | 
 | 	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ | 
 | 	> examples/uImage.TQM850L | 
 | 	Image Name:   2.4.4 kernel for TQM850L | 
 | 	Created:      Wed Jul 19 02:34:59 2000 | 
 | 	Image Type:   PowerPC Linux Kernel Image (gzip compressed) | 
 | 	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB | 
 | 	Load Address: 0x00000000 | 
 | 	Entry Point:  0x00000000 | 
 |  | 
 | To verify the contents of the image (or check for corruption): | 
 |  | 
 | 	-> tools/mkimage -l examples/uImage.TQM850L | 
 | 	Image Name:   2.4.4 kernel for TQM850L | 
 | 	Created:      Wed Jul 19 02:34:59 2000 | 
 | 	Image Type:   PowerPC Linux Kernel Image (gzip compressed) | 
 | 	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB | 
 | 	Load Address: 0x00000000 | 
 | 	Entry Point:  0x00000000 | 
 |  | 
 | NOTE: for embedded systems where boot time is critical you can trade | 
 | speed for memory and install an UNCOMPRESSED image instead: this | 
 | needs more space in Flash, but boots much faster since it does not | 
 | need to be uncompressed: | 
 |  | 
 | 	-> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz | 
 | 	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \ | 
 | 	> -A ppc -O linux -T kernel -C none -a 0 -e 0 \ | 
 | 	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ | 
 | 	> examples/uImage.TQM850L-uncompressed | 
 | 	Image Name:   2.4.4 kernel for TQM850L | 
 | 	Created:      Wed Jul 19 02:34:59 2000 | 
 | 	Image Type:   PowerPC Linux Kernel Image (uncompressed) | 
 | 	Data Size:    792160 Bytes = 773.59 kB = 0.76 MB | 
 | 	Load Address: 0x00000000 | 
 | 	Entry Point:  0x00000000 | 
 |  | 
 |  | 
 | Similar you can build U-Boot images from a 'ramdisk.image.gz' file | 
 | when your kernel is intended to use an initial ramdisk: | 
 |  | 
 | 	-> tools/mkimage -n 'Simple Ramdisk Image' \ | 
 | 	> -A ppc -O linux -T ramdisk -C gzip \ | 
 | 	> -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd | 
 | 	Image Name:   Simple Ramdisk Image | 
 | 	Created:      Wed Jan 12 14:01:50 2000 | 
 | 	Image Type:   PowerPC Linux RAMDisk Image (gzip compressed) | 
 | 	Data Size:    566530 Bytes = 553.25 kB = 0.54 MB | 
 | 	Load Address: 0x00000000 | 
 | 	Entry Point:  0x00000000 | 
 |  | 
 |  | 
 | Installing a Linux Image: | 
 | ------------------------- | 
 |  | 
 | To downloading a U-Boot image over the serial (console) interface, | 
 | you must convert the image to S-Record format: | 
 |  | 
 | 	objcopy -I binary -O srec examples/image examples/image.srec | 
 |  | 
 | The 'objcopy' does not understand the information in the U-Boot | 
 | image header, so the resulting S-Record file will be relative to | 
 | address 0x00000000. To load it to a given address, you need to | 
 | specify the target address as 'offset' parameter with the 'loads' | 
 | command. | 
 |  | 
 | Example: install the image to address 0x40100000 (which on the | 
 | TQM8xxL is in the first Flash bank): | 
 |  | 
 | 	=> erase 40100000 401FFFFF | 
 |  | 
 | 	.......... done | 
 | 	Erased 8 sectors | 
 |  | 
 | 	=> loads 40100000 | 
 | 	## Ready for S-Record download ... | 
 | 	~>examples/image.srec | 
 | 	1 2 3 4 5 6 7 8 9 10 11 12 13 ... | 
 | 	... | 
 | 	15989 15990 15991 15992 | 
 | 	[file transfer complete] | 
 | 	[connected] | 
 | 	## Start Addr = 0x00000000 | 
 |  | 
 |  | 
 | You can check the success of the download using the 'iminfo' command; | 
 | this includes a checksum verification so you  can  be  sure  no	 data | 
 | corruption happened: | 
 |  | 
 | 	=> imi 40100000 | 
 |  | 
 | 	## Checking Image at 40100000 ... | 
 | 	   Image Name:	 2.2.13 for initrd on TQM850L | 
 | 	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed) | 
 | 	   Data Size:	 335725 Bytes = 327 kB = 0 MB | 
 | 	   Load Address: 00000000 | 
 | 	   Entry Point:	 0000000c | 
 | 	   Verifying Checksum ... OK | 
 |  | 
 |  | 
 | Boot Linux: | 
 | ----------- | 
 |  | 
 | The "bootm" command is used to boot an application that is stored in | 
 | memory (RAM or Flash). In case of a Linux kernel image, the contents | 
 | of the "bootargs" environment variable is passed to the kernel as | 
 | parameters. You can check and modify this variable using the | 
 | "printenv" and "setenv" commands: | 
 |  | 
 |  | 
 | 	=> printenv bootargs | 
 | 	bootargs=root=/dev/ram | 
 |  | 
 | 	=> setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 | 
 |  | 
 | 	=> printenv bootargs | 
 | 	bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 | 
 |  | 
 | 	=> bootm 40020000 | 
 | 	## Booting Linux kernel at 40020000 ... | 
 | 	   Image Name:	 2.2.13 for NFS on TQM850L | 
 | 	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed) | 
 | 	   Data Size:	 381681 Bytes = 372 kB = 0 MB | 
 | 	   Load Address: 00000000 | 
 | 	   Entry Point:	 0000000c | 
 | 	   Verifying Checksum ... OK | 
 | 	   Uncompressing Kernel Image ... OK | 
 | 	Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000 | 
 | 	Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 | 
 | 	time_init: decrementer frequency = 187500000/60 | 
 | 	Calibrating delay loop... 49.77 BogoMIPS | 
 | 	Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] | 
 | 	... | 
 |  | 
 | If you want to boot a Linux kernel with initial ram disk, you pass | 
 | the memory addresses of both the kernel and the initrd image (PPBCOOT | 
 | format!) to the "bootm" command: | 
 |  | 
 | 	=> imi 40100000 40200000 | 
 |  | 
 | 	## Checking Image at 40100000 ... | 
 | 	   Image Name:	 2.2.13 for initrd on TQM850L | 
 | 	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed) | 
 | 	   Data Size:	 335725 Bytes = 327 kB = 0 MB | 
 | 	   Load Address: 00000000 | 
 | 	   Entry Point:	 0000000c | 
 | 	   Verifying Checksum ... OK | 
 |  | 
 | 	## Checking Image at 40200000 ... | 
 | 	   Image Name:	 Simple Ramdisk Image | 
 | 	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed) | 
 | 	   Data Size:	 566530 Bytes = 553 kB = 0 MB | 
 | 	   Load Address: 00000000 | 
 | 	   Entry Point:	 00000000 | 
 | 	   Verifying Checksum ... OK | 
 |  | 
 | 	=> bootm 40100000 40200000 | 
 | 	## Booting Linux kernel at 40100000 ... | 
 | 	   Image Name:	 2.2.13 for initrd on TQM850L | 
 | 	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed) | 
 | 	   Data Size:	 335725 Bytes = 327 kB = 0 MB | 
 | 	   Load Address: 00000000 | 
 | 	   Entry Point:	 0000000c | 
 | 	   Verifying Checksum ... OK | 
 | 	   Uncompressing Kernel Image ... OK | 
 | 	## Loading RAMDisk Image at 40200000 ... | 
 | 	   Image Name:	 Simple Ramdisk Image | 
 | 	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed) | 
 | 	   Data Size:	 566530 Bytes = 553 kB = 0 MB | 
 | 	   Load Address: 00000000 | 
 | 	   Entry Point:	 00000000 | 
 | 	   Verifying Checksum ... OK | 
 | 	   Loading Ramdisk ... OK | 
 | 	Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000 | 
 | 	Boot arguments: root=/dev/ram | 
 | 	time_init: decrementer frequency = 187500000/60 | 
 | 	Calibrating delay loop... 49.77 BogoMIPS | 
 | 	... | 
 | 	RAMDISK: Compressed image found at block 0 | 
 | 	VFS: Mounted root (ext2 filesystem). | 
 |  | 
 | 	bash# | 
 |  | 
 | More About U-Boot Image Types: | 
 | ------------------------------ | 
 |  | 
 | U-Boot supports the following image types: | 
 |  | 
 |    "Standalone Programs" are directly runnable in the environment | 
 | 	provided by U-Boot; it is expected that (if they behave | 
 | 	well) you can continue to work in U-Boot after return from | 
 | 	the Standalone Program. | 
 |    "OS Kernel Images" are usually images of some Embedded OS which | 
 | 	will take over control completely. Usually these programs | 
 | 	will install their own set of exception handlers, device | 
 | 	drivers, set up the MMU, etc. - this means, that you cannot | 
 | 	expect to re-enter U-Boot except by resetting the CPU. | 
 |    "RAMDisk Images" are more or less just data blocks, and their | 
 | 	parameters (address, size) are passed to an OS kernel that is | 
 | 	being started. | 
 |    "Multi-File Images" contain several images, typically an OS | 
 | 	(Linux) kernel image and one or more data images like | 
 | 	RAMDisks. This construct is useful for instance when you want | 
 | 	to boot over the network using BOOTP etc., where the boot | 
 | 	server provides just a single image file, but you want to get | 
 | 	for instance an OS kernel and a RAMDisk image. | 
 |  | 
 | 	"Multi-File Images" start with a list of image sizes, each | 
 | 	image size (in bytes) specified by an "uint32_t" in network | 
 | 	byte order. This list is terminated by an "(uint32_t)0". | 
 | 	Immediately after the terminating 0 follow the images, one by | 
 | 	one, all aligned on "uint32_t" boundaries (size rounded up to | 
 | 	a multiple of 4 bytes). | 
 |  | 
 |    "Firmware Images" are binary images containing firmware (like | 
 | 	U-Boot or FPGA images) which usually will be programmed to | 
 | 	flash memory. | 
 |  | 
 |    "Script files" are command sequences that will be executed by | 
 | 	U-Boot's command interpreter; this feature is especially | 
 | 	useful when you configure U-Boot to use a real shell (hush) | 
 | 	as command interpreter. | 
 |  | 
 |  | 
 | Standalone HOWTO: | 
 | ================= | 
 |  | 
 | One of the features of U-Boot is that you can dynamically load and | 
 | run "standalone" applications, which can use some resources of | 
 | U-Boot like console I/O functions or interrupt services. | 
 |  | 
 | Two simple examples are included with the sources: | 
 |  | 
 | "Hello World" Demo: | 
 | ------------------- | 
 |  | 
 | 'examples/hello_world.c' contains a small "Hello World" Demo | 
 | application; it is automatically compiled when you build U-Boot. | 
 | It's configured to run at address 0x00040004, so you can play with it | 
 | like that: | 
 |  | 
 | 	=> loads | 
 | 	## Ready for S-Record download ... | 
 | 	~>examples/hello_world.srec | 
 | 	1 2 3 4 5 6 7 8 9 10 11 ... | 
 | 	[file transfer complete] | 
 | 	[connected] | 
 | 	## Start Addr = 0x00040004 | 
 |  | 
 | 	=> go 40004 Hello World! This is a test. | 
 | 	## Starting application at 0x00040004 ... | 
 | 	Hello World | 
 | 	argc = 7 | 
 | 	argv[0] = "40004" | 
 | 	argv[1] = "Hello" | 
 | 	argv[2] = "World!" | 
 | 	argv[3] = "This" | 
 | 	argv[4] = "is" | 
 | 	argv[5] = "a" | 
 | 	argv[6] = "test." | 
 | 	argv[7] = "<NULL>" | 
 | 	Hit any key to exit ... | 
 |  | 
 | 	## Application terminated, rc = 0x0 | 
 |  | 
 | Another example, which demonstrates how to register a CPM interrupt | 
 | handler with the U-Boot code, can be found in 'examples/timer.c'. | 
 | Here, a CPM timer is set up to generate an interrupt every second. | 
 | The interrupt service routine is trivial, just printing a '.' | 
 | character, but this is just a demo program. The application can be | 
 | controlled by the following keys: | 
 |  | 
 | 	? - print current values og the CPM Timer registers | 
 | 	b - enable interrupts and start timer | 
 | 	e - stop timer and disable interrupts | 
 | 	q - quit application | 
 |  | 
 | 	=> loads | 
 | 	## Ready for S-Record download ... | 
 | 	~>examples/timer.srec | 
 | 	1 2 3 4 5 6 7 8 9 10 11 ... | 
 | 	[file transfer complete] | 
 | 	[connected] | 
 | 	## Start Addr = 0x00040004 | 
 |  | 
 | 	=> go 40004 | 
 | 	## Starting application at 0x00040004 ... | 
 | 	TIMERS=0xfff00980 | 
 | 	Using timer 1 | 
 | 	  tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 | 
 |  | 
 | Hit 'b': | 
 | 	[q, b, e, ?] Set interval 1000000 us | 
 | 	Enabling timer | 
 | Hit '?': | 
 | 	[q, b, e, ?] ........ | 
 | 	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 | 
 | Hit '?': | 
 | 	[q, b, e, ?] . | 
 | 	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 | 
 | Hit '?': | 
 | 	[q, b, e, ?] . | 
 | 	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 | 
 | Hit '?': | 
 | 	[q, b, e, ?] . | 
 | 	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 | 
 | Hit 'e': | 
 | 	[q, b, e, ?] ...Stopping timer | 
 | Hit 'q': | 
 | 	[q, b, e, ?] ## Application terminated, rc = 0x0 | 
 |  | 
 |  | 
 | Minicom warning: | 
 | ================ | 
 |  | 
 | Over time, many people have reported problems when trying to use the | 
 | "minicom" terminal emulation program for serial download. I (wd) | 
 | consider minicom to be broken, and recommend not to use it. Under | 
 | Unix, I recommend to use C-Kermit for general purpose use (and | 
 | especially for kermit binary protocol download ("loadb" command), and | 
 | use "cu" for S-Record download ("loads" command). | 
 |  | 
 | Nevertheless, if you absolutely want to use it try adding this | 
 | configuration to your "File transfer protocols" section: | 
 |  | 
 | 	   Name	   Program			Name U/D FullScr IO-Red. Multi | 
 | 	X  kermit  /usr/bin/kermit -i -l %l -s	 Y    U	   Y	   N	  N | 
 | 	Y  kermit  /usr/bin/kermit -i -l %l -r	 N    D	   Y	   N	  N | 
 |  | 
 |  | 
 | NetBSD Notes: | 
 | ============= | 
 |  | 
 | Starting at version 0.9.2, U-Boot supports NetBSD both as host | 
 | (build U-Boot) and target system (boots NetBSD/mpc8xx). | 
 |  | 
 | Building requires a cross environment; it is known to work on | 
 | NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also | 
 | need gmake since the Makefiles are not compatible with BSD make). | 
 | Note that the cross-powerpc package does not install include files; | 
 | attempting to build U-Boot will fail because <machine/ansi.h> is | 
 | missing.  This file has to be installed and patched manually: | 
 |  | 
 | 	# cd /usr/pkg/cross/powerpc-netbsd/include | 
 | 	# mkdir powerpc | 
 | 	# ln -s powerpc machine | 
 | 	# cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h | 
 | 	# ${EDIT} powerpc/ansi.h	## must remove __va_list, _BSD_VA_LIST | 
 |  | 
 | Native builds *don't* work due to incompatibilities between native | 
 | and U-Boot include files. | 
 |  | 
 | Booting assumes that (the first part of) the image booted is a | 
 | stage-2 loader which in turn loads and then invokes the kernel | 
 | proper. Loader sources will eventually appear in the NetBSD source | 
 | tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the | 
 | meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz | 
 |  | 
 |  | 
 | Implementation Internals: | 
 | ========================= | 
 |  | 
 | The following is not intended to be a complete description of every | 
 | implementation detail. However, it should help to understand the | 
 | inner workings of U-Boot and make it easier to port it to custom | 
 | hardware. | 
 |  | 
 |  | 
 | Initial Stack, Global Data: | 
 | --------------------------- | 
 |  | 
 | The implementation of U-Boot is complicated by the fact that U-Boot | 
 | starts running out of ROM (flash memory), usually without access to | 
 | system RAM (because the memory controller is not initialized yet). | 
 | This means that we don't have writable Data or BSS segments, and BSS | 
 | is not initialized as zero. To be able to get a C environment working | 
 | at all, we have to allocate at least a minimal stack. Implementation | 
 | options for this are defined and restricted by the CPU used: Some CPU | 
 | models provide on-chip memory (like the IMMR area on MPC8xx and | 
 | MPC826x processors), on others (parts of) the data cache can be | 
 | locked as (mis-) used as memory, etc. | 
 |  | 
 | 	Chris Hallinan posted a good summary of	 these	issues	to  the | 
 | 	u-boot-users mailing list: | 
 |  | 
 | 	Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? | 
 | 	From: "Chris Hallinan" <clh@net1plus.com> | 
 | 	Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) | 
 | 	... | 
 |  | 
 | 	Correct me if I'm wrong, folks, but the way I understand it | 
 | 	is this: Using DCACHE as initial RAM for Stack, etc, does not | 
 | 	require any physical RAM backing up the cache. The cleverness | 
 | 	is that the cache is being used as a temporary supply of | 
 | 	necessary storage before the SDRAM controller is setup. It's | 
 | 	beyond the scope of this list to expain the details, but you | 
 | 	can see how this works by studying the cache architecture and | 
 | 	operation in the architecture and processor-specific manuals. | 
 |  | 
 | 	OCM is On Chip Memory, which I believe the 405GP has 4K. It | 
 | 	is another option for the system designer to use as an | 
 | 	initial stack/ram area prior to SDRAM being available. Either | 
 | 	option should work for you. Using CS 4 should be fine if your | 
 | 	board designers haven't used it for something that would | 
 | 	cause you grief during the initial boot! It is frequently not | 
 | 	used. | 
 |  | 
 | 	CFG_INIT_RAM_ADDR should be somewhere that won't interfere | 
 | 	with your processor/board/system design. The default value | 
 | 	you will find in any recent u-boot distribution in | 
 | 	walnut.h should work for you. I'd set it to a value larger | 
 | 	than your SDRAM module. If you have a 64MB SDRAM module, set | 
 | 	it above 400_0000. Just make sure your board has no resources | 
 | 	that are supposed to respond to that address! That code in | 
 | 	start.S has been around a while and should work as is when | 
 | 	you get the config right. | 
 |  | 
 | 	-Chris Hallinan | 
 | 	DS4.COM, Inc. | 
 |  | 
 | It is essential to remember this, since it has some impact on the C | 
 | code for the initialization procedures: | 
 |  | 
 | * Initialized global data (data segment) is read-only. Do not attempt | 
 |   to write it. | 
 |  | 
 | * Do not use any unitialized global data (or implicitely initialized | 
 |   as zero data - BSS segment) at all - this is undefined, initiali- | 
 |   zation is performed later (when relocating to RAM). | 
 |  | 
 | * Stack space is very limited. Avoid big data buffers or things like | 
 |   that. | 
 |  | 
 | Having only the stack as writable memory limits means we cannot use | 
 | normal global data to share information beween the code. But it | 
 | turned out that the implementation of U-Boot can be greatly | 
 | simplified by making a global data structure (gd_t) available to all | 
 | functions. We could pass a pointer to this data as argument to _all_ | 
 | functions, but this would bloat the code. Instead we use a feature of | 
 | the GCC compiler (Global Register Variables) to share the data: we | 
 | place a pointer (gd) to the global data into a register which we | 
 | reserve for this purpose. | 
 |  | 
 | When choosing a register for such a purpose we are restricted by the | 
 | relevant  (E)ABI  specifications for the current architecture, and by | 
 | GCC's implementation. | 
 |  | 
 | For PowerPC, the following registers have specific use: | 
 | 	R1:	stack pointer | 
 | 	R2:	TOC pointer | 
 | 	R3-R4:	parameter passing and return values | 
 | 	R5-R10: parameter passing | 
 | 	R13:	small data area pointer | 
 | 	R30:	GOT pointer | 
 | 	R31:	frame pointer | 
 |  | 
 | 	(U-Boot also uses R14 as internal GOT pointer.) | 
 |  | 
 |     ==> U-Boot will use R29 to hold a pointer to the global data | 
 |  | 
 |     Note: on PPC, we could use a static initializer (since the | 
 |     address of the global data structure is known at compile time), | 
 |     but it turned out that reserving a register results in somewhat | 
 |     smaller code - although the code savings are not that big (on | 
 |     average for all boards 752 bytes for the whole U-Boot image, | 
 |     624 text + 127 data). | 
 |  | 
 | On ARM, the following registers are used: | 
 |  | 
 | 	R0:	function argument word/integer result | 
 | 	R1-R3:	function argument word | 
 | 	R9:	GOT pointer | 
 | 	R10:	stack limit (used only if stack checking if enabled) | 
 | 	R11:	argument (frame) pointer | 
 | 	R12:	temporary workspace | 
 | 	R13:	stack pointer | 
 | 	R14:	link register | 
 | 	R15:	program counter | 
 |  | 
 |     ==> U-Boot will use R8 to hold a pointer to the global data | 
 |  | 
 | NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, | 
 | or current versions of GCC may "optimize" the code too much. | 
 |  | 
 | Memory Management: | 
 | ------------------ | 
 |  | 
 | U-Boot runs in system state and uses physical addresses, i.e. the | 
 | MMU is not used either for address mapping nor for memory protection. | 
 |  | 
 | The available memory is mapped to fixed addresses using the memory | 
 | controller. In this process, a contiguous block is formed for each | 
 | memory type (Flash, SDRAM, SRAM), even when it consists of several | 
 | physical memory banks. | 
 |  | 
 | U-Boot is installed in the first 128 kB of the first Flash bank (on | 
 | TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After | 
 | booting and sizing and initializing DRAM, the code relocates itself | 
 | to the upper end of DRAM. Immediately below the U-Boot code some | 
 | memory is reserved for use by malloc() [see CFG_MALLOC_LEN | 
 | configuration setting]. Below that, a structure with global Board | 
 | Info data is placed, followed by the stack (growing downward). | 
 |  | 
 | Additionally, some exception handler code is copied to the low 8 kB | 
 | of DRAM (0x00000000 ... 0x00001FFF). | 
 |  | 
 | So a typical memory configuration with 16 MB of DRAM could look like | 
 | this: | 
 |  | 
 | 	0x0000 0000	Exception Vector code | 
 | 	      : | 
 | 	0x0000 1FFF | 
 | 	0x0000 2000	Free for Application Use | 
 | 	      : | 
 | 	      : | 
 |  | 
 | 	      : | 
 | 	      : | 
 | 	0x00FB FF20	Monitor Stack (Growing downward) | 
 | 	0x00FB FFAC	Board Info Data and permanent copy of global data | 
 | 	0x00FC 0000	Malloc Arena | 
 | 	      : | 
 | 	0x00FD FFFF | 
 | 	0x00FE 0000	RAM Copy of Monitor Code | 
 | 	...		eventually: LCD or video framebuffer | 
 | 	...		eventually: pRAM (Protected RAM - unchanged by reset) | 
 | 	0x00FF FFFF	[End of RAM] | 
 |  | 
 |  | 
 | System Initialization: | 
 | ---------------------- | 
 |  | 
 | In the reset configuration, U-Boot starts at the reset entry point | 
 | (on most PowerPC systens at address 0x00000100). Because of the reset | 
 | configuration for CS0# this is a mirror of the onboard Flash memory. | 
 | To be able to re-map memory U-Boot then jumps to its link address. | 
 | To be able to implement the initialization code in C, a (small!) | 
 | initial stack is set up in the internal Dual Ported RAM (in case CPUs | 
 | which provide such a feature like MPC8xx or MPC8260), or in a locked | 
 | part of the data cache. After that, U-Boot initializes the CPU core, | 
 | the caches and the SIU. | 
 |  | 
 | Next, all (potentially) available memory banks are mapped using a | 
 | preliminary mapping. For example, we put them on 512 MB boundaries | 
 | (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash | 
 | on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is | 
 | programmed for SDRAM access. Using the temporary configuration, a | 
 | simple memory test is run that determines the size of the SDRAM | 
 | banks. | 
 |  | 
 | When there is more than one SDRAM bank, and the banks are of | 
 | different size, the largest is mapped first. For equal size, the first | 
 | bank (CS2#) is mapped first. The first mapping is always for address | 
 | 0x00000000, with any additional banks following immediately to create | 
 | contiguous memory starting from 0. | 
 |  | 
 | Then, the monitor installs itself at the upper end of the SDRAM area | 
 | and allocates memory for use by malloc() and for the global Board | 
 | Info data; also, the exception vector code is copied to the low RAM | 
 | pages, and the final stack is set up. | 
 |  | 
 | Only after this relocation will you have a "normal" C environment; | 
 | until that you are restricted in several ways, mostly because you are | 
 | running from ROM, and because the code will have to be relocated to a | 
 | new address in RAM. | 
 |  | 
 |  | 
 | U-Boot Porting Guide: | 
 | ---------------------- | 
 |  | 
 | [Based on messages by Jerry Van Baren in the U-Boot-Users mailing | 
 | list, October 2002] | 
 |  | 
 |  | 
 | int main (int argc, char *argv[]) | 
 | { | 
 | 	sighandler_t no_more_time; | 
 |  | 
 | 	signal (SIGALRM, no_more_time); | 
 | 	alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); | 
 |  | 
 | 	if (available_money > available_manpower) { | 
 | 		pay consultant to port U-Boot; | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	Download latest U-Boot source; | 
 |  | 
 | 	Subscribe to u-boot-users mailing list; | 
 |  | 
 | 	if (clueless) { | 
 | 		email ("Hi, I am new to U-Boot, how do I get started?"); | 
 | 	} | 
 |  | 
 | 	while (learning) { | 
 | 		Read the README file in the top level directory; | 
 | 		Read http://www.denx.de/twiki/bin/view/DULG/Manual ; | 
 | 		Read the source, Luke; | 
 | 	} | 
 |  | 
 | 	if (available_money > toLocalCurrency ($2500)) { | 
 | 		Buy a BDI2000; | 
 | 	} else { | 
 | 		Add a lot of aggravation and time; | 
 | 	} | 
 |  | 
 | 	Create your own board support subdirectory; | 
 |  | 
 | 	Create your own board config file; | 
 |  | 
 | 	while (!running) { | 
 | 		do { | 
 | 			Add / modify source code; | 
 | 		} until (compiles); | 
 | 		Debug; | 
 | 		if (clueless) | 
 | 			email ("Hi, I am having problems..."); | 
 | 	} | 
 | 	Send patch file to Wolfgang; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | void no_more_time (int sig) | 
 | { | 
 |       hire_a_guru(); | 
 | } | 
 |  | 
 |  | 
 | Coding Standards: | 
 | ----------------- | 
 |  | 
 | All contributions to U-Boot should conform to the Linux kernel | 
 | coding style; see the file "Documentation/CodingStyle" in your Linux | 
 | kernel source directory. | 
 |  | 
 | Please note that U-Boot is implemented in C (and to some small parts | 
 | in Assembler); no C++ is used, so please do not use C++ style | 
 | comments (//) in your code. | 
 |  | 
 | Please also stick to the following formatting rules: | 
 | - remove any trailing white space | 
 | - use TAB characters for indentation, not spaces | 
 | - make sure NOT to use DOS '\r\n' line feeds | 
 | - do not add more than 2 empty lines to source files | 
 | - do not add trailing empty lines to source files | 
 |  | 
 | Submissions which do not conform to the standards may be returned | 
 | with a request to reformat the changes. | 
 |  | 
 |  | 
 | Submitting Patches: | 
 | ------------------- | 
 |  | 
 | Since the number of patches for U-Boot is growing, we need to | 
 | establish some rules. Submissions which do not conform to these rules | 
 | may be rejected, even when they contain important and valuable stuff. | 
 |  | 
 | Patches shall be sent to the u-boot-users mailing list. | 
 |  | 
 | When you send a patch, please include the following information with | 
 | it: | 
 |  | 
 | * For bug fixes: a description of the bug and how your patch fixes | 
 |   this bug. Please try to include a way of demonstrating that the | 
 |   patch actually fixes something. | 
 |  | 
 | * For new features: a description of the feature and your | 
 |   implementation. | 
 |  | 
 | * A CHANGELOG entry as plaintext (separate from the patch) | 
 |  | 
 | * For major contributions, your entry to the CREDITS file | 
 |  | 
 | * When you add support for a new board, don't forget to add this | 
 |   board to the MAKEALL script, too. | 
 |  | 
 | * If your patch adds new configuration options, don't forget to | 
 |   document these in the README file. | 
 |  | 
 | * The patch itself. If you are accessing the CVS repository use "cvs | 
 |   update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your | 
 |   version of diff does not support these options, then get the latest | 
 |   version of GNU diff. | 
 |  | 
 |   The current directory when running this command shall be the top | 
 |   level directory of the U-Boot source tree, or it's parent directory | 
 |   (i. e. please make sure that your patch includes sufficient | 
 |   directory information for the affected files). | 
 |  | 
 |   We accept patches as plain text, MIME attachments or as uuencoded | 
 |   gzipped text. | 
 |  | 
 | * If one logical set of modifications affects or creates several | 
 |   files, all these changes shall be submitted in a SINGLE patch file. | 
 |  | 
 | * Changesets that contain different, unrelated modifications shall be | 
 |   submitted as SEPARATE patches, one patch per changeset. | 
 |  | 
 |  | 
 | Notes: | 
 |  | 
 | * Before sending the patch, run the MAKEALL script on your patched | 
 |   source tree and make sure that no errors or warnings are reported | 
 |   for any of the boards. | 
 |  | 
 | * Keep your modifications to the necessary minimum: A patch | 
 |   containing several unrelated changes or arbitrary reformats will be | 
 |   returned with a request to re-formatting / split it. | 
 |  | 
 | * If you modify existing code, make sure that your new code does not | 
 |   add to the memory footprint of the code ;-) Small is beautiful! | 
 |   When adding new features, these should compile conditionally only | 
 |   (using #ifdef), and the resulting code with the new feature | 
 |   disabled must not need more memory than the old code without your | 
 |   modification. | 
 |  | 
 | * Remember that there is a size limit of 40 kB per message on the | 
 |   u-boot-users mailing list. Compression may help. |