|  | /* | 
|  | *  Copyright (C) 1998	Dan Malek <dmalek@jlc.net> | 
|  | *  Copyright (C) 1999	Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> | 
|  | *  Copyright (C) 2000, 2001,2002 Wolfgang Denk <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 | 
|  | */ | 
|  |  | 
|  | /* | 
|  | *  U-Boot - Startup Code for MPC8260 PowerPC based Embedded Boards | 
|  | */ | 
|  | #include <config.h> | 
|  | #include <mpc8260.h> | 
|  | #include <timestamp.h> | 
|  | #include <version.h> | 
|  |  | 
|  | #define CONFIG_8260 1		/* needed for Linux kernel header files */ | 
|  | #define _LINUX_CONFIG_H 1	/* avoid reading Linux autoconf.h file	*/ | 
|  |  | 
|  | #include <ppc_asm.tmpl> | 
|  | #include <ppc_defs.h> | 
|  |  | 
|  | #include <asm/cache.h> | 
|  | #include <asm/mmu.h> | 
|  |  | 
|  | #ifndef  CONFIG_IDENT_STRING | 
|  | #define  CONFIG_IDENT_STRING "" | 
|  | #endif | 
|  |  | 
|  | /* We don't want the  MMU yet. | 
|  | */ | 
|  | #undef	MSR_KERNEL | 
|  | /* Floating Point enable, Machine Check and Recoverable Interr. */ | 
|  | #ifdef DEBUG | 
|  | #define MSR_KERNEL (MSR_FP|MSR_RI) | 
|  | #else | 
|  | #define MSR_KERNEL (MSR_FP|MSR_ME|MSR_RI) | 
|  | #endif | 
|  |  | 
|  | /* | 
|  | * Set up GOT: Global Offset Table | 
|  | * | 
|  | * Use r14 to access the GOT | 
|  | */ | 
|  | START_GOT | 
|  | GOT_ENTRY(_GOT2_TABLE_) | 
|  | GOT_ENTRY(_FIXUP_TABLE_) | 
|  |  | 
|  | GOT_ENTRY(_start) | 
|  | GOT_ENTRY(_start_of_vectors) | 
|  | GOT_ENTRY(_end_of_vectors) | 
|  | GOT_ENTRY(transfer_to_handler) | 
|  |  | 
|  | GOT_ENTRY(__init_end) | 
|  | GOT_ENTRY(_end) | 
|  | GOT_ENTRY(__bss_start) | 
|  | #if defined(CONFIG_HYMOD) | 
|  | GOT_ENTRY(environment) | 
|  | #endif | 
|  | END_GOT | 
|  |  | 
|  | /* | 
|  | * Version string - must be in data segment because MPC8260 uses the first | 
|  | * 256 bytes for the Hard Reset Configuration Word table (see below). | 
|  | * Similarly, can't have the U-Boot Magic Number as the first thing in | 
|  | * the image - don't know how this will affect the image tools, but I guess | 
|  | * I'll find out soon | 
|  | */ | 
|  | .data | 
|  | .globl	version_string | 
|  | version_string: | 
|  | .ascii U_BOOT_VERSION | 
|  | .ascii " (", U_BOOT_DATE, " - ", U_BOOT_TIME, ")" | 
|  | .ascii CONFIG_IDENT_STRING, "\0" | 
|  |  | 
|  | /* | 
|  | *  Hard Reset Configuration Word (HRCW) table | 
|  | * | 
|  | *  The Hard Reset Configuration Word (HRCW) sets a number of useful things | 
|  | *  such as whether there is an external memory controller, whether the | 
|  | *  PowerPC core is disabled (i.e. only the communications processor is | 
|  | *  active, accessed by another CPU on the bus), whether using external | 
|  | *  arbitration, external bus mode, boot port size, core initial prefix, | 
|  | *  internal space base, boot memory space, etc. | 
|  | * | 
|  | *  These things dictate where the processor begins execution, where the | 
|  | *  boot ROM appears in memory, the memory controller setup when access | 
|  | *  boot ROM, etc. The HRCW is *extremely* important. | 
|  | * | 
|  | *  The HRCW is read from the bus during reset. One CPU on the bus will | 
|  | *  be a hard reset configuration master, any others will be hard reset | 
|  | *  configuration slaves. The master reads eight HRCWs from flash during | 
|  | *  reset - the first it uses for itself, the other 7 it communicates to | 
|  | *  up to 7 configuration slaves by some complicated mechanism, which is | 
|  | *  not really important here. | 
|  | * | 
|  | *  The configuration master performs 32 successive reads starting at address | 
|  | *  0 and incrementing by 8 each read (i.e. on 64 bit boundaries) but only 8 | 
|  | *  bits is read, and always from byte lane D[0-7] (so that port size of the | 
|  | *  boot device does not matter). The first four reads form the 32 bit HRCW | 
|  | *  for the master itself. The second four reads form the HRCW for the first | 
|  | *  slave, and so on, up to seven slaves. The 32 bit HRCW is formed by | 
|  | *  concatenating the four bytes, with the first read placed in byte 0 (the | 
|  | *  most significant byte), and so on with the fourth read placed in byte 3 | 
|  | *  (the least significant byte). | 
|  | */ | 
|  | #define _HRCW_TABLE_ENTRY(w)		\ | 
|  | .fill	8,1,(((w)>>24)&0xff);	\ | 
|  | .fill	8,1,(((w)>>16)&0xff);	\ | 
|  | .fill	8,1,(((w)>> 8)&0xff);	\ | 
|  | .fill	8,1,(((w)    )&0xff) | 
|  | .text | 
|  | .globl	_hrcw_table | 
|  | _hrcw_table: | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_MASTER) | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_SLAVE1) | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_SLAVE2) | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_SLAVE3) | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_SLAVE4) | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_SLAVE5) | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_SLAVE6) | 
|  | _HRCW_TABLE_ENTRY(CONFIG_SYS_HRCW_SLAVE7) | 
|  | /* | 
|  | *  After configuration, a system reset exception is executed using the | 
|  | *  vector at offset 0x100 relative to the base set by MSR[IP]. If MSR[IP] | 
|  | *  is 0, the base address is 0x00000000. If MSR[IP] is 1, the base address | 
|  | *  is 0xfff00000. In the case of a Power On Reset or Hard Reset, the value | 
|  | *  of MSR[IP] is determined by the CIP field in the HRCW. | 
|  | * | 
|  | *  Other bits in the HRCW set up the Base Address and Port Size in BR0. | 
|  | *  This determines the location of the boot ROM (flash or EPROM) in the | 
|  | *  processor's address space at boot time. As long as the HRCW is set up | 
|  | *  so that we eventually end up executing the code below when the processor | 
|  | *  executes the reset exception, the actual values used should not matter. | 
|  | * | 
|  | *  Once we have got here, the address mask in OR0 is cleared so that the | 
|  | *  bottom 32K of the boot ROM is effectively repeated all throughout the | 
|  | *  processor's address space, after which we can jump to the absolute | 
|  | *  address at which the boot ROM was linked at compile time, and proceed | 
|  | *  to initialise the memory controller without worrying if the rug will be | 
|  | *  pulled out from under us, so to speak (it will be fine as long as we | 
|  | *  configure BR0 with the same boot ROM link address). | 
|  | */ | 
|  | . = EXC_OFF_SYS_RESET | 
|  |  | 
|  | .globl	_start | 
|  | _start: | 
|  | li	r21, BOOTFLAG_COLD	/* Normal Power-On: Boot from FLASH*/ | 
|  | nop | 
|  | b	boot_cold | 
|  |  | 
|  | . = EXC_OFF_SYS_RESET + 0x10 | 
|  |  | 
|  | .globl	_start_warm | 
|  | _start_warm: | 
|  | li	r21, BOOTFLAG_WARM	/* Software reboot		*/ | 
|  | b	boot_warm | 
|  |  | 
|  | boot_cold: | 
|  | #if defined(CONFIG_MPC8260ADS) && defined(CONFIG_SYS_DEFAULT_IMMR) | 
|  | lis	r3, CONFIG_SYS_DEFAULT_IMMR@h | 
|  | nop | 
|  | lwz	r4, 0(r3) | 
|  | nop | 
|  | rlwinm	r4, r4, 0, 8, 5 | 
|  | nop | 
|  | oris	r4, r4, 0x0200 | 
|  | nop | 
|  | stw	r4, 0(r3) | 
|  | nop | 
|  | #endif /* CONFIG_MPC8260ADS && CONFIG_SYS_DEFAULT_IMMR */ | 
|  | boot_warm: | 
|  | mfmsr	r5			/* save msr contents		*/ | 
|  |  | 
|  | #if defined(CONFIG_COGENT) | 
|  | /* this is what the cogent EPROM does */ | 
|  | li	r0, 0 | 
|  | mtmsr	r0 | 
|  | isync | 
|  | bl	cogent_init_8260 | 
|  | #endif	/* CONFIG_COGENT */ | 
|  |  | 
|  | #if defined(CONFIG_SYS_DEFAULT_IMMR) | 
|  | lis	r3, CONFIG_SYS_IMMR@h | 
|  | ori	r3, r3, CONFIG_SYS_IMMR@l | 
|  | lis	r4, CONFIG_SYS_DEFAULT_IMMR@h | 
|  | stw	r3, 0x1A8(r4) | 
|  | #endif /* CONFIG_SYS_DEFAULT_IMMR */ | 
|  |  | 
|  | /* Initialise the MPC8260 processor core			*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | bl	init_8260_core | 
|  |  | 
|  | #ifndef CONFIG_SYS_RAMBOOT | 
|  | /* When booting from ROM (Flash or EPROM), clear the		*/ | 
|  | /* Address Mask in OR0 so ROM appears everywhere		*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | lis	r3, (CONFIG_SYS_IMMR+IM_REGBASE)@h | 
|  | lwz	r4, IM_OR0@l(r3) | 
|  | li	r5, 0x7fff | 
|  | and	r4, r4, r5 | 
|  | stw	r4, IM_OR0@l(r3) | 
|  |  | 
|  | /* Calculate absolute address in FLASH and jump there		*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | lis	r3, CONFIG_SYS_MONITOR_BASE@h | 
|  | ori	r3, r3, CONFIG_SYS_MONITOR_BASE@l | 
|  | addi	r3, r3, in_flash - _start + EXC_OFF_SYS_RESET | 
|  | mtlr	r3 | 
|  | blr | 
|  |  | 
|  | in_flash: | 
|  | #endif	/* CONFIG_SYS_RAMBOOT */ | 
|  |  | 
|  | /* initialize some things that are hard to access from C	*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | lis	r3, CONFIG_SYS_IMMR@h		/* set up stack in internal DPRAM */ | 
|  | ori	r1, r3, CONFIG_SYS_INIT_SP_OFFSET | 
|  | li	r0, 0			/* Make room for stack frame header and	*/ | 
|  | stwu	r0, -4(r1)		/* clear final stack frame so that	*/ | 
|  | stwu	r0, -4(r1)		/* stack backtraces terminate cleanly	*/ | 
|  |  | 
|  | /* let the C-code set up the rest				*/ | 
|  | /*								*/ | 
|  | /* Be careful to keep code relocatable !			*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | GET_GOT			/* initialize GOT access		*/ | 
|  |  | 
|  | /* r3: IMMR */ | 
|  | bl	cpu_init_f	/* run low-level CPU init code (in Flash)*/ | 
|  |  | 
|  | #ifdef DEBUG | 
|  | bl	init_debug	/* set up debugging stuff		*/ | 
|  | #endif | 
|  |  | 
|  | mr	r3, r21 | 
|  | /* r3: BOOTFLAG */ | 
|  | bl	board_init_f	/* run 1st part of board init code (in Flash)*/ | 
|  |  | 
|  | /* | 
|  | * Vector Table | 
|  | */ | 
|  |  | 
|  | .globl	_start_of_vectors | 
|  | _start_of_vectors: | 
|  |  | 
|  | /* Machine check */ | 
|  | STD_EXCEPTION(0x200, MachineCheck, MachineCheckException) | 
|  |  | 
|  | /* Data Storage exception. */ | 
|  | STD_EXCEPTION(0x300, DataStorage, UnknownException) | 
|  |  | 
|  | /* Instruction Storage exception. */ | 
|  | STD_EXCEPTION(0x400, InstStorage, UnknownException) | 
|  |  | 
|  | /* External Interrupt exception. */ | 
|  | STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt) | 
|  |  | 
|  | /* Alignment exception. */ | 
|  | . = 0x600 | 
|  | Alignment: | 
|  | EXCEPTION_PROLOG(SRR0, SRR1) | 
|  | mfspr	r4,DAR | 
|  | stw	r4,_DAR(r21) | 
|  | mfspr	r5,DSISR | 
|  | stw	r5,_DSISR(r21) | 
|  | addi	r3,r1,STACK_FRAME_OVERHEAD | 
|  | li	r20,MSR_KERNEL | 
|  | rlwimi	r20,r23,0,16,16		/* copy EE bit from saved MSR */ | 
|  | rlwimi	r20,r23,0,25,25		/* copy IP bit from saved MSR */ | 
|  | lwz	r6,GOT(transfer_to_handler) | 
|  | mtlr	r6 | 
|  | blrl | 
|  | .L_Alignment: | 
|  | .long	AlignmentException - _start + EXC_OFF_SYS_RESET | 
|  | .long	int_return - _start + EXC_OFF_SYS_RESET | 
|  |  | 
|  | /* Program check exception */ | 
|  | . = 0x700 | 
|  | ProgramCheck: | 
|  | EXCEPTION_PROLOG(SRR0, SRR1) | 
|  | addi	r3,r1,STACK_FRAME_OVERHEAD | 
|  | li	r20,MSR_KERNEL | 
|  | rlwimi	r20,r23,0,16,16		/* copy EE bit from saved MSR */ | 
|  | rlwimi	r20,r23,0,25,25		/* copy IP bit from saved MSR */ | 
|  | lwz	r6,GOT(transfer_to_handler) | 
|  | mtlr	r6 | 
|  | blrl | 
|  | .L_ProgramCheck: | 
|  | .long	ProgramCheckException - _start + EXC_OFF_SYS_RESET | 
|  | .long	int_return - _start + EXC_OFF_SYS_RESET | 
|  |  | 
|  | STD_EXCEPTION(0x800, FPUnavailable, UnknownException) | 
|  |  | 
|  | /* I guess we could implement decrementer, and may have | 
|  | * to someday for timekeeping. | 
|  | */ | 
|  | STD_EXCEPTION(0x900, Decrementer, timer_interrupt) | 
|  |  | 
|  | STD_EXCEPTION(0xa00, Trap_0a, UnknownException) | 
|  | STD_EXCEPTION(0xb00, Trap_0b, UnknownException) | 
|  | STD_EXCEPTION(0xc00, SystemCall, UnknownException) | 
|  | STD_EXCEPTION(0xd00, SingleStep, UnknownException) | 
|  |  | 
|  | STD_EXCEPTION(0xe00, Trap_0e, UnknownException) | 
|  | STD_EXCEPTION(0xf00, Trap_0f, UnknownException) | 
|  |  | 
|  | STD_EXCEPTION(0x1000, InstructionTLBMiss, UnknownException) | 
|  | STD_EXCEPTION(0x1100, DataLoadTLBMiss, UnknownException) | 
|  | STD_EXCEPTION(0x1200, DataStoreTLBMiss, UnknownException) | 
|  | #ifdef DEBUG | 
|  | . = 0x1300 | 
|  | /* | 
|  | * This exception occurs when the program counter matches the | 
|  | * Instruction Address Breakpoint Register (IABR). | 
|  | * | 
|  | * I want the cpu to halt if this occurs so I can hunt around | 
|  | * with the debugger and look at things. | 
|  | * | 
|  | * When DEBUG is defined, both machine check enable (in the MSR) | 
|  | * and checkstop reset enable (in the reset mode register) are | 
|  | * turned off and so a checkstop condition will result in the cpu | 
|  | * halting. | 
|  | * | 
|  | * I force the cpu into a checkstop condition by putting an illegal | 
|  | * instruction here (at least this is the theory). | 
|  | * | 
|  | * well - that didnt work, so just do an infinite loop! | 
|  | */ | 
|  | 1:	b	1b | 
|  | #else | 
|  | STD_EXCEPTION(0x1300, InstructionBreakpoint, DebugException) | 
|  | #endif | 
|  | STD_EXCEPTION(0x1400, SMI, UnknownException) | 
|  |  | 
|  | STD_EXCEPTION(0x1500, Trap_15, UnknownException) | 
|  | STD_EXCEPTION(0x1600, Trap_16, UnknownException) | 
|  | STD_EXCEPTION(0x1700, Trap_17, UnknownException) | 
|  | STD_EXCEPTION(0x1800, Trap_18, UnknownException) | 
|  | STD_EXCEPTION(0x1900, Trap_19, UnknownException) | 
|  | STD_EXCEPTION(0x1a00, Trap_1a, UnknownException) | 
|  | STD_EXCEPTION(0x1b00, Trap_1b, UnknownException) | 
|  | STD_EXCEPTION(0x1c00, Trap_1c, UnknownException) | 
|  | STD_EXCEPTION(0x1d00, Trap_1d, UnknownException) | 
|  | STD_EXCEPTION(0x1e00, Trap_1e, UnknownException) | 
|  | STD_EXCEPTION(0x1f00, Trap_1f, UnknownException) | 
|  | STD_EXCEPTION(0x2000, Trap_20, UnknownException) | 
|  | STD_EXCEPTION(0x2100, Trap_21, UnknownException) | 
|  | STD_EXCEPTION(0x2200, Trap_22, UnknownException) | 
|  | STD_EXCEPTION(0x2300, Trap_23, UnknownException) | 
|  | STD_EXCEPTION(0x2400, Trap_24, UnknownException) | 
|  | STD_EXCEPTION(0x2500, Trap_25, UnknownException) | 
|  | STD_EXCEPTION(0x2600, Trap_26, UnknownException) | 
|  | STD_EXCEPTION(0x2700, Trap_27, UnknownException) | 
|  | STD_EXCEPTION(0x2800, Trap_28, UnknownException) | 
|  | STD_EXCEPTION(0x2900, Trap_29, UnknownException) | 
|  | STD_EXCEPTION(0x2a00, Trap_2a, UnknownException) | 
|  | STD_EXCEPTION(0x2b00, Trap_2b, UnknownException) | 
|  | STD_EXCEPTION(0x2c00, Trap_2c, UnknownException) | 
|  | STD_EXCEPTION(0x2d00, Trap_2d, UnknownException) | 
|  | STD_EXCEPTION(0x2e00, Trap_2e, UnknownException) | 
|  | STD_EXCEPTION(0x2f00, Trap_2f, UnknownException) | 
|  |  | 
|  |  | 
|  | .globl	_end_of_vectors | 
|  | _end_of_vectors: | 
|  |  | 
|  | . = 0x3000 | 
|  |  | 
|  | /* | 
|  | * This code finishes saving the registers to the exception frame | 
|  | * and jumps to the appropriate handler for the exception. | 
|  | * Register r21 is pointer into trap frame, r1 has new stack pointer. | 
|  | */ | 
|  | .globl	transfer_to_handler | 
|  | transfer_to_handler: | 
|  | stw	r22,_NIP(r21) | 
|  | lis	r22,MSR_POW@h | 
|  | andc	r23,r23,r22 | 
|  | stw	r23,_MSR(r21) | 
|  | SAVE_GPR(7, r21) | 
|  | SAVE_4GPRS(8, r21) | 
|  | SAVE_8GPRS(12, r21) | 
|  | SAVE_8GPRS(24, r21) | 
|  | mflr	r23 | 
|  | andi.	r24,r23,0x3f00		/* get vector offset */ | 
|  | stw	r24,TRAP(r21) | 
|  | li	r22,0 | 
|  | stw	r22,RESULT(r21) | 
|  | lwz	r24,0(r23)		/* virtual address of handler */ | 
|  | lwz	r23,4(r23)		/* where to go when done */ | 
|  | mtspr	SRR0,r24 | 
|  | mtspr	SRR1,r20 | 
|  | mtlr	r23 | 
|  | SYNC | 
|  | rfi				/* jump to handler, enable MMU */ | 
|  |  | 
|  | int_return: | 
|  | mfmsr	r28		/* Disable interrupts */ | 
|  | li	r4,0 | 
|  | ori	r4,r4,MSR_EE | 
|  | andc	r28,r28,r4 | 
|  | SYNC			/* Some chip revs need this... */ | 
|  | mtmsr	r28 | 
|  | SYNC | 
|  | lwz	r2,_CTR(r1) | 
|  | lwz	r0,_LINK(r1) | 
|  | mtctr	r2 | 
|  | mtlr	r0 | 
|  | lwz	r2,_XER(r1) | 
|  | lwz	r0,_CCR(r1) | 
|  | mtspr	XER,r2 | 
|  | mtcrf	0xFF,r0 | 
|  | REST_10GPRS(3, r1) | 
|  | REST_10GPRS(13, r1) | 
|  | REST_8GPRS(23, r1) | 
|  | REST_GPR(31, r1) | 
|  | lwz	r2,_NIP(r1)	/* Restore environment */ | 
|  | lwz	r0,_MSR(r1) | 
|  | mtspr	SRR0,r2 | 
|  | mtspr	SRR1,r0 | 
|  | lwz	r0,GPR0(r1) | 
|  | lwz	r2,GPR2(r1) | 
|  | lwz	r1,GPR1(r1) | 
|  | SYNC | 
|  | rfi | 
|  |  | 
|  | #if defined(CONFIG_COGENT) | 
|  |  | 
|  | /* | 
|  | * This code initialises the MPC8260 processor core | 
|  | * (conforms to PowerPC 603e spec) | 
|  | */ | 
|  |  | 
|  | .globl	cogent_init_8260 | 
|  | cogent_init_8260: | 
|  |  | 
|  | /* Taken from page 14 of CMA282 manual				*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | lis	r4, (CONFIG_SYS_IMMR+IM_REGBASE)@h | 
|  | lis	r3, CONFIG_SYS_IMMR@h | 
|  | stw	r3, IM_IMMR@l(r4) | 
|  | lwz	r3, IM_IMMR@l(r4) | 
|  | stw	r3, 0(r0) | 
|  | lis	r3, CONFIG_SYS_SYPCR@h | 
|  | ori	r3, r3, CONFIG_SYS_SYPCR@l | 
|  | stw	r3, IM_SYPCR@l(r4) | 
|  | lwz	r3, IM_SYPCR@l(r4) | 
|  | stw	r3, 4(r0) | 
|  | lis	r3, CONFIG_SYS_SCCR@h | 
|  | ori	r3, r3, CONFIG_SYS_SCCR@l | 
|  | stw	r3, IM_SCCR@l(r4) | 
|  | lwz	r3, IM_SCCR@l(r4) | 
|  | stw	r3, 8(r0) | 
|  |  | 
|  | /* the rest of this was disassembled from the			*/ | 
|  | /* EPROM code that came with my CMA282 CPU module		*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | lis	r1, 0x1234 | 
|  | ori	r1, r1, 0x5678 | 
|  | stw	r1, 0x20(r0) | 
|  | lwz	r1, 0x20(r0) | 
|  | stw	r1, 0x24(r0) | 
|  | lwz	r1, 0x24(r0) | 
|  | lis	r3, 0x0e80 | 
|  | ori	r3, r3, 0 | 
|  | stw	r1, 4(r3) | 
|  | lwz	r1, 4(r3) | 
|  |  | 
|  | /* Done!							*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | blr | 
|  |  | 
|  | #endif	/* CONFIG_COGENT */ | 
|  |  | 
|  | /* | 
|  | * This code initialises the MPC8260 processor core | 
|  | * (conforms to PowerPC 603e spec) | 
|  | * Note: expects original MSR contents to be in r5. | 
|  | */ | 
|  |  | 
|  | .globl	init_8260_core | 
|  | init_8260_core: | 
|  |  | 
|  | /* Initialize machine status; enable machine check interrupt	*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | li	r3, MSR_KERNEL		/* Set ME and RI flags */ | 
|  | rlwimi	r3, r5, 0, 25, 25	/* preserve IP bit set by HRCW */ | 
|  | #ifdef DEBUG | 
|  | rlwimi	r3, r5, 0, 21, 22	/* debugger might set SE & BE bits */ | 
|  | #endif | 
|  | SYNC				/* Some chip revs need this... */ | 
|  | mtmsr	r3 | 
|  | SYNC | 
|  | mtspr	SRR1, r3		/* Make SRR1 match MSR */ | 
|  |  | 
|  | /* Initialise the SYPCR early, and reset the watchdog (if req)	*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | lis	r3, (CONFIG_SYS_IMMR+IM_REGBASE)@h | 
|  | #if !defined(CONFIG_COGENT) | 
|  | lis	r4, CONFIG_SYS_SYPCR@h | 
|  | ori	r4, r4, CONFIG_SYS_SYPCR@l | 
|  | stw	r4, IM_SYPCR@l(r3) | 
|  | #endif /* !CONFIG_COGENT */ | 
|  | #if defined(CONFIG_WATCHDOG) | 
|  | li	r4, 21868		/* = 0x556c */ | 
|  | sth	r4, IM_SWSR@l(r3) | 
|  | li	r4, -21959		/* = 0xaa39 */ | 
|  | sth	r4, IM_SWSR@l(r3) | 
|  | #endif /* CONFIG_WATCHDOG */ | 
|  |  | 
|  | /* Initialize the Hardware Implementation-dependent Registers	*/ | 
|  | /* HID0 also contains cache control				*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | lis	r3, CONFIG_SYS_HID0_INIT@h | 
|  | ori	r3, r3, CONFIG_SYS_HID0_INIT@l | 
|  | SYNC | 
|  | mtspr	HID0, r3 | 
|  |  | 
|  | lis	r3, CONFIG_SYS_HID0_FINAL@h | 
|  | ori	r3, r3, CONFIG_SYS_HID0_FINAL@l | 
|  | SYNC | 
|  | mtspr	HID0, r3 | 
|  |  | 
|  | lis	r3, CONFIG_SYS_HID2@h | 
|  | ori	r3, r3, CONFIG_SYS_HID2@l | 
|  | mtspr	HID2, r3 | 
|  |  | 
|  | /* clear all BAT's						*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | li	r0, 0 | 
|  | mtspr	DBAT0U, r0 | 
|  | mtspr	DBAT0L, r0 | 
|  | mtspr	DBAT1U, r0 | 
|  | mtspr	DBAT1L, r0 | 
|  | mtspr	DBAT2U, r0 | 
|  | mtspr	DBAT2L, r0 | 
|  | mtspr	DBAT3U, r0 | 
|  | mtspr	DBAT3L, r0 | 
|  | mtspr	IBAT0U, r0 | 
|  | mtspr	IBAT0L, r0 | 
|  | mtspr	IBAT1U, r0 | 
|  | mtspr	IBAT1L, r0 | 
|  | mtspr	IBAT2U, r0 | 
|  | mtspr	IBAT2L, r0 | 
|  | mtspr	IBAT3U, r0 | 
|  | mtspr	IBAT3L, r0 | 
|  | SYNC | 
|  |  | 
|  | /* invalidate all tlb's						*/ | 
|  | /*								*/ | 
|  | /* From the 603e User Manual: "The 603e provides the ability to	*/ | 
|  | /* invalidate a TLB entry. The TLB Invalidate Entry (tlbie)	*/ | 
|  | /* instruction invalidates the TLB entry indexed by the EA, and	*/ | 
|  | /* operates on both the instruction and data TLBs simultaneously*/ | 
|  | /* invalidating four TLB entries (both sets in each TLB). The	*/ | 
|  | /* index corresponds to bits 15-19 of the EA. To invalidate all	*/ | 
|  | /* entries within both TLBs, 32 tlbie instructions should be	*/ | 
|  | /* issued, incrementing this field by one each time."		*/ | 
|  | /*								*/ | 
|  | /* "Note that the tlbia instruction is not implemented on the	*/ | 
|  | /* 603e."							*/ | 
|  | /*								*/ | 
|  | /* bits 15-19 correspond to addresses 0x00000000 to 0x0001F000	*/ | 
|  | /* incrementing by 0x1000 each time. The code below is sort of	*/ | 
|  | /* based on code in "flush_tlbs" from arch/ppc/kernel/head.S	*/ | 
|  | /*								*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | li	r3, 32 | 
|  | mtctr	r3 | 
|  | li	r3, 0 | 
|  | 1:	tlbie	r3 | 
|  | addi	r3, r3, 0x1000 | 
|  | bdnz	1b | 
|  | SYNC | 
|  |  | 
|  | /* Done!							*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | blr | 
|  |  | 
|  | #ifdef DEBUG | 
|  |  | 
|  | /* | 
|  | * initialise things related to debugging. | 
|  | * | 
|  | * must be called after the global offset table (GOT) is initialised | 
|  | * (GET_GOT) and after cpu_init_f() has executed. | 
|  | */ | 
|  |  | 
|  | .globl	init_debug | 
|  | init_debug: | 
|  |  | 
|  | lis	r3, (CONFIG_SYS_IMMR+IM_REGBASE)@h | 
|  |  | 
|  | /* Quick and dirty hack to enable the RAM and copy the		*/ | 
|  | /* vectors so that we can take exceptions.			*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  | /* write Memory Refresh Prescaler */ | 
|  | li	r4, CONFIG_SYS_MPTPR | 
|  | sth	r4, IM_MPTPR@l(r3) | 
|  | /* write 60x Refresh Timer */ | 
|  | li	r4, CONFIG_SYS_PSRT | 
|  | stb	r4, IM_PSRT@l(r3) | 
|  | /* init the 60x SDRAM Mode Register */ | 
|  | lis	r4, (CONFIG_SYS_PSDMR|PSDMR_OP_NORM)@h | 
|  | ori	r4, r4, (CONFIG_SYS_PSDMR|PSDMR_OP_NORM)@l | 
|  | stw	r4, IM_PSDMR@l(r3) | 
|  | /* write Precharge All Banks command */ | 
|  | lis	r4, (CONFIG_SYS_PSDMR|PSDMR_OP_PREA)@h | 
|  | ori	r4, r4, (CONFIG_SYS_PSDMR|PSDMR_OP_PREA)@l | 
|  | stw	r4, IM_PSDMR@l(r3) | 
|  | stb	r0, 0(0) | 
|  | /* write eight CBR Refresh commands */ | 
|  | lis	r4, (CONFIG_SYS_PSDMR|PSDMR_OP_CBRR)@h | 
|  | ori	r4, r4, (CONFIG_SYS_PSDMR|PSDMR_OP_CBRR)@l | 
|  | stw	r4, IM_PSDMR@l(r3) | 
|  | stb	r0, 0(0) | 
|  | stb	r0, 0(0) | 
|  | stb	r0, 0(0) | 
|  | stb	r0, 0(0) | 
|  | stb	r0, 0(0) | 
|  | stb	r0, 0(0) | 
|  | stb	r0, 0(0) | 
|  | stb	r0, 0(0) | 
|  | /* write Mode Register Write command */ | 
|  | lis	r4, (CONFIG_SYS_PSDMR|PSDMR_OP_MRW)@h | 
|  | ori	r4, r4, (CONFIG_SYS_PSDMR|PSDMR_OP_MRW)@l | 
|  | stw	r4, IM_PSDMR@l(r3) | 
|  | stb	r0, 0(0) | 
|  | /* write Normal Operation command and enable Refresh */ | 
|  | lis	r4, (CONFIG_SYS_PSDMR|PSDMR_OP_NORM|PSDMR_RFEN)@h | 
|  | ori	r4, r4, (CONFIG_SYS_PSDMR|PSDMR_OP_NORM|PSDMR_RFEN)@l | 
|  | stw	r4, IM_PSDMR@l(r3) | 
|  | stb	r0, 0(0) | 
|  | /* RAM should now be operational */ | 
|  |  | 
|  | #define VEC_WRD_CNT	((_end_of_vectors - _start + EXC_OFF_SYS_RESET) / 4) | 
|  |  | 
|  | lwz	r3, GOT(_end_of_vectors) | 
|  | rlwinm	r4, r3, 0, 18, 31	/* _end_of_vectors & 0x3FFF	*/ | 
|  | lis	r5, VEC_WRD_CNT@h | 
|  | ori	r5, r5, VEC_WRD_CNT@l | 
|  | mtctr	r5 | 
|  | 1: | 
|  | lwzu	r5, -4(r3) | 
|  | stwu	r5, -4(r4) | 
|  | bdnz	1b | 
|  |  | 
|  | /* Load the Instruction Address Breakpoint Register (IABR).	*/ | 
|  | /*								*/ | 
|  | /* The address to load is stored in the first word of dual port	*/ | 
|  | /* ram and should be preserved while the power is on, so you	*/ | 
|  | /* can plug addresses into that location then reset the cpu and	*/ | 
|  | /* this code will load that address into the IABR after the	*/ | 
|  | /* reset.							*/ | 
|  | /*								*/ | 
|  | /* When the program counter matches the contents of the IABR,	*/ | 
|  | /* an exception is generated (before the instruction at that	*/ | 
|  | /* location completes). The vector for this exception is 0x1300 */ | 
|  | /*--------------------------------------------------------------*/ | 
|  | lis	r3, CONFIG_SYS_IMMR@h | 
|  | lwz	r3, 0(r3) | 
|  | mtspr	IABR, r3 | 
|  |  | 
|  | /* Set the entire dual port RAM (where the initial stack	*/ | 
|  | /* resides) to a known value - makes it easier to see where	*/ | 
|  | /* the stack has been written					*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  | lis	r3, (CONFIG_SYS_IMMR + CONFIG_SYS_INIT_SP_OFFSET)@h | 
|  | ori	r3, r3, (CONFIG_SYS_IMMR + CONFIG_SYS_INIT_SP_OFFSET)@l | 
|  | li	r4, ((CONFIG_SYS_INIT_SP_OFFSET - 4) / 4) | 
|  | mtctr	r4 | 
|  | lis	r4, 0xdeadbeaf@h | 
|  | ori	r4, r4, 0xdeadbeaf@l | 
|  | 1: | 
|  | stwu	r4, -4(r3) | 
|  | bdnz	1b | 
|  |  | 
|  | /* Done!							*/ | 
|  | /*--------------------------------------------------------------*/ | 
|  |  | 
|  | blr | 
|  | #endif | 
|  |  | 
|  | /* Cache functions. | 
|  | * | 
|  | * Note: requires that all cache bits in | 
|  | * HID0 are in the low half word. | 
|  | */ | 
|  | .globl	icache_enable | 
|  | icache_enable: | 
|  | mfspr	r3, HID0 | 
|  | ori	r3, r3, HID0_ICE | 
|  | lis	r4, 0 | 
|  | ori	r4, r4, HID0_ILOCK | 
|  | andc	r3, r3, r4 | 
|  | ori	r4, r3, HID0_ICFI | 
|  | isync | 
|  | mtspr	HID0, r4	/* sets enable and invalidate, clears lock */ | 
|  | isync | 
|  | mtspr	HID0, r3	/* clears invalidate */ | 
|  | blr | 
|  |  | 
|  | .globl	icache_disable | 
|  | icache_disable: | 
|  | mfspr	r3, HID0 | 
|  | lis	r4, 0 | 
|  | ori	r4, r4, HID0_ICE|HID0_ILOCK | 
|  | andc	r3, r3, r4 | 
|  | ori	r4, r3, HID0_ICFI | 
|  | isync | 
|  | mtspr	HID0, r4	/* sets invalidate, clears enable and lock */ | 
|  | isync | 
|  | mtspr	HID0, r3	/* clears invalidate */ | 
|  | blr | 
|  |  | 
|  | .globl	icache_status | 
|  | icache_status: | 
|  | mfspr	r3, HID0 | 
|  | rlwinm	r3, r3, HID0_ICE_BITPOS + 1, 31, 31 | 
|  | blr | 
|  |  | 
|  | .globl	dcache_enable | 
|  | dcache_enable: | 
|  | mfspr	r3, HID0 | 
|  | ori	r3, r3, HID0_DCE | 
|  | lis	r4, 0 | 
|  | ori	r4, r4, HID0_DLOCK | 
|  | andc	r3, r3, r4 | 
|  | ori	r4, r3, HID0_DCI | 
|  | sync | 
|  | mtspr	HID0, r4	/* sets enable and invalidate, clears lock */ | 
|  | sync | 
|  | mtspr	HID0, r3	/* clears invalidate */ | 
|  | blr | 
|  |  | 
|  | .globl	dcache_disable | 
|  | dcache_disable: | 
|  | mfspr	r3, HID0 | 
|  | lis	r4, 0 | 
|  | ori	r4, r4, HID0_DCE|HID0_DLOCK | 
|  | andc	r3, r3, r4 | 
|  | ori	r4, r3, HID0_DCI | 
|  | sync | 
|  | mtspr	HID0, r4	/* sets invalidate, clears enable and lock */ | 
|  | sync | 
|  | mtspr	HID0, r3	/* clears invalidate */ | 
|  | blr | 
|  |  | 
|  | .globl	dcache_status | 
|  | dcache_status: | 
|  | mfspr	r3, HID0 | 
|  | rlwinm	r3, r3, HID0_DCE_BITPOS + 1, 31, 31 | 
|  | blr | 
|  |  | 
|  | .globl get_pvr | 
|  | get_pvr: | 
|  | mfspr	r3, PVR | 
|  | blr | 
|  |  | 
|  | /*------------------------------------------------------------------------------*/ | 
|  |  | 
|  | /* | 
|  | * void relocate_code (addr_sp, gd, addr_moni) | 
|  | * | 
|  | * This "function" does not return, instead it continues in RAM | 
|  | * after relocating the monitor code. | 
|  | * | 
|  | * r3 = dest | 
|  | * r4 = src | 
|  | * r5 = length in bytes | 
|  | * r6 = cachelinesize | 
|  | */ | 
|  | .globl	relocate_code | 
|  | relocate_code: | 
|  | mr	r1,  r3		/* Set new stack pointer		*/ | 
|  | mr	r9,  r4		/* Save copy of Global Data pointer	*/ | 
|  | mr	r10, r5		/* Save copy of Destination Address	*/ | 
|  |  | 
|  | mr	r3,  r5				/* Destination Address	*/ | 
|  | lis	r4, CONFIG_SYS_MONITOR_BASE@h		/* Source      Address	*/ | 
|  | ori	r4, r4, CONFIG_SYS_MONITOR_BASE@l | 
|  | lwz	r5, GOT(__init_end) | 
|  | sub	r5, r5, r4 | 
|  | li	r6, CONFIG_SYS_CACHELINE_SIZE		/* Cache Line Size	*/ | 
|  |  | 
|  | /* | 
|  | * Fix GOT pointer: | 
|  | * | 
|  | * New GOT-PTR = (old GOT-PTR - CONFIG_SYS_MONITOR_BASE) + Destination Address | 
|  | * | 
|  | * Offset: | 
|  | */ | 
|  | sub	r15, r10, r4 | 
|  |  | 
|  | /* First our own GOT */ | 
|  | add	r14, r14, r15 | 
|  | /* then the one used by the C code */ | 
|  | add	r30, r30, r15 | 
|  |  | 
|  | /* | 
|  | * Now relocate code | 
|  | */ | 
|  |  | 
|  | cmplw	cr1,r3,r4 | 
|  | addi	r0,r5,3 | 
|  | srwi.	r0,r0,2 | 
|  | beq	cr1,4f		/* In place copy is not necessary	*/ | 
|  | beq	7f		/* Protect against 0 count		*/ | 
|  | mtctr	r0 | 
|  | bge	cr1,2f | 
|  |  | 
|  | la	r8,-4(r4) | 
|  | la	r7,-4(r3) | 
|  | 1:	lwzu	r0,4(r8) | 
|  | stwu	r0,4(r7) | 
|  | bdnz	1b | 
|  | b	4f | 
|  |  | 
|  | 2:	slwi	r0,r0,2 | 
|  | add	r8,r4,r0 | 
|  | add	r7,r3,r0 | 
|  | 3:	lwzu	r0,-4(r8) | 
|  | stwu	r0,-4(r7) | 
|  | bdnz	3b | 
|  |  | 
|  | /* | 
|  | * Now flush the cache: note that we must start from a cache aligned | 
|  | * address. Otherwise we might miss one cache line. | 
|  | */ | 
|  | 4:	cmpwi	r6,0 | 
|  | add	r5,r3,r5 | 
|  | beq	7f		/* Always flush prefetch queue in any case */ | 
|  | subi	r0,r6,1 | 
|  | andc	r3,r3,r0 | 
|  | mfspr	r7,HID0		/* don't do dcbst if dcache is disabled */ | 
|  | rlwinm	r7,r7,HID0_DCE_BITPOS+1,31,31 | 
|  | cmpwi	r7,0 | 
|  | beq	9f | 
|  | mr	r4,r3 | 
|  | 5:	dcbst	0,r4 | 
|  | add	r4,r4,r6 | 
|  | cmplw	r4,r5 | 
|  | blt	5b | 
|  | sync			/* Wait for all dcbst to complete on bus */ | 
|  | 9:	mfspr	r7,HID0		/* don't do icbi if icache is disabled */ | 
|  | rlwinm	r7,r7,HID0_ICE_BITPOS+1,31,31 | 
|  | cmpwi	r7,0 | 
|  | beq	7f | 
|  | mr	r4,r3 | 
|  | 6:	icbi	0,r4 | 
|  | add	r4,r4,r6 | 
|  | cmplw	r4,r5 | 
|  | blt	6b | 
|  | 7:	sync			/* Wait for all icbi to complete on bus	*/ | 
|  | isync | 
|  |  | 
|  | /* | 
|  | * We are done. Do not return, instead branch to second part of board | 
|  | * initialization, now running from RAM. | 
|  | */ | 
|  |  | 
|  | addi	r0, r10, in_ram - _start + EXC_OFF_SYS_RESET | 
|  | mtlr	r0 | 
|  | blr | 
|  |  | 
|  | in_ram: | 
|  |  | 
|  | /* | 
|  | * Relocation Function, r14 point to got2+0x8000 | 
|  | * | 
|  | * Adjust got2 pointers, no need to check for 0, this code | 
|  | * already puts a few entries in the table. | 
|  | */ | 
|  | li	r0,__got2_entries@sectoff@l | 
|  | la	r3,GOT(_GOT2_TABLE_) | 
|  | lwz	r11,GOT(_GOT2_TABLE_) | 
|  | mtctr	r0 | 
|  | sub	r11,r3,r11 | 
|  | addi	r3,r3,-4 | 
|  | 1:	lwzu	r0,4(r3) | 
|  | add	r0,r0,r11 | 
|  | stw	r0,0(r3) | 
|  | bdnz	1b | 
|  |  | 
|  | /* | 
|  | * Now adjust the fixups and the pointers to the fixups | 
|  | * in case we need to move ourselves again. | 
|  | */ | 
|  | 2:	li	r0,__fixup_entries@sectoff@l | 
|  | lwz	r3,GOT(_FIXUP_TABLE_) | 
|  | cmpwi	r0,0 | 
|  | mtctr	r0 | 
|  | addi	r3,r3,-4 | 
|  | beq	4f | 
|  | 3:	lwzu	r4,4(r3) | 
|  | lwzux	r0,r4,r11 | 
|  | add	r0,r0,r11 | 
|  | stw	r10,0(r3) | 
|  | stw	r0,0(r4) | 
|  | bdnz	3b | 
|  | 4: | 
|  | clear_bss: | 
|  | /* | 
|  | * Now clear BSS segment | 
|  | */ | 
|  | lwz	r3,GOT(__bss_start) | 
|  | #if defined(CONFIG_HYMOD) | 
|  | /* | 
|  | * For HYMOD - the environment is the very last item in flash. | 
|  | * The real .bss stops just before environment starts, so only | 
|  | * clear up to that point. | 
|  | * | 
|  | * taken from mods for FADS board | 
|  | */ | 
|  | lwz	r4,GOT(environment) | 
|  | #else | 
|  | lwz	r4,GOT(_end) | 
|  | #endif | 
|  |  | 
|  | cmplw	0, r3, r4 | 
|  | beq	6f | 
|  |  | 
|  | li	r0, 0 | 
|  | 5: | 
|  | stw	r0, 0(r3) | 
|  | addi	r3, r3, 4 | 
|  | cmplw	0, r3, r4 | 
|  | bne	5b | 
|  | 6: | 
|  |  | 
|  | mr	r3, r9		/* Global Data pointer		*/ | 
|  | mr	r4, r10		/* Destination Address		*/ | 
|  | bl	board_init_r | 
|  |  | 
|  | /* | 
|  | * Copy exception vector code to low memory | 
|  | * | 
|  | * r3: dest_addr | 
|  | * r7: source address, r8: end address, r9: target address | 
|  | */ | 
|  | .globl	trap_init | 
|  | trap_init: | 
|  | lwz	r7, GOT(_start) | 
|  | lwz	r8, GOT(_end_of_vectors) | 
|  |  | 
|  | li	r9, 0x100		/* reset vector always at 0x100 */ | 
|  |  | 
|  | cmplw	0, r7, r8 | 
|  | bgelr				/* return if r7>=r8 - just in case */ | 
|  |  | 
|  | mflr	r4			/* save link register		*/ | 
|  | 1: | 
|  | lwz	r0, 0(r7) | 
|  | stw	r0, 0(r9) | 
|  | addi	r7, r7, 4 | 
|  | addi	r9, r9, 4 | 
|  | cmplw	0, r7, r8 | 
|  | bne	1b | 
|  |  | 
|  | /* | 
|  | * relocate `hdlr' and `int_return' entries | 
|  | */ | 
|  | li	r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET | 
|  | li	r8, Alignment - _start + EXC_OFF_SYS_RESET | 
|  | 2: | 
|  | bl	trap_reloc | 
|  | addi	r7, r7, 0x100		/* next exception vector	*/ | 
|  | cmplw	0, r7, r8 | 
|  | blt	2b | 
|  |  | 
|  | li	r7, .L_Alignment - _start + EXC_OFF_SYS_RESET | 
|  | bl	trap_reloc | 
|  |  | 
|  | li	r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET | 
|  | bl	trap_reloc | 
|  |  | 
|  | li	r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET | 
|  | li	r8, SystemCall - _start + EXC_OFF_SYS_RESET | 
|  | 3: | 
|  | bl	trap_reloc | 
|  | addi	r7, r7, 0x100		/* next exception vector	*/ | 
|  | cmplw	0, r7, r8 | 
|  | blt	3b | 
|  |  | 
|  | li	r7, .L_SingleStep - _start + EXC_OFF_SYS_RESET | 
|  | li	r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET | 
|  | 4: | 
|  | bl	trap_reloc | 
|  | addi	r7, r7, 0x100		/* next exception vector	*/ | 
|  | cmplw	0, r7, r8 | 
|  | blt	4b | 
|  |  | 
|  | mfmsr	r3			/* now that the vectors have	*/ | 
|  | lis	r7, MSR_IP@h		/* relocated into low memory	*/ | 
|  | ori	r7, r7, MSR_IP@l	/* MSR[IP] can be turned off	*/ | 
|  | andc	r3, r3, r7		/* (if it was on)		*/ | 
|  | SYNC				/* Some chip revs need this... */ | 
|  | mtmsr	r3 | 
|  | SYNC | 
|  |  | 
|  | mtlr	r4			/* restore link register    */ | 
|  | blr | 
|  |  | 
|  | /* | 
|  | * Function: relocate entries for one exception vector | 
|  | */ | 
|  | trap_reloc: | 
|  | lwz	r0, 0(r7)		/* hdlr ...			*/ | 
|  | add	r0, r0, r3		/*  ... += dest_addr		*/ | 
|  | stw	r0, 0(r7) | 
|  |  | 
|  | lwz	r0, 4(r7)		/* int_return ...		*/ | 
|  | add	r0, r0, r3		/*  ... += dest_addr		*/ | 
|  | stw	r0, 4(r7) | 
|  |  | 
|  | blr |