|  | /* | 
|  | * Copyright (C) 1998  Dan Malek <dmalek@jlc.net> | 
|  | * Copyright (C) 1999  Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> | 
|  | * Copyright (C) 2000-2009 Wolfgang Denk <wd@denx.de> | 
|  | * Copyright Freescale Semiconductor, Inc. 2004, 2006. All rights reserved. | 
|  | * | 
|  | * 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 | 
|  | * | 
|  | * Based on the MPC83xx code. | 
|  | */ | 
|  |  | 
|  | /* | 
|  | *  U-Boot - Startup Code for MPC512x based Embedded Boards | 
|  | */ | 
|  |  | 
|  | #include <config.h> | 
|  | #include <timestamp.h> | 
|  | #include <version.h> | 
|  |  | 
|  | #define CONFIG_521X	1		/* needed for Linux kernel header files*/ | 
|  |  | 
|  | #include <asm/immap_512x.h> | 
|  | #include "asm-offsets.h" | 
|  |  | 
|  | #include <ppc_asm.tmpl> | 
|  | #include <ppc_defs.h> | 
|  |  | 
|  | #include <asm/cache.h> | 
|  | #include <asm/mmu.h> | 
|  |  | 
|  | #ifndef  CONFIG_IDENT_STRING | 
|  | #define  CONFIG_IDENT_STRING "MPC512X" | 
|  | #endif | 
|  |  | 
|  | /* | 
|  | * Floating Point enable, Machine Check and Recoverable Interr. | 
|  | */ | 
|  | #undef	MSR_KERNEL | 
|  | #ifdef DEBUG | 
|  | #define MSR_KERNEL (MSR_FP|MSR_RI) | 
|  | #else | 
|  | #define MSR_KERNEL (MSR_FP|MSR_ME|MSR_RI) | 
|  | #endif | 
|  |  | 
|  | /* Macros for manipulating CSx_START/STOP */ | 
|  | #define START_REG(start)	((start) >> 16) | 
|  | #define STOP_REG(start, size)	(((start) + (size) - 1) >> 16) | 
|  |  | 
|  | /* | 
|  | * 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) | 
|  | END_GOT | 
|  |  | 
|  | /* | 
|  | * Magic number and version string | 
|  | */ | 
|  | .long	0x27051956		/* U-Boot Magic Number */ | 
|  | .globl	version_string | 
|  | version_string: | 
|  | .ascii U_BOOT_VERSION | 
|  | .ascii " (", U_BOOT_DATE, " - ", U_BOOT_TIME, ")" | 
|  | .ascii " ", CONFIG_IDENT_STRING, "\0" | 
|  |  | 
|  | /* | 
|  | * Vector Table | 
|  | */ | 
|  | .text | 
|  | . = EXC_OFF_SYS_RESET | 
|  |  | 
|  | .globl	_start | 
|  | /* Start from here after reset/power on */ | 
|  | _start: | 
|  | li	r21, BOOTFLAG_COLD  /* Normal Power-On: Boot from FLASH */ | 
|  | b	boot_cold | 
|  |  | 
|  | .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, UnknownException) | 
|  |  | 
|  | /* 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 | 
|  |  | 
|  | /* Floating Point Unit unavailable exception */ | 
|  | STD_EXCEPTION(0x800, FPUnavailable, UnknownException) | 
|  |  | 
|  | /* Decrementer */ | 
|  | STD_EXCEPTION(0x900, Decrementer, timer_interrupt) | 
|  |  | 
|  | /* Critical interrupt */ | 
|  | STD_EXCEPTION(0xa00, Critical, UnknownException) | 
|  |  | 
|  | /* System Call */ | 
|  | STD_EXCEPTION(0xc00, SystemCall, UnknownException) | 
|  |  | 
|  | /* Trace interrupt */ | 
|  | STD_EXCEPTION(0xd00, Trace, UnknownException) | 
|  |  | 
|  | /* Performance Monitor interrupt */ | 
|  | STD_EXCEPTION(0xf00, PerfMon, UnknownException) | 
|  |  | 
|  | /* Intruction Translation Miss */ | 
|  | STD_EXCEPTION(0x1000, InstructionTLBMiss, UnknownException) | 
|  |  | 
|  | /* Data Load Translation Miss */ | 
|  | STD_EXCEPTION(0x1100, DataLoadTLBMiss, UnknownException) | 
|  |  | 
|  | /* Data Store Translation Miss */ | 
|  | STD_EXCEPTION(0x1200, DataStoreTLBMiss, UnknownException) | 
|  |  | 
|  | /* Instruction Address Breakpoint */ | 
|  | STD_EXCEPTION(0x1300, InstructionAddrBreakpoint, DebugException) | 
|  |  | 
|  | /* System Management interrupt */ | 
|  | STD_EXCEPTION(0x1400, SystemMgmtInterrupt, UnknownException) | 
|  |  | 
|  | .globl	_end_of_vectors | 
|  | _end_of_vectors: | 
|  |  | 
|  | . = 0x3000 | 
|  | boot_cold: | 
|  | /* Save msr contents */ | 
|  | mfmsr	r5 | 
|  |  | 
|  | /* Set IMMR area to our preferred location */ | 
|  | lis	r4, CONFIG_DEFAULT_IMMR@h | 
|  | lis	r3, CONFIG_SYS_IMMR@h | 
|  | ori	r3, r3, CONFIG_SYS_IMMR@l | 
|  | stw	r3, IMMRBAR(r4) | 
|  | mtspr	MBAR, r3		/* IMMRBAR is mirrored into the MBAR SPR (311) */ | 
|  |  | 
|  | /* Initialise the machine */ | 
|  | bl	cpu_early_init | 
|  |  | 
|  | /* | 
|  | * Set up Local Access Windows: | 
|  | * | 
|  | * 1) Boot/CS0 (boot FLASH) | 
|  | * 2) On-chip SRAM (initial stack purposes) | 
|  | */ | 
|  |  | 
|  | /* Boot CS/CS0 window range */ | 
|  | lis     r3, CONFIG_SYS_IMMR@h | 
|  | ori     r3, r3, CONFIG_SYS_IMMR@l | 
|  |  | 
|  | lis	r4, START_REG(CONFIG_SYS_FLASH_BASE) | 
|  | ori	r4, r4, STOP_REG(CONFIG_SYS_FLASH_BASE, CONFIG_SYS_FLASH_SIZE) | 
|  | stw	r4, LPCS0AW(r3) | 
|  |  | 
|  | /* | 
|  | * The SRAM window has a fixed size (256K), so only the start address | 
|  | * is necessary | 
|  | */ | 
|  | lis	r4, START_REG(CONFIG_SYS_SRAM_BASE) & 0xff00 | 
|  | stw	r4, SRAMBAR(r3) | 
|  |  | 
|  | /* | 
|  | * According to MPC5121e RM, configuring local access windows should | 
|  | * be followed by a dummy read of the config register that was | 
|  | * modified last and an isync | 
|  | */ | 
|  | lwz	r4, SRAMBAR(r3) | 
|  | isync | 
|  |  | 
|  | /* | 
|  | * Set configuration of the Boot/CS0, the SRAM window does not have a | 
|  | * config register so no params can be set for it | 
|  | */ | 
|  | lis     r3, (CONFIG_SYS_IMMR + LPC_OFFSET)@h | 
|  | ori     r3, r3, (CONFIG_SYS_IMMR + LPC_OFFSET)@l | 
|  |  | 
|  | lis     r4, CONFIG_SYS_CS0_CFG@h | 
|  | ori     r4, r4, CONFIG_SYS_CS0_CFG@l | 
|  | stw     r4, CS0_CONFIG(r3) | 
|  |  | 
|  | /* Master enable all CS's */ | 
|  | lis	r4, CS_CTRL_ME@h | 
|  | ori	r4, r4, CS_CTRL_ME@l | 
|  | stw	r4, CS_CTRL(r3) | 
|  |  | 
|  | lis	r4, (CONFIG_SYS_MONITOR_BASE)@h | 
|  | ori	r4, r4, (CONFIG_SYS_MONITOR_BASE)@l | 
|  | addi	r5, r4, in_flash - _start + EXC_OFF_SYS_RESET | 
|  | mtlr	r5 | 
|  | blr | 
|  |  | 
|  | in_flash: | 
|  | lis	r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@h | 
|  | ori	r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@l | 
|  |  | 
|  | 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 & stack humble	*/ | 
|  | /*------------------------------------------------------*/ | 
|  |  | 
|  | GET_GOT			/* initialize GOT access	*/ | 
|  |  | 
|  | /* r3: IMMR */ | 
|  | lis	r3, CONFIG_SYS_IMMR@h | 
|  | /* run low-level CPU init code (in Flash) */ | 
|  | bl	cpu_init_f | 
|  |  | 
|  | /* r3: BOOTFLAG */ | 
|  | mr	r3, r21 | 
|  | /* run 1st part of board init code (in Flash) */ | 
|  | bl	board_init_f | 
|  |  | 
|  | /* NOTREACHED - board_init_f() does not return */ | 
|  |  | 
|  | /* | 
|  | * 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 | 
|  |  | 
|  | /* | 
|  | * This code initialises the machine, it expects original MSR contents to be in r5. | 
|  | */ | 
|  | cpu_early_init: | 
|  | /* 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 */ | 
|  | #ifdef DEBUG | 
|  | rlwimi	r3, r5, 0, 21, 22		/* debugger might set SE, BE bits */ | 
|  | #endif | 
|  | mtmsr	r3 | 
|  | SYNC | 
|  | mtspr	SRR1, r3			/* Mirror current MSR state in SRR1 */ | 
|  |  | 
|  | lis	r3, CONFIG_SYS_IMMR@h | 
|  |  | 
|  | #if defined(CONFIG_WATCHDOG) | 
|  | /* Initialise the watchdog and reset it */ | 
|  | /*--------------------------------------*/ | 
|  | lis r4, CONFIG_SYS_WATCHDOG_VALUE | 
|  | ori r4, r4, (SWCRR_SWEN | SWCRR_SWRI | SWCRR_SWPR) | 
|  | stw r4, SWCRR(r3) | 
|  |  | 
|  | /* reset */ | 
|  | li	r4, 0x556C | 
|  | sth	r4, SWSRR@l(r3) | 
|  | li	r4, 0x0 | 
|  | ori	r4, r4, 0xAA39 | 
|  | sth	r4, SWSRR@l(r3) | 
|  | #else | 
|  | /* Disable the watchdog */ | 
|  | /*----------------------*/ | 
|  | lwz r4, SWCRR(r3) | 
|  | /* | 
|  | * Check to see if it's enabled for disabling: once disabled by s/w | 
|  | * it's not possible to re-enable it | 
|  | */ | 
|  | andi. r4, r4, 0x4 | 
|  | beq 1f | 
|  | xor r4, r4, r4 | 
|  | stw r4, SWCRR(r3) | 
|  | 1: | 
|  | #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 | 
|  | SYNC | 
|  | mtspr	HID2, r3 | 
|  | sync | 
|  | blr | 
|  |  | 
|  |  | 
|  | /* 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, (31 - HID0_ICE_SHIFT + 1), 31, 31 | 
|  | blr | 
|  |  | 
|  | .globl	dcache_enable | 
|  | dcache_enable: | 
|  | mfspr	r3, HID0 | 
|  | li	r5, HID0_DCFI|HID0_DLOCK | 
|  | andc	r3, r3, r5 | 
|  | mtspr	HID0, r3		/* no invalidate, unlock */ | 
|  | ori	r3, r3, HID0_DCE | 
|  | ori	r5, r3, HID0_DCFI | 
|  | mtspr	HID0, r5		/* enable + invalidate */ | 
|  | mtspr	HID0, r3		/* enable */ | 
|  | sync | 
|  | 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, (31 - HID0_DCE_SHIFT + 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) | 
|  |  | 
|  | /* copy */ | 
|  | 1:	lwzu	r0,4(r8) | 
|  | stwu	r0,4(r7) | 
|  | bdnz	1b | 
|  |  | 
|  | addi	r0,r5,3 | 
|  | srwi.	r0,r0,2 | 
|  | mtctr	r0 | 
|  | la	r8,-4(r4) | 
|  | la	r7,-4(r3) | 
|  |  | 
|  | /* and compare */ | 
|  | 20:	lwzu	r20,4(r8) | 
|  | lwzu	r21,4(r7) | 
|  | xor. r22, r20, r21 | 
|  | bne  30f | 
|  | bdnz	20b | 
|  | b 4f | 
|  |  | 
|  | /* compare failed */ | 
|  | 30:	li r3, 0 | 
|  | blr | 
|  |  | 
|  | 2:	slwi	r0,r0,2 /* re copy in reverse order ... y do we needed it? */ | 
|  | 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 | 
|  | 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 */ | 
|  | 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) | 
|  | lwz	r4,GOT(_end) | 
|  |  | 
|  | 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 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_Trace - _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 |