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authorwdenk <wdenk>2002-11-03 00:07:02 +0000
committerwdenk <wdenk>2002-11-03 00:07:02 +0000
commit5b1d713721c3ea02549940133f09236783dda1f9 (patch)
tree78c0a58b5cc48142617190669a7598e0ca3307dc /cpu/mpc8xx/start.S
parent47d1a6e1ed87fe1fb3d737acdb85f69bc3259522 (diff)
Initial revision
Diffstat (limited to 'cpu/mpc8xx/start.S')
-rw-r--r--cpu/mpc8xx/start.S782
1 files changed, 782 insertions, 0 deletions
diff --git a/cpu/mpc8xx/start.S b/cpu/mpc8xx/start.S
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+/*
+ * 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 PowerPC based Embedded Boards
+ *
+ *
+ * The processor starts at 0x00000100 and the code is executed
+ * from flash. The code is organized to be at an other address
+ * in memory, but as long we don't jump around before relocating.
+ * board_init lies at a quite high address and when the cpu has
+ * jumped there, everything is ok.
+ * This works because the cpu gives the FLASH (CS0) the whole
+ * address space at startup, and board_init lies as a echo of
+ * the flash somewhere up there in the memorymap.
+ *
+ * board_init will change CS0 to be positioned at the correct
+ * address and (s)dram will be positioned at address 0
+ */
+#include <config.h>
+#include <mpc8xx.h>
+#include <version.h>
+
+#define CONFIG_8xx 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
+#define MSR_KERNEL ( MSR_ME | MSR_RI ) /* Machine Check and Recoverable Interr. */
+
+/*
+ * 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(_end)
+ GOT_ENTRY(.bss)
+#if defined(CONFIG_FADS) || defined(CONFIG_ICU862)
+ GOT_ENTRY(environment)
+#endif
+ END_GOT
+
+/*
+ * r3 - 1st arg to board_init(): IMMP pointer
+ * r4 - 2nd arg to board_init(): boot flag
+ */
+ .text
+ .long 0x27051956 /* U-Boot Magic Number */
+ .globl version_string
+version_string:
+ .ascii U_BOOT_VERSION
+ .ascii " (", __DATE__, " - ", __TIME__, ")"
+ .ascii CONFIG_IDENT_STRING, "\0"
+
+ . = EXC_OFF_SYS_RESET
+ .globl _start
+_start:
+ lis r3, CFG_IMMR@h /* position IMMR */
+ mtspr 638, r3
+ li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH */
+ b boot_cold
+
+ . = EXC_OFF_SYS_RESET + 0x10
+
+ .globl _start_warm
+_start_warm:
+ li r21, BOOTFLAG_WARM /* Software reboot */
+ b boot_warm
+
+boot_cold:
+boot_warm:
+
+ /* Initialize machine status; enable machine check interrupt */
+ /*----------------------------------------------------------------------*/
+ li r3, MSR_KERNEL /* Set ME, RI flags */
+ mtmsr r3
+ mtspr SRR1, r3 /* Make SRR1 match MSR */
+
+ mfspr r3, ICR /* clear Interrupt Cause Register */
+
+ /* Initialize debug port registers */
+ /*----------------------------------------------------------------------*/
+ xor r0, r0, r0 /* Clear R0 */
+ mtspr LCTRL1, r0 /* Initialize debug port regs */
+ mtspr LCTRL2, r0
+ mtspr COUNTA, r0
+ mtspr COUNTB, r0
+
+ /* Reset the caches */
+ /*----------------------------------------------------------------------*/
+
+ mfspr r3, IC_CST /* Clear error bits */
+ mfspr r3, DC_CST
+
+ lis r3, IDC_UNALL@h /* Unlock all */
+ mtspr IC_CST, r3
+ mtspr DC_CST, r3
+
+ lis r3, IDC_INVALL@h /* Invalidate all */
+ mtspr IC_CST, r3
+ mtspr DC_CST, r3
+
+ lis r3, IDC_DISABLE@h /* Disable data cache */
+ mtspr DC_CST, r3
+
+#if !(defined(CONFIG_IP860) || defined(CONFIG_PCU_E) || defined (CONFIG_FLAGADM))
+ /* On IP860 and PCU E,
+ * we cannot enable IC yet
+ */
+ lis r3, IDC_ENABLE@h /* Enable instruction cache */
+#endif
+ mtspr IC_CST, r3
+
+ /* invalidate all tlb's */
+ /*----------------------------------------------------------------------*/
+
+ tlbia
+ isync
+
+ /*
+ * Calculate absolute address in FLASH and jump there
+ *----------------------------------------------------------------------*/
+
+ lis r3, CFG_MONITOR_BASE@h
+ ori r3, r3, CFG_MONITOR_BASE@l
+ addi r3, r3, in_flash - _start + EXC_OFF_SYS_RESET
+ mtlr r3
+ blr
+
+in_flash:
+
+ /* initialize some SPRs that are hard to access from C */
+ /*----------------------------------------------------------------------*/
+
+ lis r3, CFG_IMMR@h /* pass IMMR as arg1 to C routine */
+ ori r1, r3, CFG_INIT_SP_OFFSET /* set up the stack in internal DPRAM */
+ /* Note: R0 is still 0 here */
+ stwu r0, -4(r1) /* clear final stack frame so that */
+ stwu r0, -4(r1) /* stack backtraces terminate cleanly */
+
+ /*
+ * Disable serialized ifetch and show cycles
+ * (i.e. set processor to normal mode).
+ * This is also a silicon bug workaround, see errata
+ */
+
+ li r2, 0x0007
+ mtspr ICTRL, r2
+
+ /* Set up debug mode entry */
+
+ lis r2, CFG_DER@h
+ ori r2, r2, CFG_DER@l
+ mtspr DER, r2
+
+ /* 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 (from Flash) */
+
+ mr r3, r21
+ /* r3: BOOTFLAG */
+ bl board_init_f /* run 1st part of board init code (from Flash) */
+
+
+
+ .globl _start_of_vectors
+_start_of_vectors:
+
+/* Machine check */
+ STD_EXCEPTION(0x200, MachineCheck, MachineCheckException)
+
+/* Data Storage exception. "Never" generated on the 860. */
+ STD_EXCEPTION(0x300, DataStorage, UnknownException)
+
+/* Instruction Storage exception. "Never" generated on the 860. */
+ STD_EXCEPTION(0x400, InstStorage, UnknownException)
+
+/* External Interrupt exception. */
+ STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt)
+
+/* Alignment exception. */
+ . = 0x600
+Alignment:
+ EXCEPTION_PROLOG
+ 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 */
+ 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
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ li r20,MSR_KERNEL
+ rlwimi r20,r23,0,16,16 /* copy EE 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
+
+ /* No FPU on MPC8xx. This exception is not supposed to happen.
+ */
+ 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)
+
+ . = 0xc00
+/*
+ * r0 - SYSCALL number
+ * r3-... arguments
+ */
+SystemCall:
+ addis r11,r0,0 /* get functions table addr */
+ ori r11,r11,0 /* Note: this code is patched in trap_init */
+ addis r12,r0,0 /* get number of functions */
+ ori r12,r12,0
+
+ cmplw 0, r0, r12
+ bge 1f
+
+ rlwinm r0,r0,2,0,31 /* fn_addr = fn_tbl[r0] */
+ add r11,r11,r0
+ lwz r11,0(r11)
+
+ li r12,0xd00-4*3 /* save LR & SRRx */
+ mflr r0
+ stw r0,0(r12)
+ mfspr r0,SRR0
+ stw r0,4(r12)
+ mfspr r0,SRR1
+ stw r0,8(r12)
+
+ li r12,0xc00+_back-SystemCall
+ mtlr r12
+ mtspr SRR0,r11
+
+1: SYNC
+ rfi
+
+_back:
+
+ mfmsr r11 /* Disable interrupts */
+ li r12,0
+ ori r12,r12,MSR_EE
+ andc r11,r11,r12
+ SYNC /* Some chip revs need this... */
+ mtmsr r11
+ SYNC
+
+ li r12,0xd00-4*3 /* restore regs */
+ lwz r11,0(r12)
+ mtlr r11
+ lwz r11,4(r12)
+ mtspr SRR0,r11
+ lwz r11,8(r12)
+ mtspr SRR1,r11
+
+ SYNC
+ rfi
+
+ STD_EXCEPTION(0xd00, SingleStep, UnknownException)
+
+ STD_EXCEPTION(0xe00, Trap_0e, UnknownException)
+ STD_EXCEPTION(0xf00, Trap_0f, UnknownException)
+
+ /* On the MPC8xx, this is a software emulation interrupt. It occurs
+ * for all unimplemented and illegal instructions.
+ */
+ STD_EXCEPTION(0x1000, SoftEmu, SoftEmuException)
+
+ STD_EXCEPTION(0x1100, InstructionTLBMiss, UnknownException)
+ STD_EXCEPTION(0x1200, DataTLBMiss, UnknownException)
+ STD_EXCEPTION(0x1300, InstructionTLBError, UnknownException)
+ STD_EXCEPTION(0x1400, DataTLBError, UnknownException)
+
+ STD_EXCEPTION(0x1500, Reserved5, UnknownException)
+ STD_EXCEPTION(0x1600, Reserved6, UnknownException)
+ STD_EXCEPTION(0x1700, Reserved7, UnknownException)
+ STD_EXCEPTION(0x1800, Reserved8, UnknownException)
+ STD_EXCEPTION(0x1900, Reserved9, UnknownException)
+ STD_EXCEPTION(0x1a00, ReservedA, UnknownException)
+ STD_EXCEPTION(0x1b00, ReservedB, UnknownException)
+
+ STD_EXCEPTION(0x1c00, DataBreakpoint, UnknownException)
+ STD_EXCEPTION(0x1d00, InstructionBreakpoint, DebugException)
+ STD_EXCEPTION(0x1e00, PeripheralBreakpoint, UnknownException)
+ STD_EXCEPTION(0x1f00, DevPortBreakpoint, UnknownException)
+
+
+ .globl _end_of_vectors
+_end_of_vectors:
+
+
+ . = 0x2000
+
+/*
+ * 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)
+ mtspr SPRG2,r22 /* r1 is now kernel sp */
+ 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
+
+/* Cache functions.
+*/
+ .globl icache_enable
+icache_enable:
+ SYNC
+ lis r3, IDC_INVALL@h
+ mtspr IC_CST, r3
+ lis r3, IDC_ENABLE@h
+ mtspr IC_CST, r3
+ blr
+
+ .globl icache_disable
+icache_disable:
+ SYNC
+ lis r3, IDC_DISABLE@h
+ mtspr IC_CST, r3
+ blr
+
+ .globl icache_status
+icache_status:
+ mfspr r3, IC_CST
+ srwi r3, r3, 31 /* >>31 => select bit 0 */
+ blr
+
+ .globl dcache_enable
+dcache_enable:
+#if 0
+ SYNC
+#endif
+#if 1
+ lis r3, 0x0400 /* Set cache mode with MMU off */
+ mtspr MD_CTR, r3
+#endif
+
+ lis r3, IDC_INVALL@h
+ mtspr DC_CST, r3
+#if 0
+ lis r3, DC_SFWT@h
+ mtspr DC_CST, r3
+#endif
+ lis r3, IDC_ENABLE@h
+ mtspr DC_CST, r3
+ blr
+
+ .globl dcache_disable
+dcache_disable:
+ SYNC
+ lis r3, IDC_DISABLE@h
+ mtspr DC_CST, r3
+ lis r3, IDC_INVALL@h
+ mtspr DC_CST, r3
+ blr
+
+ .globl dcache_status
+dcache_status:
+ mfspr r3, DC_CST
+ srwi r3, r3, 31 /* >>31 => select bit 0 */
+ blr
+
+ .globl dc_read
+dc_read:
+ mtspr DC_ADR, r3
+ mfspr r3, DC_DAT
+ blr
+
+/*
+ * unsigned int get_immr (unsigned int mask)
+ *
+ * return (mask ? (IMMR & mask) : IMMR);
+ */
+ .globl get_immr
+get_immr:
+ mr r4,r3 /* save mask */
+ mfspr r3, IMMR /* IMMR */
+ cmpwi 0,r4,0 /* mask != 0 ? */
+ beq 4f
+ and r3,r3,r4 /* IMMR & mask */
+4:
+ blr
+
+ .globl get_pvr
+get_pvr:
+ mfspr r3, PVR
+ blr
+
+
+ .globl wr_ic_cst
+wr_ic_cst:
+ mtspr IC_CST, r3
+ blr
+
+ .globl rd_ic_cst
+rd_ic_cst:
+ mfspr r3, IC_CST
+ blr
+
+ .globl wr_ic_adr
+wr_ic_adr:
+ mtspr IC_ADR, r3
+ blr
+
+
+ .globl wr_dc_cst
+wr_dc_cst:
+ mtspr DC_CST, r3
+ blr
+
+ .globl rd_dc_cst
+rd_dc_cst:
+ mfspr r3, DC_CST
+ blr
+
+ .globl wr_dc_adr
+wr_dc_adr:
+ mtspr DC_ADR, r3
+ 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, CFG_MONITOR_BASE@h /* Source Address */
+ ori r4, r4, CFG_MONITOR_BASE@l
+ lis r5, CFG_MONITOR_LEN@h /* Length in Bytes */
+ ori r5, r5, CFG_MONITOR_LEN@l
+ li r6, CFG_CACHELINE_SIZE /* Cache Line Size */
+
+ /*
+ * Fix GOT pointer:
+ *
+ * New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address
+ *
+ * Offset:
+ */
+ sub r15, r10, r4
+
+ /* First our own GOT */
+ add r14, r14, r15
+ /* the 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
+ 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)
+#if defined(CONFIG_FADS) || defined(CONFIG_ICU862)
+ /*
+ * For the FADS - the environment is the very last item in flash.
+ * The real .bss stops just before environment starts, so only
+ * clear up to that point.
+ */
+ 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
+
+ /* Problems accessing "end" in C, so do it here */
+ .globl get_endaddr
+get_endaddr:
+ lwz r3,GOT(_end)
+ blr
+
+ /*
+ * 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)
+
+ rlwinm r9, r7, 0, 22, 31 /* _start & 0x3FF */
+
+ 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
+
+ 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)
+
+ sync
+ isync
+
+ blr