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authorStefan Roese <sr@denx.de>2010-04-15 16:07:28 +0200
committerWolfgang Denk <wd@denx.de>2010-04-21 23:42:38 +0200
commita47a12becf66f02a56da91c161e2edb625e9f20c (patch)
tree6efae7137d26d1e610c5fd56b7aaa3c043ad2b71 /arch/powerpc/cpu/mpc512x/start.S
parent254ab7bd464657600aba69d840406f9358f3e116 (diff)
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Move arch/ppc to arch/powerpc
As discussed on the list, move "arch/ppc" to "arch/powerpc" to better match the Linux directory structure. Please note that this patch also changes the "ppc" target in MAKEALL to "powerpc" to match this new infrastructure. But "ppc" is kept as an alias for now, to not break compatibility with scripts using this name. Signed-off-by: Stefan Roese <sr@denx.de> Acked-by: Wolfgang Denk <wd@denx.de> Acked-by: Detlev Zundel <dzu@denx.de> Acked-by: Kim Phillips <kim.phillips@freescale.com> Cc: Peter Tyser <ptyser@xes-inc.com> Cc: Anatolij Gustschin <agust@denx.de>
Diffstat (limited to 'arch/powerpc/cpu/mpc512x/start.S')
-rw-r--r--arch/powerpc/cpu/mpc512x/start.S711
1 files changed, 711 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc512x/start.S b/arch/powerpc/cpu/mpc512x/start.S
new file mode 100644
index 0000000..d26b617
--- /dev/null
+++ b/arch/powerpc/cpu/mpc512x/start.S
@@ -0,0 +1,711 @@
+/*
+ * 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.
+ *
+ * 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 r12 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
+ EXC_XFER_TEMPLATE(Alignment, AlignmentException, MSR_KERNEL, COPY_EE)
+
+/* Program check exception */
+ . = 0x700
+ProgramCheck:
+ EXCEPTION_PROLOG(SRR0, SRR1)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_TEMPLATE(ProgramCheck, ProgramCheckException,
+ MSR_KERNEL, COPY_EE)
+
+/* 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 */
+
+ GET_GOT
+ 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 r12, r12, 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, r12 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)
+ cmpwi r0,0
+ beq- 2f
+ add r0,r0,r11
+ stw r0,0(r3)
+2: bdnz 1b
+
+ /*
+ * Now adjust the fixups and the pointers to the fixups
+ * in case we need to move ourselves again.
+ */
+ 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:
+ mflr r4 /* save link register */
+ GET_GOT
+ 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 */
+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