cpu/74xx_7xx/start.S

/*
 *  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>
 *  Copyright (C) 2001  Josh Huber <huber@mclx.com>
 *
 * 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 0xfff00100 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.
 */
#include <config.h>
#include <74xx_7xx.h>
#include <version.h>

#include <ppc_asm.tmpl>
#include <ppc_defs.h>

#include <asm/cache.h>
#include <asm/mmu.h>

#include <galileo/gt64260R.h>

#ifndef  CONFIG_IDENT_STRING
#define  CONFIG_IDENT_STRING ""
#endif

/* We don't want the  MMU yet.
*/
#undef	MSR_KERNEL
/* Machine Check and Recoverable Interr. */
#define MSR_KERNEL ( MSR_ME | MSR_RI )

/*
 * 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)
	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:
	li	r21, BOOTFLAG_COLD	/* Normal Power-On: Boot from FLASH */
	b	boot_cold
	sync

	. = EXC_OFF_SYS_RESET + 0x10

	.globl	_start_warm
_start_warm:
	li	r21, BOOTFLAG_WARM	/* Software reboot		*/
	b	boot_warm
	sync

	/* the boot code is located below the exception table */

	.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	r20,0xd00-4		/* Get stack pointer */
	lwz	r12,0(r20)
	subi	r12,r12,12		/* Adjust stack pointer */
	li	r0,0xc00+_end_back-SystemCall
	cmplw	0, r0, r12		/* Check stack overflow */
	bgt	1f
	stw	r12,0(r20)

	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		/* restore regs */
	lwz	r12,0(r12)

	lwz	r11,0(r12)
	mtlr	r11
	lwz	r11,4(r12)
	mtspr	SRR0,r11
	lwz	r11,8(r12)
	mtspr	SRR1,r11

	addi	r12,r12,12		/* Adjust stack pointer */
	li	r20,0xd00-4
	stw	r12,0(r20)

	SYNC
	rfi
_end_back:

	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, UnknownException)
	STD_EXCEPTION(0x1e00, PeripheralBreakpoint, UnknownException)
	STD_EXCEPTION(0x1f00, DevPortBreakpoint, UnknownException)

	.globl	_end_of_vectors
_end_of_vectors:

	. = 0x2000

boot_cold:
boot_warm:
	/* disable everything */
	li	r0, 0
	mtspr	HID0, r0
	sync
	mtmsr	0
	bl	invalidate_bats
	sync

#ifdef CFG_L2
	/* init the L2 cache */
	addis	r3, r0, L2_INIT@h
	ori	r3, r3, L2_INIT@l
	sync
	mtspr	l2cr, r3
#endif
#if defined(CONFIG_ALTIVEC) && defined(CONFIG_74xx)
	.long	0x7e00066c
		/*
                 * dssall instruction, gas doesn't have it yet
                 * ...for altivec, data stream stop all this probably
                 * isn't needed unless we warm (software) reboot U-Boot
		 */
#endif

#ifdef CFG_L2
	/* invalidate the L2 cache */
	bl	l2cache_invalidate
	sync
#endif
#ifdef CFG_BOARD_ASM_INIT
	/* do early init */
	bl	board_asm_init
#endif

	/*
	 * 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:
	/* let the C-code set up the rest			*/
	/*							*/
	/* Be careful to keep code relocatable !		*/
	/*------------------------------------------------------*/

	/* perform low-level init */
	/* sdram init, galileo init, etc */
	/* r3:	NHR bit from HID0 */

	/* setup the bats */
	bl	setup_bats
	sync

	/*
	 * Cache must be enabled here for stack-in-cache trick.
	 * This means we need to enable the BATS.
	 * This means:
         *   1) for the EVB, original gt regs need to be mapped
	 *   2) need to have an IBAT for the 0xf region,
	 *      we are running there!
         * Cache should be turned on after BATs, since by default
         * everything is write-through.
         * The init-mem BAT can be reused after reloc. The old
         * gt-regs BAT can be reused after board_init_f calls
         * board_pre_init (EVB only).
         */
#if !defined(CONFIG_BAB7xx) && !defined(CONFIG_ELPPC)
	/* enable address translation */
	bl	enable_addr_trans
	sync

	/* enable and invalidate the data cache */
	bl	l1dcache_enable
	sync
#endif
#ifdef CFG_INIT_RAM_LOCK
	bl	lock_ram_in_cache
	sync
#endif

	/* set up the stack pointer in our newly created
	 * cache-ram (r1) */
	lis	r1, (CFG_INIT_RAM_ADDR + CFG_GBL_DATA_OFFSET)@h
	ori	r1, r1, (CFG_INIT_RAM_ADDR + CFG_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	*/

	GET_GOT			/* initialize GOT access	*/

	/* run low-level CPU init code     (from Flash)	*/
	bl	cpu_init_f
	sync

	mr	r3, r21

	/* r3: BOOTFLAG */
	/* run 1st part of board init code (from Flash)   */
	bl	board_init_f
	sync

	/* NOTREACHED */

	.globl	invalidate_bats
invalidate_bats:
	/* invalidate BATs */
	mtspr	IBAT0U, r0
	mtspr	IBAT1U, r0
	mtspr	IBAT2U, r0
	mtspr	IBAT3U, r0
	isync
	mtspr	DBAT0U, r0
	mtspr	DBAT1U, r0
	mtspr	DBAT2U, r0
	mtspr	DBAT3U, r0
	isync
	sync
	blr

	/* setup_bats - set them up to some initial state */
	.globl	setup_bats
setup_bats:
	addis	r0, r0, 0x0000

	/* IBAT 0 */
	addis	r4, r0, CFG_IBAT0L@h
	ori	r4, r4, CFG_IBAT0L@l
	addis	r3, r0, CFG_IBAT0U@h
	ori	r3, r3, CFG_IBAT0U@l
	mtspr	IBAT0L, r4
	mtspr	IBAT0U, r3
	isync

	/* DBAT 0 */
	addis	r4, r0, CFG_DBAT0L@h
	ori	r4, r4, CFG_DBAT0L@l
	addis	r3, r0, CFG_DBAT0U@h
	ori	r3, r3, CFG_DBAT0U@l
	mtspr	DBAT0L, r4
	mtspr	DBAT0U, r3
	isync

	/* IBAT 1 */
	addis	r4, r0, CFG_IBAT1L@h
	ori	r4, r4, CFG_IBAT1L@l
	addis	r3, r0, CFG_IBAT1U@h
	ori	r3, r3, CFG_IBAT1U@l
	mtspr	IBAT1L, r4
	mtspr	IBAT1U, r3
	isync

	/* DBAT 1 */
	addis	r4, r0, CFG_DBAT1L@h
	ori	r4, r4, CFG_DBAT1L@l
	addis	r3, r0, CFG_DBAT1U@h
	ori	r3, r3, CFG_DBAT1U@l
	mtspr	DBAT1L, r4
	mtspr	DBAT1U, r3
	isync

	/* IBAT 2 */
	addis	r4, r0, CFG_IBAT2L@h
	ori	r4, r4, CFG_IBAT2L@l
	addis	r3, r0, CFG_IBAT2U@h
	ori	r3, r3, CFG_IBAT2U@l
	mtspr	IBAT2L, r4
	mtspr	IBAT2U, r3
	isync

	/* DBAT 2 */
	addis	r4, r0, CFG_DBAT2L@h
	ori	r4, r4, CFG_DBAT2L@l
	addis	r3, r0, CFG_DBAT2U@h
	ori	r3, r3, CFG_DBAT2U@l
	mtspr	DBAT2L, r4
	mtspr	DBAT2U, r3
	isync

	/* IBAT 3 */
	addis	r4, r0, CFG_IBAT3L@h
	ori	r4, r4, CFG_IBAT3L@l
	addis	r3, r0, CFG_IBAT3U@h
	ori	r3, r3, CFG_IBAT3U@l
	mtspr	IBAT3L, r4
	mtspr	IBAT3U, r3
	isync

	/* DBAT 3 */
	addis	r4, r0, CFG_DBAT3L@h
	ori	r4, r4, CFG_DBAT3L@l
	addis	r3, r0, CFG_DBAT3U@h
	ori	r3, r3, CFG_DBAT3U@l
	mtspr	DBAT3L, r4
	mtspr	DBAT3U, r3
	isync

	/* bats are done, now invalidate the TLBs */

	addis	r3, 0, 0x0000
	addis	r5, 0, 0x4    /* upper bound of 0x00040000 for 7400/750 */

	isync

tlblp:
	tlbie	r3
	sync
	addi	r3, r3, 0x1000
	cmp	0, 0, r3, r5
	blt tlblp

	blr

	.globl enable_addr_trans
enable_addr_trans:
	/* enable address translation */
	mfmsr	r5
	ori	r5, r5, (MSR_IR | MSR_DR)
	mtmsr	r5
	isync
	blr

	.globl disable_addr_trans
disable_addr_trans:
	/* disable address translation */
	mflr	r4
	mfmsr	r3
	andi.	r0, r3, (MSR_IR | MSR_DR)
	beqlr
	andc	r3, r3, r0
	mtspr	SRR0, r4
	mtspr	SRR1, r3
	rfi

/*
 * 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

	.globl	dc_read
dc_read:
	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, 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
	/* then the one used by the C code */
	add	r30, r30, r15

	/*
	 * Now relocate code
	 */
#ifdef CONFIG_ECC
	bl	board_relocate_rom
	sync
	mr	r3, r10				/* 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	*/
#else
	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
#endif
/*
 * 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:
#ifdef CONFIG_ECC
	bl	board_init_ecc
#endif
	/*
	 * 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)
	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, r10		/* Destination Address		*/
#ifdef CONFIG_AMIGAONEG3SE
	mr	r4, r9		/* Use RAM copy of the global data */
#endif
	bl	after_reloc

	/* not reached - end relocate_code */
/*-----------------------------------------------------------------------*/

	/* 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, 18, 31	/* _start & 0x3FFF	*/

	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

	/* enable execptions from RAM vectors */
	mfmsr	r7
	li	r8,MSR_IP
	andc	r7,r7,r8
	mtmsr	r7

	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

#ifdef CFG_INIT_RAM_LOCK
lock_ram_in_cache:
	/* Allocate Initial RAM in data cache.
	 */
	lis	r3, (CFG_INIT_RAM_ADDR & ~31)@h
	ori	r3, r3, (CFG_INIT_RAM_ADDR & ~31)@l
	li	r2, ((CFG_INIT_RAM_END & ~31) + \
		     (CFG_INIT_RAM_ADDR & 31) + 31) / 32
	mtctr	r2
1:
	dcbz	r0, r3
	addi	r3, r3, 32
	bdnz	1b

	/* Lock the data cache */
	mfspr	r0, HID0
	ori	r0, r0, 0x1000
	sync
	mtspr	HID0, r0
	sync
	blr

.globl unlock_ram_in_cache
unlock_ram_in_cache:
	/* invalidate the INIT_RAM section */
	lis	r3, (CFG_INIT_RAM_ADDR & ~31)@h
	ori	r3, r3, (CFG_INIT_RAM_ADDR & ~31)@l
	li	r2, ((CFG_INIT_RAM_END & ~31) + \
		     (CFG_INIT_RAM_ADDR & 31) + 31) / 32
	mtctr	r2
1:	icbi	r0, r3
	addi	r3, r3, 32
	bdnz	1b
	sync			/* Wait for all icbi to complete on bus	*/
	isync

	/* Unlock the data cache and invalidate it */
	mfspr   r0, HID0
	li      r3,0x1000
	andc    r0,r0,r3
	li	r3,0x0400
	or	r0,r0,r3
	sync
	mtspr   HID0, r0
	sync
	blr
#endif