[ADS5121] Support for the ADS5121 board

The following MPC5121e subsystems are supported:

- low-level CPU init
- NOR Boot Flash (common CFI driver)
- DDR SDRAM
- FEC
- I2C
- Watchdog

Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>
Signed-off-by: Rafal Jaworowski <raj@semihalf.com>
Signed-off-by: Jan Wrobel <wrr@semihalf.com>

1 files changed, 780 insertions, 0 deletions

diff --git a/cpu/mpc512x/start.S b/cpu/mpc512x/start.S
new file mode 100644
index 0000000..8b749ac
--- /dev/null
+++ b/cpu/mpc512x/start.S
@@ -0,0 +1,780 @@
+/*
+ * 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, 2007 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 <mpc512x.h>
+#include <version.h>
+
+#define CONFIG_521X	1		/* needed for Linux kernel header files*/
+
+#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 " (", __DATE__, " - ", __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, CFG_IMMR@h
+	ori	r3, r3, CFG_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, CFG_IMMR@h
+        ori     r3, r3, CFG_IMMR@l
+
+	lis	r4, START_REG(CFG_FLASH_BASE)
+	ori	r4, r4, STOP_REG(CFG_FLASH_BASE, CFG_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(CFG_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, (CFG_IMMR + LPC_OFFSET)@h
+        ori     r3, r3, (CFG_IMMR + LPC_OFFSET)@l
+
+        lis     r4, CFG_CS0_CFG@h
+        ori     r4, r4, CFG_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, (CFG_MONITOR_BASE)@h
+	ori	r4, r4, (CFG_MONITOR_BASE)@l
+	addi	r5, r4, in_flash - _start + EXC_OFF_SYS_RESET
+	mtlr	r5
+	blr
+
+in_flash:
+	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	*/
+
+	/* 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, CFG_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, CFG_IMMR@h
+
+#if defined(CONFIG_WATCHDOG)
+	/* Initialise the watchdog and reset it */
+	/*--------------------------------------*/
+	lis r4, CFG_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, CFG_HID0_INIT@h
+	ori	r3, r3, CFG_HID0_INIT@l
+	SYNC
+	mtspr	HID0, r3
+
+	lis	r3, CFG_HID0_FINAL@h
+	ori	r3, r3, CFG_HID0_FINAL@l
+	SYNC
+	mtspr	HID0, r3
+
+	lis	r3, CFG_HID2@h
+	ori	r3, r3, CFG_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
+
+/*------------------------------------------------------------------------------- */
+/* Function:	 ppcDcbf */
+/* Description:	 Data Cache block flush */
+/* Input:	 r3 = effective address */
+/* Output:	 none. */
+/*------------------------------------------------------------------------------- */
+	.globl	ppcDcbf
+ppcDcbf:
+	dcbf	r0,r3
+	blr
+
+/*------------------------------------------------------------------------------- */
+/* Function:	 ppcDcbi */
+/* Description:	 Data Cache block Invalidate */
+/* Input:	 r3 = effective address */
+/* Output:	 none. */
+/*------------------------------------------------------------------------------- */
+	.globl	ppcDcbi
+ppcDcbi:
+	dcbi	r0,r3
+	blr
+
+/*--------------------------------------------------------------------------
+ * Function:	 ppcDcbz
+ * Description:	 Data Cache block zero.
+ * Input:	 r3 = effective address
+ * Output:	 none.
+ *-------------------------------------------------------------------------- */
+
+	.globl	ppcDcbz
+ppcDcbz:
+	dcbz	r0,r3
+	blr
+
+	.globl	ppcDWstore
+ppcDWstore:
+	lfd	1, 0(r4)
+	stfd	1, 0(r3)
+	blr
+
+	.globl	ppcDWload
+ppcDWload:
+	lfd	1, 0(r3)
+	stfd	1, 0(r4)
+	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
+	lwz	r5, GOT(__init_end)
+	sub	r5, r5, r4
+	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
+	 */
+	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