summaryrefslogtreecommitdiff
path: root/arch/powerpc/cpu/mpc512x/start.S
blob: 1047c513f9d3dee71948d883a053789d413160e7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
/*
 * 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:
	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

	/* 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