blob: c5dc5a973afae6343a845da07dae3684541aa133 [file] [log] [blame]
wdenk5b1d7132002-11-03 00:07:02 +00001/*
2 * Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
3 * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
4 * Copyright (C) 2000,2001,2002 Wolfgang Denk <wd@denx.de>
5 *
6 * See file CREDITS for list of people who contributed to this
7 * project.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22 * MA 02111-1307 USA
23 */
24
25/* U-Boot - Startup Code for PowerPC based Embedded Boards
26 *
27 *
28 * The processor starts at 0x00000100 and the code is executed
29 * from flash. The code is organized to be at an other address
30 * in memory, but as long we don't jump around before relocating.
31 * board_init lies at a quite high address and when the cpu has
32 * jumped there, everything is ok.
33 * This works because the cpu gives the FLASH (CS0) the whole
34 * address space at startup, and board_init lies as a echo of
35 * the flash somewhere up there in the memorymap.
36 *
37 * board_init will change CS0 to be positioned at the correct
38 * address and (s)dram will be positioned at address 0
39 */
40#include <config.h>
41#include <mpc8xx.h>
42#include <version.h>
43
44#define CONFIG_8xx 1 /* needed for Linux kernel header files */
45#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
46
47#include <ppc_asm.tmpl>
48#include <ppc_defs.h>
49
50#include <asm/cache.h>
51#include <asm/mmu.h>
52
53#ifndef CONFIG_IDENT_STRING
54#define CONFIG_IDENT_STRING ""
55#endif
56
57/* We don't want the MMU yet.
58*/
59#undef MSR_KERNEL
60#define MSR_KERNEL ( MSR_ME | MSR_RI ) /* Machine Check and Recoverable Interr. */
61
62/*
63 * Set up GOT: Global Offset Table
64 *
65 * Use r14 to access the GOT
66 */
67 START_GOT
68 GOT_ENTRY(_GOT2_TABLE_)
69 GOT_ENTRY(_FIXUP_TABLE_)
70
71 GOT_ENTRY(_start)
72 GOT_ENTRY(_start_of_vectors)
73 GOT_ENTRY(_end_of_vectors)
74 GOT_ENTRY(transfer_to_handler)
75
wdenkb9a83a92003-05-30 12:48:29 +000076 GOT_ENTRY(__init_end)
wdenk5b1d7132002-11-03 00:07:02 +000077 GOT_ENTRY(_end)
wdenkbf2f8c92003-05-22 22:52:13 +000078 GOT_ENTRY(__bss_start)
wdenk5b1d7132002-11-03 00:07:02 +000079#if defined(CONFIG_FADS) || defined(CONFIG_ICU862)
80 GOT_ENTRY(environment)
81#endif
82 END_GOT
83
84/*
85 * r3 - 1st arg to board_init(): IMMP pointer
86 * r4 - 2nd arg to board_init(): boot flag
87 */
88 .text
89 .long 0x27051956 /* U-Boot Magic Number */
90 .globl version_string
91version_string:
92 .ascii U_BOOT_VERSION
93 .ascii " (", __DATE__, " - ", __TIME__, ")"
94 .ascii CONFIG_IDENT_STRING, "\0"
95
96 . = EXC_OFF_SYS_RESET
97 .globl _start
98_start:
99 lis r3, CFG_IMMR@h /* position IMMR */
100 mtspr 638, r3
101 li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH */
102 b boot_cold
103
104 . = EXC_OFF_SYS_RESET + 0x10
105
106 .globl _start_warm
107_start_warm:
108 li r21, BOOTFLAG_WARM /* Software reboot */
109 b boot_warm
110
111boot_cold:
112boot_warm:
113
114 /* Initialize machine status; enable machine check interrupt */
115 /*----------------------------------------------------------------------*/
116 li r3, MSR_KERNEL /* Set ME, RI flags */
117 mtmsr r3
118 mtspr SRR1, r3 /* Make SRR1 match MSR */
119
120 mfspr r3, ICR /* clear Interrupt Cause Register */
121
122 /* Initialize debug port registers */
123 /*----------------------------------------------------------------------*/
124 xor r0, r0, r0 /* Clear R0 */
125 mtspr LCTRL1, r0 /* Initialize debug port regs */
126 mtspr LCTRL2, r0
127 mtspr COUNTA, r0
128 mtspr COUNTB, r0
129
130 /* Reset the caches */
131 /*----------------------------------------------------------------------*/
132
133 mfspr r3, IC_CST /* Clear error bits */
134 mfspr r3, DC_CST
135
136 lis r3, IDC_UNALL@h /* Unlock all */
137 mtspr IC_CST, r3
138 mtspr DC_CST, r3
139
140 lis r3, IDC_INVALL@h /* Invalidate all */
141 mtspr IC_CST, r3
142 mtspr DC_CST, r3
143
144 lis r3, IDC_DISABLE@h /* Disable data cache */
145 mtspr DC_CST, r3
146
147#if !(defined(CONFIG_IP860) || defined(CONFIG_PCU_E) || defined (CONFIG_FLAGADM))
148 /* On IP860 and PCU E,
149 * we cannot enable IC yet
150 */
151 lis r3, IDC_ENABLE@h /* Enable instruction cache */
152#endif
153 mtspr IC_CST, r3
154
155 /* invalidate all tlb's */
156 /*----------------------------------------------------------------------*/
157
158 tlbia
159 isync
160
161 /*
162 * Calculate absolute address in FLASH and jump there
163 *----------------------------------------------------------------------*/
164
165 lis r3, CFG_MONITOR_BASE@h
166 ori r3, r3, CFG_MONITOR_BASE@l
167 addi r3, r3, in_flash - _start + EXC_OFF_SYS_RESET
168 mtlr r3
169 blr
170
171in_flash:
172
173 /* initialize some SPRs that are hard to access from C */
174 /*----------------------------------------------------------------------*/
175
176 lis r3, CFG_IMMR@h /* pass IMMR as arg1 to C routine */
177 ori r1, r3, CFG_INIT_SP_OFFSET /* set up the stack in internal DPRAM */
178 /* Note: R0 is still 0 here */
179 stwu r0, -4(r1) /* clear final stack frame so that */
180 stwu r0, -4(r1) /* stack backtraces terminate cleanly */
181
182 /*
183 * Disable serialized ifetch and show cycles
184 * (i.e. set processor to normal mode).
185 * This is also a silicon bug workaround, see errata
186 */
187
188 li r2, 0x0007
189 mtspr ICTRL, r2
190
191 /* Set up debug mode entry */
192
193 lis r2, CFG_DER@h
194 ori r2, r2, CFG_DER@l
195 mtspr DER, r2
196
197 /* let the C-code set up the rest */
198 /* */
199 /* Be careful to keep code relocatable ! */
200 /*----------------------------------------------------------------------*/
201
202 GET_GOT /* initialize GOT access */
203
204 /* r3: IMMR */
205 bl cpu_init_f /* run low-level CPU init code (from Flash) */
206
207 mr r3, r21
208 /* r3: BOOTFLAG */
209 bl board_init_f /* run 1st part of board init code (from Flash) */
210
211
212
213 .globl _start_of_vectors
214_start_of_vectors:
215
216/* Machine check */
217 STD_EXCEPTION(0x200, MachineCheck, MachineCheckException)
218
219/* Data Storage exception. "Never" generated on the 860. */
220 STD_EXCEPTION(0x300, DataStorage, UnknownException)
221
222/* Instruction Storage exception. "Never" generated on the 860. */
223 STD_EXCEPTION(0x400, InstStorage, UnknownException)
224
225/* External Interrupt exception. */
226 STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt)
227
228/* Alignment exception. */
229 . = 0x600
230Alignment:
231 EXCEPTION_PROLOG
232 mfspr r4,DAR
233 stw r4,_DAR(r21)
234 mfspr r5,DSISR
235 stw r5,_DSISR(r21)
236 addi r3,r1,STACK_FRAME_OVERHEAD
237 li r20,MSR_KERNEL
238 rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
239 lwz r6,GOT(transfer_to_handler)
240 mtlr r6
241 blrl
242.L_Alignment:
243 .long AlignmentException - _start + EXC_OFF_SYS_RESET
244 .long int_return - _start + EXC_OFF_SYS_RESET
245
246/* Program check exception */
247 . = 0x700
248ProgramCheck:
249 EXCEPTION_PROLOG
250 addi r3,r1,STACK_FRAME_OVERHEAD
251 li r20,MSR_KERNEL
252 rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
253 lwz r6,GOT(transfer_to_handler)
254 mtlr r6
255 blrl
256.L_ProgramCheck:
257 .long ProgramCheckException - _start + EXC_OFF_SYS_RESET
258 .long int_return - _start + EXC_OFF_SYS_RESET
259
260 /* No FPU on MPC8xx. This exception is not supposed to happen.
261 */
262 STD_EXCEPTION(0x800, FPUnavailable, UnknownException)
263
264 /* I guess we could implement decrementer, and may have
265 * to someday for timekeeping.
266 */
267 STD_EXCEPTION(0x900, Decrementer, timer_interrupt)
268 STD_EXCEPTION(0xa00, Trap_0a, UnknownException)
269 STD_EXCEPTION(0xb00, Trap_0b, UnknownException)
270
271 . = 0xc00
272/*
273 * r0 - SYSCALL number
274 * r3-... arguments
275 */
276SystemCall:
277 addis r11,r0,0 /* get functions table addr */
278 ori r11,r11,0 /* Note: this code is patched in trap_init */
279 addis r12,r0,0 /* get number of functions */
280 ori r12,r12,0
281
282 cmplw 0, r0, r12
283 bge 1f
284
285 rlwinm r0,r0,2,0,31 /* fn_addr = fn_tbl[r0] */
286 add r11,r11,r0
287 lwz r11,0(r11)
288
wdenkbb444c92002-12-07 00:20:59 +0000289 li r20,0xd00-4 /* Get stack pointer */
290 lwz r12,0(r20)
291 subi r12,r12,12 /* Adjust stack pointer */
292 li r0,0xc00+_end_back-SystemCall
293 cmplw 0, r0, r12 /* Check stack overflow */
294 bgt 1f
295 stw r12,0(r20)
296
wdenk5b1d7132002-11-03 00:07:02 +0000297 mflr r0
298 stw r0,0(r12)
299 mfspr r0,SRR0
300 stw r0,4(r12)
301 mfspr r0,SRR1
302 stw r0,8(r12)
303
304 li r12,0xc00+_back-SystemCall
305 mtlr r12
306 mtspr SRR0,r11
307
3081: SYNC
309 rfi
310
311_back:
312
313 mfmsr r11 /* Disable interrupts */
314 li r12,0
315 ori r12,r12,MSR_EE
316 andc r11,r11,r12
317 SYNC /* Some chip revs need this... */
318 mtmsr r11
319 SYNC
320
wdenkbb444c92002-12-07 00:20:59 +0000321 li r12,0xd00-4 /* restore regs */
322 lwz r12,0(r12)
323
wdenk5b1d7132002-11-03 00:07:02 +0000324 lwz r11,0(r12)
325 mtlr r11
326 lwz r11,4(r12)
327 mtspr SRR0,r11
328 lwz r11,8(r12)
329 mtspr SRR1,r11
330
wdenkbb444c92002-12-07 00:20:59 +0000331 addi r12,r12,12 /* Adjust stack pointer */
332 li r20,0xd00-4
333 stw r12,0(r20)
334
wdenk5b1d7132002-11-03 00:07:02 +0000335 SYNC
336 rfi
wdenkbb444c92002-12-07 00:20:59 +0000337_end_back:
wdenk5b1d7132002-11-03 00:07:02 +0000338
339 STD_EXCEPTION(0xd00, SingleStep, UnknownException)
340
341 STD_EXCEPTION(0xe00, Trap_0e, UnknownException)
342 STD_EXCEPTION(0xf00, Trap_0f, UnknownException)
343
344 /* On the MPC8xx, this is a software emulation interrupt. It occurs
345 * for all unimplemented and illegal instructions.
346 */
347 STD_EXCEPTION(0x1000, SoftEmu, SoftEmuException)
348
349 STD_EXCEPTION(0x1100, InstructionTLBMiss, UnknownException)
350 STD_EXCEPTION(0x1200, DataTLBMiss, UnknownException)
351 STD_EXCEPTION(0x1300, InstructionTLBError, UnknownException)
352 STD_EXCEPTION(0x1400, DataTLBError, UnknownException)
353
354 STD_EXCEPTION(0x1500, Reserved5, UnknownException)
355 STD_EXCEPTION(0x1600, Reserved6, UnknownException)
356 STD_EXCEPTION(0x1700, Reserved7, UnknownException)
357 STD_EXCEPTION(0x1800, Reserved8, UnknownException)
358 STD_EXCEPTION(0x1900, Reserved9, UnknownException)
359 STD_EXCEPTION(0x1a00, ReservedA, UnknownException)
360 STD_EXCEPTION(0x1b00, ReservedB, UnknownException)
361
362 STD_EXCEPTION(0x1c00, DataBreakpoint, UnknownException)
363 STD_EXCEPTION(0x1d00, InstructionBreakpoint, DebugException)
364 STD_EXCEPTION(0x1e00, PeripheralBreakpoint, UnknownException)
365 STD_EXCEPTION(0x1f00, DevPortBreakpoint, UnknownException)
366
367
368 .globl _end_of_vectors
369_end_of_vectors:
370
371
372 . = 0x2000
373
374/*
375 * This code finishes saving the registers to the exception frame
376 * and jumps to the appropriate handler for the exception.
377 * Register r21 is pointer into trap frame, r1 has new stack pointer.
378 */
379 .globl transfer_to_handler
380transfer_to_handler:
381 stw r22,_NIP(r21)
382 lis r22,MSR_POW@h
383 andc r23,r23,r22
384 stw r23,_MSR(r21)
385 SAVE_GPR(7, r21)
386 SAVE_4GPRS(8, r21)
387 SAVE_8GPRS(12, r21)
388 SAVE_8GPRS(24, r21)
389 mflr r23
390 andi. r24,r23,0x3f00 /* get vector offset */
391 stw r24,TRAP(r21)
392 li r22,0
393 stw r22,RESULT(r21)
394 mtspr SPRG2,r22 /* r1 is now kernel sp */
395 lwz r24,0(r23) /* virtual address of handler */
396 lwz r23,4(r23) /* where to go when done */
397 mtspr SRR0,r24
398 mtspr SRR1,r20
399 mtlr r23
400 SYNC
401 rfi /* jump to handler, enable MMU */
402
403int_return:
404 mfmsr r28 /* Disable interrupts */
405 li r4,0
406 ori r4,r4,MSR_EE
407 andc r28,r28,r4
408 SYNC /* Some chip revs need this... */
409 mtmsr r28
410 SYNC
411 lwz r2,_CTR(r1)
412 lwz r0,_LINK(r1)
413 mtctr r2
414 mtlr r0
415 lwz r2,_XER(r1)
416 lwz r0,_CCR(r1)
417 mtspr XER,r2
418 mtcrf 0xFF,r0
419 REST_10GPRS(3, r1)
420 REST_10GPRS(13, r1)
421 REST_8GPRS(23, r1)
422 REST_GPR(31, r1)
423 lwz r2,_NIP(r1) /* Restore environment */
424 lwz r0,_MSR(r1)
425 mtspr SRR0,r2
426 mtspr SRR1,r0
427 lwz r0,GPR0(r1)
428 lwz r2,GPR2(r1)
429 lwz r1,GPR1(r1)
430 SYNC
431 rfi
432
433/* Cache functions.
434*/
435 .globl icache_enable
436icache_enable:
437 SYNC
438 lis r3, IDC_INVALL@h
439 mtspr IC_CST, r3
440 lis r3, IDC_ENABLE@h
441 mtspr IC_CST, r3
442 blr
443
444 .globl icache_disable
445icache_disable:
446 SYNC
447 lis r3, IDC_DISABLE@h
448 mtspr IC_CST, r3
449 blr
450
451 .globl icache_status
452icache_status:
453 mfspr r3, IC_CST
454 srwi r3, r3, 31 /* >>31 => select bit 0 */
455 blr
456
457 .globl dcache_enable
458dcache_enable:
459#if 0
460 SYNC
461#endif
462#if 1
463 lis r3, 0x0400 /* Set cache mode with MMU off */
464 mtspr MD_CTR, r3
465#endif
466
467 lis r3, IDC_INVALL@h
468 mtspr DC_CST, r3
469#if 0
470 lis r3, DC_SFWT@h
471 mtspr DC_CST, r3
472#endif
473 lis r3, IDC_ENABLE@h
474 mtspr DC_CST, r3
475 blr
476
477 .globl dcache_disable
478dcache_disable:
479 SYNC
480 lis r3, IDC_DISABLE@h
481 mtspr DC_CST, r3
482 lis r3, IDC_INVALL@h
483 mtspr DC_CST, r3
484 blr
485
486 .globl dcache_status
487dcache_status:
488 mfspr r3, DC_CST
489 srwi r3, r3, 31 /* >>31 => select bit 0 */
490 blr
491
492 .globl dc_read
493dc_read:
494 mtspr DC_ADR, r3
495 mfspr r3, DC_DAT
496 blr
497
498/*
499 * unsigned int get_immr (unsigned int mask)
500 *
501 * return (mask ? (IMMR & mask) : IMMR);
502 */
503 .globl get_immr
504get_immr:
505 mr r4,r3 /* save mask */
506 mfspr r3, IMMR /* IMMR */
507 cmpwi 0,r4,0 /* mask != 0 ? */
508 beq 4f
509 and r3,r3,r4 /* IMMR & mask */
5104:
511 blr
512
513 .globl get_pvr
514get_pvr:
515 mfspr r3, PVR
516 blr
517
518
519 .globl wr_ic_cst
520wr_ic_cst:
521 mtspr IC_CST, r3
522 blr
523
524 .globl rd_ic_cst
525rd_ic_cst:
526 mfspr r3, IC_CST
527 blr
528
529 .globl wr_ic_adr
530wr_ic_adr:
531 mtspr IC_ADR, r3
532 blr
533
534
535 .globl wr_dc_cst
536wr_dc_cst:
537 mtspr DC_CST, r3
538 blr
539
540 .globl rd_dc_cst
541rd_dc_cst:
542 mfspr r3, DC_CST
543 blr
544
545 .globl wr_dc_adr
546wr_dc_adr:
547 mtspr DC_ADR, r3
548 blr
549
550/*------------------------------------------------------------------------------*/
551
552/*
553 * void relocate_code (addr_sp, gd, addr_moni)
554 *
555 * This "function" does not return, instead it continues in RAM
556 * after relocating the monitor code.
557 *
558 * r3 = dest
559 * r4 = src
560 * r5 = length in bytes
561 * r6 = cachelinesize
562 */
563 .globl relocate_code
564relocate_code:
565 mr r1, r3 /* Set new stack pointer */
566 mr r9, r4 /* Save copy of Global Data pointer */
567 mr r10, r5 /* Save copy of Destination Address */
568
569 mr r3, r5 /* Destination Address */
570 lis r4, CFG_MONITOR_BASE@h /* Source Address */
571 ori r4, r4, CFG_MONITOR_BASE@l
wdenkb9a83a92003-05-30 12:48:29 +0000572 lwz r5, GOT(__init_end)
573 sub r5, r5, r4
wdenk5b1d7132002-11-03 00:07:02 +0000574 li r6, CFG_CACHELINE_SIZE /* Cache Line Size */
575
576 /*
577 * Fix GOT pointer:
578 *
579 * New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address
580 *
581 * Offset:
582 */
583 sub r15, r10, r4
584
585 /* First our own GOT */
586 add r14, r14, r15
wdenke7f34c62003-01-11 09:48:40 +0000587 /* then the one used by the C code */
wdenk5b1d7132002-11-03 00:07:02 +0000588 add r30, r30, r15
589
590 /*
591 * Now relocate code
592 */
593
594 cmplw cr1,r3,r4
595 addi r0,r5,3
596 srwi. r0,r0,2
597 beq cr1,4f /* In place copy is not necessary */
598 beq 7f /* Protect against 0 count */
599 mtctr r0
600 bge cr1,2f
601
602 la r8,-4(r4)
603 la r7,-4(r3)
6041: lwzu r0,4(r8)
605 stwu r0,4(r7)
606 bdnz 1b
607 b 4f
608
6092: slwi r0,r0,2
610 add r8,r4,r0
611 add r7,r3,r0
6123: lwzu r0,-4(r8)
613 stwu r0,-4(r7)
614 bdnz 3b
615
616/*
617 * Now flush the cache: note that we must start from a cache aligned
618 * address. Otherwise we might miss one cache line.
619 */
6204: cmpwi r6,0
621 add r5,r3,r5
622 beq 7f /* Always flush prefetch queue in any case */
623 subi r0,r6,1
624 andc r3,r3,r0
625 mr r4,r3
6265: dcbst 0,r4
627 add r4,r4,r6
628 cmplw r4,r5
629 blt 5b
630 sync /* Wait for all dcbst to complete on bus */
631 mr r4,r3
6326: icbi 0,r4
633 add r4,r4,r6
634 cmplw r4,r5
635 blt 6b
6367: sync /* Wait for all icbi to complete on bus */
637 isync
638
639/*
640 * We are done. Do not return, instead branch to second part of board
641 * initialization, now running from RAM.
642 */
643
644 addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET
645 mtlr r0
646 blr
647
648in_ram:
649
650 /*
651 * Relocation Function, r14 point to got2+0x8000
652 *
653 * Adjust got2 pointers, no need to check for 0, this code
654 * already puts a few entries in the table.
655 */
656 li r0,__got2_entries@sectoff@l
657 la r3,GOT(_GOT2_TABLE_)
658 lwz r11,GOT(_GOT2_TABLE_)
659 mtctr r0
660 sub r11,r3,r11
661 addi r3,r3,-4
6621: lwzu r0,4(r3)
663 add r0,r0,r11
664 stw r0,0(r3)
665 bdnz 1b
666
667 /*
668 * Now adjust the fixups and the pointers to the fixups
669 * in case we need to move ourselves again.
670 */
6712: li r0,__fixup_entries@sectoff@l
672 lwz r3,GOT(_FIXUP_TABLE_)
673 cmpwi r0,0
674 mtctr r0
675 addi r3,r3,-4
676 beq 4f
6773: lwzu r4,4(r3)
678 lwzux r0,r4,r11
679 add r0,r0,r11
680 stw r10,0(r3)
681 stw r0,0(r4)
682 bdnz 3b
6834:
684clear_bss:
685 /*
686 * Now clear BSS segment
687 */
wdenkbf2f8c92003-05-22 22:52:13 +0000688 lwz r3,GOT(__bss_start)
wdenk5b1d7132002-11-03 00:07:02 +0000689#if defined(CONFIG_FADS) || defined(CONFIG_ICU862)
690 /*
691 * For the FADS - the environment is the very last item in flash.
692 * The real .bss stops just before environment starts, so only
693 * clear up to that point.
694 */
695 lwz r4,GOT(environment)
696#else
697 lwz r4,GOT(_end)
698#endif
699
700 cmplw 0, r3, r4
701 beq 6f
702
703 li r0, 0
7045:
705 stw r0, 0(r3)
706 addi r3, r3, 4
707 cmplw 0, r3, r4
708 bne 5b
7096:
710
711 mr r3, r9 /* Global Data pointer */
712 mr r4, r10 /* Destination Address */
713 bl board_init_r
714
wdenk5b1d7132002-11-03 00:07:02 +0000715 /*
716 * Copy exception vector code to low memory
717 *
718 * r3: dest_addr
719 * r7: source address, r8: end address, r9: target address
720 */
721 .globl trap_init
722trap_init:
723 lwz r7, GOT(_start)
724 lwz r8, GOT(_end_of_vectors)
725
726 rlwinm r9, r7, 0, 22, 31 /* _start & 0x3FF */
727
728 cmplw 0, r7, r8
729 bgelr /* return if r7>=r8 - just in case */
730
731 mflr r4 /* save link register */
7321:
733 lwz r0, 0(r7)
734 stw r0, 0(r9)
735 addi r7, r7, 4
736 addi r9, r9, 4
737 cmplw 0, r7, r8
738 bne 1b
739
740 /*
741 * relocate `hdlr' and `int_return' entries
742 */
743 li r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET
744 li r8, Alignment - _start + EXC_OFF_SYS_RESET
7452:
746 bl trap_reloc
747 addi r7, r7, 0x100 /* next exception vector */
748 cmplw 0, r7, r8
749 blt 2b
750
751 li r7, .L_Alignment - _start + EXC_OFF_SYS_RESET
752 bl trap_reloc
753
754 li r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET
755 bl trap_reloc
756
757 li r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET
758 li r8, SystemCall - _start + EXC_OFF_SYS_RESET
7593:
760 bl trap_reloc
761 addi r7, r7, 0x100 /* next exception vector */
762 cmplw 0, r7, r8
763 blt 3b
764
765 li r7, .L_SingleStep - _start + EXC_OFF_SYS_RESET
766 li r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET
7674:
768 bl trap_reloc
769 addi r7, r7, 0x100 /* next exception vector */
770 cmplw 0, r7, r8
771 blt 4b
772
773 mtlr r4 /* restore link register */
774 blr
775
776 /*
777 * Function: relocate entries for one exception vector
778 */
779trap_reloc:
780 lwz r0, 0(r7) /* hdlr ... */
781 add r0, r0, r3 /* ... += dest_addr */
782 stw r0, 0(r7)
783
784 lwz r0, 4(r7) /* int_return ... */
785 add r0, r0, r3 /* ... += dest_addr */
786 stw r0, 4(r7)
787
788 sync
789 isync
790
791 blr