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1/*
2 * armboot - Startup Code for ARM920 CPU-core
3 *
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4 * Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
5 * Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
792a09eb 6 * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
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7 *
8 * See file CREDITS for list of people who contributed to this
9 * project.
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 of
14 * the License, or (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
24 * MA 02111-1307 USA
25 */
26
25ddd1fb 27#include <asm-offsets.h>
9689ddcc 28#include <common.h>
fe8c2806 29#include <config.h>
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30
31/*
32 *************************************************************************
33 *
34 * Jump vector table as in table 3.1 in [1]
35 *
36 *************************************************************************
37 */
38
39
40.globl _start
d67cce2d 41_start: b start_code
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42 ldr pc, _undefined_instruction
43 ldr pc, _software_interrupt
44 ldr pc, _prefetch_abort
45 ldr pc, _data_abort
46 ldr pc, _not_used
47 ldr pc, _irq
48 ldr pc, _fiq
49
50_undefined_instruction: .word undefined_instruction
51_software_interrupt: .word software_interrupt
52_prefetch_abort: .word prefetch_abort
53_data_abort: .word data_abort
54_not_used: .word not_used
55_irq: .word irq
56_fiq: .word fiq
57
58 .balignl 16,0xdeadbeef
59
60
61/*
62 *************************************************************************
63 *
80767a6c 64 * Startup Code (called from the ARM reset exception vector)
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65 *
66 * do important init only if we don't start from memory!
67 * relocate armboot to ram
68 * setup stack
69 * jump to second stage
70 *
71 *************************************************************************
72 */
73
cc7cdcbd 74.globl _TEXT_BASE
fe8c2806 75_TEXT_BASE:
14d0a02a 76 .word CONFIG_SYS_TEXT_BASE
fe8c2806 77
fe8c2806 78/*
f6e20fc6 79 * These are defined in the board-specific linker script.
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80 * Subtracting _start from them lets the linker put their
81 * relative position in the executable instead of leaving
82 * them null.
fe8c2806 83 */
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84.globl _bss_start_ofs
85_bss_start_ofs:
86 .word __bss_start - _start
f6e20fc6 87
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88.globl _bss_end_ofs
89_bss_end_ofs:
44c6e659 90 .word __bss_end__ - _start
fe8c2806 91
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92.globl _end_ofs
93_end_ofs:
94 .word _end - _start
95
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96#ifdef CONFIG_USE_IRQ
97/* IRQ stack memory (calculated at run-time) */
98.globl IRQ_STACK_START
99IRQ_STACK_START:
100 .word 0x0badc0de
101
102/* IRQ stack memory (calculated at run-time) */
103.globl FIQ_STACK_START
104FIQ_STACK_START:
105 .word 0x0badc0de
106#endif
107
cc7cdcbd
HS
108/* IRQ stack memory (calculated at run-time) + 8 bytes */
109.globl IRQ_STACK_START_IN
110IRQ_STACK_START_IN:
111 .word 0x0badc0de
112
fe8c2806 113/*
80767a6c 114 * the actual start code
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115 */
116
80767a6c 117start_code:
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118 /*
119 * set the cpu to SVC32 mode
120 */
d67cce2d 121 mrs r0, cpsr
122 bic r0, r0, #0x1f
123 orr r0, r0, #0xd3
124 msr cpsr, r0
80767a6c 125
ed3b18e0 126#if defined(CONFIG_AT91RM9200DK) || defined(CONFIG_AT91RM9200EK)
d4fc6012 127 /*
80767a6c 128 * relocate exception table
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129 */
130 ldr r0, =_start
131 ldr r1, =0x0
132 mov r2, #16
133copyex:
134 subs r2, r2, #1
135 ldr r3, [r0], #4
136 str r3, [r1], #4
137 bne copyex
138#endif
139
ac67804f 140#ifdef CONFIG_S3C24X0
80767a6c
PP
141 /* turn off the watchdog */
142
143# if defined(CONFIG_S3C2400)
d67cce2d 144# define pWTCON 0x15300000
16263087 145# define INTMSK 0x14400008 /* Interrupt-Controller base addresses */
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146# define CLKDIVN 0x14800014 /* clock divisor register */
147#else
d67cce2d 148# define pWTCON 0x53000000
16263087 149# define INTMSK 0x4A000008 /* Interrupt-Controller base addresses */
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150# define INTSUBMSK 0x4A00001C
151# define CLKDIVN 0x4C000014 /* clock divisor register */
152# endif
153
d67cce2d 154 ldr r0, =pWTCON
155 mov r1, #0x0
156 str r1, [r0]
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157
158 /*
159 * mask all IRQs by setting all bits in the INTMR - default
160 */
161 mov r1, #0xffffffff
162 ldr r0, =INTMSK
163 str r1, [r0]
281e00a3 164# if defined(CONFIG_S3C2410)
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165 ldr r1, =0x3ff
166 ldr r0, =INTSUBMSK
167 str r1, [r0]
281e00a3 168# endif
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169
170 /* FCLK:HCLK:PCLK = 1:2:4 */
171 /* default FCLK is 120 MHz ! */
172 ldr r0, =CLKDIVN
173 mov r1, #3
174 str r1, [r0]
ac67804f 175#endif /* CONFIG_S3C24X0 */
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176
177 /*
178 * we do sys-critical inits only at reboot,
179 * not when booting from ram!
180 */
8aa1a2d1 181#ifndef CONFIG_SKIP_LOWLEVEL_INIT
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182 bl cpu_init_crit
183#endif
184
cc7cdcbd
HS
185/* Set stackpointer in internal RAM to call board_init_f */
186call_board_init_f:
187 ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
296cae73 188 bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
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189 ldr r0,=0x00000000
190 bl board_init_f
191
192/*------------------------------------------------------------------------------*/
193
194/*
195 * void relocate_code (addr_sp, gd, addr_moni)
196 *
197 * This "function" does not return, instead it continues in RAM
198 * after relocating the monitor code.
199 *
200 */
201 .globl relocate_code
202relocate_code:
203 mov r4, r0 /* save addr_sp */
204 mov r5, r1 /* save addr of gd */
205 mov r6, r2 /* save addr of destination */
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206
207 /* Set up the stack */
208stack_setup:
209 mov sp, r4
210
211 adr r0, _start
a1a47d3c 212 cmp r0, r6
76abfa57 213 moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */
a1a47d3c 214 beq clear_bss /* skip relocation */
a78fb68f 215 mov r1, r6 /* r1 <- scratch for copy_loop */
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216 ldr r3, _bss_start_ofs
217 add r2, r0, r3 /* r2 <- source end address */
cc7cdcbd 218
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219copy_loop:
220 ldmia r0!, {r9-r10} /* copy from source address [r0] */
a78fb68f 221 stmia r1!, {r9-r10} /* copy to target address [r1] */
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222 cmp r0, r2 /* until source end address [r2] */
223 blo copy_loop
cc7cdcbd 224
401bb30b 225#ifndef CONFIG_SPL_BUILD
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226 /*
227 * fix .rel.dyn relocations
228 */
229 ldr r0, _TEXT_BASE /* r0 <- Text base */
a78fb68f 230 sub r9, r6, r0 /* r9 <- relocation offset */
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231 ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */
232 add r10, r10, r0 /* r10 <- sym table in FLASH */
233 ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */
234 add r2, r2, r0 /* r2 <- rel dyn start in FLASH */
235 ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */
236 add r3, r3, r0 /* r3 <- rel dyn end in FLASH */
cc7cdcbd 237fixloop:
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238 ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */
239 add r0, r0, r9 /* r0 <- location to fix up in RAM */
240 ldr r1, [r2, #4]
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241 and r7, r1, #0xff
242 cmp r7, #23 /* relative fixup? */
3336ca60 243 beq fixrel
1f52d89f 244 cmp r7, #2 /* absolute fixup? */
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245 beq fixabs
246 /* ignore unknown type of fixup */
247 b fixnext
248fixabs:
249 /* absolute fix: set location to (offset) symbol value */
250 mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */
251 add r1, r10, r1 /* r1 <- address of symbol in table */
252 ldr r1, [r1, #4] /* r1 <- symbol value */
3600945b 253 add r1, r1, r9 /* r1 <- relocated sym addr */
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254 b fixnext
255fixrel:
256 /* relative fix: increase location by offset */
257 ldr r1, [r0]
258 add r1, r1, r9
259fixnext:
260 str r1, [r0]
261 add r2, r2, #8 /* each rel.dyn entry is 8 bytes */
cc7cdcbd 262 cmp r2, r3
79e63139 263 blo fixloop
cc7cdcbd 264#endif
cc7cdcbd
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265
266clear_bss:
401bb30b 267#ifndef CONFIG_SPL_BUILD
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268 ldr r0, _bss_start_ofs
269 ldr r1, _bss_end_ofs
a78fb68f 270 mov r4, r6 /* reloc addr */
cc7cdcbd 271 add r0, r0, r4
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272 add r1, r1, r4
273 mov r2, #0x00000000 /* clear */
274
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275clbss_l:cmp r0, r1 /* clear loop... */
276 bhs clbss_e /* if reached end of bss, exit */
277 str r2, [r0]
cc7cdcbd 278 add r0, r0, #4
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279 b clbss_l
280clbss_e:
cc7cdcbd
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281
282 bl coloured_LED_init
2d3be7c4 283 bl red_led_on
cc7cdcbd
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284#endif
285
286/*
287 * We are done. Do not return, instead branch to second part of board
288 * initialization, now running from RAM.
289 */
290#ifdef CONFIG_NAND_SPL
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291 ldr r0, _nand_boot_ofs
292 mov pc, r0
cc7cdcbd 293
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294_nand_boot_ofs:
295 .word nand_boot
cc7cdcbd 296#else
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297 ldr r0, _board_init_r_ofs
298 adr r1, _start
299 add lr, r0, r1
300 add lr, lr, r9
cc7cdcbd
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301 /* setup parameters for board_init_r */
302 mov r0, r5 /* gd_t */
a78fb68f 303 mov r1, r6 /* dest_addr */
cc7cdcbd 304 /* jump to it ... */
cc7cdcbd
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305 mov pc, lr
306
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307_board_init_r_ofs:
308 .word board_init_r - _start
cc7cdcbd
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309#endif
310
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311_rel_dyn_start_ofs:
312 .word __rel_dyn_start - _start
313_rel_dyn_end_ofs:
314 .word __rel_dyn_end - _start
315_dynsym_start_ofs:
316 .word __dynsym_start - _start
317
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318/*
319 *************************************************************************
320 *
321 * CPU_init_critical registers
322 *
323 * setup important registers
324 * setup memory timing
325 *
326 *************************************************************************
327 */
328
329
db28ddb4 330#ifndef CONFIG_SKIP_LOWLEVEL_INIT
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331cpu_init_crit:
332 /*
333 * flush v4 I/D caches
334 */
335 mov r0, #0
336 mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
337 mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
338
339 /*
340 * disable MMU stuff and caches
341 */
342 mrc p15, 0, r0, c1, c0, 0
343 bic r0, r0, #0x00002300 @ clear bits 13, 9:8 (--V- --RS)
344 bic r0, r0, #0x00000087 @ clear bits 7, 2:0 (B--- -CAM)
345 orr r0, r0, #0x00000002 @ set bit 2 (A) Align
346 orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache
347 mcr p15, 0, r0, c1, c0, 0
348
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349 /*
350 * before relocating, we have to setup RAM timing
351 * because memory timing is board-dependend, you will
400558b5 352 * find a lowlevel_init.S in your board directory.
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353 */
354 mov ip, lr
d4fc6012 355
400558b5 356 bl lowlevel_init
cb82a532 357
fe8c2806 358 mov lr, ip
fe8c2806 359 mov pc, lr
db28ddb4 360#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
fe8c2806 361
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362/*
363 *************************************************************************
364 *
365 * Interrupt handling
366 *
367 *************************************************************************
368 */
369
370@
371@ IRQ stack frame.
372@
373#define S_FRAME_SIZE 72
374
375#define S_OLD_R0 68
376#define S_PSR 64
377#define S_PC 60
378#define S_LR 56
379#define S_SP 52
380
381#define S_IP 48
382#define S_FP 44
383#define S_R10 40
384#define S_R9 36
385#define S_R8 32
386#define S_R7 28
387#define S_R6 24
388#define S_R5 20
389#define S_R4 16
390#define S_R3 12
391#define S_R2 8
392#define S_R1 4
393#define S_R0 0
394
d67cce2d 395#define MODE_SVC 0x13
396#define I_BIT 0x80
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397
398/*
399 * use bad_save_user_regs for abort/prefetch/undef/swi ...
400 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
401 */
402
403 .macro bad_save_user_regs
404 sub sp, sp, #S_FRAME_SIZE
405 stmia sp, {r0 - r12} @ Calling r0-r12
cc7cdcbd 406 ldr r2, IRQ_STACK_START_IN
f07771cc 407 ldmia r2, {r2 - r3} @ get pc, cpsr
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408 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
409
410 add r5, sp, #S_SP
411 mov r1, lr
f07771cc 412 stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
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413 mov r0, sp
414 .endm
415
416 .macro irq_save_user_regs
417 sub sp, sp, #S_FRAME_SIZE
418 stmia sp, {r0 - r12} @ Calling r0-r12
d67cce2d 419 add r7, sp, #S_PC
420 stmdb r7, {sp, lr}^ @ Calling SP, LR
421 str lr, [r7, #0] @ Save calling PC
422 mrs r6, spsr
423 str r6, [r7, #4] @ Save CPSR
424 str r0, [r7, #8] @ Save OLD_R0
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425 mov r0, sp
426 .endm
427
428 .macro irq_restore_user_regs
429 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
430 mov r0, r0
431 ldr lr, [sp, #S_PC] @ Get PC
432 add sp, sp, #S_FRAME_SIZE
d67cce2d 433 /* return & move spsr_svc into cpsr */
434 subs pc, lr, #4
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435 .endm
436
437 .macro get_bad_stack
cc7cdcbd 438 ldr r13, IRQ_STACK_START_IN @ setup our mode stack
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439
440 str lr, [r13] @ save caller lr / spsr
441 mrs lr, spsr
d67cce2d 442 str lr, [r13, #4]
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443
444 mov r13, #MODE_SVC @ prepare SVC-Mode
445 @ msr spsr_c, r13
446 msr spsr, r13
447 mov lr, pc
448 movs pc, lr
449 .endm
450
451 .macro get_irq_stack @ setup IRQ stack
452 ldr sp, IRQ_STACK_START
453 .endm
454
455 .macro get_fiq_stack @ setup FIQ stack
456 ldr sp, FIQ_STACK_START
457 .endm
458
459/*
460 * exception handlers
461 */
462 .align 5
463undefined_instruction:
464 get_bad_stack
465 bad_save_user_regs
53677ef1 466 bl do_undefined_instruction
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467
468 .align 5
469software_interrupt:
470 get_bad_stack
471 bad_save_user_regs
53677ef1 472 bl do_software_interrupt
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473
474 .align 5
475prefetch_abort:
476 get_bad_stack
477 bad_save_user_regs
53677ef1 478 bl do_prefetch_abort
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479
480 .align 5
481data_abort:
482 get_bad_stack
483 bad_save_user_regs
53677ef1 484 bl do_data_abort
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485
486 .align 5
487not_used:
488 get_bad_stack
489 bad_save_user_regs
53677ef1 490 bl do_not_used
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491
492#ifdef CONFIG_USE_IRQ
493
494 .align 5
495irq:
496 get_irq_stack
497 irq_save_user_regs
53677ef1 498 bl do_irq
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499 irq_restore_user_regs
500
501 .align 5
502fiq:
503 get_fiq_stack
504 /* someone ought to write a more effiction fiq_save_user_regs */
505 irq_save_user_regs
53677ef1 506 bl do_fiq
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507 irq_restore_user_regs
508
509#else
510
511 .align 5
512irq:
513 get_bad_stack
514 bad_save_user_regs
53677ef1 515 bl do_irq
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516
517 .align 5
518fiq:
519 get_bad_stack
520 bad_save_user_regs
53677ef1 521 bl do_fiq
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522
523#endif