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1/* vi: set ts=8 sw=8 noet: */
2/*
3 * u-boot - Startup Code for XScale IXP
4 *
5 * Copyright (C) 2003 Kyle Harris <kharris@nexus-tech.net>
6 *
7 * Based on startup code example contained in the
8 * Intel IXP4xx Programmer's Guide and past u-boot Start.S
9 * samples.
10 *
11 * See file CREDITS for list of people who contributed to this
12 * project.
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License as
16 * published by the Free Software Foundation; either version 2 of
17 * the License, or (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 * MA 02111-1307 USA
28 */
29
25ddd1fb 30#include <asm-offsets.h>
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31#include <config.h>
32#include <version.h>
33#include <asm/arch/ixp425.h>
34
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35#define MMU_Control_M 0x001 /* Enable MMU */
36#define MMU_Control_A 0x002 /* Enable address alignment faults */
37#define MMU_Control_C 0x004 /* Enable cache */
38#define MMU_Control_W 0x008 /* Enable write-buffer */
39#define MMU_Control_P 0x010 /* Compatability: 32 bit code */
40#define MMU_Control_D 0x020 /* Compatability: 32 bit data */
41#define MMU_Control_L 0x040 /* Compatability: */
42#define MMU_Control_B 0x080 /* Enable Big-Endian */
43#define MMU_Control_S 0x100 /* Enable system protection */
44#define MMU_Control_R 0x200 /* Enable ROM protection */
45#define MMU_Control_I 0x1000 /* Enable Instruction cache */
46#define MMU_Control_X 0x2000 /* Set interrupt vectors at 0xFFFF0000 */
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47#define MMU_Control_Init (MMU_Control_P|MMU_Control_D|MMU_Control_L)
48
49
50/*
51 * Macro definitions
52 */
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53 /* Delay a bit */
54 .macro DELAY_FOR cycles, reg0
55 ldr \reg0, =\cycles
56 subs \reg0, \reg0, #1
57 subne pc, pc, #0xc
58 .endm
59
60 /* wait for coprocessor write complete */
61 .macro CPWAIT reg
62 mrc p15,0,\reg,c2,c0,0
63 mov \reg,\reg
64 sub pc,pc,#4
65 .endm
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66
67.globl _start
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68_start:
69 ldr pc, _reset
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70 ldr pc, _undefined_instruction
71 ldr pc, _software_interrupt
72 ldr pc, _prefetch_abort
73 ldr pc, _data_abort
74 ldr pc, _not_used
75 ldr pc, _irq
76 ldr pc, _fiq
77
ce04bb41 78_reset: .word reset
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79_undefined_instruction: .word undefined_instruction
80_software_interrupt: .word software_interrupt
81_prefetch_abort: .word prefetch_abort
82_data_abort: .word data_abort
83_not_used: .word not_used
84_irq: .word irq
85_fiq: .word fiq
86
87 .balignl 16,0xdeadbeef
88
89
90/*
91 * Startup Code (reset vector)
92 *
93 * do important init only if we don't start from memory!
94 * - relocate armboot to ram
95 * - setup stack
96 * - jump to second stage
97 */
98
2af0a099 99.globl _TEXT_BASE
2d5b561e 100_TEXT_BASE:
14d0a02a 101 .word CONFIG_SYS_TEXT_BASE
2d5b561e 102
2d5b561e 103/*
f6e20fc6 104 * These are defined in the board-specific linker script.
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105 * Subtracting _start from them lets the linker put their
106 * relative position in the executable instead of leaving
107 * them null.
2d5b561e 108 */
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109.globl _bss_start_ofs
110_bss_start_ofs:
111 .word __bss_start - _start
2d5b561e 112
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113.globl _bss_end_ofs
114_bss_end_ofs:
44c6e659 115 .word __bss_end__ - _start
2d5b561e 116
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117.globl _end_ofs
118_end_ofs:
119 .word _end - _start
120
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121#ifdef CONFIG_USE_IRQ
122/* IRQ stack memory (calculated at run-time) */
123.globl IRQ_STACK_START
124IRQ_STACK_START:
125 .word 0x0badc0de
126
127/* IRQ stack memory (calculated at run-time) */
128.globl FIQ_STACK_START
129FIQ_STACK_START:
130 .word 0x0badc0de
131#endif
132
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133/* IRQ stack memory (calculated at run-time) + 8 bytes */
134.globl IRQ_STACK_START_IN
135IRQ_STACK_START_IN:
136 .word 0x0badc0de
137
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138/*
139 * the actual reset code
140 */
141
142reset:
143 /* disable mmu, set big-endian */
144 mov r0, #0xf8
145 mcr p15, 0, r0, c1, c0, 0
146 CPWAIT r0
147
148 /* invalidate I & D caches & BTB */
149 mcr p15, 0, r0, c7, c7, 0
150 CPWAIT r0
151
152 /* invalidate I & Data TLB */
153 mcr p15, 0, r0, c8, c7, 0
154 CPWAIT r0
155
156 /* drain write and fill buffers */
157 mcr p15, 0, r0, c7, c10, 4
158 CPWAIT r0
159
160 /* disable write buffer coalescing */
161 mrc p15, 0, r0, c1, c0, 1
162 orr r0, r0, #1
163 mcr p15, 0, r0, c1, c0, 1
164 CPWAIT r0
165
166 /* set EXP CS0 to the optimum timing */
167 ldr r1, =CONFIG_SYS_EXP_CS0
168 ldr r2, =IXP425_EXP_CS0
169 str r1, [r2]
170
171 /* make sure flash is visible at 0 */
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172 mov r1, #CONFIG_SYS_SDR_CONFIG
173 ldr r2, =IXP425_SDR_CONFIG
174 str r1, [r2]
175
176 /* disable refresh cycles */
177 mov r1, #0
178 ldr r3, =IXP425_SDR_REFRESH
179 str r1, [r3]
180
181 /* send nop command */
182 mov r1, #3
183 ldr r4, =IXP425_SDR_IR
184 str r1, [r4]
185 DELAY_FOR 0x4000, r0
186
187 /* set SDRAM internal refresh val */
188 ldr r1, =CONFIG_SYS_SDRAM_REFRESH_CNT
189 str r1, [r3]
190 DELAY_FOR 0x4000, r0
191
192 /* send precharge-all command to close all open banks */
193 mov r1, #2
194 str r1, [r4]
195 DELAY_FOR 0x4000, r0
196
197 /* provide 8 auto-refresh cycles */
198 mov r1, #4
199 mov r5, #8
200111: str r1, [r4]
201 DELAY_FOR 0x100, r0
202 subs r5, r5, #1
203 bne 111b
204
205 /* set mode register in sdram */
206 mov r1, #CONFIG_SYS_SDR_MODE_CONFIG
207 str r1, [r4]
208 DELAY_FOR 0x4000, r0
209
210 /* send normal operation command */
211 mov r1, #6
212 str r1, [r4]
213 DELAY_FOR 0x4000, r0
214
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215 /* invalidate I & D caches & BTB */
216 mcr p15, 0, r0, c7, c7, 0
217 CPWAIT r0
218
219 /* invalidate I & Data TLB */
220 mcr p15, 0, r0, c8, c7, 0
221 CPWAIT r0
222
223 /* drain write and fill buffers */
224 mcr p15, 0, r0, c7, c10, 4
225 CPWAIT r0
226
ce04bb41 227 /* remove flash mirror at 0x00000000 */
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228 ldr r2, =IXP425_EXP_CFG0
229 ldr r1, [r2]
230 bic r1, r1, #0x80000000
231 str r1, [r2]
232
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233 /* invalidate I & Data TLB */
234 mcr p15, 0, r0, c8, c7, 0
235 CPWAIT r0
236
237 /* enable I cache */
238 mrc p15, 0, r0, c1, c0, 0
239 orr r0, r0, #MMU_Control_I
240 mcr p15, 0, r0, c1, c0, 0
241 CPWAIT r0
242
243 mrs r0,cpsr /* set the cpu to SVC32 mode */
244 bic r0,r0,#0x1f /* (superviser mode, M=10011) */
245 orr r0,r0,#0x13
246 msr cpsr,r0
247
ce04bb41 248/* Set initial stackpointer in SDRAM to call board_init_f */
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249call_board_init_f:
250 ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
296cae73 251 bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
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252 ldr r0,=0x00000000
253 bl board_init_f
254
255/*------------------------------------------------------------------------------*/
256
257/*
258 * void relocate_code (addr_sp, gd, addr_moni)
259 *
260 * This "function" does not return, instead it continues in RAM
261 * after relocating the monitor code.
262 *
263 */
264 .globl relocate_code
265relocate_code:
266 mov r4, r0 /* save addr_sp */
267 mov r5, r1 /* save addr of gd */
268 mov r6, r2 /* save addr of destination */
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269
270 /* Set up the stack */
271stack_setup:
272 mov sp, r4
273
274 adr r0, _start
a1a47d3c 275 cmp r0, r6
76abfa57 276 moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */
a1a47d3c 277 beq clear_bss /* skip relocation */
a78fb68f 278 mov r1, r6 /* r1 <- scratch for copy_loop */
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279 ldr r3, _bss_start_ofs
280 add r2, r0, r3 /* r2 <- source end address */
2af0a099 281
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282copy_loop:
283 ldmia r0!, {r9-r10} /* copy from source address [r0] */
a78fb68f 284 stmia r1!, {r9-r10} /* copy to target address [r1] */
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285 cmp r0, r2 /* until source end address [r2] */
286 blo copy_loop
2af0a099 287
401bb30b 288#ifndef CONFIG_SPL_BUILD
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289 /*
290 * fix .rel.dyn relocations
291 */
292 ldr r0, _TEXT_BASE /* r0 <- Text base */
a78fb68f 293 sub r9, r6, r0 /* r9 <- relocation offset */
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294 ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */
295 add r10, r10, r0 /* r10 <- sym table in FLASH */
296 ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */
297 add r2, r2, r0 /* r2 <- rel dyn start in FLASH */
298 ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */
299 add r3, r3, r0 /* r3 <- rel dyn end in FLASH */
2af0a099 300fixloop:
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301 ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */
302 add r0, r0, r9 /* r0 <- location to fix up in RAM */
303 ldr r1, [r2, #4]
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304 and r7, r1, #0xff
305 cmp r7, #23 /* relative fixup? */
3336ca60 306 beq fixrel
1f52d89f 307 cmp r7, #2 /* absolute fixup? */
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308 beq fixabs
309 /* ignore unknown type of fixup */
310 b fixnext
311fixabs:
312 /* absolute fix: set location to (offset) symbol value */
313 mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */
314 add r1, r10, r1 /* r1 <- address of symbol in table */
315 ldr r1, [r1, #4] /* r1 <- symbol value */
3600945b 316 add r1, r1, r9 /* r1 <- relocated sym addr */
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317 b fixnext
318fixrel:
319 /* relative fix: increase location by offset */
320 ldr r1, [r0]
321 add r1, r1, r9
322fixnext:
323 str r1, [r0]
324 add r2, r2, #8 /* each rel.dyn entry is 8 bytes */
2af0a099 325 cmp r2, r3
79e63139 326 blo fixloop
2af0a099 327#endif
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328
329clear_bss:
401bb30b 330#ifndef CONFIG_SPL_BUILD
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331 ldr r0, _bss_start_ofs
332 ldr r1, _bss_end_ofs
a78fb68f 333 mov r4, r6 /* reloc addr */
2af0a099 334 add r0, r0, r4
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335 add r1, r1, r4
336 mov r2, #0x00000000 /* clear */
337
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338clbss_l:cmp r0, r1 /* clear loop... */
339 bhs clbss_e /* if reached end of bss, exit */
340 str r2, [r0]
2af0a099 341 add r0, r0, #4
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342 b clbss_l
343clbss_e:
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344
345 bl coloured_LED_init
2d3be7c4 346 bl red_led_on
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347#endif
348
349/*
350 * We are done. Do not return, instead branch to second part of board
351 * initialization, now running from RAM.
352 */
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353 ldr r0, _board_init_r_ofs
354 adr r1, _start
355 add lr, r0, r1
356 add lr, lr, r9
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357 /* setup parameters for board_init_r */
358 mov r0, r5 /* gd_t */
a78fb68f 359 mov r1, r6 /* dest_addr */
2af0a099 360 /* jump to it ... */
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361 mov pc, lr
362
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363_board_init_r_ofs:
364 .word board_init_r - _start
2af0a099 365
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366_rel_dyn_start_ofs:
367 .word __rel_dyn_start - _start
368_rel_dyn_end_ofs:
369 .word __rel_dyn_end - _start
370_dynsym_start_ofs:
371 .word __dynsym_start - _start
2d5b561e 372
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373/****************************************************************************/
374/* */
375/* Interrupt handling */
376/* */
377/****************************************************************************/
378
379/* IRQ stack frame */
380
381#define S_FRAME_SIZE 72
382
383#define S_OLD_R0 68
384#define S_PSR 64
385#define S_PC 60
386#define S_LR 56
387#define S_SP 52
388
389#define S_IP 48
390#define S_FP 44
391#define S_R10 40
392#define S_R9 36
393#define S_R8 32
394#define S_R7 28
395#define S_R6 24
396#define S_R5 20
397#define S_R4 16
398#define S_R3 12
399#define S_R2 8
400#define S_R1 4
401#define S_R0 0
402
403#define MODE_SVC 0x13
404
405 /* use bad_save_user_regs for abort/prefetch/undef/swi ... */
406
407 .macro bad_save_user_regs
408 sub sp, sp, #S_FRAME_SIZE
409 stmia sp, {r0 - r12} /* Calling r0-r12 */
410 add r8, sp, #S_PC
411
2af0a099 412 ldr r2, IRQ_STACK_START_IN
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413 ldmia r2, {r2 - r4} /* get pc, cpsr, old_r0 */
414 add r0, sp, #S_FRAME_SIZE /* restore sp_SVC */
415
416 add r5, sp, #S_SP
417 mov r1, lr
418 stmia r5, {r0 - r4} /* save sp_SVC, lr_SVC, pc, cpsr, old_r */
419 mov r0, sp
420 .endm
421
422
423 /* use irq_save_user_regs / irq_restore_user_regs for */
424 /* IRQ/FIQ handling */
425
426 .macro irq_save_user_regs
427 sub sp, sp, #S_FRAME_SIZE
428 stmia sp, {r0 - r12} /* Calling r0-r12 */
429 add r8, sp, #S_PC
430 stmdb r8, {sp, lr}^ /* Calling SP, LR */
431 str lr, [r8, #0] /* Save calling PC */
432 mrs r6, spsr
433 str r6, [r8, #4] /* Save CPSR */
434 str r0, [r8, #8] /* Save OLD_R0 */
435 mov r0, sp
436 .endm
437
438 .macro irq_restore_user_regs
439 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
440 mov r0, r0
441 ldr lr, [sp, #S_PC] @ Get PC
442 add sp, sp, #S_FRAME_SIZE
443 subs pc, lr, #4 @ return & move spsr_svc into cpsr
444 .endm
445
446 .macro get_bad_stack
2af0a099 447 ldr r13, IRQ_STACK_START_IN @ setup our mode stack
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448
449 str lr, [r13] @ save caller lr / spsr
450 mrs lr, spsr
451 str lr, [r13, #4]
452
453 mov r13, #MODE_SVC @ prepare SVC-Mode
454 msr spsr_c, r13
455 mov lr, pc
456 movs pc, lr
457 .endm
458
459 .macro get_irq_stack @ setup IRQ stack
460 ldr sp, IRQ_STACK_START
461 .endm
462
463 .macro get_fiq_stack @ setup FIQ stack
464 ldr sp, FIQ_STACK_START
465 .endm
466
467
468/****************************************************************************/
469/* */
470/* exception handlers */
471/* */
472/****************************************************************************/
473
474 .align 5
475undefined_instruction:
476 get_bad_stack
477 bad_save_user_regs
478 bl do_undefined_instruction
479
480 .align 5
481software_interrupt:
482 get_bad_stack
483 bad_save_user_regs
484 bl do_software_interrupt
485
486 .align 5
487prefetch_abort:
488 get_bad_stack
489 bad_save_user_regs
490 bl do_prefetch_abort
491
492 .align 5
493data_abort:
494 get_bad_stack
495 bad_save_user_regs
496 bl do_data_abort
497
498 .align 5
499not_used:
500 get_bad_stack
501 bad_save_user_regs
502 bl do_not_used
503
504#ifdef CONFIG_USE_IRQ
505
506 .align 5
507irq:
508 get_irq_stack
509 irq_save_user_regs
510 bl do_irq
511 irq_restore_user_regs
512
513 .align 5
514fiq:
515 get_fiq_stack
516 irq_save_user_regs /* someone ought to write a more */
517 bl do_fiq /* effiction fiq_save_user_regs */
518 irq_restore_user_regs
519
520#else
521
522 .align 5
523irq:
524 get_bad_stack
525 bad_save_user_regs
526 bl do_irq
527
528 .align 5
529fiq:
530 get_bad_stack
531 bad_save_user_regs
532 bl do_fiq
533
534#endif
535
536/****************************************************************************/
537/* */
538/* Reset function: Use Watchdog to reset */
539/* */
540/****************************************************************************/
541
542 .align 5
543.globl reset_cpu
544
545reset_cpu:
53677ef1 546 ldr r1, =0x482e
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547 ldr r2, =IXP425_OSWK
548 str r1, [r2]
53677ef1 549 ldr r1, =0x0fff
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550 ldr r2, =IXP425_OSWT
551 str r1, [r2]
53677ef1 552 ldr r1, =0x5
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553 ldr r2, =IXP425_OSWE
554 str r1, [r2]
555 b reset_endless
556
2d5b561e 557reset_endless:
2d5b561e 558 b reset_endless