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wdenk2d5b5612003-10-14 19:43:55 +00001/* 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
30#include <config.h>
31#include <version.h>
32#include <asm/arch/ixp425.h>
33
wdenk42d1f032003-10-15 23:53:47 +000034#define MMU_Control_M 0x001 /* Enable MMU */
35#define MMU_Control_A 0x002 /* Enable address alignment faults */
36#define MMU_Control_C 0x004 /* Enable cache */
37#define MMU_Control_W 0x008 /* Enable write-buffer */
38#define MMU_Control_P 0x010 /* Compatability: 32 bit code */
39#define MMU_Control_D 0x020 /* Compatability: 32 bit data */
40#define MMU_Control_L 0x040 /* Compatability: */
41#define MMU_Control_B 0x080 /* Enable Big-Endian */
42#define MMU_Control_S 0x100 /* Enable system protection */
43#define MMU_Control_R 0x200 /* Enable ROM protection */
44#define MMU_Control_I 0x1000 /* Enable Instruction cache */
45#define MMU_Control_X 0x2000 /* Set interrupt vectors at 0xFFFF0000 */
wdenk2d5b5612003-10-14 19:43:55 +000046#define MMU_Control_Init (MMU_Control_P|MMU_Control_D|MMU_Control_L)
47
48
49/*
50 * Macro definitions
51 */
wdenk42d1f032003-10-15 23:53:47 +000052 /* Delay a bit */
53 .macro DELAY_FOR cycles, reg0
54 ldr \reg0, =\cycles
55 subs \reg0, \reg0, #1
56 subne pc, pc, #0xc
57 .endm
wdenk2d5b5612003-10-14 19:43:55 +000058
wdenk42d1f032003-10-15 23:53:47 +000059 /* wait for coprocessor write complete */
60 .macro CPWAIT reg
61 mrc p15,0,\reg,c2,c0,0
62 mov \reg,\reg
63 sub pc,pc,#4
64 .endm
wdenk2d5b5612003-10-14 19:43:55 +000065
66.globl _start
67_start: b reset
68 ldr pc, _undefined_instruction
69 ldr pc, _software_interrupt
70 ldr pc, _prefetch_abort
71 ldr pc, _data_abort
72 ldr pc, _not_used
73 ldr pc, _irq
74 ldr pc, _fiq
75
76_undefined_instruction: .word undefined_instruction
77_software_interrupt: .word software_interrupt
78_prefetch_abort: .word prefetch_abort
79_data_abort: .word data_abort
80_not_used: .word not_used
81_irq: .word irq
82_fiq: .word fiq
83
84 .balignl 16,0xdeadbeef
85
86
87/*
88 * Startup Code (reset vector)
89 *
90 * do important init only if we don't start from memory!
91 * - relocate armboot to ram
92 * - setup stack
93 * - jump to second stage
94 */
95
96_TEXT_BASE:
97 .word TEXT_BASE
98
99.globl _armboot_start
100_armboot_start:
101 .word _start
102
103/*
wdenkf6e20fc2004-02-08 19:38:38 +0000104 * These are defined in the board-specific linker script.
wdenk2d5b5612003-10-14 19:43:55 +0000105 */
106.globl _bss_start
107_bss_start:
wdenkf6e20fc2004-02-08 19:38:38 +0000108 .word __bss_start
wdenk2d5b5612003-10-14 19:43:55 +0000109
110.globl _bss_end
111_bss_end:
wdenkf6e20fc2004-02-08 19:38:38 +0000112 .word _end
wdenk2d5b5612003-10-14 19:43:55 +0000113
114#ifdef CONFIG_USE_IRQ
115/* IRQ stack memory (calculated at run-time) */
116.globl IRQ_STACK_START
117IRQ_STACK_START:
118 .word 0x0badc0de
119
120/* IRQ stack memory (calculated at run-time) */
121.globl FIQ_STACK_START
122FIQ_STACK_START:
123 .word 0x0badc0de
124#endif
125
126/****************************************************************************/
127/* */
128/* the actual reset code */
129/* */
130/****************************************************************************/
131
132reset:
133 /* disable mmu, set big-endian */
134 mov r0, #0xf8
135 mcr p15, 0, r0, c1, c0, 0
wdenk42d1f032003-10-15 23:53:47 +0000136 CPWAIT r0
wdenk2d5b5612003-10-14 19:43:55 +0000137
138 /* invalidate I & D caches & BTB */
139 mcr p15, 0, r0, c7, c7, 0
140 CPWAIT r0
141
142 /* invalidate I & Data TLB */
wdenk42d1f032003-10-15 23:53:47 +0000143 mcr p15, 0, r0, c8, c7, 0
144 CPWAIT r0
wdenk2d5b5612003-10-14 19:43:55 +0000145
146 /* drain write and fill buffers */
147 mcr p15, 0, r0, c7, c10, 4
148 CPWAIT r0
149
150 /* disable write buffer coalescing */
151 mrc p15, 0, r0, c1, c0, 1
152 orr r0, r0, #1
153 mcr p15, 0, r0, c1, c0, 1
154 CPWAIT r0
155
156 /* set EXP CS0 to the optimum timing */
157 ldr r1, =CFG_EXP_CS0
158 ldr r2, =IXP425_EXP_CS0
159 str r1, [r2]
160
wdenk42d1f032003-10-15 23:53:47 +0000161 /* make sure flash is visible at 0 */
wdenka1191902005-01-09 17:12:27 +0000162#if 0
wdenk2d5b5612003-10-14 19:43:55 +0000163 ldr r2, =IXP425_EXP_CFG0
164 ldr r1, [r2]
165 orr r1, r1, #0x80000000
166 str r1, [r2]
wdenka1191902005-01-09 17:12:27 +0000167#endif
wdenk2d5b5612003-10-14 19:43:55 +0000168 mov r1, #CFG_SDR_CONFIG
169 ldr r2, =IXP425_SDR_CONFIG
170 str r1, [r2]
171
172 /* disable refresh cycles */
173 mov r1, #0
174 ldr r3, =IXP425_SDR_REFRESH
175 str r1, [r3]
176
177 /* send nop command */
178 mov r1, #3
179 ldr r4, =IXP425_SDR_IR
180 str r1, [r4]
wdenk42d1f032003-10-15 23:53:47 +0000181 DELAY_FOR 0x4000, r0
wdenk2d5b5612003-10-14 19:43:55 +0000182
183 /* set SDRAM internal refresh val */
184 ldr r1, =CFG_SDRAM_REFRESH_CNT
185 str r1, [r3]
186 DELAY_FOR 0x4000, r0
187
188 /* send precharge-all command to close all open banks */
189 mov r1, #2
190 str r1, [r4]
191 DELAY_FOR 0x4000, r0
192
193 /* provide 8 auto-refresh cycles */
194 mov r1, #4
195 mov r5, #8
196111: str r1, [r4]
197 DELAY_FOR 0x100, r0
198 subs r5, r5, #1
199 bne 111b
200
201 /* set mode register in sdram */
wdenka1191902005-01-09 17:12:27 +0000202 mov r1, #CFG_SDR_MODE_CONFIG
wdenk2d5b5612003-10-14 19:43:55 +0000203 str r1, [r4]
204 DELAY_FOR 0x4000, r0
205
206 /* send normal operation command */
207 mov r1, #6
208 str r1, [r4]
209 DELAY_FOR 0x4000, r0
210
211 /* copy */
wdenk42d1f032003-10-15 23:53:47 +0000212 mov r0, #0
213 mov r4, r0
Wolfgang Denkba94a1b2006-05-30 15:56:48 +0200214 add r2, r0, #CFG_MONITOR_LEN
wdenk2d5b5612003-10-14 19:43:55 +0000215 mov r1, #0x10000000
wdenk42d1f032003-10-15 23:53:47 +0000216 mov r5, r1
wdenk2d5b5612003-10-14 19:43:55 +0000217
218 30:
wdenk42d1f032003-10-15 23:53:47 +0000219 ldr r3, [r0], #4
220 str r3, [r1], #4
221 cmp r0, r2
222 bne 30b
wdenk2d5b5612003-10-14 19:43:55 +0000223
224 /* invalidate I & D caches & BTB */
225 mcr p15, 0, r0, c7, c7, 0
226 CPWAIT r0
227
228 /* invalidate I & Data TLB */
wdenk42d1f032003-10-15 23:53:47 +0000229 mcr p15, 0, r0, c8, c7, 0
230 CPWAIT r0
wdenk2d5b5612003-10-14 19:43:55 +0000231
232 /* drain write and fill buffers */
233 mcr p15, 0, r0, c7, c10, 4
234 CPWAIT r0
235
wdenk42d1f032003-10-15 23:53:47 +0000236 /* move flash to 0x50000000 */
wdenk2d5b5612003-10-14 19:43:55 +0000237 ldr r2, =IXP425_EXP_CFG0
238 ldr r1, [r2]
239 bic r1, r1, #0x80000000
240 str r1, [r2]
241
242 nop
243 nop
244 nop
245 nop
246 nop
247 nop
248
249 /* invalidate I & Data TLB */
wdenk42d1f032003-10-15 23:53:47 +0000250 mcr p15, 0, r0, c8, c7, 0
251 CPWAIT r0
wdenk2d5b5612003-10-14 19:43:55 +0000252
wdenk42d1f032003-10-15 23:53:47 +0000253 /* enable I cache */
254 mrc p15, 0, r0, c1, c0, 0
255 orr r0, r0, #MMU_Control_I
256 mcr p15, 0, r0, c1, c0, 0
257 CPWAIT r0
wdenk2d5b5612003-10-14 19:43:55 +0000258
259 mrs r0,cpsr /* set the cpu to SVC32 mode */
260 bic r0,r0,#0x1f /* (superviser mode, M=10011) */
261 orr r0,r0,#0x13
262 msr cpsr,r0
263
wdenk8aa1a2d2005-04-04 12:44:11 +0000264#ifndef CONFIG_SKIP_RELOCATE_UBOOT
wdenk2d5b5612003-10-14 19:43:55 +0000265relocate: /* relocate U-Boot to RAM */
266 adr r0, _start /* r0 <- current position of code */
267 ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
268 cmp r0, r1 /* don't reloc during debug */
269 beq stack_setup
270
271 ldr r2, _armboot_start
wdenkf6e20fc2004-02-08 19:38:38 +0000272 ldr r3, _bss_start
wdenk2d5b5612003-10-14 19:43:55 +0000273 sub r2, r3, r2 /* r2 <- size of armboot */
274 add r2, r0, r2 /* r2 <- source end address */
275
276copy_loop:
277 ldmia r0!, {r3-r10} /* copy from source address [r0] */
278 stmia r1!, {r3-r10} /* copy to target address [r1] */
279 cmp r0, r2 /* until source end addreee [r2] */
280 ble copy_loop
wdenk8aa1a2d2005-04-04 12:44:11 +0000281#endif /* CONFIG_SKIP_RELOCATE_UBOOT */
wdenk2d5b5612003-10-14 19:43:55 +0000282
283 /* Set up the stack */
wdenk2d5b5612003-10-14 19:43:55 +0000284stack_setup:
wdenkf6e20fc2004-02-08 19:38:38 +0000285 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
286 sub r0, r0, #CFG_MALLOC_LEN /* malloc area */
287 sub r0, r0, #CFG_GBL_DATA_SIZE /* bdinfo */
288#ifdef CONFIG_USE_IRQ
289 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
290#endif
wdenk2d5b5612003-10-14 19:43:55 +0000291 sub sp, r0, #12 /* leave 3 words for abort-stack */
292
293clear_bss:
wdenk2d5b5612003-10-14 19:43:55 +0000294 ldr r0, _bss_start /* find start of bss segment */
wdenk2d5b5612003-10-14 19:43:55 +0000295 ldr r1, _bss_end /* stop here */
296 mov r2, #0x00000000 /* clear */
297
298clbss_l:str r2, [r0] /* clear loop... */
299 add r0, r0, #4
300 cmp r0, r1
wdenka1191902005-01-09 17:12:27 +0000301 ble clbss_l
wdenk2d5b5612003-10-14 19:43:55 +0000302
wdenk2d5b5612003-10-14 19:43:55 +0000303 ldr pc, _start_armboot
304
305_start_armboot: .word start_armboot
306
307
wdenk2d5b5612003-10-14 19:43:55 +0000308/****************************************************************************/
309/* */
310/* Interrupt handling */
311/* */
312/****************************************************************************/
313
314/* IRQ stack frame */
315
316#define S_FRAME_SIZE 72
317
318#define S_OLD_R0 68
319#define S_PSR 64
320#define S_PC 60
321#define S_LR 56
322#define S_SP 52
323
324#define S_IP 48
325#define S_FP 44
326#define S_R10 40
327#define S_R9 36
328#define S_R8 32
329#define S_R7 28
330#define S_R6 24
331#define S_R5 20
332#define S_R4 16
333#define S_R3 12
334#define S_R2 8
335#define S_R1 4
336#define S_R0 0
337
338#define MODE_SVC 0x13
339
340 /* use bad_save_user_regs for abort/prefetch/undef/swi ... */
341
342 .macro bad_save_user_regs
343 sub sp, sp, #S_FRAME_SIZE
344 stmia sp, {r0 - r12} /* Calling r0-r12 */
345 add r8, sp, #S_PC
346
wdenkf6e20fc2004-02-08 19:38:38 +0000347 ldr r2, _armboot_start
348 sub r2, r2, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
349 sub r2, r2, #(CFG_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
wdenk2d5b5612003-10-14 19:43:55 +0000350 ldmia r2, {r2 - r4} /* get pc, cpsr, old_r0 */
351 add r0, sp, #S_FRAME_SIZE /* restore sp_SVC */
352
353 add r5, sp, #S_SP
354 mov r1, lr
355 stmia r5, {r0 - r4} /* save sp_SVC, lr_SVC, pc, cpsr, old_r */
356 mov r0, sp
357 .endm
358
359
360 /* use irq_save_user_regs / irq_restore_user_regs for */
361 /* IRQ/FIQ handling */
362
363 .macro irq_save_user_regs
364 sub sp, sp, #S_FRAME_SIZE
365 stmia sp, {r0 - r12} /* Calling r0-r12 */
366 add r8, sp, #S_PC
367 stmdb r8, {sp, lr}^ /* Calling SP, LR */
368 str lr, [r8, #0] /* Save calling PC */
369 mrs r6, spsr
370 str r6, [r8, #4] /* Save CPSR */
371 str r0, [r8, #8] /* Save OLD_R0 */
372 mov r0, sp
373 .endm
374
375 .macro irq_restore_user_regs
376 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
377 mov r0, r0
378 ldr lr, [sp, #S_PC] @ Get PC
379 add sp, sp, #S_FRAME_SIZE
380 subs pc, lr, #4 @ return & move spsr_svc into cpsr
381 .endm
382
383 .macro get_bad_stack
wdenkf6e20fc2004-02-08 19:38:38 +0000384 ldr r13, _armboot_start @ setup our mode stack
385 sub r13, r13, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
386 sub r13, r13, #(CFG_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
wdenk2d5b5612003-10-14 19:43:55 +0000387
388 str lr, [r13] @ save caller lr / spsr
389 mrs lr, spsr
390 str lr, [r13, #4]
391
392 mov r13, #MODE_SVC @ prepare SVC-Mode
393 msr spsr_c, r13
394 mov lr, pc
395 movs pc, lr
396 .endm
397
398 .macro get_irq_stack @ setup IRQ stack
399 ldr sp, IRQ_STACK_START
400 .endm
401
402 .macro get_fiq_stack @ setup FIQ stack
403 ldr sp, FIQ_STACK_START
404 .endm
405
406
407/****************************************************************************/
408/* */
409/* exception handlers */
410/* */
411/****************************************************************************/
412
413 .align 5
414undefined_instruction:
415 get_bad_stack
416 bad_save_user_regs
417 bl do_undefined_instruction
418
419 .align 5
420software_interrupt:
421 get_bad_stack
422 bad_save_user_regs
423 bl do_software_interrupt
424
425 .align 5
426prefetch_abort:
427 get_bad_stack
428 bad_save_user_regs
429 bl do_prefetch_abort
430
431 .align 5
432data_abort:
433 get_bad_stack
434 bad_save_user_regs
435 bl do_data_abort
436
437 .align 5
438not_used:
439 get_bad_stack
440 bad_save_user_regs
441 bl do_not_used
442
443#ifdef CONFIG_USE_IRQ
444
445 .align 5
446irq:
447 get_irq_stack
448 irq_save_user_regs
449 bl do_irq
450 irq_restore_user_regs
451
452 .align 5
453fiq:
454 get_fiq_stack
455 irq_save_user_regs /* someone ought to write a more */
456 bl do_fiq /* effiction fiq_save_user_regs */
457 irq_restore_user_regs
458
459#else
460
461 .align 5
462irq:
463 get_bad_stack
464 bad_save_user_regs
465 bl do_irq
466
467 .align 5
468fiq:
469 get_bad_stack
470 bad_save_user_regs
471 bl do_fiq
472
473#endif
474
475/****************************************************************************/
476/* */
477/* Reset function: Use Watchdog to reset */
478/* */
479/****************************************************************************/
480
481 .align 5
482.globl reset_cpu
483
484reset_cpu:
485 ldr r1, =0x482e
486 ldr r2, =IXP425_OSWK
487 str r1, [r2]
488 ldr r1, =0x0fff
489 ldr r2, =IXP425_OSWT
490 str r1, [r2]
491 ldr r1, =0x5
492 ldr r2, =IXP425_OSWE
493 str r1, [r2]
494 b reset_endless
495
496
497reset_endless:
498
499 b reset_endless
Wolfgang Denkba94a1b2006-05-30 15:56:48 +0200500
501#ifdef CONFIG_USE_IRQ
502
503.LC0: .word loops_per_jiffy
504
505/*
506 * 0 <= r0 <= 2000
507 */
508.globl udelay
509udelay:
510 mov r2, #0x6800
511 orr r2, r2, #0x00db
512 mul r0, r2, r0
513 ldr r2, .LC0
514 ldr r2, [r2] @ max = 0x0fffffff
515 mov r0, r0, lsr #11 @ max = 0x00003fff
516 mov r2, r2, lsr #11 @ max = 0x0003ffff
517 mul r0, r2, r0 @ max = 2^32-1
518 movs r0, r0, lsr #6
519
520delay_loop:
521 subs r0, r0, #1
522 bne delay_loop
523 mov pc, lr
524
525#endif /* CONFIG_USE_IRQ */