summaryrefslogtreecommitdiff
path: root/cpu/mips/start.S
blob: 0ecdd83636e9b0ad36ca7530899277b2d6cdd50e (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
/*
 *  Startup Code for MIPS32 CPU-core
 *
 *  Copyright (c) 2003	Wolfgang Denk <wd@denx.de>
 *
 * 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
 */

#include <config.h>
#include <version.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>

#define RVECENT(f,n) \
   b f; nop
#define XVECENT(f,bev) \
   b f     ;           \
   li k0,bev

	.set noreorder

	.globl _start
	.text
_start:
	RVECENT(reset,0)	/* U-boot entry point */
	RVECENT(reset,1)	/* software reboot */
#if defined(CONFIG_INCA_IP)
	.word INFINEON_EBU_BOOTCFG /* EBU init code, fetched during booting */
	.word 0x00000000           /* phase of the flash                    */
#elif defined(CONFIG_PURPLE)
	.word INFINEON_EBU_BOOTCFG /* EBU init code, fetched during booting */
	.word INFINEON_EBU_BOOTCFG /* EBU init code, fetched during booting */
#else
	RVECENT(romReserved,2)
#endif
	RVECENT(romReserved,3)
	RVECENT(romReserved,4)
	RVECENT(romReserved,5)
	RVECENT(romReserved,6)
	RVECENT(romReserved,7)
	RVECENT(romReserved,8)
	RVECENT(romReserved,9)
	RVECENT(romReserved,10)
	RVECENT(romReserved,11)
	RVECENT(romReserved,12)
	RVECENT(romReserved,13)
	RVECENT(romReserved,14)
	RVECENT(romReserved,15)
	RVECENT(romReserved,16)
	RVECENT(romReserved,17)
	RVECENT(romReserved,18)
	RVECENT(romReserved,19)
	RVECENT(romReserved,20)
	RVECENT(romReserved,21)
	RVECENT(romReserved,22)
	RVECENT(romReserved,23)
	RVECENT(romReserved,24)
	RVECENT(romReserved,25)
	RVECENT(romReserved,26)
	RVECENT(romReserved,27)
	RVECENT(romReserved,28)
	RVECENT(romReserved,29)
	RVECENT(romReserved,30)
	RVECENT(romReserved,31)
	RVECENT(romReserved,32)
	RVECENT(romReserved,33)
	RVECENT(romReserved,34)
	RVECENT(romReserved,35)
	RVECENT(romReserved,36)
	RVECENT(romReserved,37)
	RVECENT(romReserved,38)
	RVECENT(romReserved,39)
	RVECENT(romReserved,40)
	RVECENT(romReserved,41)
	RVECENT(romReserved,42)
	RVECENT(romReserved,43)
	RVECENT(romReserved,44)
	RVECENT(romReserved,45)
	RVECENT(romReserved,46)
	RVECENT(romReserved,47)
	RVECENT(romReserved,48)
	RVECENT(romReserved,49)
	RVECENT(romReserved,50)
	RVECENT(romReserved,51)
	RVECENT(romReserved,52)
	RVECENT(romReserved,53)
	RVECENT(romReserved,54)
	RVECENT(romReserved,55)
	RVECENT(romReserved,56)
	RVECENT(romReserved,57)
	RVECENT(romReserved,58)
	RVECENT(romReserved,59)
	RVECENT(romReserved,60)
	RVECENT(romReserved,61)
	RVECENT(romReserved,62)
	RVECENT(romReserved,63)
	XVECENT(romExcHandle,0x200)	/* bfc00200: R4000 tlbmiss vector */
	RVECENT(romReserved,65)
	RVECENT(romReserved,66)
	RVECENT(romReserved,67)
	RVECENT(romReserved,68)
	RVECENT(romReserved,69)
	RVECENT(romReserved,70)
	RVECENT(romReserved,71)
	RVECENT(romReserved,72)
	RVECENT(romReserved,73)
	RVECENT(romReserved,74)
	RVECENT(romReserved,75)
	RVECENT(romReserved,76)
	RVECENT(romReserved,77)
	RVECENT(romReserved,78)
	RVECENT(romReserved,79)
	XVECENT(romExcHandle,0x280)	/* bfc00280: R4000 xtlbmiss vector */
	RVECENT(romReserved,81)
	RVECENT(romReserved,82)
	RVECENT(romReserved,83)
	RVECENT(romReserved,84)
	RVECENT(romReserved,85)
	RVECENT(romReserved,86)
	RVECENT(romReserved,87)
	RVECENT(romReserved,88)
	RVECENT(romReserved,89)
	RVECENT(romReserved,90)
	RVECENT(romReserved,91)
	RVECENT(romReserved,92)
	RVECENT(romReserved,93)
	RVECENT(romReserved,94)
	RVECENT(romReserved,95)
	XVECENT(romExcHandle,0x300)	/* bfc00300: R4000 cache vector */
	RVECENT(romReserved,97)
	RVECENT(romReserved,98)
	RVECENT(romReserved,99)
	RVECENT(romReserved,100)
	RVECENT(romReserved,101)
	RVECENT(romReserved,102)
	RVECENT(romReserved,103)
	RVECENT(romReserved,104)
	RVECENT(romReserved,105)
	RVECENT(romReserved,106)
	RVECENT(romReserved,107)
	RVECENT(romReserved,108)
	RVECENT(romReserved,109)
	RVECENT(romReserved,110)
	RVECENT(romReserved,111)
	XVECENT(romExcHandle,0x380)	/* bfc00380: R4000 general vector */
	RVECENT(romReserved,113)
	RVECENT(romReserved,114)
	RVECENT(romReserved,115)
	RVECENT(romReserved,116)
	RVECENT(romReserved,116)
	RVECENT(romReserved,118)
	RVECENT(romReserved,119)
	RVECENT(romReserved,120)
	RVECENT(romReserved,121)
	RVECENT(romReserved,122)
	RVECENT(romReserved,123)
	RVECENT(romReserved,124)
	RVECENT(romReserved,125)
	RVECENT(romReserved,126)
	RVECENT(romReserved,127)

	/* We hope there are no more reserved vectors!
	 * 128 * 8 == 1024 == 0x400
	 * so this is address R_VEC+0x400 == 0xbfc00400
	 */
#ifdef CONFIG_PURPLE
/* 0xbfc00400 */
	.word	0xdc870000
	.word	0xfca70000
	.word	0x20840008
	.word	0x20a50008
	.word	0x20c6ffff
	.word	0x14c0fffa
	.word	0x00000000
	.word	0x03e00008
	.word	0x00000000
	.word	0x00000000
/* 0xbfc00428 */
	.word	0xdc870000
	.word	0xfca70000
	.word	0x20840008
	.word	0x20a50008
	.word	0x20c6ffff
	.word	0x14c0fffa
	.word	0x00000000
	.word	0x03e00008
	.word	0x00000000
	.word	0x00000000
#endif /* CONFIG_PURPLE */
	.align 4
reset:

	/* Clear watch registers.
	 */
	mtc0	zero, CP0_WATCHLO
	mtc0	zero, CP0_WATCHHI

	/* WP(Watch Pending), SW0/1 should be cleared. */
	mtc0	zero, CP0_CAUSE

	/* STATUS register */
#ifdef  CONFIG_TB0229
	li	k0, ST0_CU0
#else
	mfc0	k0, CP0_STATUS
#endif
	li	k1, ~ST0_IE
	and	k0, k1
	mtc0	k0, CP0_STATUS

	/* Init Timer */
	mtc0	zero, CP0_COUNT
	mtc0	zero, CP0_COMPARE

	/* CONFIG0 register */
	li	t0, CONF_CM_UNCACHED
	mtc0	t0, CP0_CONFIG

	/* Initialize $gp.
	 */
	bal	1f
	nop
	.word	_gp
1:
	lw	gp, 0(ra)

	/* Initialize any external memory.
	 */
	la	t9, lowlevel_init
	jalr	t9
	nop

	/* Initialize caches...
	 */
	la	t9, mips_cache_reset
	jalr	t9
	nop

	/* ... and enable them.
	 */
	li	t0, CONF_CM_CACHABLE_NONCOHERENT
	mtc0	t0, CP0_CONFIG

	/* Set up temporary stack.
	 */
#ifdef CFG_INIT_RAM_LOCK_MIPS
	li	a0, CFG_INIT_SP_OFFSET
	la	t9, mips_cache_lock
	jalr	t9
	nop
#endif

	li	t0, CFG_SDRAM_BASE + CFG_INIT_SP_OFFSET
	la	sp, 0(t0)

	la	t9, board_init_f
	j	t9
	nop

/*
 * void relocate_code (addr_sp, gd, addr_moni)
 *
 * This "function" does not return, instead it continues in RAM
 * after relocating the monitor code.
 *
 * a0 = addr_sp
 * a1 = gd
 * a2 = destination address
 */
	.globl	relocate_code
	.ent	relocate_code
relocate_code:
	move	sp, a0		/* Set new stack pointer	*/

	li	t0, CFG_MONITOR_BASE
	la	t3, in_ram
	lw	t2, -12(t3)	/* t2 <-- uboot_end_data	*/
	move	t1, a2

	/*
	 * Fix $gp:
	 *
	 * New $gp = (Old $gp - CFG_MONITOR_BASE) + Destination Address
	 */
	move	t6, gp
	sub	gp, CFG_MONITOR_BASE
	add	gp, a2		/* gp now adjusted		*/
	sub	t6, gp, t6	/* t6 <-- relocation offset	*/

	/*
	 * t0 = source address
	 * t1 = target address
	 * t2 = source end address
	 */
	/* On the purple board we copy the code earlier in a special way
	 * in order to solve flash problems
	 */
#ifndef CONFIG_PURPLE
1:
	lw	t3, 0(t0)
	sw	t3, 0(t1)
	addu	t0, 4
	ble	t0, t2, 1b
	addu	t1, 4		/* delay slot			*/
#endif

	/* If caches were enabled, we would have to flush them here.
	 */

	/* Jump to where we've relocated ourselves.
	 */
	addi	t0, a2, in_ram - _start
	j	t0
	nop

	.gpword	_GLOBAL_OFFSET_TABLE_	/* _GLOBAL_OFFSET_TABLE_ - _gp	*/
	.word	uboot_end_data
	.word	uboot_end
	.word	num_got_entries

in_ram:
	/*
	 * Now we want to update GOT.
	 *
	 * GOT[0] is reserved. GOT[1] is also reserved for the dynamic object
	 * generated by GNU ld. Skip these reserved entries from relocation.
	 */
	lw	t3, -4(t0)	/* t3 <-- num_got_entries	*/
	lw	t4, -16(t0)	/* t4 <-- (_GLOBAL_OFFSET_TABLE_ - _gp)	*/
	add	t4, t4, gp	/* t4 now holds _GLOBAL_OFFSET_TABLE_	*/
	addi	t4, t4, 8	/* Skipping first two entries.	*/
	li	t2, 2
1:
	lw	t1, 0(t4)
	beqz	t1, 2f
	add	t1, t6
	sw	t1, 0(t4)
2:
	addi	t2, 1
	blt	t2, t3, 1b
	addi	t4, 4		/* delay slot			*/

	/* Clear BSS.
	 */
	lw	t1, -12(t0)	/* t1 <-- uboot_end_data	*/
	lw	t2, -8(t0)	/* t2 <-- uboot_end		*/
	add	t1, t6		/* adjust pointers		*/
	add	t2, t6

	sub	t1, 4
1:
	addi	t1, 4
	bltl	t1, t2, 1b
	sw	zero, 0(t1)	/* delay slot			*/

	move	a0, a1
	la	t9, board_init_r
	j	t9
	move	a1, a2		/* delay slot			*/

	.end	relocate_code

	/* Exception handlers.
	 */
romReserved:
	b	romReserved

romExcHandle:
	b	romExcHandle