Gitiles
Code Review Sign In
gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 5b7dd8163d517c8f52971bc16fe92f831553d2bb / . / arch / mips / cpu / mips32 / start.S
blob: a4fc1ec0a48b3dbce5869c08185f964c38950103 [file] [log] [blame]
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]1/*
2 * Startup Code for MIPS32 CPU-core
3 *
4 * Copyright (c) 2003 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
Wolfgang Denk25ddd1f2010-10-26 14:34:52 +0200[diff] [blame]25#include <asm-offsets.h>
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]26#include <config.h>
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]27#include <asm/regdef.h>
28#include <asm/mipsregs.h>
29
Daniel Schwierzeckab2a98b2011-07-27 13:22:38 +0200[diff] [blame]30#ifndef CONFIG_SYS_MIPS_CACHE_MODE
31#define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT
32#endif
33
Shinya Kuribayashidecaba62008-03-25 21:30:07 +0900[diff] [blame]34 /*
35 * For the moment disable interrupts, mark the kernel mode and
36 * set ST0_KX so that the CPU does not spit fire when using
37 * 64-bit addresses.
38 */
39 .macro setup_c0_status set clr
40 .set push
41 mfc0 t0, CP0_STATUS
42 or t0, ST0_CU0 | \set | 0x1f | \clr
43 xor t0, 0x1f | \clr
44 mtc0 t0, CP0_STATUS
45 .set noreorder
46 sll zero, 3 # ehb
47 .set pop
48 .endm
49
50 .macro setup_c0_status_reset
51#ifdef CONFIG_64BIT
52 setup_c0_status ST0_KX 0
53#else
54 setup_c0_status 0 0
55#endif
56 .endm
57
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]58#define RVECENT(f,n) \
59 b f; nop
60#define XVECENT(f,bev) \
61 b f ; \
62 li k0,bev
63
64 .set noreorder
65
66 .globl _start
67 .text
68_start:
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]69 RVECENT(reset,0) # U-boot entry point
70 RVECENT(reset,1) # software reboot
Daniel Schwierzeck7185adb2011-07-27 13:22:37 +0200[diff] [blame]71#ifdef CONFIG_SYS_XWAY_EBU_BOOTCFG
72 /*
73 * Almost all Lantiq XWAY SoC devices have an external bus unit (EBU) to
74 * access external NOR flashes. If the board boots from NOR flash the
75 * internal BootROM does a blind read at address 0xB0000010 to read the
76 * initial configuration for that EBU in order to access the flash
77 * device with correct parameters. This config option is board-specific.
78 */
79 .word CONFIG_SYS_XWAY_EBU_BOOTCFG
80 .word 0x00000000
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]81#else
82 RVECENT(romReserved,2)
83#endif
84 RVECENT(romReserved,3)
85 RVECENT(romReserved,4)
86 RVECENT(romReserved,5)
87 RVECENT(romReserved,6)
88 RVECENT(romReserved,7)
89 RVECENT(romReserved,8)
90 RVECENT(romReserved,9)
91 RVECENT(romReserved,10)
92 RVECENT(romReserved,11)
93 RVECENT(romReserved,12)
94 RVECENT(romReserved,13)
95 RVECENT(romReserved,14)
96 RVECENT(romReserved,15)
97 RVECENT(romReserved,16)
wdenk8bde7f72003-06-27 21:31:46 +0000[diff] [blame]98 RVECENT(romReserved,17)
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]99 RVECENT(romReserved,18)
100 RVECENT(romReserved,19)
101 RVECENT(romReserved,20)
102 RVECENT(romReserved,21)
103 RVECENT(romReserved,22)
104 RVECENT(romReserved,23)
105 RVECENT(romReserved,24)
106 RVECENT(romReserved,25)
107 RVECENT(romReserved,26)
108 RVECENT(romReserved,27)
109 RVECENT(romReserved,28)
110 RVECENT(romReserved,29)
111 RVECENT(romReserved,30)
112 RVECENT(romReserved,31)
113 RVECENT(romReserved,32)
114 RVECENT(romReserved,33)
115 RVECENT(romReserved,34)
116 RVECENT(romReserved,35)
117 RVECENT(romReserved,36)
118 RVECENT(romReserved,37)
119 RVECENT(romReserved,38)
120 RVECENT(romReserved,39)
121 RVECENT(romReserved,40)
122 RVECENT(romReserved,41)
123 RVECENT(romReserved,42)
124 RVECENT(romReserved,43)
125 RVECENT(romReserved,44)
126 RVECENT(romReserved,45)
127 RVECENT(romReserved,46)
128 RVECENT(romReserved,47)
129 RVECENT(romReserved,48)
130 RVECENT(romReserved,49)
131 RVECENT(romReserved,50)
132 RVECENT(romReserved,51)
133 RVECENT(romReserved,52)
134 RVECENT(romReserved,53)
135 RVECENT(romReserved,54)
136 RVECENT(romReserved,55)
137 RVECENT(romReserved,56)
138 RVECENT(romReserved,57)
139 RVECENT(romReserved,58)
140 RVECENT(romReserved,59)
141 RVECENT(romReserved,60)
142 RVECENT(romReserved,61)
143 RVECENT(romReserved,62)
wdenk8bde7f72003-06-27 21:31:46 +0000[diff] [blame]144 RVECENT(romReserved,63)
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]145 XVECENT(romExcHandle,0x200) # bfc00200: R4000 tlbmiss vector
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]146 RVECENT(romReserved,65)
147 RVECENT(romReserved,66)
148 RVECENT(romReserved,67)
149 RVECENT(romReserved,68)
150 RVECENT(romReserved,69)
151 RVECENT(romReserved,70)
152 RVECENT(romReserved,71)
153 RVECENT(romReserved,72)
154 RVECENT(romReserved,73)
155 RVECENT(romReserved,74)
156 RVECENT(romReserved,75)
157 RVECENT(romReserved,76)
158 RVECENT(romReserved,77)
159 RVECENT(romReserved,78)
wdenk8bde7f72003-06-27 21:31:46 +0000[diff] [blame]160 RVECENT(romReserved,79)
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]161 XVECENT(romExcHandle,0x280) # bfc00280: R4000 xtlbmiss vector
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]162 RVECENT(romReserved,81)
163 RVECENT(romReserved,82)
164 RVECENT(romReserved,83)
165 RVECENT(romReserved,84)
166 RVECENT(romReserved,85)
167 RVECENT(romReserved,86)
168 RVECENT(romReserved,87)
169 RVECENT(romReserved,88)
170 RVECENT(romReserved,89)
171 RVECENT(romReserved,90)
172 RVECENT(romReserved,91)
173 RVECENT(romReserved,92)
174 RVECENT(romReserved,93)
175 RVECENT(romReserved,94)
wdenk8bde7f72003-06-27 21:31:46 +0000[diff] [blame]176 RVECENT(romReserved,95)
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]177 XVECENT(romExcHandle,0x300) # bfc00300: R4000 cache vector
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]178 RVECENT(romReserved,97)
179 RVECENT(romReserved,98)
180 RVECENT(romReserved,99)
181 RVECENT(romReserved,100)
182 RVECENT(romReserved,101)
183 RVECENT(romReserved,102)
184 RVECENT(romReserved,103)
185 RVECENT(romReserved,104)
186 RVECENT(romReserved,105)
187 RVECENT(romReserved,106)
188 RVECENT(romReserved,107)
189 RVECENT(romReserved,108)
190 RVECENT(romReserved,109)
191 RVECENT(romReserved,110)
192 RVECENT(romReserved,111)
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]193 XVECENT(romExcHandle,0x380) # bfc00380: R4000 general vector
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]194 RVECENT(romReserved,113)
195 RVECENT(romReserved,114)
196 RVECENT(romReserved,115)
197 RVECENT(romReserved,116)
198 RVECENT(romReserved,116)
199 RVECENT(romReserved,118)
200 RVECENT(romReserved,119)
201 RVECENT(romReserved,120)
202 RVECENT(romReserved,121)
203 RVECENT(romReserved,122)
204 RVECENT(romReserved,123)
205 RVECENT(romReserved,124)
206 RVECENT(romReserved,125)
207 RVECENT(romReserved,126)
208 RVECENT(romReserved,127)
wdenk8bde7f72003-06-27 21:31:46 +0000[diff] [blame]209
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]210 /*
211 * We hope there are no more reserved vectors!
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]212 * 128 * 8 == 1024 == 0x400
213 * so this is address R_VEC+0x400 == 0xbfc00400
214 */
215 .align 4
216reset:
217
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]218 /* Clear watch registers */
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]219 mtc0 zero, CP0_WATCHLO
220 mtc0 zero, CP0_WATCHHI
221
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]222 /* WP(Watch Pending), SW0/1 should be cleared */
Shinya Kuribayashid43d43e2008-03-25 21:30:07 +0900[diff] [blame]223 mtc0 zero, CP0_CAUSE
224
Shinya Kuribayashidecaba62008-03-25 21:30:07 +0900[diff] [blame]225 setup_c0_status_reset
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]226
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]227 /* Init Timer */
228 mtc0 zero, CP0_COUNT
229 mtc0 zero, CP0_COMPARE
230
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]231#ifndef CONFIG_SKIP_LOWLEVEL_INIT
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]232 /* CONFIG0 register */
233 li t0, CONF_CM_UNCACHED
234 mtc0 t0, CP0_CONFIG
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]235#endif
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]236
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]237 /* Initialize $gp */
Shinya Kuribayashi03c031d2007-10-27 15:27:06 +0900[diff] [blame]238 bal 1f
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]239 nop
Shinya Kuribayashi22069212007-10-21 10:55:36 +0900[diff] [blame]240 .word _gp
Shinya Kuribayashi03c031d2007-10-27 15:27:06 +0900[diff] [blame]2411:
Shinya Kuribayashi16664f72007-11-17 20:05:26 +0900[diff] [blame]242 lw gp, 0(ra)
Wolfgang Denkc75eba32005-12-01 02:15:07 +0100[diff] [blame]243
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]244#ifndef CONFIG_SKIP_LOWLEVEL_INIT
245 /* Initialize any external memory */
Shinya Kuribayashi03c031d2007-10-27 15:27:06 +0900[diff] [blame]246 la t9, lowlevel_init
247 jalr t9
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]248 nop
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]249
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]250 /* Initialize caches... */
Shinya Kuribayashi03c031d2007-10-27 15:27:06 +0900[diff] [blame]251 la t9, mips_cache_reset
252 jalr t9
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]253 nop
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]254
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]255 /* ... and enable them */
Daniel Schwierzeckab2a98b2011-07-27 13:22:38 +0200[diff] [blame]256 li t0, CONFIG_SYS_MIPS_CACHE_MODE
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]257 mtc0 t0, CP0_CONFIG
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]258#endif
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]259
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]260 /* Set up temporary stack */
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200[diff] [blame]261 li t0, CONFIG_SYS_SDRAM_BASE + CONFIG_SYS_INIT_SP_OFFSET
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]262 la sp, 0(t0)
263
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]264 la t9, board_init_f
Shinya Kuribayashi43c50922008-04-17 23:35:13 +0900[diff] [blame]265 jr t9
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]266 nop
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]267
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]268/*
269 * void relocate_code (addr_sp, gd, addr_moni)
270 *
271 * This "function" does not return, instead it continues in RAM
272 * after relocating the monitor code.
273 *
274 * a0 = addr_sp
275 * a1 = gd
276 * a2 = destination address
277 */
278 .globl relocate_code
279 .ent relocate_code
280relocate_code:
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]281 move sp, a0 # set new stack pointer
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]282
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200[diff] [blame]283 li t0, CONFIG_SYS_MONITOR_BASE
wdenk27b207f2003-07-24 23:38:38 +0000[diff] [blame]284 la t3, in_ram
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]285 lw t2, -12(t3) # t2 <-- uboot_end_data
wdenk27b207f2003-07-24 23:38:38 +0000[diff] [blame]286 move t1, a2
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]287 move s2, a2 # s2 <-- destination address
wdenk27b207f2003-07-24 23:38:38 +0000[diff] [blame]288
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]289 /*
Shinya Kuribayashi22069212007-10-21 10:55:36 +0900[diff] [blame]290 * Fix $gp:
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]291 *
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200[diff] [blame]292 * New $gp = (Old $gp - CONFIG_SYS_MONITOR_BASE) + Destination Address
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]293 */
294 move t6, gp
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200[diff] [blame]295 sub gp, CONFIG_SYS_MONITOR_BASE
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]296 add gp, a2 # gp now adjusted
297 sub s1, gp, t6 # s1 <-- relocation offset
wdenk8bde7f72003-06-27 21:31:46 +0000[diff] [blame]298
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]299 /*
300 * t0 = source address
301 * t1 = target address
302 * t2 = source end address
303 */
Stefan Roese71fa0712008-11-18 16:36:12 +0100[diff] [blame]304
305 /*
306 * Save destination address and size for later usage in flush_cache()
307 */
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]308 move s0, a1 # save gd in s0
309 move a0, t1 # a0 <-- destination addr
310 sub a1, t2, t0 # a1 <-- size
Stefan Roese71fa0712008-11-18 16:36:12 +0100[diff] [blame]311
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]3121:
313 lw t3, 0(t0)
314 sw t3, 0(t1)
315 addu t0, 4
Gabor Juhos5b7dd812013-01-24 06:27:51 +0000[diff] [blame^]316 blt t0, t2, 1b
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]317 addu t1, 4
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]318
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]319 /* If caches were enabled, we would have to flush them here. */
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]320
Stefan Roese71fa0712008-11-18 16:36:12 +0100[diff] [blame]321 /* a0 & a1 are already set up for flush_cache(start, size) */
322 la t9, flush_cache
323 jalr t9
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]324 nop
Stefan Roese71fa0712008-11-18 16:36:12 +0100[diff] [blame]325
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]326 /* Jump to where we've relocated ourselves */
Stefan Roese71fa0712008-11-18 16:36:12 +0100[diff] [blame]327 addi t0, s2, in_ram - _start
Shinya Kuribayashi43c50922008-04-17 23:35:13 +0900[diff] [blame]328 jr t0
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]329 nop
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]330
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200[diff] [blame]331 .word _gp
Vlad Lungu0f8c62a2008-05-05 14:04:00 +0300[diff] [blame]332 .word _GLOBAL_OFFSET_TABLE_
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]333 .word uboot_end_data
334 .word uboot_end
335 .word num_got_entries
336
337in_ram:
Shinya Kuribayashi22069212007-10-21 10:55:36 +0900[diff] [blame]338 /*
339 * Now we want to update GOT.
340 *
341 * GOT[0] is reserved. GOT[1] is also reserved for the dynamic object
342 * generated by GNU ld. Skip these reserved entries from relocation.
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]343 */
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]344 lw t3, -4(t0) # t3 <-- num_got_entries
345 lw t4, -16(t0) # t4 <-- _GLOBAL_OFFSET_TABLE_
346 lw t5, -20(t0) # t5 <-- _gp
347 sub t4, t5 # compute offset
348 add t4, t4, gp # t4 now holds relocated _G_O_T_
349 addi t4, t4, 8 # skipping first two entries
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]350 li t2, 2
3511:
352 lw t1, 0(t4)
353 beqz t1, 2f
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]354 add t1, s1
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]355 sw t1, 0(t4)
3562:
357 addi t2, 1
358 blt t2, t3, 1b
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]359 addi t4, 4
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]360
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]361 /* Clear BSS */
362 lw t1, -12(t0) # t1 <-- uboot_end_data
363 lw t2, -8(t0) # t2 <-- uboot_end
364 add t1, s1 # adjust pointers
Stefan Roese71fa0712008-11-18 16:36:12 +0100[diff] [blame]365 add t2, s1
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]366
367 sub t1, 4
Shinya Kuribayashi03c031d2007-10-27 15:27:06 +0900[diff] [blame]3681:
369 addi t1, 4
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]370 bltl t1, t2, 1b
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]371 sw zero, 0(t1)
wdenk8bde7f72003-06-27 21:31:46 +0000[diff] [blame]372
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]373 move a0, s0 # a0 <-- gd
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]374 la t9, board_init_r
Shinya Kuribayashi43c50922008-04-17 23:35:13 +0900[diff] [blame]375 jr t9
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]376 move a1, s2
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]377
378 .end relocate_code
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]379
Shinya Kuribayashi7aa1f192011-05-07 00:18:13 +0900[diff] [blame]380 /* Exception handlers */
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]381romReserved:
Shinya Kuribayashi03c031d2007-10-27 15:27:06 +0900[diff] [blame]382 b romReserved
Gabor Juhos14fdd1a2013-01-16 03:05:01 +0000[diff] [blame]383 nop
wdenkc0218802003-03-27 12:09:35 +0000[diff] [blame]384
385romExcHandle:
Shinya Kuribayashi03c031d2007-10-27 15:27:06 +0900[diff] [blame]386 b romExcHandle
Gabor Juhos14fdd1a2013-01-16 03:05:01 +0000[diff] [blame]387 nop