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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 6d8622788020265a9e98e8345c6435c8680c992c / . / arch / mips / cpu / xburst / start.S
blob: 50b7fb102172f6c32ea50b2f8b65ebf6485f9a1f [file] [log] [blame]
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]1/*
2 * Startup Code for MIPS32 XBURST CPU-core
3 *
4 * Copyright (c) 2010 Xiangfu Liu <xiangfu@sharism.cc>
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
25#include <config.h>
26#include <version.h>
27#include <asm/regdef.h>
28#include <asm/mipsregs.h>
29#include <asm/addrspace.h>
30#include <asm/cacheops.h>
31
32 .set noreorder
33
34 .globl _start
35 .text
36_start:
37 /* Initialize $gp */
38 bal 1f
39 nop
40 .word _gp
411:
42 lw gp, 0(ra)
43
44 /* Set up temporary stack */
45 li sp, CONFIG_SYS_SDRAM_BASE + CONFIG_SYS_INIT_SP_OFFSET
46
47 la t9, board_init_f
48 jr t9
49 nop
50
51/*
52 * void relocate_code (addr_sp, gd, addr_moni)
53 *
54 * This "function" does not return, instead it continues in RAM
55 * after relocating the monitor code.
56 *
57 * a0 = addr_sp
58 * a1 = gd
59 * a2 = destination address
60 */
61 .globl relocate_code
62 .ent relocate_code
63relocate_code:
64 move sp, a0 # set new stack pointer
65
66 li t0, CONFIG_SYS_MONITOR_BASE
Gabor Juhos6d862272013-01-30 04:51:06 +0000[diff] [blame^]67 sub t6, a2, t0 # t6 <-- relocation offset
68
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]69 la t3, in_ram
70 lw t2, -12(t3) # t2 <-- uboot_end_data
71 move t1, a2
72
Gabor Juhos6d862272013-01-30 04:51:06 +0000[diff] [blame^]73 add gp, t6 # adjust gp
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]74
75 /*
76 * t0 = source address
77 * t1 = target address
78 * t2 = source end address
79 */
801:
81 lw t3, 0(t0)
82 sw t3, 0(t1)
83 addu t0, 4
Gabor Juhos5b7dd812013-01-24 06:27:51 +0000[diff] [blame]84 blt t0, t2, 1b
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]85 addu t1, 4
86
87 /* If caches were enabled, we would have to flush them here. */
88
89 /* flush d-cache */
90 li t0, KSEG0
91 addi t1, t0, CONFIG_SYS_DCACHE_SIZE
922:
Zhi-zhou Zhangcb0a6a12012-10-16 15:02:08 +0200[diff] [blame]93 cache INDEX_WRITEBACK_INV_D, 0(t0)
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]94 bne t0, t1, 2b
95 addi t0, CONFIG_SYS_CACHELINE_SIZE
96
97 sync
98
99 /* flush i-cache */
100 li t0, KSEG0
101 addi t1, t0, CONFIG_SYS_ICACHE_SIZE
1023:
Zhi-zhou Zhangcb0a6a12012-10-16 15:02:08 +0200[diff] [blame]103 cache INDEX_INVALIDATE_I, 0(t0)
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]104 bne t0, t1, 3b
105 addi t0, CONFIG_SYS_CACHELINE_SIZE
106
107 /* Invalidate BTB */
108 mfc0 t0, CP0_CONFIG, 7
109 nop
110 ori t0, 2
111 mtc0 t0, CP0_CONFIG, 7
112 nop
113
114 /* Jump to where we've relocated ourselves */
115 addi t0, a2, in_ram - _start
116 jr t0
117 nop
118
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]119 .word _GLOBAL_OFFSET_TABLE_
120 .word uboot_end_data
121 .word uboot_end
122 .word num_got_entries
123
124in_ram:
125 /*
126 * Now we want to update GOT.
127 *
128 * GOT[0] is reserved. GOT[1] is also reserved for the dynamic object
129 * generated by GNU ld. Skip these reserved entries from relocation.
130 */
131 lw t3, -4(t0) # t3 <-- num_got_entries
132 lw t4, -16(t0) # t4 <-- _GLOBAL_OFFSET_TABLE_
Gabor Juhos025f2b32013-01-30 04:56:37 +0000[diff] [blame]133 add t4, t6 # t4 now holds relocated _G_O_T_
Xiangfu Liu80421fc2011-10-12 12:24:06 +0800[diff] [blame]134 addi t4, t4, 8 # skipping first two entries
135 li t2, 2
1361:
137 lw t1, 0(t4)
138 beqz t1, 2f
139 add t1, t6
140 sw t1, 0(t4)
1412:
142 addi t2, 1
143 blt t2, t3, 1b
144 addi t4, 4
145
146 /* Clear BSS */
147 lw t1, -12(t0) # t1 <-- uboot_end_data
148 lw t2, -8(t0) # t2 <-- uboot_end
149 add t1, t6 # adjust pointers
150 add t2, t6
151
152 sub t1, 4
1531: addi t1, 4
154 bltl t1, t2, 1b
155 sw zero, 0(t1)
156
157 move a0, a1 # a0 <-- gd
158 la t9, board_init_r
159 jr t9
160 move a1, a2
161
162 .end relocate_code