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
|
/*
* (C) Copyright 2007 Michal Simek
* (C) Copyright 2004 Atmark Techno, Inc.
*
* Michal SIMEK <monstr@monstr.eu>
* Yasushi SHOJI <yashi@atmark-techno.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm-offsets.h>
#include <config.h>
.text
.global _start
_start:
/*
* reserve registers:
* r10: Stores little/big endian offset for vectors
* r2: Stores imm opcode
* r3: Stores brai opcode
*/
mts rmsr, r0 /* disable cache */
addi r8, r0, __end
mts rslr, r8
#if defined(CONFIG_SPL_BUILD)
addi r1, r0, CONFIG_SPL_STACK_ADDR
mts rshr, r1
addi r1, r1, -4 /* Decrement SP to top of memory */
#else
addi r1, r0, CONFIG_SYS_INIT_SP_OFFSET
mts rshr, r1
addi r1, r1, -4 /* Decrement SP to top of memory */
/* Find-out if u-boot is running on BIG/LITTLE endian platform
* There are some steps which is necessary to keep in mind:
* 1. Setup offset value to r6
* 2. Store word offset value to address 0x0
* 3. Load just byte from address 0x0
* 4a) LITTLE endian - r10 contains 0x2 because it is the smallest
* value that's why is on address 0x0
* 4b) BIG endian - r10 contains 0x0 because 0x2 offset is on addr 0x3
*/
addik r6, r0, 0x2 /* BIG/LITTLE endian offset */
lwi r7, r0, 0x28
swi r6, r0, 0x28 /* used first unused MB vector */
lbui r10, r0, 0x28 /* used first unused MB vector */
swi r7, r0, 0x28
/* add opcode instruction for 32bit jump - 2 instruction imm & brai */
addi r2, r0, 0xb0000000 /* hex b000 opcode imm */
addi r3, r0, 0xb8080000 /* hew b808 opcode brai */
#ifdef CONFIG_SYS_RESET_ADDRESS
/* reset address */
swi r2, r0, 0x0 /* reset address - imm opcode */
swi r3, r0, 0x4 /* reset address - brai opcode */
addik r6, r0, CONFIG_SYS_RESET_ADDRESS
sw r6, r1, r0
lhu r7, r1, r10
rsubi r8, r10, 0x2
sh r7, r0, r8
rsubi r8, r10, 0x6
sh r6, r0, r8
#endif
#ifdef CONFIG_SYS_USR_EXCEP
/* user_vector_exception */
swi r2, r0, 0x8 /* user vector exception - imm opcode */
swi r3, r0, 0xC /* user vector exception - brai opcode */
addik r6, r0, _exception_handler
sw r6, r1, r0
/*
* BIG ENDIAN memory map for user exception
* 0x8: 0xB000XXXX
* 0xC: 0xB808XXXX
*
* then it is necessary to count address for storing the most significant
* 16bits from _exception_handler address and copy it to
* 0xa address. Big endian use offset in r10=0 that's why is it just
* 0xa address. The same is done for the least significant 16 bits
* for 0xe address.
*
* LITTLE ENDIAN memory map for user exception
* 0x8: 0xXXXX00B0
* 0xC: 0xXXXX08B8
*
* Offset is for little endian setup to 0x2. rsubi instruction decrease
* address value to ensure that points to proper place which is
* 0x8 for the most significant 16 bits and
* 0xC for the least significant 16 bits
*/
lhu r7, r1, r10
rsubi r8, r10, 0xa
sh r7, r0, r8
rsubi r8, r10, 0xe
sh r6, r0, r8
#endif
/* interrupt_handler */
swi r2, r0, 0x10 /* interrupt - imm opcode */
swi r3, r0, 0x14 /* interrupt - brai opcode */
addik r6, r0, _interrupt_handler
sw r6, r1, r0
lhu r7, r1, r10
rsubi r8, r10, 0x12
sh r7, r0, r8
rsubi r8, r10, 0x16
sh r6, r0, r8
/* hardware exception */
swi r2, r0, 0x20 /* hardware exception - imm opcode */
swi r3, r0, 0x24 /* hardware exception - brai opcode */
addik r6, r0, _hw_exception_handler
sw r6, r1, r0
lhu r7, r1, r10
rsubi r8, r10, 0x22
sh r7, r0, r8
rsubi r8, r10, 0x26
sh r6, r0, r8
#endif /* BUILD_SPL */
/* Flush cache before enable cache */
addik r5, r0, 0
addik r6, r0, XILINX_DCACHE_BYTE_SIZE
bralid r15, flush_cache
nop
/* enable instruction and data cache */
mfs r12, rmsr
ori r12, r12, 0x1a0
mts rmsr, r12
clear_bss:
/* clear BSS segments */
addi r5, r0, __bss_start
addi r4, r0, __bss_end
cmp r6, r5, r4
beqi r6, 3f
2:
swi r0, r5, 0 /* write zero to loc */
addi r5, r5, 4 /* increment to next loc */
cmp r6, r5, r4 /* check if we have reach the end */
bnei r6, 2b
3: /* jumping to board_init */
#ifndef CONFIG_SPL_BUILD
or r5, r0, r0 /* flags - empty */
brai board_init_f
#else
addi r31, r0, CONFIG_SYS_SPL_MALLOC_END
brai board_init_r
#endif
1: bri 1b
#ifndef CONFIG_SPL_BUILD
/*
* Read 16bit little endian
*/
.text
.global in16
.ent in16
.align 2
in16: lhu r3, r0, r5
bslli r4, r3, 8
bsrli r3, r3, 8
andi r4, r4, 0xffff
or r3, r3, r4
rtsd r15, 8
sext16 r3, r3
.end in16
/*
* Write 16bit little endian
* first parameter(r5) - address, second(r6) - short value
*/
.text
.global out16
.ent out16
.align 2
out16: bslli r3, r6, 8
bsrli r6, r6, 8
andi r3, r3, 0xffff
or r3, r3, r6
sh r3, r0, r5
rtsd r15, 8
or r0, r0, r0
.end out16
/*
* Relocate u-boot
*/
.text
.global relocate_code
.ent relocate_code
.align 2
relocate_code:
/*
* r5 - start_addr_sp
* r6 - new_gd
* r7 - reloc_addr
*/
addi r1, r5, 0 /* Start to use new SP */
addi r31, r6, 0 /* Start to use new GD */
add r23, r0, r7 /* Move reloc addr to r23 */
/* Relocate text and data - r12 temp value */
addi r21, r0, _start
addi r22, r0, __end - 4 /* Include BSS too */
rsub r6, r21, r22
or r5, r0, r0
1: lw r12, r21, r5 /* Load u-boot data */
sw r12, r23, r5 /* Write zero to loc */
cmp r12, r5, r6 /* Check if we have reach the end */
bneid r12, 1b
addi r5, r5, 4 /* Increment to next loc - relocate code */
/* R23 points to the base address. */
add r23, r0, r7 /* Move reloc addr to r23 */
addi r24, r0, CONFIG_SYS_TEXT_BASE /* Get reloc offset */
rsub r23, r24, r23 /* keep - this is already here gd->reloc_off */
addik r6, r0, 0x2 /* BIG/LITTLE endian offset */
lwi r7, r0, 0x28
swi r6, r0, 0x28 /* used first unused MB vector */
lbui r10, r0, 0x28 /* used first unused MB vector */
swi r7, r0, 0x28
#ifdef CONFIG_SYS_USR_EXCEP
addik r6, r0, _exception_handler
addk r6, r6, r23 /* add offset */
sw r6, r1, r0
lhu r7, r1, r10
rsubi r8, r10, 0xa
sh r7, r0, r8
rsubi r8, r10, 0xe
sh r6, r0, r8
#endif
addik r6, r0, _hw_exception_handler
addk r6, r6, r23 /* add offset */
sw r6, r1, r0
lhu r7, r1, r10
rsubi r8, r10, 0x22
sh r7, r0, r8
rsubi r8, r10, 0x26
sh r6, r0, r8
addik r6, r0, _interrupt_handler
addk r6, r6, r23 /* add offset */
sw r6, r1, r0
lhu r7, r1, r10
rsubi r8, r10, 0x12
sh r7, r0, r8
rsubi r8, r10, 0x16
sh r6, r0, r8
/* Check if GOT exist */
addik r21, r23, _got_start
addik r22, r23, _got_end
cmpu r12, r21, r22
beqi r12, 2f /* No GOT table - jump over */
/* Skip last 3 entries plus 1 because of loop boundary below */
addik r22, r22, -0x10
/* Relocate the GOT. */
3: lw r12, r21, r0 /* Load entry */
addk r12, r12, r23 /* Add reloc offset */
sw r12, r21, r0 /* Save entry back */
cmpu r12, r21, r22 /* Check if this cross boundary */
bneid r12, 3b
addik r21. r21, 4
/* Update pointer to GOT */
mfs r20, rpc
addik r20, r20, _GLOBAL_OFFSET_TABLE_ + 8
addk r20, r20, r23
/* Flush caches to ensure consistency */
addik r5, r0, 0
addik r6, r0, XILINX_DCACHE_BYTE_SIZE
bralid r15, flush_cache
nop
2: addi r5, r31, 0 /* gd is initialized in board_r.c */
addi r6, r0, CONFIG_SYS_TEXT_BASE
addi r12, r23, board_init_r
bra r12 /* Jump to relocated code */
.end relocate_code
#endif
|
