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
|
/*
* Copyright (C) Paul Mackerras 1997.
*
* Adapted for 64 bit LE PowerPC by Andrew Tauferner
*
* 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.
*
*/
#include "ppc_asm.h"
RELA = 7
RELACOUNT = 0x6ffffff9
.data
/* A procedure descriptor used when booting this as a COFF file.
* When making COFF, this comes first in the link and we're
* linked at 0x500000.
*/
.globl _zimage_start_opd
_zimage_start_opd:
.long 0x500000, 0, 0, 0
.text
b _zimage_start
#ifdef __powerpc64__
.balign 8
p_start: .8byte _start
p_etext: .8byte _etext
p_bss_start: .8byte __bss_start
p_end: .8byte _end
p_toc: .8byte __toc_start + 0x8000 - p_base
p_dyn: .8byte __dynamic_start - p_base
p_rela: .8byte __rela_dyn_start - p_base
p_prom: .8byte 0
.weak _platform_stack_top
p_pstack: .8byte _platform_stack_top
#else
p_start: .long _start
p_etext: .long _etext
p_bss_start: .long __bss_start
p_end: .long _end
.weak _platform_stack_top
p_pstack: .long _platform_stack_top
#endif
.weak _zimage_start
_zimage_start:
.globl _zimage_start_lib
_zimage_start_lib:
/* Work out the offset between the address we were linked at
and the address where we're running. */
bl .+4
p_base: mflr r10 /* r10 now points to runtime addr of p_base */
#ifndef __powerpc64__
/* grab the link address of the dynamic section in r11 */
addis r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha
lwz r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11)
cmpwi r11,0
beq 3f /* if not linked -pie */
/* get the runtime address of the dynamic section in r12 */
.weak __dynamic_start
addis r12,r10,(__dynamic_start-p_base)@ha
addi r12,r12,(__dynamic_start-p_base)@l
subf r11,r11,r12 /* runtime - linktime offset */
/* The dynamic section contains a series of tagged entries.
* We need the RELA and RELACOUNT entries. */
li r9,0
li r0,0
9: lwz r8,0(r12) /* get tag */
cmpwi r8,0
beq 10f /* end of list */
cmpwi r8,RELA
bne 11f
lwz r9,4(r12) /* get RELA pointer in r9 */
b 12f
11: addis r8,r8,(-RELACOUNT)@ha
cmpwi r8,RELACOUNT@l
bne 12f
lwz r0,4(r12) /* get RELACOUNT value in r0 */
12: addi r12,r12,8
b 9b
/* The relocation section contains a list of relocations.
* We now do the R_PPC_RELATIVE ones, which point to words
* which need to be initialized with addend + offset.
* The R_PPC_RELATIVE ones come first and there are RELACOUNT
* of them. */
10: /* skip relocation if we don't have both */
cmpwi r0,0
beq 3f
cmpwi r9,0
beq 3f
add r9,r9,r11 /* Relocate RELA pointer */
mtctr r0
2: lbz r0,4+3(r9) /* ELF32_R_INFO(reloc->r_info) */
cmpwi r0,22 /* R_PPC_RELATIVE */
bne 3f
lwz r12,0(r9) /* reloc->r_offset */
lwz r0,8(r9) /* reloc->r_addend */
add r0,r0,r11
stwx r0,r11,r12
addi r9,r9,12
bdnz 2b
/* Do a cache flush for our text, in case the loader didn't */
3: lwz r9,p_start-p_base(r10) /* note: these are relocated now */
lwz r8,p_etext-p_base(r10)
4: dcbf r0,r9
icbi r0,r9
addi r9,r9,0x20
cmplw cr0,r9,r8
blt 4b
sync
isync
/* Clear the BSS */
lwz r9,p_bss_start-p_base(r10)
lwz r8,p_end-p_base(r10)
li r0,0
5: stw r0,0(r9)
addi r9,r9,4
cmplw cr0,r9,r8
blt 5b
/* Possibly set up a custom stack */
lwz r8,p_pstack-p_base(r10)
cmpwi r8,0
beq 6f
lwz r1,0(r8)
li r0,0
stwu r0,-16(r1) /* establish a stack frame */
6:
#else /* __powerpc64__ */
/* Save the prom pointer at p_prom. */
std r5,(p_prom-p_base)(r10)
/* Set r2 to the TOC. */
ld r2,(p_toc-p_base)(r10)
add r2,r2,r10
/* Grab the link address of the dynamic section in r11. */
ld r11,-32768(r2)
cmpwi r11,0
beq 3f /* if not linked -pie then no dynamic section */
ld r11,(p_dyn-p_base)(r10)
add r11,r11,r10
ld r9,(p_rela-p_base)(r10)
add r9,r9,r10
li r13,0
li r8,0
9: ld r12,0(r11) /* get tag */
cmpdi r12,0
beq 12f /* end of list */
cmpdi r12,RELA
bne 10f
ld r13,8(r11) /* get RELA pointer in r13 */
b 11f
10: addis r12,r12,(-RELACOUNT)@ha
cmpdi r12,RELACOUNT@l
bne 11f
ld r8,8(r11) /* get RELACOUNT value in r8 */
11: addi r11,r11,16
b 9b
12:
cmpdi r13,0 /* check we have both RELA and RELACOUNT */
cmpdi cr1,r8,0
beq 3f
beq cr1,3f
/* Calcuate the runtime offset. */
subf r13,r13,r9
/* Run through the list of relocations and process the
* R_PPC64_RELATIVE ones. */
mtctr r8
13: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */
cmpdi r0,22 /* R_PPC64_RELATIVE */
bne 3f
ld r12,0(r9) /* reloc->r_offset */
ld r0,16(r9) /* reloc->r_addend */
add r0,r0,r13
stdx r0,r13,r12
addi r9,r9,24
bdnz 13b
/* Do a cache flush for our text, in case the loader didn't */
3: ld r9,p_start-p_base(r10) /* note: these are relocated now */
ld r8,p_etext-p_base(r10)
4: dcbf r0,r9
icbi r0,r9
addi r9,r9,0x20
cmpld cr0,r9,r8
blt 4b
sync
isync
/* Clear the BSS */
ld r9,p_bss_start-p_base(r10)
ld r8,p_end-p_base(r10)
li r0,0
5: std r0,0(r9)
addi r9,r9,8
cmpld cr0,r9,r8
blt 5b
/* Possibly set up a custom stack */
ld r8,p_pstack-p_base(r10)
cmpdi r8,0
beq 6f
ld r1,0(r8)
li r0,0
stdu r0,-112(r1) /* establish a stack frame */
6:
#endif /* __powerpc64__ */
/* Call platform_init() */
bl platform_init
/* Call start */
b start
#ifdef __powerpc64__
#define PROM_FRAME_SIZE 512
#define SAVE_GPR(n, base) std n,8*(n)(base)
#define REST_GPR(n, base) ld n,8*(n)(base)
#define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base)
#define SAVE_4GPRS(n, base) SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base)
#define SAVE_8GPRS(n, base) SAVE_4GPRS(n, base); SAVE_4GPRS(n+4, base)
#define SAVE_10GPRS(n, base) SAVE_8GPRS(n, base); SAVE_2GPRS(n+8, base)
#define REST_2GPRS(n, base) REST_GPR(n, base); REST_GPR(n+1, base)
#define REST_4GPRS(n, base) REST_2GPRS(n, base); REST_2GPRS(n+2, base)
#define REST_8GPRS(n, base) REST_4GPRS(n, base); REST_4GPRS(n+4, base)
#define REST_10GPRS(n, base) REST_8GPRS(n, base); REST_2GPRS(n+8, base)
/* prom handles the jump into and return from firmware. The prom args pointer
is loaded in r3. */
.globl prom
prom:
mflr r0
std r0,16(r1)
stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
SAVE_GPR(2, r1)
SAVE_GPR(13, r1)
SAVE_8GPRS(14, r1)
SAVE_10GPRS(22, r1)
mfcr r10
std r10,8*32(r1)
mfmsr r10
std r10,8*33(r1)
/* remove MSR_LE from msr but keep MSR_SF */
mfmsr r10
rldicr r10,r10,0,62
mtsrr1 r10
/* Load FW address, set LR to label 1, and jump to FW */
bl 0f
0: mflr r10
addi r11,r10,(1f-0b)
mtlr r11
ld r10,(p_prom-0b)(r10)
mtsrr0 r10
rfid
1: /* Return from OF */
FIXUP_ENDIAN
/* Restore registers and return. */
rldicl r1,r1,0,32
/* Restore the MSR (back to 64 bits) */
ld r10,8*(33)(r1)
mtmsr r10
isync
/* Restore other registers */
REST_GPR(2, r1)
REST_GPR(13, r1)
REST_8GPRS(14, r1)
REST_10GPRS(22, r1)
ld r10,8*32(r1)
mtcr r10
addi r1,r1,PROM_FRAME_SIZE
ld r0,16(r1)
mtlr r0
blr
#endif
|
