Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
[ARM] nommu: start-up code
This patch adds nommu version start-up code head-nommu.S.
The common part of the start-up codes is moved to head-common.S.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
authored by
Hyok S. Choi
and committed by
Russell King
75d90832
10c2df65
+1
-1
arch/arm/Makefile
+1
-1
arch/arm/Makefile
+217
arch/arm/kernel/head-common.S
+217
arch/arm/kernel/head-common.S
···
1
+
/*
2
+
* linux/arch/arm/kernel/head-common.S
3
+
*
4
+
* Copyright (C) 1994-2002 Russell King
5
+
* Copyright (c) 2003 ARM Limited
6
+
* All Rights Reserved
7
+
*
8
+
* This program is free software; you can redistribute it and/or modify
9
+
* it under the terms of the GNU General Public License version 2 as
10
+
* published by the Free Software Foundation.
11
+
*
12
+
*/
13
+
14
+
.type __switch_data, %object
15
+
__switch_data:
16
+
.long __mmap_switched
17
+
.long __data_loc @ r4
18
+
.long __data_start @ r5
19
+
.long __bss_start @ r6
20
+
.long _end @ r7
21
+
.long processor_id @ r4
22
+
.long __machine_arch_type @ r5
23
+
.long cr_alignment @ r6
24
+
.long init_thread_union + THREAD_START_SP @ sp
25
+
26
+
/*
27
+
* The following fragment of code is executed with the MMU on in MMU mode,
28
+
* and uses absolute addresses; this is not position independent.
29
+
*
30
+
* r0 = cp#15 control register
31
+
* r1 = machine ID
32
+
* r9 = processor ID
33
+
*/
34
+
.type __mmap_switched, %function
35
+
__mmap_switched:
36
+
adr r3, __switch_data + 4
37
+
38
+
ldmia r3!, {r4, r5, r6, r7}
39
+
cmp r4, r5 @ Copy data segment if needed
40
+
1: cmpne r5, r6
41
+
ldrne fp, [r4], #4
42
+
strne fp, [r5], #4
43
+
bne 1b
44
+
45
+
mov fp, #0 @ Clear BSS (and zero fp)
46
+
1: cmp r6, r7
47
+
strcc fp, [r6],#4
48
+
bcc 1b
49
+
50
+
ldmia r3, {r4, r5, r6, sp}
51
+
str r9, [r4] @ Save processor ID
52
+
str r1, [r5] @ Save machine type
53
+
bic r4, r0, #CR_A @ Clear 'A' bit
54
+
stmia r6, {r0, r4} @ Save control register values
55
+
b start_kernel
56
+
57
+
/*
58
+
* Exception handling. Something went wrong and we can't proceed. We
59
+
* ought to tell the user, but since we don't have any guarantee that
60
+
* we're even running on the right architecture, we do virtually nothing.
61
+
*
62
+
* If CONFIG_DEBUG_LL is set we try to print out something about the error
63
+
* and hope for the best (useful if bootloader fails to pass a proper
64
+
* machine ID for example).
65
+
*/
66
+
67
+
.type __error_p, %function
68
+
__error_p:
69
+
#ifdef CONFIG_DEBUG_LL
70
+
adr r0, str_p1
71
+
bl printascii
72
+
b __error
73
+
str_p1: .asciz "\nError: unrecognized/unsupported processor variant.\n"
74
+
.align
75
+
#endif
76
+
77
+
.type __error_a, %function
78
+
__error_a:
79
+
#ifdef CONFIG_DEBUG_LL
80
+
mov r4, r1 @ preserve machine ID
81
+
adr r0, str_a1
82
+
bl printascii
83
+
mov r0, r4
84
+
bl printhex8
85
+
adr r0, str_a2
86
+
bl printascii
87
+
adr r3, 3f
88
+
ldmia r3, {r4, r5, r6} @ get machine desc list
89
+
sub r4, r3, r4 @ get offset between virt&phys
90
+
add r5, r5, r4 @ convert virt addresses to
91
+
add r6, r6, r4 @ physical address space
92
+
1: ldr r0, [r5, #MACHINFO_TYPE] @ get machine type
93
+
bl printhex8
94
+
mov r0, #'\t'
95
+
bl printch
96
+
ldr r0, [r5, #MACHINFO_NAME] @ get machine name
97
+
add r0, r0, r4
98
+
bl printascii
99
+
mov r0, #'\n'
100
+
bl printch
101
+
add r5, r5, #SIZEOF_MACHINE_DESC @ next machine_desc
102
+
cmp r5, r6
103
+
blo 1b
104
+
adr r0, str_a3
105
+
bl printascii
106
+
b __error
107
+
str_a1: .asciz "\nError: unrecognized/unsupported machine ID (r1 = 0x"
108
+
str_a2: .asciz ").\n\nAvailable machine support:\n\nID (hex)\tNAME\n"
109
+
str_a3: .asciz "\nPlease check your kernel config and/or bootloader.\n"
110
+
.align
111
+
#endif
112
+
113
+
.type __error, %function
114
+
__error:
115
+
#ifdef CONFIG_ARCH_RPC
116
+
/*
117
+
* Turn the screen red on a error - RiscPC only.
118
+
*/
119
+
mov r0, #0x02000000
120
+
mov r3, #0x11
121
+
orr r3, r3, r3, lsl #8
122
+
orr r3, r3, r3, lsl #16
123
+
str r3, [r0], #4
124
+
str r3, [r0], #4
125
+
str r3, [r0], #4
126
+
str r3, [r0], #4
127
+
#endif
128
+
1: mov r0, r0
129
+
b 1b
130
+
131
+
132
+
/*
133
+
* Read processor ID register (CP#15, CR0), and look up in the linker-built
134
+
* supported processor list. Note that we can't use the absolute addresses
135
+
* for the __proc_info lists since we aren't running with the MMU on
136
+
* (and therefore, we are not in the correct address space). We have to
137
+
* calculate the offset.
138
+
*
139
+
* r9 = cpuid
140
+
* Returns:
141
+
* r3, r4, r6 corrupted
142
+
* r5 = proc_info pointer in physical address space
143
+
* r9 = cpuid (preserved)
144
+
*/
145
+
.type __lookup_processor_type, %function
146
+
__lookup_processor_type:
147
+
adr r3, 3f
148
+
ldmda r3, {r5 - r7}
149
+
sub r3, r3, r7 @ get offset between virt&phys
150
+
add r5, r5, r3 @ convert virt addresses to
151
+
add r6, r6, r3 @ physical address space
152
+
1: ldmia r5, {r3, r4} @ value, mask
153
+
and r4, r4, r9 @ mask wanted bits
154
+
teq r3, r4
155
+
beq 2f
156
+
add r5, r5, #PROC_INFO_SZ @ sizeof(proc_info_list)
157
+
cmp r5, r6
158
+
blo 1b
159
+
mov r5, #0 @ unknown processor
160
+
2: mov pc, lr
161
+
162
+
/*
163
+
* This provides a C-API version of the above function.
164
+
*/
165
+
ENTRY(lookup_processor_type)
166
+
stmfd sp!, {r4 - r7, r9, lr}
167
+
mov r9, r0
168
+
bl __lookup_processor_type
169
+
mov r0, r5
170
+
ldmfd sp!, {r4 - r7, r9, pc}
171
+
172
+
/*
173
+
* Look in include/asm-arm/procinfo.h and arch/arm/kernel/arch.[ch] for
174
+
* more information about the __proc_info and __arch_info structures.
175
+
*/
176
+
.long __proc_info_begin
177
+
.long __proc_info_end
178
+
3: .long .
179
+
.long __arch_info_begin
180
+
.long __arch_info_end
181
+
182
+
/*
183
+
* Lookup machine architecture in the linker-build list of architectures.
184
+
* Note that we can't use the absolute addresses for the __arch_info
185
+
* lists since we aren't running with the MMU on (and therefore, we are
186
+
* not in the correct address space). We have to calculate the offset.
187
+
*
188
+
* r1 = machine architecture number
189
+
* Returns:
190
+
* r3, r4, r6 corrupted
191
+
* r5 = mach_info pointer in physical address space
192
+
*/
193
+
.type __lookup_machine_type, %function
194
+
__lookup_machine_type:
195
+
adr r3, 3b
196
+
ldmia r3, {r4, r5, r6}
197
+
sub r3, r3, r4 @ get offset between virt&phys
198
+
add r5, r5, r3 @ convert virt addresses to
199
+
add r6, r6, r3 @ physical address space
200
+
1: ldr r3, [r5, #MACHINFO_TYPE] @ get machine type
201
+
teq r3, r1 @ matches loader number?
202
+
beq 2f @ found
203
+
add r5, r5, #SIZEOF_MACHINE_DESC @ next machine_desc
204
+
cmp r5, r6
205
+
blo 1b
206
+
mov r5, #0 @ unknown machine
207
+
2: mov pc, lr
208
+
209
+
/*
210
+
* This provides a C-API version of the above function.
211
+
*/
212
+
ENTRY(lookup_machine_type)
213
+
stmfd sp!, {r4 - r6, lr}
214
+
mov r1, r0
215
+
bl __lookup_machine_type
216
+
mov r0, r5
217
+
ldmfd sp!, {r4 - r6, pc}
+83
arch/arm/kernel/head-nommu.S
+83
arch/arm/kernel/head-nommu.S
···
1
+
/*
2
+
* linux/arch/arm/kernel/head-nommu.S
3
+
*
4
+
* Copyright (C) 1994-2002 Russell King
5
+
* Copyright (C) 2003-2006 Hyok S. Choi
6
+
*
7
+
* This program is free software; you can redistribute it and/or modify
8
+
* it under the terms of the GNU General Public License version 2 as
9
+
* published by the Free Software Foundation.
10
+
*
11
+
* Common kernel startup code (non-paged MM)
12
+
* for 32-bit CPUs which has a process ID register(CP15).
13
+
*
14
+
*/
15
+
#include <linux/config.h>
16
+
#include <linux/linkage.h>
17
+
#include <linux/init.h>
18
+
19
+
#include <asm/assembler.h>
20
+
#include <asm/mach-types.h>
21
+
#include <asm/procinfo.h>
22
+
#include <asm/ptrace.h>
23
+
#include <asm/constants.h>
24
+
#include <asm/system.h>
25
+
26
+
#define PROCINFO_INITFUNC 12
27
+
28
+
/*
29
+
* Kernel startup entry point.
30
+
* ---------------------------
31
+
*
32
+
* This is normally called from the decompressor code. The requirements
33
+
* are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
34
+
* r1 = machine nr.
35
+
*
36
+
* See linux/arch/arm/tools/mach-types for the complete list of machine
37
+
* numbers for r1.
38
+
*
39
+
*/
40
+
__INIT
41
+
.type stext, %function
42
+
ENTRY(stext)
43
+
msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode
44
+
@ and irqs disabled
45
+
mrc p15, 0, r9, c0, c0 @ get processor id
46
+
bl __lookup_processor_type @ r5=procinfo r9=cpuid
47
+
movs r10, r5 @ invalid processor (r5=0)?
48
+
beq __error_p @ yes, error 'p'
49
+
bl __lookup_machine_type @ r5=machinfo
50
+
movs r8, r5 @ invalid machine (r5=0)?
51
+
beq __error_a @ yes, error 'a'
52
+
53
+
ldr r13, __switch_data @ address to jump to after
54
+
@ the initialization is done
55
+
adr lr, __after_proc_init @ return (PIC) address
56
+
add pc, r10, #PROCINFO_INITFUNC
57
+
58
+
/*
59
+
* Set the Control Register and Read the process ID.
60
+
*/
61
+
.type __after_proc_init, %function
62
+
__after_proc_init:
63
+
mrc p15, 0, r0, c1, c0, 0 @ read control reg
64
+
#ifdef CONFIG_ALIGNMENT_TRAP
65
+
orr r0, r0, #CR_A
66
+
#else
67
+
bic r0, r0, #CR_A
68
+
#endif
69
+
#ifdef CONFIG_CPU_DCACHE_DISABLE
70
+
bic r0, r0, #CR_C
71
+
#endif
72
+
#ifdef CONFIG_CPU_BPREDICT_DISABLE
73
+
bic r0, r0, #CR_Z
74
+
#endif
75
+
#ifdef CONFIG_CPU_ICACHE_DISABLE
76
+
bic r0, r0, #CR_I
77
+
#endif
78
+
mcr p15, 0, r0, c1, c0, 0 @ write control reg
79
+
80
+
mov pc, r13 @ clear the BSS and jump
81
+
@ to start_kernel
82
+
83
+
#include "head-common.S"
+1
-206
arch/arm/kernel/head.S
+1
-206
arch/arm/kernel/head.S
···
103
103
adr lr, __enable_mmu @ return (PIC) address
104
104
add pc, r10, #PROCINFO_INITFUNC
105
105
106
-
.type __switch_data, %object
107
-
__switch_data:
108
-
.long __mmap_switched
109
-
.long __data_loc @ r4
110
-
.long __data_start @ r5
111
-
.long __bss_start @ r6
112
-
.long _end @ r7
113
-
.long processor_id @ r4
114
-
.long __machine_arch_type @ r5
115
-
.long cr_alignment @ r6
116
-
.long init_thread_union + THREAD_START_SP @ sp
117
-
118
-
/*
119
-
* The following fragment of code is executed with the MMU on, and uses
120
-
* absolute addresses; this is not position independent.
121
-
*
122
-
* r0 = cp#15 control register
123
-
* r1 = machine ID
124
-
* r9 = processor ID
125
-
*/
126
-
.type __mmap_switched, %function
127
-
__mmap_switched:
128
-
adr r3, __switch_data + 4
129
-
130
-
ldmia r3!, {r4, r5, r6, r7}
131
-
cmp r4, r5 @ Copy data segment if needed
132
-
1: cmpne r5, r6
133
-
ldrne fp, [r4], #4
134
-
strne fp, [r5], #4
135
-
bne 1b
136
-
137
-
mov fp, #0 @ Clear BSS (and zero fp)
138
-
1: cmp r6, r7
139
-
strcc fp, [r6],#4
140
-
bcc 1b
141
-
142
-
ldmia r3, {r4, r5, r6, sp}
143
-
str r9, [r4] @ Save processor ID
144
-
str r1, [r5] @ Save machine type
145
-
bic r4, r0, #CR_A @ Clear 'A' bit
146
-
stmia r6, {r0, r4} @ Save control register values
147
-
b start_kernel
148
-
149
106
#if defined(CONFIG_SMP)
150
107
.type secondary_startup, #function
151
108
ENTRY(secondary_startup)
···
325
368
mov pc, lr
326
369
.ltorg
327
370
328
-
329
-
330
-
/*
331
-
* Exception handling. Something went wrong and we can't proceed. We
332
-
* ought to tell the user, but since we don't have any guarantee that
333
-
* we're even running on the right architecture, we do virtually nothing.
334
-
*
335
-
* If CONFIG_DEBUG_LL is set we try to print out something about the error
336
-
* and hope for the best (useful if bootloader fails to pass a proper
337
-
* machine ID for example).
338
-
*/
339
-
340
-
.type __error_p, %function
341
-
__error_p:
342
-
#ifdef CONFIG_DEBUG_LL
343
-
adr r0, str_p1
344
-
bl printascii
345
-
b __error
346
-
str_p1: .asciz "\nError: unrecognized/unsupported processor variant.\n"
347
-
.align
348
-
#endif
349
-
350
-
.type __error_a, %function
351
-
__error_a:
352
-
#ifdef CONFIG_DEBUG_LL
353
-
mov r4, r1 @ preserve machine ID
354
-
adr r0, str_a1
355
-
bl printascii
356
-
mov r0, r4
357
-
bl printhex8
358
-
adr r0, str_a2
359
-
bl printascii
360
-
adr r3, 3f
361
-
ldmia r3, {r4, r5, r6} @ get machine desc list
362
-
sub r4, r3, r4 @ get offset between virt&phys
363
-
add r5, r5, r4 @ convert virt addresses to
364
-
add r6, r6, r4 @ physical address space
365
-
1: ldr r0, [r5, #MACHINFO_TYPE] @ get machine type
366
-
bl printhex8
367
-
mov r0, #'\t'
368
-
bl printch
369
-
ldr r0, [r5, #MACHINFO_NAME] @ get machine name
370
-
add r0, r0, r4
371
-
bl printascii
372
-
mov r0, #'\n'
373
-
bl printch
374
-
add r5, r5, #SIZEOF_MACHINE_DESC @ next machine_desc
375
-
cmp r5, r6
376
-
blo 1b
377
-
adr r0, str_a3
378
-
bl printascii
379
-
b __error
380
-
str_a1: .asciz "\nError: unrecognized/unsupported machine ID (r1 = 0x"
381
-
str_a2: .asciz ").\n\nAvailable machine support:\n\nID (hex)\tNAME\n"
382
-
str_a3: .asciz "\nPlease check your kernel config and/or bootloader.\n"
383
-
.align
384
-
#endif
385
-
386
-
.type __error, %function
387
-
__error:
388
-
#ifdef CONFIG_ARCH_RPC
389
-
/*
390
-
* Turn the screen red on a error - RiscPC only.
391
-
*/
392
-
mov r0, #0x02000000
393
-
mov r3, #0x11
394
-
orr r3, r3, r3, lsl #8
395
-
orr r3, r3, r3, lsl #16
396
-
str r3, [r0], #4
397
-
str r3, [r0], #4
398
-
str r3, [r0], #4
399
-
str r3, [r0], #4
400
-
#endif
401
-
1: mov r0, r0
402
-
b 1b
403
-
404
-
405
-
/*
406
-
* Read processor ID register (CP#15, CR0), and look up in the linker-built
407
-
* supported processor list. Note that we can't use the absolute addresses
408
-
* for the __proc_info lists since we aren't running with the MMU on
409
-
* (and therefore, we are not in the correct address space). We have to
410
-
* calculate the offset.
411
-
*
412
-
* r9 = cpuid
413
-
* Returns:
414
-
* r3, r4, r6 corrupted
415
-
* r5 = proc_info pointer in physical address space
416
-
* r9 = cpuid (preserved)
417
-
*/
418
-
.type __lookup_processor_type, %function
419
-
__lookup_processor_type:
420
-
adr r3, 3f
421
-
ldmda r3, {r5 - r7}
422
-
sub r3, r3, r7 @ get offset between virt&phys
423
-
add r5, r5, r3 @ convert virt addresses to
424
-
add r6, r6, r3 @ physical address space
425
-
1: ldmia r5, {r3, r4} @ value, mask
426
-
and r4, r4, r9 @ mask wanted bits
427
-
teq r3, r4
428
-
beq 2f
429
-
add r5, r5, #PROC_INFO_SZ @ sizeof(proc_info_list)
430
-
cmp r5, r6
431
-
blo 1b
432
-
mov r5, #0 @ unknown processor
433
-
2: mov pc, lr
434
-
435
-
/*
436
-
* This provides a C-API version of the above function.
437
-
*/
438
-
ENTRY(lookup_processor_type)
439
-
stmfd sp!, {r4 - r7, r9, lr}
440
-
mov r9, r0
441
-
bl __lookup_processor_type
442
-
mov r0, r5
443
-
ldmfd sp!, {r4 - r7, r9, pc}
444
-
445
-
/*
446
-
* Look in include/asm-arm/procinfo.h and arch/arm/kernel/arch.[ch] for
447
-
* more information about the __proc_info and __arch_info structures.
448
-
*/
449
-
.long __proc_info_begin
450
-
.long __proc_info_end
451
-
3: .long .
452
-
.long __arch_info_begin
453
-
.long __arch_info_end
454
-
455
-
/*
456
-
* Lookup machine architecture in the linker-build list of architectures.
457
-
* Note that we can't use the absolute addresses for the __arch_info
458
-
* lists since we aren't running with the MMU on (and therefore, we are
459
-
* not in the correct address space). We have to calculate the offset.
460
-
*
461
-
* r1 = machine architecture number
462
-
* Returns:
463
-
* r3, r4, r6 corrupted
464
-
* r5 = mach_info pointer in physical address space
465
-
*/
466
-
.type __lookup_machine_type, %function
467
-
__lookup_machine_type:
468
-
adr r3, 3b
469
-
ldmia r3, {r4, r5, r6}
470
-
sub r3, r3, r4 @ get offset between virt&phys
471
-
add r5, r5, r3 @ convert virt addresses to
472
-
add r6, r6, r3 @ physical address space
473
-
1: ldr r3, [r5, #MACHINFO_TYPE] @ get machine type
474
-
teq r3, r1 @ matches loader number?
475
-
beq 2f @ found
476
-
add r5, r5, #SIZEOF_MACHINE_DESC @ next machine_desc
477
-
cmp r5, r6
478
-
blo 1b
479
-
mov r5, #0 @ unknown machine
480
-
2: mov pc, lr
481
-
482
-
/*
483
-
* This provides a C-API version of the above function.
484
-
*/
485
-
ENTRY(lookup_machine_type)
486
-
stmfd sp!, {r4 - r6, lr}
487
-
mov r1, r0
488
-
bl __lookup_machine_type
489
-
mov r0, r5
490
-
ldmfd sp!, {r4 - r6, pc}
371
+
#include "head-common.S"