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
|
/*
* linux/arch/arm/mm/proc-v7m.S
*
* Copyright (C) 2008 ARM Ltd.
* Copyright (C) 2001 Deep Blue Solutions Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This is the "shell" of the ARMv7-M processor support.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/memory.h>
#include <asm/v7m.h>
#include "proc-macros.S"
ENTRY(cpu_v7m_proc_init)
ret lr
ENDPROC(cpu_v7m_proc_init)
ENTRY(cpu_v7m_proc_fin)
ret lr
ENDPROC(cpu_v7m_proc_fin)
/*
* cpu_v7m_reset(loc)
*
* Perform a soft reset of the system. Put the CPU into the
* same state as it would be if it had been reset, and branch
* to what would be the reset vector.
*
* - loc - location to jump to for soft reset
*/
.align 5
ENTRY(cpu_v7m_reset)
ret r0
ENDPROC(cpu_v7m_reset)
/*
* cpu_v7m_do_idle()
*
* Idle the processor (eg, wait for interrupt).
*
* IRQs are already disabled.
*/
ENTRY(cpu_v7m_do_idle)
wfi
ret lr
ENDPROC(cpu_v7m_do_idle)
ENTRY(cpu_v7m_dcache_clean_area)
ret lr
ENDPROC(cpu_v7m_dcache_clean_area)
/*
* There is no MMU, so here is nothing to do.
*/
ENTRY(cpu_v7m_switch_mm)
ret lr
ENDPROC(cpu_v7m_switch_mm)
.globl cpu_v7m_suspend_size
.equ cpu_v7m_suspend_size, 0
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_v7m_do_suspend)
ret lr
ENDPROC(cpu_v7m_do_suspend)
ENTRY(cpu_v7m_do_resume)
ret lr
ENDPROC(cpu_v7m_do_resume)
#endif
ENTRY(cpu_cm7_dcache_clean_area)
dcache_line_size r2, r3
movw r3, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
movt r3, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
1: str r0, [r3] @ clean D entry
add r0, r0, r2
subs r1, r1, r2
bhi 1b
dsb
ret lr
ENDPROC(cpu_cm7_dcache_clean_area)
ENTRY(cpu_cm7_proc_fin)
movw r2, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
movt r2, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
ldr r0, [r2]
bic r0, r0, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC)
str r0, [r2]
ret lr
ENDPROC(cpu_cm7_proc_fin)
.section ".init.text", #alloc, #execinstr
__v7m_cm7_setup:
mov r8, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC| V7M_SCB_CCR_BP)
b __v7m_setup_cont
/*
* __v7m_setup
*
* This should be able to cover all ARMv7-M cores.
*/
__v7m_setup:
mov r8, 0
__v7m_setup_cont:
@ Configure the vector table base address
ldr r0, =BASEADDR_V7M_SCB
ldr r12, =vector_table
str r12, [r0, V7M_SCB_VTOR]
@ enable UsageFault, BusFault and MemManage fault.
ldr r5, [r0, #V7M_SCB_SHCSR]
orr r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
str r5, [r0, #V7M_SCB_SHCSR]
@ Lower the priority of the SVC and PendSV exceptions
mov r5, #0x80000000
str r5, [r0, V7M_SCB_SHPR2] @ set SVC priority
mov r5, #0x00800000
str r5, [r0, V7M_SCB_SHPR3] @ set PendSV priority
@ SVC to switch to handler mode. Notice that this requires sp to
@ point to writeable memory because the processor saves
@ some registers to the stack.
badr r1, 1f
ldr r5, [r12, #11 * 4] @ read the SVC vector entry
str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
dsb
mov r6, lr @ save LR
ldr sp, =init_thread_union + THREAD_START_SP
cpsie i
svc #0
1: cpsid i
str r5, [r12, #11 * 4] @ restore the original SVC vector entry
mov lr, r6 @ restore LR
@ Special-purpose control register
mov r1, #1
msr control, r1 @ Thread mode has unpriviledged access
@ Configure caches (if implemented)
teq r8, #0
stmneia r12, {r0-r6, lr} @ v7m_invalidate_l1 touches r0-r6
blne v7m_invalidate_l1
teq r8, #0 @ re-evalutae condition
ldmneia r12, {r0-r6, lr}
@ Configure the System Control Register to ensure 8-byte stack alignment
@ Note the STKALIGN bit is either RW or RAO.
ldr r0, [r0, V7M_SCB_CCR] @ system control register
orr r0, #V7M_SCB_CCR_STKALIGN
orr r0, r0, r8
ret lr
ENDPROC(__v7m_setup)
/*
* Cortex-M7 processor functions
*/
globl_equ cpu_cm7_proc_init, cpu_v7m_proc_init
globl_equ cpu_cm7_reset, cpu_v7m_reset
globl_equ cpu_cm7_do_idle, cpu_v7m_do_idle
globl_equ cpu_cm7_switch_mm, cpu_v7m_switch_mm
define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
define_processor_functions cm7, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
.section ".rodata"
string cpu_arch_name, "armv7m"
string cpu_elf_name "v7m"
string cpu_v7m_name "ARMv7-M"
.section ".proc.info.init", #alloc
.macro __v7m_proc name, initfunc, cache_fns = nop_cache_fns, hwcaps = 0, proc_fns = v7m_processor_functions
.long 0 /* proc_info_list.__cpu_mm_mmu_flags */
.long 0 /* proc_info_list.__cpu_io_mmu_flags */
initfn \initfunc, \name
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \hwcaps
.long cpu_v7m_name
.long \proc_fns
.long 0 /* proc_info_list.tlb */
.long 0 /* proc_info_list.user */
.long \cache_fns
.endm
/*
* Match ARM Cortex-M7 processor.
*/
.type __v7m_cm7_proc_info, #object
__v7m_cm7_proc_info:
.long 0x410fc270 /* ARM Cortex-M7 0xC27 */
.long 0xff0ffff0 /* Mask off revision, patch release */
__v7m_proc __v7m_cm7_proc_info, __v7m_cm7_setup, hwcaps = HWCAP_EDSP, cache_fns = v7m_cache_fns, proc_fns = cm7_processor_functions
.size __v7m_cm7_proc_info, . - __v7m_cm7_proc_info
/*
* Match ARM Cortex-M4 processor.
*/
.type __v7m_cm4_proc_info, #object
__v7m_cm4_proc_info:
.long 0x410fc240 /* ARM Cortex-M4 0xC24 */
.long 0xff0ffff0 /* Mask off revision, patch release */
__v7m_proc __v7m_cm4_proc_info, __v7m_setup, hwcaps = HWCAP_EDSP
.size __v7m_cm4_proc_info, . - __v7m_cm4_proc_info
/*
* Match ARM Cortex-M3 processor.
*/
.type __v7m_cm3_proc_info, #object
__v7m_cm3_proc_info:
.long 0x410fc230 /* ARM Cortex-M3 0xC23 */
.long 0xff0ffff0 /* Mask off revision, patch release */
__v7m_proc __v7m_cm3_proc_info, __v7m_setup
.size __v7m_cm3_proc_info, . - __v7m_cm3_proc_info
/*
* Match any ARMv7-M processor core.
*/
.type __v7m_proc_info, #object
__v7m_proc_info:
.long 0x000f0000 @ Required ID value
.long 0x000f0000 @ Mask for ID
__v7m_proc __v7m_proc_info, __v7m_setup
.size __v7m_proc_info, . - __v7m_proc_info
|
