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-rw-r--r--arch/arm/kernel/head-common.S305
1 files changed, 159 insertions, 146 deletions
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index b9505aa267c0..bbecaac1e013 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -15,55 +15,6 @@
15#define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2) 15#define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2)
16#define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2) 16#define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2)
17 17
18 .align 2
19 .type __switch_data, %object
20__switch_data:
21 .long __mmap_switched
22 .long __data_loc @ r4
23 .long _data @ r5
24 .long __bss_start @ r6
25 .long _end @ r7
26 .long processor_id @ r4
27 .long __machine_arch_type @ r5
28 .long __atags_pointer @ r6
29 .long cr_alignment @ r7
30 .long init_thread_union + THREAD_START_SP @ sp
31
32/*
33 * The following fragment of code is executed with the MMU on in MMU mode,
34 * and uses absolute addresses; this is not position independent.
35 *
36 * r0 = cp#15 control register
37 * r1 = machine ID
38 * r2 = atags pointer
39 * r9 = processor ID
40 */
41__mmap_switched:
42 adr r3, __switch_data + 4
43
44 ldmia r3!, {r4, r5, r6, r7}
45 cmp r4, r5 @ Copy data segment if needed
461: cmpne r5, r6
47 ldrne fp, [r4], #4
48 strne fp, [r5], #4
49 bne 1b
50
51 mov fp, #0 @ Clear BSS (and zero fp)
521: cmp r6, r7
53 strcc fp, [r6],#4
54 bcc 1b
55
56 ARM( ldmia r3, {r4, r5, r6, r7, sp})
57 THUMB( ldmia r3, {r4, r5, r6, r7} )
58 THUMB( ldr sp, [r3, #16] )
59 str r9, [r4] @ Save processor ID
60 str r1, [r5] @ Save machine type
61 str r2, [r6] @ Save atags pointer
62 bic r4, r0, #CR_A @ Clear 'A' bit
63 stmia r7, {r0, r4} @ Save control register values
64 b start_kernel
65ENDPROC(__mmap_switched)
66
67/* 18/*
68 * Exception handling. Something went wrong and we can't proceed. We 19 * Exception handling. Something went wrong and we can't proceed. We
69 * ought to tell the user, but since we don't have any guarantee that 20 * ought to tell the user, but since we don't have any guarantee that
@@ -73,21 +24,7 @@ ENDPROC(__mmap_switched)
73 * and hope for the best (useful if bootloader fails to pass a proper 24 * and hope for the best (useful if bootloader fails to pass a proper
74 * machine ID for example). 25 * machine ID for example).
75 */ 26 */
76__error_p: 27 __HEAD
77#ifdef CONFIG_DEBUG_LL
78 adr r0, str_p1
79 bl printascii
80 mov r0, r9
81 bl printhex8
82 adr r0, str_p2
83 bl printascii
84 b __error
85str_p1: .asciz "\nError: unrecognized/unsupported processor variant (0x"
86str_p2: .asciz ").\n"
87 .align
88#endif
89ENDPROC(__error_p)
90
91__error_a: 28__error_a:
92#ifdef CONFIG_DEBUG_LL 29#ifdef CONFIG_DEBUG_LL
93 mov r4, r1 @ preserve machine ID 30 mov r4, r1 @ preserve machine ID
@@ -97,7 +34,7 @@ __error_a:
97 bl printhex8 34 bl printhex8
98 adr r0, str_a2 35 adr r0, str_a2
99 bl printascii 36 bl printascii
100 adr r3, 4f 37 adr r3, __lookup_machine_type_data
101 ldmia r3, {r4, r5, r6} @ get machine desc list 38 ldmia r3, {r4, r5, r6} @ get machine desc list
102 sub r4, r3, r4 @ get offset between virt&phys 39 sub r4, r3, r4 @ get offset between virt&phys
103 add r5, r5, r4 @ convert virt addresses to 40 add r5, r5, r4 @ convert virt addresses to
@@ -125,78 +62,6 @@ str_a3: .asciz "\nPlease check your kernel config and/or bootloader.\n"
125 .align 62 .align
126#endif 63#endif
127 64
128__error:
129#ifdef CONFIG_ARCH_RPC
130/*
131 * Turn the screen red on a error - RiscPC only.
132 */
133 mov r0, #0x02000000
134 mov r3, #0x11
135 orr r3, r3, r3, lsl #8
136 orr r3, r3, r3, lsl #16
137 str r3, [r0], #4
138 str r3, [r0], #4
139 str r3, [r0], #4
140 str r3, [r0], #4
141#endif
1421: mov r0, r0
143 b 1b
144ENDPROC(__error)
145
146
147/*
148 * Read processor ID register (CP#15, CR0), and look up in the linker-built
149 * supported processor list. Note that we can't use the absolute addresses
150 * for the __proc_info lists since we aren't running with the MMU on
151 * (and therefore, we are not in the correct address space). We have to
152 * calculate the offset.
153 *
154 * r9 = cpuid
155 * Returns:
156 * r3, r4, r6 corrupted
157 * r5 = proc_info pointer in physical address space
158 * r9 = cpuid (preserved)
159 */
160__lookup_processor_type:
161 adr r3, 3f
162 ldmia r3, {r5 - r7}
163 add r3, r3, #8
164 sub r3, r3, r7 @ get offset between virt&phys
165 add r5, r5, r3 @ convert virt addresses to
166 add r6, r6, r3 @ physical address space
1671: ldmia r5, {r3, r4} @ value, mask
168 and r4, r4, r9 @ mask wanted bits
169 teq r3, r4
170 beq 2f
171 add r5, r5, #PROC_INFO_SZ @ sizeof(proc_info_list)
172 cmp r5, r6
173 blo 1b
174 mov r5, #0 @ unknown processor
1752: mov pc, lr
176ENDPROC(__lookup_processor_type)
177
178/*
179 * This provides a C-API version of the above function.
180 */
181ENTRY(lookup_processor_type)
182 stmfd sp!, {r4 - r7, r9, lr}
183 mov r9, r0
184 bl __lookup_processor_type
185 mov r0, r5
186 ldmfd sp!, {r4 - r7, r9, pc}
187ENDPROC(lookup_processor_type)
188
189/*
190 * Look in <asm/procinfo.h> and arch/arm/kernel/arch.[ch] for
191 * more information about the __proc_info and __arch_info structures.
192 */
193 .align 2
1943: .long __proc_info_begin
195 .long __proc_info_end
1964: .long .
197 .long __arch_info_begin
198 .long __arch_info_end
199
200/* 65/*
201 * Lookup machine architecture in the linker-build list of architectures. 66 * Lookup machine architecture in the linker-build list of architectures.
202 * Note that we can't use the absolute addresses for the __arch_info 67 * Note that we can't use the absolute addresses for the __arch_info
@@ -209,7 +74,7 @@ ENDPROC(lookup_processor_type)
209 * r5 = mach_info pointer in physical address space 74 * r5 = mach_info pointer in physical address space
210 */ 75 */
211__lookup_machine_type: 76__lookup_machine_type:
212 adr r3, 4b 77 adr r3, __lookup_machine_type_data
213 ldmia r3, {r4, r5, r6} 78 ldmia r3, {r4, r5, r6}
214 sub r3, r3, r4 @ get offset between virt&phys 79 sub r3, r3, r4 @ get offset between virt&phys
215 add r5, r5, r3 @ convert virt addresses to 80 add r5, r5, r3 @ convert virt addresses to
@@ -225,15 +90,16 @@ __lookup_machine_type:
225ENDPROC(__lookup_machine_type) 90ENDPROC(__lookup_machine_type)
226 91
227/* 92/*
228 * This provides a C-API version of the above function. 93 * Look in arch/arm/kernel/arch.[ch] for information about the
94 * __arch_info structures.
229 */ 95 */
230ENTRY(lookup_machine_type) 96 .align 2
231 stmfd sp!, {r4 - r6, lr} 97 .type __lookup_machine_type_data, %object
232 mov r1, r0 98__lookup_machine_type_data:
233 bl __lookup_machine_type 99 .long .
234 mov r0, r5 100 .long __arch_info_begin
235 ldmfd sp!, {r4 - r6, pc} 101 .long __arch_info_end
236ENDPROC(lookup_machine_type) 102 .size __lookup_machine_type_data, . - __lookup_machine_type_data
237 103
238/* Determine validity of the r2 atags pointer. The heuristic requires 104/* Determine validity of the r2 atags pointer. The heuristic requires
239 * that the pointer be aligned, in the first 16k of physical RAM and 105 * that the pointer be aligned, in the first 16k of physical RAM and
@@ -265,3 +131,150 @@ __vet_atags:
2651: mov r2, #0 1311: mov r2, #0
266 mov pc, lr 132 mov pc, lr
267ENDPROC(__vet_atags) 133ENDPROC(__vet_atags)
134
135/*
136 * The following fragment of code is executed with the MMU on in MMU mode,
137 * and uses absolute addresses; this is not position independent.
138 *
139 * r0 = cp#15 control register
140 * r1 = machine ID
141 * r2 = atags pointer
142 * r9 = processor ID
143 */
144 __INIT
145__mmap_switched:
146 adr r3, __mmap_switched_data
147
148 ldmia r3!, {r4, r5, r6, r7}
149 cmp r4, r5 @ Copy data segment if needed
1501: cmpne r5, r6
151 ldrne fp, [r4], #4
152 strne fp, [r5], #4
153 bne 1b
154
155 mov fp, #0 @ Clear BSS (and zero fp)
1561: cmp r6, r7
157 strcc fp, [r6],#4
158 bcc 1b
159
160 ARM( ldmia r3, {r4, r5, r6, r7, sp})
161 THUMB( ldmia r3, {r4, r5, r6, r7} )
162 THUMB( ldr sp, [r3, #16] )
163 str r9, [r4] @ Save processor ID
164 str r1, [r5] @ Save machine type
165 str r2, [r6] @ Save atags pointer
166 bic r4, r0, #CR_A @ Clear 'A' bit
167 stmia r7, {r0, r4} @ Save control register values
168 b start_kernel
169ENDPROC(__mmap_switched)
170
171 .align 2
172 .type __mmap_switched_data, %object
173__mmap_switched_data:
174 .long __data_loc @ r4
175 .long _sdata @ r5
176 .long __bss_start @ r6
177 .long _end @ r7
178 .long processor_id @ r4
179 .long __machine_arch_type @ r5
180 .long __atags_pointer @ r6
181 .long cr_alignment @ r7
182 .long init_thread_union + THREAD_START_SP @ sp
183 .size __mmap_switched_data, . - __mmap_switched_data
184
185/*
186 * This provides a C-API version of __lookup_machine_type
187 */
188ENTRY(lookup_machine_type)
189 stmfd sp!, {r4 - r6, lr}
190 mov r1, r0
191 bl __lookup_machine_type
192 mov r0, r5
193 ldmfd sp!, {r4 - r6, pc}
194ENDPROC(lookup_machine_type)
195
196/*
197 * This provides a C-API version of __lookup_processor_type
198 */
199ENTRY(lookup_processor_type)
200 stmfd sp!, {r4 - r6, r9, lr}
201 mov r9, r0
202 bl __lookup_processor_type
203 mov r0, r5
204 ldmfd sp!, {r4 - r6, r9, pc}
205ENDPROC(lookup_processor_type)
206
207/*
208 * Read processor ID register (CP#15, CR0), and look up in the linker-built
209 * supported processor list. Note that we can't use the absolute addresses
210 * for the __proc_info lists since we aren't running with the MMU on
211 * (and therefore, we are not in the correct address space). We have to
212 * calculate the offset.
213 *
214 * r9 = cpuid
215 * Returns:
216 * r3, r4, r6 corrupted
217 * r5 = proc_info pointer in physical address space
218 * r9 = cpuid (preserved)
219 */
220 __CPUINIT
221__lookup_processor_type:
222 adr r3, __lookup_processor_type_data
223 ldmia r3, {r4 - r6}
224 sub r3, r3, r4 @ get offset between virt&phys
225 add r5, r5, r3 @ convert virt addresses to
226 add r6, r6, r3 @ physical address space
2271: ldmia r5, {r3, r4} @ value, mask
228 and r4, r4, r9 @ mask wanted bits
229 teq r3, r4
230 beq 2f
231 add r5, r5, #PROC_INFO_SZ @ sizeof(proc_info_list)
232 cmp r5, r6
233 blo 1b
234 mov r5, #0 @ unknown processor
2352: mov pc, lr
236ENDPROC(__lookup_processor_type)
237
238/*
239 * Look in <asm/procinfo.h> for information about the __proc_info structure.
240 */
241 .align 2
242 .type __lookup_processor_type_data, %object
243__lookup_processor_type_data:
244 .long .
245 .long __proc_info_begin
246 .long __proc_info_end
247 .size __lookup_processor_type_data, . - __lookup_processor_type_data
248
249__error_p:
250#ifdef CONFIG_DEBUG_LL
251 adr r0, str_p1
252 bl printascii
253 mov r0, r9
254 bl printhex8
255 adr r0, str_p2
256 bl printascii
257 b __error
258str_p1: .asciz "\nError: unrecognized/unsupported processor variant (0x"
259str_p2: .asciz ").\n"
260 .align
261#endif
262ENDPROC(__error_p)
263
264__error:
265#ifdef CONFIG_ARCH_RPC
266/*
267 * Turn the screen red on a error - RiscPC only.
268 */
269 mov r0, #0x02000000
270 mov r3, #0x11
271 orr r3, r3, r3, lsl #8
272 orr r3, r3, r3, lsl #16
273 str r3, [r0], #4
274 str r3, [r0], #4
275 str r3, [r0], #4
276 str r3, [r0], #4
277#endif
2781: mov r0, r0
279 b 1b
280ENDPROC(__error)