-
Notifications
You must be signed in to change notification settings - Fork 4.8k
/
head.S
1531 lines (1374 loc) · 38.1 KB
/
head.S
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
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/boot/compressed/head.S
*
* Copyright (C) 1996-2002 Russell King
* Copyright (C) 2004 Hyok S. Choi (MPU support)
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/v7m.h>
#include "efi-header.S"
#ifdef __ARMEB__
#define OF_DT_MAGIC 0xd00dfeed
#else
#define OF_DT_MAGIC 0xedfe0dd0
#endif
AR_CLASS( .arch armv7-a )
M_CLASS( .arch armv7-m )
/*
* Debugging stuff
*
* Note that these macros must not contain any code which is not
* 100% relocatable. Any attempt to do so will result in a crash.
* Please select one of the following when turning on debugging.
*/
#ifdef DEBUG
#if defined(CONFIG_DEBUG_ICEDCC)
#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
.macro loadsp, rb, tmp1, tmp2
.endm
.macro writeb, ch, rb, tmp
mcr p14, 0, \ch, c0, c5, 0
.endm
#elif defined(CONFIG_CPU_XSCALE)
.macro loadsp, rb, tmp1, tmp2
.endm
.macro writeb, ch, rb, tmp
mcr p14, 0, \ch, c8, c0, 0
.endm
#else
.macro loadsp, rb, tmp1, tmp2
.endm
.macro writeb, ch, rb, tmp
mcr p14, 0, \ch, c1, c0, 0
.endm
#endif
#else
#include CONFIG_DEBUG_LL_INCLUDE
.macro writeb, ch, rb, tmp
#ifdef CONFIG_DEBUG_UART_FLOW_CONTROL
waituartcts \tmp, \rb
#endif
waituarttxrdy \tmp, \rb
senduart \ch, \rb
busyuart \tmp, \rb
.endm
#if defined(CONFIG_ARCH_SA1100)
.macro loadsp, rb, tmp1, tmp2
mov \rb, #0x80000000 @ physical base address
add \rb, \rb, #0x00010000 @ Ser1
.endm
#else
.macro loadsp, rb, tmp1, tmp2
addruart \rb, \tmp1, \tmp2
.endm
#endif
#endif
#endif
.macro kputc,val
mov r0, \val
bl putc
.endm
.macro kphex,val,len
mov r0, \val
mov r1, #\len
bl phex
.endm
/*
* Debug kernel copy by printing the memory addresses involved
*/
.macro dbgkc, begin, end, cbegin, cend
#ifdef DEBUG
kputc #'C'
kputc #':'
kputc #'0'
kputc #'x'
kphex \begin, 8 /* Start of compressed kernel */
kputc #'-'
kputc #'0'
kputc #'x'
kphex \end, 8 /* End of compressed kernel */
kputc #'-'
kputc #'>'
kputc #'0'
kputc #'x'
kphex \cbegin, 8 /* Start of kernel copy */
kputc #'-'
kputc #'0'
kputc #'x'
kphex \cend, 8 /* End of kernel copy */
kputc #'\n'
#endif
.endm
/*
* Debug print of the final appended DTB location
*/
.macro dbgadtb, begin, size
#ifdef DEBUG
kputc #'D'
kputc #'T'
kputc #'B'
kputc #':'
kputc #'0'
kputc #'x'
kphex \begin, 8 /* Start of appended DTB */
kputc #' '
kputc #'('
kputc #'0'
kputc #'x'
kphex \size, 8 /* Size of appended DTB */
kputc #')'
kputc #'\n'
#endif
.endm
.macro enable_cp15_barriers, reg
mrc p15, 0, \reg, c1, c0, 0 @ read SCTLR
tst \reg, #(1 << 5) @ CP15BEN bit set?
bne .L_\@
orr \reg, \reg, #(1 << 5) @ CP15 barrier instructions
mcr p15, 0, \reg, c1, c0, 0 @ write SCTLR
ARM( .inst 0xf57ff06f @ v7+ isb )
THUMB( isb )
.L_\@:
.endm
/*
* The kernel build system appends the size of the
* decompressed kernel at the end of the compressed data
* in little-endian form.
*/
.macro get_inflated_image_size, res:req, tmp1:req, tmp2:req
adr \res, .Linflated_image_size_offset
ldr \tmp1, [\res]
add \tmp1, \tmp1, \res @ address of inflated image size
ldrb \res, [\tmp1] @ get_unaligned_le32
ldrb \tmp2, [\tmp1, #1]
orr \res, \res, \tmp2, lsl #8
ldrb \tmp2, [\tmp1, #2]
ldrb \tmp1, [\tmp1, #3]
orr \res, \res, \tmp2, lsl #16
orr \res, \res, \tmp1, lsl #24
.endm
.macro be32tocpu, val, tmp
#ifndef __ARMEB__
/* convert to little endian */
rev_l \val, \tmp
#endif
.endm
.section ".start", "ax"
/*
* sort out different calling conventions
*/
.align
/*
* Always enter in ARM state for CPUs that support the ARM ISA.
* As of today (2014) that's exactly the members of the A and R
* classes.
*/
AR_CLASS( .arm )
start:
.type start,#function
/*
* These 7 nops along with the 1 nop immediately below for
* !THUMB2 form 8 nops that make the compressed kernel bootable
* on legacy ARM systems that were assuming the kernel in a.out
* binary format. The boot loaders on these systems would
* jump 32 bytes into the image to skip the a.out header.
* with these 8 nops filling exactly 32 bytes, things still
* work as expected on these legacy systems. Thumb2 mode keeps
* 7 of the nops as it turns out that some boot loaders
* were patching the initial instructions of the kernel, i.e
* had started to exploit this "patch area".
*/
__initial_nops
.rept 5
__nop
.endr
#ifndef CONFIG_THUMB2_KERNEL
__nop
#else
AR_CLASS( sub pc, pc, #3 ) @ A/R: switch to Thumb2 mode
M_CLASS( nop.w ) @ M: already in Thumb2 mode
.thumb
#endif
W(b) 1f
.word _magic_sig @ Magic numbers to help the loader
.word _magic_start @ absolute load/run zImage address
.word _magic_end @ zImage end address
.word 0x04030201 @ endianness flag
.word 0x45454545 @ another magic number to indicate
.word _magic_table @ additional data table
__EFI_HEADER
1:
ARM_BE8( setend be ) @ go BE8 if compiled for BE8
AR_CLASS( mrs r9, cpsr )
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install @ get into SVC mode, reversibly
#endif
mov r7, r1 @ save architecture ID
mov r8, r2 @ save atags pointer
#ifndef CONFIG_CPU_V7M
/*
* Booting from Angel - need to enter SVC mode and disable
* FIQs/IRQs (numeric definitions from angel arm.h source).
* We only do this if we were in user mode on entry.
*/
mrs r2, cpsr @ get current mode
tst r2, #3 @ not user?
bne not_angel
mov r0, #0x17 @ angel_SWIreason_EnterSVC
ARM( swi 0x123456 ) @ angel_SWI_ARM
THUMB( svc 0xab ) @ angel_SWI_THUMB
not_angel:
safe_svcmode_maskall r0
msr spsr_cxsf, r9 @ Save the CPU boot mode in
@ SPSR
#endif
/*
* Note that some cache flushing and other stuff may
* be needed here - is there an Angel SWI call for this?
*/
/*
* some architecture specific code can be inserted
* by the linker here, but it should preserve r7, r8, and r9.
*/
.text
#ifdef CONFIG_AUTO_ZRELADDR
/*
* Find the start of physical memory. As we are executing
* without the MMU on, we are in the physical address space.
* We just need to get rid of any offset by aligning the
* address.
*
* This alignment is a balance between the requirements of
* different platforms - we have chosen 128MB to allow
* platforms which align the start of their physical memory
* to 128MB to use this feature, while allowing the zImage
* to be placed within the first 128MB of memory on other
* platforms. Increasing the alignment means we place
* stricter alignment requirements on the start of physical
* memory, but relaxing it means that we break people who
* are already placing their zImage in (eg) the top 64MB
* of this range.
*/
mov r0, pc
and r0, r0, #0xf8000000
#ifdef CONFIG_USE_OF
adr r1, LC1
#ifdef CONFIG_ARM_APPENDED_DTB
/*
* Look for an appended DTB. If found, we cannot use it to
* validate the calculated start of physical memory, as its
* memory nodes may need to be augmented by ATAGS stored at
* an offset from the same start of physical memory.
*/
ldr r2, [r1, #4] @ get &_edata
add r2, r2, r1 @ relocate it
ldr r2, [r2] @ get DTB signature
ldr r3, =OF_DT_MAGIC
cmp r2, r3 @ do we have a DTB there?
beq 1f @ if yes, skip validation
#endif /* CONFIG_ARM_APPENDED_DTB */
/*
* Make sure we have some stack before calling C code.
* No GOT fixup has occurred yet, but none of the code we're
* about to call uses any global variables.
*/
ldr sp, [r1] @ get stack location
add sp, sp, r1 @ apply relocation
/* Validate calculated start against passed DTB */
mov r1, r8
bl fdt_check_mem_start
1:
#endif /* CONFIG_USE_OF */
/* Determine final kernel image address. */
add r4, r0, #TEXT_OFFSET
#else
ldr r4, =zreladdr
#endif
/*
* Set up a page table only if it won't overwrite ourself.
* That means r4 < pc || r4 - 16k page directory > &_end.
* Given that r4 > &_end is most unfrequent, we add a rough
* additional 1MB of room for a possible appended DTB.
*/
mov r0, pc
cmp r0, r4
ldrcc r0, .Lheadroom
addcc r0, r0, pc
cmpcc r4, r0
orrcc r4, r4, #1 @ remember we skipped cache_on
blcs cache_on
restart: adr r0, LC1
ldr sp, [r0]
ldr r6, [r0, #4]
add sp, sp, r0
add r6, r6, r0
get_inflated_image_size r9, r10, lr
#ifndef CONFIG_ZBOOT_ROM
/* malloc space is above the relocated stack (64k max) */
add r10, sp, #MALLOC_SIZE
#else
/*
* With ZBOOT_ROM the bss/stack is non relocatable,
* but someone could still run this code from RAM,
* in which case our reference is _edata.
*/
mov r10, r6
#endif
mov r5, #0 @ init dtb size to 0
#ifdef CONFIG_ARM_APPENDED_DTB
/*
* r4 = final kernel address (possibly with LSB set)
* r5 = appended dtb size (still unknown)
* r6 = _edata
* r7 = architecture ID
* r8 = atags/device tree pointer
* r9 = size of decompressed image
* r10 = end of this image, including bss/stack/malloc space if non XIP
* sp = stack pointer
*
* if there are device trees (dtb) appended to zImage, advance r10 so that the
* dtb data will get relocated along with the kernel if necessary.
*/
ldr lr, [r6, #0]
ldr r1, =OF_DT_MAGIC
cmp lr, r1
bne dtb_check_done @ not found
#ifdef CONFIG_ARM_ATAG_DTB_COMPAT
/*
* OK... Let's do some funky business here.
* If we do have a DTB appended to zImage, and we do have
* an ATAG list around, we want the later to be translated
* and folded into the former here. No GOT fixup has occurred
* yet, but none of the code we're about to call uses any
* global variable.
*/
/* Get the initial DTB size */
ldr r5, [r6, #4]
be32tocpu r5, r1
dbgadtb r6, r5
/* 50% DTB growth should be good enough */
add r5, r5, r5, lsr #1
/* preserve 64-bit alignment */
add r5, r5, #7
bic r5, r5, #7
/* clamp to 32KB min and 1MB max */
cmp r5, #(1 << 15)
movlo r5, #(1 << 15)
cmp r5, #(1 << 20)
movhi r5, #(1 << 20)
/* temporarily relocate the stack past the DTB work space */
add sp, sp, r5
mov r0, r8
mov r1, r6
mov r2, r5
bl atags_to_fdt
/*
* If returned value is 1, there is no ATAG at the location
* pointed by r8. Try the typical 0x100 offset from start
* of RAM and hope for the best.
*/
cmp r0, #1
sub r0, r4, #TEXT_OFFSET
bic r0, r0, #1
add r0, r0, #0x100
mov r1, r6
mov r2, r5
bleq atags_to_fdt
sub sp, sp, r5
#endif
mov r8, r6 @ use the appended device tree
/*
* Make sure that the DTB doesn't end up in the final
* kernel's .bss area. To do so, we adjust the decompressed
* kernel size to compensate if that .bss size is larger
* than the relocated code.
*/
ldr r5, =_kernel_bss_size
adr r1, wont_overwrite
sub r1, r6, r1
subs r1, r5, r1
addhi r9, r9, r1
/* Get the current DTB size */
ldr r5, [r6, #4]
be32tocpu r5, r1
/* preserve 64-bit alignment */
add r5, r5, #7
bic r5, r5, #7
/* relocate some pointers past the appended dtb */
add r6, r6, r5
add r10, r10, r5
add sp, sp, r5
dtb_check_done:
#endif
/*
* Check to see if we will overwrite ourselves.
* r4 = final kernel address (possibly with LSB set)
* r9 = size of decompressed image
* r10 = end of this image, including bss/stack/malloc space if non XIP
* We basically want:
* r4 - 16k page directory >= r10 -> OK
* r4 + image length <= address of wont_overwrite -> OK
* Note: the possible LSB in r4 is harmless here.
*/
add r10, r10, #16384
cmp r4, r10
bhs wont_overwrite
add r10, r4, r9
adr r9, wont_overwrite
cmp r10, r9
bls wont_overwrite
/*
* Relocate ourselves past the end of the decompressed kernel.
* r6 = _edata
* r10 = end of the decompressed kernel
* Because we always copy ahead, we need to do it from the end and go
* backward in case the source and destination overlap.
*/
/*
* Bump to the next 256-byte boundary with the size of
* the relocation code added. This avoids overwriting
* ourself when the offset is small.
*/
add r10, r10, #((reloc_code_end - restart + 256) & ~255)
bic r10, r10, #255
/* Get start of code we want to copy and align it down. */
adr r5, restart
bic r5, r5, #31
/* Relocate the hyp vector base if necessary */
#ifdef CONFIG_ARM_VIRT_EXT
mrs r0, spsr
and r0, r0, #MODE_MASK
cmp r0, #HYP_MODE
bne 1f
/*
* Compute the address of the hyp vectors after relocation.
* Call __hyp_set_vectors with the new address so that we
* can HVC again after the copy.
*/
adr_l r0, __hyp_stub_vectors
sub r0, r0, r5
add r0, r0, r10
bl __hyp_set_vectors
1:
#endif
sub r9, r6, r5 @ size to copy
add r9, r9, #31 @ rounded up to a multiple
bic r9, r9, #31 @ ... of 32 bytes
add r6, r9, r5
add r9, r9, r10
#ifdef DEBUG
sub r10, r6, r5
sub r10, r9, r10
/*
* We are about to copy the kernel to a new memory area.
* The boundaries of the new memory area can be found in
* r10 and r9, whilst r5 and r6 contain the boundaries
* of the memory we are going to copy.
* Calling dbgkc will help with the printing of this
* information.
*/
dbgkc r5, r6, r10, r9
#endif
1: ldmdb r6!, {r0 - r3, r10 - r12, lr}
cmp r6, r5
stmdb r9!, {r0 - r3, r10 - r12, lr}
bhi 1b
/* Preserve offset to relocated code. */
sub r6, r9, r6
mov r0, r9 @ start of relocated zImage
add r1, sp, r6 @ end of relocated zImage
bl cache_clean_flush
badr r0, restart
add r0, r0, r6
mov pc, r0
wont_overwrite:
adr r0, LC0
ldmia r0, {r1, r2, r3, r11, r12}
sub r0, r0, r1 @ calculate the delta offset
/*
* If delta is zero, we are running at the address we were linked at.
* r0 = delta
* r2 = BSS start
* r3 = BSS end
* r4 = kernel execution address (possibly with LSB set)
* r5 = appended dtb size (0 if not present)
* r7 = architecture ID
* r8 = atags pointer
* r11 = GOT start
* r12 = GOT end
* sp = stack pointer
*/
orrs r1, r0, r5
beq not_relocated
add r11, r11, r0
add r12, r12, r0
#ifndef CONFIG_ZBOOT_ROM
/*
* If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
* we need to fix up pointers into the BSS region.
* Note that the stack pointer has already been fixed up.
*/
add r2, r2, r0
add r3, r3, r0
/*
* Relocate all entries in the GOT table.
* Bump bss entries to _edata + dtb size
*/
1: ldr r1, [r11, #0] @ relocate entries in the GOT
add r1, r1, r0 @ This fixes up C references
cmp r1, r2 @ if entry >= bss_start &&
cmphs r3, r1 @ bss_end > entry
addhi r1, r1, r5 @ entry += dtb size
str r1, [r11], #4 @ next entry
cmp r11, r12
blo 1b
/* bump our bss pointers too */
add r2, r2, r5
add r3, r3, r5
#else
/*
* Relocate entries in the GOT table. We only relocate
* the entries that are outside the (relocated) BSS region.
*/
1: ldr r1, [r11, #0] @ relocate entries in the GOT
cmp r1, r2 @ entry < bss_start ||
cmphs r3, r1 @ _end < entry
addlo r1, r1, r0 @ table. This fixes up the
str r1, [r11], #4 @ C references.
cmp r11, r12
blo 1b
#endif
not_relocated: mov r0, #0
1: str r0, [r2], #4 @ clear bss
str r0, [r2], #4
str r0, [r2], #4
str r0, [r2], #4
cmp r2, r3
blo 1b
/*
* Did we skip the cache setup earlier?
* That is indicated by the LSB in r4.
* Do it now if so.
*/
tst r4, #1
bic r4, r4, #1
blne cache_on
/*
* The C runtime environment should now be setup sufficiently.
* Set up some pointers, and start decompressing.
* r4 = kernel execution address
* r7 = architecture ID
* r8 = atags pointer
*/
mov r0, r4
mov r1, sp @ malloc space above stack
add r2, sp, #MALLOC_SIZE @ 64k max
mov r3, r7
bl decompress_kernel
get_inflated_image_size r1, r2, r3
mov r0, r4 @ start of inflated image
add r1, r1, r0 @ end of inflated image
bl cache_clean_flush
bl cache_off
#ifdef CONFIG_ARM_VIRT_EXT
mrs r0, spsr @ Get saved CPU boot mode
and r0, r0, #MODE_MASK
cmp r0, #HYP_MODE @ if not booted in HYP mode...
bne __enter_kernel @ boot kernel directly
adr_l r0, __hyp_reentry_vectors
bl __hyp_set_vectors
__HVC(0) @ otherwise bounce to hyp mode
b . @ should never be reached
#else
b __enter_kernel
#endif
.align 2
.type LC0, #object
LC0: .word LC0 @ r1
.word __bss_start @ r2
.word _end @ r3
.word _got_start @ r11
.word _got_end @ ip
.size LC0, . - LC0
.type LC1, #object
LC1: .word .L_user_stack_end - LC1 @ sp
.word _edata - LC1 @ r6
.size LC1, . - LC1
.Lheadroom:
.word _end - restart + 16384 + 1024*1024
.Linflated_image_size_offset:
.long (input_data_end - 4) - .
#ifdef CONFIG_ARCH_RPC
.globl params
params: ldr r0, =0x10000100 @ params_phys for RPC
mov pc, lr
.ltorg
.align
#endif
/*
* dcache_line_size - get the minimum D-cache line size from the CTR register
* on ARMv7.
*/
.macro dcache_line_size, reg, tmp
#ifdef CONFIG_CPU_V7M
movw \tmp, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_CTR
movt \tmp, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_CTR
ldr \tmp, [\tmp]
#else
mrc p15, 0, \tmp, c0, c0, 1 @ read ctr
#endif
lsr \tmp, \tmp, #16
and \tmp, \tmp, #0xf @ cache line size encoding
mov \reg, #4 @ bytes per word
mov \reg, \reg, lsl \tmp @ actual cache line size
.endm
/*
* Turn on the cache. We need to setup some page tables so that we
* can have both the I and D caches on.
*
* We place the page tables 16k down from the kernel execution address,
* and we hope that nothing else is using it. If we're using it, we
* will go pop!
*
* On entry,
* r4 = kernel execution address
* r7 = architecture number
* r8 = atags pointer
* On exit,
* r0, r1, r2, r3, r9, r10, r12 corrupted
* This routine must preserve:
* r4, r7, r8
*/
.align 5
cache_on: mov r3, #8 @ cache_on function
b call_cache_fn
/*
* Initialize the highest priority protection region, PR7
* to cover all 32bit address and cacheable and bufferable.
*/
__armv4_mpu_cache_on:
mov r0, #0x3f @ 4G, the whole
mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
mcr p15, 0, r0, c6, c7, 1
mov r0, #0x80 @ PR7
mcr p15, 0, r0, c2, c0, 0 @ D-cache on
mcr p15, 0, r0, c2, c0, 1 @ I-cache on
mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
mov r0, #0xc000
mcr p15, 0, r0, c5, c0, 1 @ I-access permission
mcr p15, 0, r0, c5, c0, 0 @ D-access permission
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
mrc p15, 0, r0, c1, c0, 0 @ read control reg
@ ...I .... ..D. WC.M
orr r0, r0, #0x002d @ .... .... ..1. 11.1
orr r0, r0, #0x1000 @ ...1 .... .... ....
mcr p15, 0, r0, c1, c0, 0 @ write control reg
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
mov pc, lr
__armv3_mpu_cache_on:
mov r0, #0x3f @ 4G, the whole
mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
mov r0, #0x80 @ PR7
mcr p15, 0, r0, c2, c0, 0 @ cache on
mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
mov r0, #0xc000
mcr p15, 0, r0, c5, c0, 0 @ access permission
mov r0, #0
mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
/*
* ?? ARMv3 MMU does not allow reading the control register,
* does this really work on ARMv3 MPU?
*/
mrc p15, 0, r0, c1, c0, 0 @ read control reg
@ .... .... .... WC.M
orr r0, r0, #0x000d @ .... .... .... 11.1
/* ?? this overwrites the value constructed above? */
mov r0, #0
mcr p15, 0, r0, c1, c0, 0 @ write control reg
/* ?? invalidate for the second time? */
mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
mov pc, lr
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
#define CB_BITS 0x08
#else
#define CB_BITS 0x0c
#endif
__setup_mmu: sub r3, r4, #16384 @ Page directory size
bic r3, r3, #0xff @ Align the pointer
bic r3, r3, #0x3f00
/*
* Initialise the page tables, turning on the cacheable and bufferable
* bits for the RAM area only.
*/
mov r0, r3
mov r9, r0, lsr #18
mov r9, r9, lsl #18 @ start of RAM
add r10, r9, #0x10000000 @ a reasonable RAM size
mov r1, #0x12 @ XN|U + section mapping
orr r1, r1, #3 << 10 @ AP=11
add r2, r3, #16384
1: cmp r1, r9 @ if virt > start of RAM
cmphs r10, r1 @ && end of RAM > virt
bic r1, r1, #0x1c @ clear XN|U + C + B
orrlo r1, r1, #0x10 @ Set XN|U for non-RAM
orrhs r1, r1, r6 @ set RAM section settings
str r1, [r0], #4 @ 1:1 mapping
add r1, r1, #1048576
teq r0, r2
bne 1b
/*
* If ever we are running from Flash, then we surely want the cache
* to be enabled also for our execution instance... We map 2MB of it
* so there is no map overlap problem for up to 1 MB compressed kernel.
* If the execution is in RAM then we would only be duplicating the above.
*/
orr r1, r6, #0x04 @ ensure B is set for this
orr r1, r1, #3 << 10
mov r2, pc
mov r2, r2, lsr #20
orr r1, r1, r2, lsl #20
add r0, r3, r2, lsl #2
str r1, [r0], #4
add r1, r1, #1048576
str r1, [r0]
mov pc, lr
ENDPROC(__setup_mmu)
@ Enable unaligned access on v6, to allow better code generation
@ for the decompressor C code:
__armv6_mmu_cache_on:
mrc p15, 0, r0, c1, c0, 0 @ read SCTLR
bic r0, r0, #2 @ A (no unaligned access fault)
orr r0, r0, #1 << 22 @ U (v6 unaligned access model)
mcr p15, 0, r0, c1, c0, 0 @ write SCTLR
b __armv4_mmu_cache_on
__arm926ejs_mmu_cache_on:
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
mov r0, #4 @ put dcache in WT mode
mcr p15, 7, r0, c15, c0, 0
#endif
__armv4_mmu_cache_on:
mov r12, lr
#ifdef CONFIG_MMU
mov r6, #CB_BITS | 0x12 @ U
bl __setup_mmu
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
mrc p15, 0, r0, c1, c0, 0 @ read control reg
orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
orr r0, r0, #0x0030
ARM_BE8( orr r0, r0, #1 << 25 ) @ big-endian page tables
bl __common_mmu_cache_on
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
#endif
mov pc, r12
__armv7_mmu_cache_on:
enable_cp15_barriers r11
mov r12, lr
#ifdef CONFIG_MMU
mrc p15, 0, r11, c0, c1, 4 @ read ID_MMFR0
tst r11, #0xf @ VMSA
movne r6, #CB_BITS | 0x02 @ !XN
blne __setup_mmu
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
tst r11, #0xf @ VMSA
mcrne p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
#endif
mrc p15, 0, r0, c1, c0, 0 @ read control reg
bic r0, r0, #1 << 28 @ clear SCTLR.TRE
orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
orr r0, r0, #0x003c @ write buffer
bic r0, r0, #2 @ A (no unaligned access fault)
orr r0, r0, #1 << 22 @ U (v6 unaligned access model)
@ (needed for ARM1176)
#ifdef CONFIG_MMU
ARM_BE8( orr r0, r0, #1 << 25 ) @ big-endian page tables
mrcne p15, 0, r6, c2, c0, 2 @ read ttb control reg
orrne r0, r0, #1 @ MMU enabled
movne r1, #0xfffffffd @ domain 0 = client
bic r6, r6, #1 << 31 @ 32-bit translation system
bic r6, r6, #(7 << 0) | (1 << 4) @ use only ttbr0
mcrne p15, 0, r3, c2, c0, 0 @ load page table pointer
mcrne p15, 0, r1, c3, c0, 0 @ load domain access control
mcrne p15, 0, r6, c2, c0, 2 @ load ttb control
#endif
mcr p15, 0, r0, c7, c5, 4 @ ISB
mcr p15, 0, r0, c1, c0, 0 @ load control register
mrc p15, 0, r0, c1, c0, 0 @ and read it back
mov r0, #0
mcr p15, 0, r0, c7, c5, 4 @ ISB
mov pc, r12
__fa526_cache_on:
mov r12, lr
mov r6, #CB_BITS | 0x12 @ U
bl __setup_mmu
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 @ Invalidate whole cache
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c8, c7, 0 @ flush UTLB
mrc p15, 0, r0, c1, c0, 0 @ read control reg
orr r0, r0, #0x1000 @ I-cache enable
bl __common_mmu_cache_on
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ flush UTLB
mov pc, r12
__common_mmu_cache_on:
#ifndef CONFIG_THUMB2_KERNEL
#ifndef DEBUG
orr r0, r0, #0x000d @ Write buffer, mmu
#endif
mov r1, #-1
mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
mcr p15, 0, r1, c3, c0, 0 @ load domain access control
b 1f
.align 5 @ cache line aligned
1: mcr p15, 0, r0, c1, c0, 0 @ load control register
mrc p15, 0, r0, c1, c0, 0 @ and read it back to
sub pc, lr, r0, lsr #32 @ properly flush pipeline
#endif
#define PROC_ENTRY_SIZE (4*5)
/*
* Here follow the relocatable cache support functions for the
* various processors. This is a generic hook for locating an
* entry and jumping to an instruction at the specified offset
* from the start of the block. Please note this is all position
* independent code.
*
* r1 = corrupted
* r2 = corrupted
* r3 = block offset
* r9 = corrupted
* r12 = corrupted
*/
call_cache_fn: adr r12, proc_types
#ifdef CONFIG_CPU_CP15
mrc p15, 0, r9, c0, c0 @ get processor ID
#elif defined(CONFIG_CPU_V7M)
/*
* On v7-M the processor id is located in the V7M_SCB_CPUID
* register, but as cache handling is IMPLEMENTATION DEFINED on
* v7-M (if existant at all) we just return early here.
* If V7M_SCB_CPUID were used the cpu ID functions (i.e.
* __armv7_mmu_cache_{on,off,flush}) would be selected which
* use cp15 registers that are not implemented on v7-M.
*/
bx lr
#else
ldr r9, =CONFIG_PROCESSOR_ID
#endif
1: ldr r1, [r12, #0] @ get value
ldr r2, [r12, #4] @ get mask
eor r1, r1, r9 @ (real ^ match)
tst r1, r2 @ & mask
ARM( addeq pc, r12, r3 ) @ call cache function
THUMB( addeq r12, r3 )
THUMB( moveq pc, r12 ) @ call cache function
add r12, r12, #PROC_ENTRY_SIZE
b 1b
/*
* Table for cache operations. This is basically:
* - CPU ID match
* - CPU ID mask
* - 'cache on' method instruction
* - 'cache off' method instruction
* - 'cache flush' method instruction
*
* We match an entry using: ((real_id ^ match) & mask) == 0
*
* Writethrough caches generally only need 'on' and 'off'
* methods. Writeback caches _must_ have the flush method
* defined.
*/
.align 2
.type proc_types,#object
proc_types:
.word 0x41000000 @ old ARM ID
.word 0xff00f000
mov pc, lr
THUMB( nop )
mov pc, lr
THUMB( nop )
mov pc, lr