| blob | 6b1148cafffdbe09070f996343287a4db9bb1baa |
1 /*
2 * linux/arch/arm/kernel/head.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 * Kernel startup code for all 32-bit CPUs
13 */
14 #include <linux/linkage.h>
15 #include <linux/init.h>
17 #include <asm/assembler.h>
18 #include <asm/cp15.h>
19 #include <asm/domain.h>
20 #include <asm/ptrace.h>
21 #include <asm/asm-offsets.h>
22 #include <asm/memory.h>
23 #include <asm/thread_info.h>
24 #include <asm/pgtable.h>
26 #if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_SEMIHOSTING)
27 #include CONFIG_DEBUG_LL_INCLUDE
28 #endif
30 /*
31 * swapper_pg_dir is the virtual address of the initial page table.
32 * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must
33 * make sure that KERNEL_RAM_VADDR is correctly set. Currently, we expect
34 * the least significant 16 bits to be 0x8000, but we could probably
35 * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000.
36 */
37 #define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET)
38 #if (KERNEL_RAM_VADDR & 0xffff) != 0x8000
39 #error KERNEL_RAM_VADDR must start at 0xXXXX8000
40 #endif
42 #ifdef CONFIG_ARM_LPAE
43 /* LPAE requires an additional page for the PGD */
44 #define PG_DIR_SIZE 0x5000
45 #define PMD_ORDER 3
46 #else
47 #define PG_DIR_SIZE 0x4000
48 #define PMD_ORDER 2
49 #endif
51 .globl swapper_pg_dir
52 .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE
54 .macro pgtbl, rd, phys
55 add \rd, \phys, #TEXT_OFFSET
56 sub \rd, \rd, #PG_DIR_SIZE
57 .endm
59 /*
60 * Kernel startup entry point.
61 * ---------------------------
62 *
63 * This is normally called from the decompressor code. The requirements
64 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
65 * r1 = machine nr, r2 = atags or dtb pointer.
66 *
67 * This code is mostly position independent, so if you link the kernel at
68 * 0xc0008000, you call this at __pa(0xc0008000).
69 *
70 * See linux/arch/arm/tools/mach-types for the complete list of machine
71 * numbers for r1.
72 *
73 * We're trying to keep crap to a minimum; DO NOT add any machine specific
74 * crap here - that's what the boot loader (or in extreme, well justified
75 * circumstances, zImage) is for.
76 */
77 .arm
79 __HEAD
80 ENTRY(stext)
81 ARM_BE8(setend be ) @ ensure we are in BE8 mode
83 THUMB( badr r9, 1f ) @ Kernel is always entered in ARM.
84 THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
85 THUMB( .thumb ) @ switch to Thumb now.
86 THUMB(1: )
88 #ifdef CONFIG_ARM_VIRT_EXT
89 bl __hyp_stub_install
90 #endif
91 @ ensure svc mode and all interrupts masked
92 safe_svcmode_maskall r9
94 mrc p15, 0, r9, c0, c0 @ get processor id
95 bl __lookup_processor_type @ r5=procinfo r9=cpuid
96 movs r10, r5 @ invalid processor (r5=0)?
97 THUMB( it eq ) @ force fixup-able long branch encoding
98 beq __error_p @ yes, error 'p'
100 #ifdef CONFIG_ARM_LPAE
101 mrc p15, 0, r3, c0, c1, 4 @ read ID_MMFR0
102 and r3, r3, #0xf @ extract VMSA support
103 cmp r3, #5 @ long-descriptor translation table format?
104 THUMB( it lo ) @ force fixup-able long branch encoding
105 blo __error_lpae @ only classic page table format
106 #endif
108 #ifndef CONFIG_XIP_KERNEL
109 adr r3, 2f
110 ldmia r3, {r4, r8}
111 sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET)
112 add r8, r8, r4 @ PHYS_OFFSET
113 #else
114 ldr r8, =PLAT_PHYS_OFFSET @ always constant in this case
115 #endif
117 /*
118 * r1 = machine no, r2 = atags or dtb,
119 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
120 */
121 bl __vet_atags
122 #ifdef CONFIG_SMP_ON_UP
123 bl __fixup_smp
124 #endif
125 #ifdef CONFIG_ARM_PATCH_PHYS_VIRT
126 bl __fixup_pv_table
127 #endif
128 bl __create_page_tables
130 /*
131 * The following calls CPU specific code in a position independent
132 * manner. See arch/arm/mm/proc-*.S for details. r10 = base of
133 * xxx_proc_info structure selected by __lookup_processor_type
134 * above.
135 *
136 * The processor init function will be called with:
137 * r1 - machine type
138 * r2 - boot data (atags/dt) pointer
139 * r4 - translation table base (low word)
140 * r5 - translation table base (high word, if LPAE)
141 * r8 - translation table base 1 (pfn if LPAE)
142 * r9 - cpuid
143 * r13 - virtual address for __enable_mmu -> __turn_mmu_on
144 *
145 * On return, the CPU will be ready for the MMU to be turned on,
146 * r0 will hold the CPU control register value, r1, r2, r4, and
147 * r9 will be preserved. r5 will also be preserved if LPAE.
148 */
149 ldr r13, =__mmap_switched @ address to jump to after
150 @ mmu has been enabled
151 badr lr, 1f @ return (PIC) address
152 #ifdef CONFIG_ARM_LPAE
153 mov r5, #0 @ high TTBR0
154 mov r8, r4, lsr #12 @ TTBR1 is swapper_pg_dir pfn
155 #else
156 mov r8, r4 @ set TTBR1 to swapper_pg_dir
157 #endif
158 ldr r12, [r10, #PROCINFO_INITFUNC]
159 add r12, r12, r10
160 ret r12
161 1: b __enable_mmu
162 ENDPROC(stext)
163 .ltorg
164 #ifndef CONFIG_XIP_KERNEL
165 2: .long .
166 .long PAGE_OFFSET
167 #endif
169 /*
170 * Setup the initial page tables. We only setup the barest
171 * amount which are required to get the kernel running, which
172 * generally means mapping in the kernel code.
173 *
174 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
175 *
176 * Returns:
177 * r0, r3, r5-r7 corrupted
178 * r4 = physical page table address
179 */
180 __create_page_tables:
181 pgtbl r4, r8 @ page table address
183 /*
184 * Clear the swapper page table
185 */
186 mov r0, r4
187 mov r3, #0
188 add r6, r0, #PG_DIR_SIZE
189 1: str r3, [r0], #4
190 str r3, [r0], #4
191 str r3, [r0], #4
192 str r3, [r0], #4
193 teq r0, r6
194 bne 1b
196 #ifdef CONFIG_ARM_LPAE
197 /*
198 * Build the PGD table (first level) to point to the PMD table. A PGD
199 * entry is 64-bit wide.
200 */
201 mov r0, r4
202 add r3, r4, #0x1000 @ first PMD table address
203 orr r3, r3, #3 @ PGD block type
204 mov r6, #4 @ PTRS_PER_PGD
205 mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER
206 1:
207 #ifdef CONFIG_CPU_ENDIAN_BE8
208 str r7, [r0], #4 @ set top PGD entry bits
209 str r3, [r0], #4 @ set bottom PGD entry bits
210 #else
211 str r3, [r0], #4 @ set bottom PGD entry bits
212 str r7, [r0], #4 @ set top PGD entry bits
213 #endif
214 add r3, r3, #0x1000 @ next PMD table
215 subs r6, r6, #1
216 bne 1b
218 add r4, r4, #0x1000 @ point to the PMD tables
219 #ifdef CONFIG_CPU_ENDIAN_BE8
220 add r4, r4, #4 @ we only write the bottom word
221 #endif
222 #endif
224 ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags
226 /*
227 * Create identity mapping to cater for __enable_mmu.
228 * This identity mapping will be removed by paging_init().
229 */
230 adr r0, __turn_mmu_on_loc
231 ldmia r0, {r3, r5, r6}
232 sub r0, r0, r3 @ virt->phys offset
233 add r5, r5, r0 @ phys __turn_mmu_on
234 add r6, r6, r0 @ phys __turn_mmu_on_end
235 mov r5, r5, lsr #SECTION_SHIFT
236 mov r6, r6, lsr #SECTION_SHIFT
238 1: orr r3, r7, r5, lsl #SECTION_SHIFT @ flags + kernel base
239 str r3, [r4, r5, lsl #PMD_ORDER] @ identity mapping
240 cmp r5, r6
241 addlo r5, r5, #1 @ next section
242 blo 1b
244 /*
245 * Map our RAM from the start to the end of the kernel .bss section.
246 */
247 add r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER)
248 ldr r6, =(_end - 1)
249 orr r3, r8, r7
250 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
251 1: str r3, [r0], #1 << PMD_ORDER
252 add r3, r3, #1 << SECTION_SHIFT
253 cmp r0, r6
254 bls 1b
256 #ifdef CONFIG_XIP_KERNEL
257 /*
258 * Map the kernel image separately as it is not located in RAM.
259 */
260 #define XIP_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
261 mov r3, pc
262 mov r3, r3, lsr #SECTION_SHIFT
263 orr r3, r7, r3, lsl #SECTION_SHIFT
264 add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER)
265 str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]!
266 ldr r6, =(_edata_loc - 1)
267 add r0, r0, #1 << PMD_ORDER
268 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
269 1: cmp r0, r6
270 add r3, r3, #1 << SECTION_SHIFT
271 strls r3, [r0], #1 << PMD_ORDER
272 bls 1b
273 #endif
275 /*
276 * Then map boot params address in r2 if specified.
277 * We map 2 sections in case the ATAGs/DTB crosses a section boundary.
278 */
279 mov r0, r2, lsr #SECTION_SHIFT
280 movs r0, r0, lsl #SECTION_SHIFT
281 subne r3, r0, r8
282 addne r3, r3, #PAGE_OFFSET
283 addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER)
284 orrne r6, r7, r0
285 strne r6, [r3], #1 << PMD_ORDER
286 addne r6, r6, #1 << SECTION_SHIFT
287 strne r6, [r3]
289 #if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
290 sub r4, r4, #4 @ Fixup page table pointer
291 @ for 64-bit descriptors
292 #endif
294 #ifdef CONFIG_DEBUG_LL
295 #if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING)
296 /*
297 * Map in IO space for serial debugging.
298 * This allows debug messages to be output
299 * via a serial console before paging_init.
300 */
301 addruart r7, r3, r0
303 mov r3, r3, lsr #SECTION_SHIFT
304 mov r3, r3, lsl #PMD_ORDER
306 add r0, r4, r3
307 mov r3, r7, lsr #SECTION_SHIFT
308 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
309 orr r3, r7, r3, lsl #SECTION_SHIFT
310 #ifdef CONFIG_ARM_LPAE
311 mov r7, #1 << (54 - 32) @ XN
312 #ifdef CONFIG_CPU_ENDIAN_BE8
313 str r7, [r0], #4
314 str r3, [r0], #4
315 #else
316 str r3, [r0], #4
317 str r7, [r0], #4
318 #endif
319 #else
320 orr r3, r3, #PMD_SECT_XN
321 str r3, [r0], #4
322 #endif
324 #else /* CONFIG_DEBUG_ICEDCC || CONFIG_DEBUG_SEMIHOSTING */
325 /* we don't need any serial debugging mappings */
326 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
327 #endif
329 #if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS)
330 /*
331 * If we're using the NetWinder or CATS, we also need to map
332 * in the 16550-type serial port for the debug messages
333 */
334 add r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_ORDER)
335 orr r3, r7, #0x7c000000
336 str r3, [r0]
337 #endif
338 #ifdef CONFIG_ARCH_RPC
339 /*
340 * Map in screen at 0x02000000 & SCREEN2_BASE
341 * Similar reasons here - for debug. This is
342 * only for Acorn RiscPC architectures.
343 */
344 add r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_ORDER)
345 orr r3, r7, #0x02000000
346 str r3, [r0]
347 add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER)
348 str r3, [r0]
349 #endif
350 #endif
351 #ifdef CONFIG_ARM_LPAE
352 sub r4, r4, #0x1000 @ point to the PGD table
353 #endif
354 ret lr
355 ENDPROC(__create_page_tables)
356 .ltorg
357 .align
358 __turn_mmu_on_loc:
359 .long .
360 .long __turn_mmu_on
361 .long __turn_mmu_on_end
363 #if defined(CONFIG_SMP)
364 .text
365 .arm
366 ENTRY(secondary_startup_arm)
367 THUMB( badr r9, 1f ) @ Kernel is entered in ARM.
368 THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
369 THUMB( .thumb ) @ switch to Thumb now.
370 THUMB(1: )
371 ENTRY(secondary_startup)
372 /*
373 * Common entry point for secondary CPUs.
374 *
375 * Ensure that we're in SVC mode, and IRQs are disabled. Lookup
376 * the processor type - there is no need to check the machine type
377 * as it has already been validated by the primary processor.
378 */
380 ARM_BE8(setend be) @ ensure we are in BE8 mode
382 #ifdef CONFIG_ARM_VIRT_EXT
383 bl __hyp_stub_install_secondary
384 #endif
385 safe_svcmode_maskall r9
387 mrc p15, 0, r9, c0, c0 @ get processor id
388 bl __lookup_processor_type
389 movs r10, r5 @ invalid processor?
390 moveq r0, #'p' @ yes, error 'p'
391 THUMB( it eq ) @ force fixup-able long branch encoding
392 beq __error_p
394 /*
395 * Use the page tables supplied from __cpu_up.
396 */
397 adr r4, __secondary_data
398 ldmia r4, {r5, r7, r12} @ address to jump to after
399 sub lr, r4, r5 @ mmu has been enabled
400 add r3, r7, lr
401 ldrd r4, [r3, #0] @ get secondary_data.pgdir
402 ARM_BE8(eor r4, r4, r5) @ Swap r5 and r4 in BE:
403 ARM_BE8(eor r5, r4, r5) @ it can be done in 3 steps
404 ARM_BE8(eor r4, r4, r5) @ without using a temp reg.
405 ldr r8, [r3, #8] @ get secondary_data.swapper_pg_dir
406 badr lr, __enable_mmu @ return address
407 mov r13, r12 @ __secondary_switched address
408 ldr r12, [r10, #PROCINFO_INITFUNC]
409 add r12, r12, r10 @ initialise processor
410 @ (return control reg)
411 ret r12
412 ENDPROC(secondary_startup)
413 ENDPROC(secondary_startup_arm)
415 /*
416 * r6 = &secondary_data
417 */
418 ENTRY(__secondary_switched)
419 ldr sp, [r7, #12] @ get secondary_data.stack
420 mov fp, #0
421 b secondary_start_kernel
422 ENDPROC(__secondary_switched)
424 .align
426 .type __secondary_data, %object
427 __secondary_data:
428 .long .
429 .long secondary_data
430 .long __secondary_switched
431 #endif /* defined(CONFIG_SMP) */
435 /*
436 * Setup common bits before finally enabling the MMU. Essentially
437 * this is just loading the page table pointer and domain access
438 * registers. All these registers need to be preserved by the
439 * processor setup function (or set in the case of r0)
440 *
441 * r0 = cp#15 control register
442 * r1 = machine ID
443 * r2 = atags or dtb pointer
444 * r4 = TTBR pointer (low word)
445 * r5 = TTBR pointer (high word if LPAE)
446 * r9 = processor ID
447 * r13 = *virtual* address to jump to upon completion
448 */
449 __enable_mmu:
450 #if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6
451 orr r0, r0, #CR_A
452 #else
453 bic r0, r0, #CR_A
454 #endif
455 #ifdef CONFIG_CPU_DCACHE_DISABLE
456 bic r0, r0, #CR_C
457 #endif
458 #ifdef CONFIG_CPU_BPREDICT_DISABLE
459 bic r0, r0, #CR_Z
460 #endif
461 #ifdef CONFIG_CPU_ICACHE_DISABLE
462 bic r0, r0, #CR_I
463 #endif
464 #ifdef CONFIG_ARM_LPAE
465 mcrr p15, 0, r4, r5, c2 @ load TTBR0
466 #else
467 mov r5, #DACR_INIT
468 mcr p15, 0, r5, c3, c0, 0 @ load domain access register
469 mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
470 #endif
471 b __turn_mmu_on
472 ENDPROC(__enable_mmu)
474 /*
475 * Enable the MMU. This completely changes the structure of the visible
476 * memory space. You will not be able to trace execution through this.
477 * If you have an enquiry about this, *please* check the linux-arm-kernel
478 * mailing list archives BEFORE sending another post to the list.
479 *
480 * r0 = cp#15 control register
481 * r1 = machine ID
482 * r2 = atags or dtb pointer
483 * r9 = processor ID
484 * r13 = *virtual* address to jump to upon completion
485 *
486 * other registers depend on the function called upon completion
487 */
488 .align 5
489 .pushsection .idmap.text, "ax"
490 ENTRY(__turn_mmu_on)
491 mov r0, r0
492 instr_sync
493 mcr p15, 0, r0, c1, c0, 0 @ write control reg
494 mrc p15, 0, r3, c0, c0, 0 @ read id reg
495 instr_sync
496 mov r3, r3
497 mov r3, r13
498 ret r3
499 __turn_mmu_on_end:
500 ENDPROC(__turn_mmu_on)
501 .popsection
504 #ifdef CONFIG_SMP_ON_UP
505 __HEAD
506 __fixup_smp:
507 and r3, r9, #0x000f0000 @ architecture version
508 teq r3, #0x000f0000 @ CPU ID supported?
509 bne __fixup_smp_on_up @ no, assume UP
511 bic r3, r9, #0x00ff0000
512 bic r3, r3, #0x0000000f @ mask 0xff00fff0
513 mov r4, #0x41000000
514 orr r4, r4, #0x0000b000
515 orr r4, r4, #0x00000020 @ val 0x4100b020
516 teq r3, r4 @ ARM 11MPCore?
517 reteq lr @ yes, assume SMP
519 mrc p15, 0, r0, c0, c0, 5 @ read MPIDR
520 and r0, r0, #0xc0000000 @ multiprocessing extensions and
521 teq r0, #0x80000000 @ not part of a uniprocessor system?
522 bne __fixup_smp_on_up @ no, assume UP
524 @ Core indicates it is SMP. Check for Aegis SOC where a single
525 @ Cortex-A9 CPU is present but SMP operations fault.
526 mov r4, #0x41000000
527 orr r4, r4, #0x0000c000
528 orr r4, r4, #0x00000090
529 teq r3, r4 @ Check for ARM Cortex-A9
530 retne lr @ Not ARM Cortex-A9,
532 @ If a future SoC *does* use 0x0 as the PERIPH_BASE, then the
533 @ below address check will need to be #ifdef'd or equivalent
534 @ for the Aegis platform.
535 mrc p15, 4, r0, c15, c0 @ get SCU base address
536 teq r0, #0x0 @ '0' on actual UP A9 hardware
537 beq __fixup_smp_on_up @ So its an A9 UP
538 ldr r0, [r0, #4] @ read SCU Config
539 ARM_BE8(rev r0, r0) @ byteswap if big endian
540 and r0, r0, #0x3 @ number of CPUs
541 teq r0, #0x0 @ is 1?
542 retne lr
544 __fixup_smp_on_up:
545 adr r0, 1f
546 ldmia r0, {r3 - r5}
547 sub r3, r0, r3
548 add r4, r4, r3
549 add r5, r5, r3
550 b __do_fixup_smp_on_up
551 ENDPROC(__fixup_smp)
553 .align
554 1: .word .
555 .word __smpalt_begin
556 .word __smpalt_end
558 .pushsection .data
559 .align 2
560 .globl smp_on_up
561 smp_on_up:
562 ALT_SMP(.long 1)
563 ALT_UP(.long 0)
564 .popsection
565 #endif
567 .text
568 __do_fixup_smp_on_up:
569 cmp r4, r5
570 reths lr
571 ldmia r4!, {r0, r6}
572 ARM( str r6, [r0, r3] )
573 THUMB( add r0, r0, r3 )
574 #ifdef __ARMEB__
575 THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian.
576 #endif
577 THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords
578 THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3.
579 THUMB( strh r6, [r0] )
580 b __do_fixup_smp_on_up
581 ENDPROC(__do_fixup_smp_on_up)
583 ENTRY(fixup_smp)
584 stmfd sp!, {r4 - r6, lr}
585 mov r4, r0
586 add r5, r0, r1
587 mov r3, #0
588 bl __do_fixup_smp_on_up
589 ldmfd sp!, {r4 - r6, pc}
590 ENDPROC(fixup_smp)
592 #ifdef __ARMEB__
593 #define LOW_OFFSET 0x4
594 #define HIGH_OFFSET 0x0
595 #else
596 #define LOW_OFFSET 0x0
597 #define HIGH_OFFSET 0x4
598 #endif
600 #ifdef CONFIG_ARM_PATCH_PHYS_VIRT
602 /* __fixup_pv_table - patch the stub instructions with the delta between
603 * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and
604 * can be expressed by an immediate shifter operand. The stub instruction
605 * has a form of '(add|sub) rd, rn, #imm'.
606 */
607 __HEAD
608 __fixup_pv_table:
609 adr r0, 1f
610 ldmia r0, {r3-r7}
611 mvn ip, #0
612 subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET
613 add r4, r4, r3 @ adjust table start address
614 add r5, r5, r3 @ adjust table end address
615 add r6, r6, r3 @ adjust __pv_phys_pfn_offset address
616 add r7, r7, r3 @ adjust __pv_offset address
617 mov r0, r8, lsr #PAGE_SHIFT @ convert to PFN
618 str r0, [r6] @ save computed PHYS_OFFSET to __pv_phys_pfn_offset
619 strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits
620 mov r6, r3, lsr #24 @ constant for add/sub instructions
621 teq r3, r6, lsl #24 @ must be 16MiB aligned
622 THUMB( it ne @ cross section branch )
623 bne __error
624 str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits
625 b __fixup_a_pv_table
626 ENDPROC(__fixup_pv_table)
628 .align
629 1: .long .
630 .long __pv_table_begin
631 .long __pv_table_end
632 2: .long __pv_phys_pfn_offset
633 .long __pv_offset
635 .text
636 __fixup_a_pv_table:
637 adr r0, 3f
638 ldr r6, [r0]
639 add r6, r6, r3
640 ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word
641 ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word
642 mov r6, r6, lsr #24
643 cmn r0, #1
644 #ifdef CONFIG_THUMB2_KERNEL
645 moveq r0, #0x200000 @ set bit 21, mov to mvn instruction
646 lsls r6, #24
647 beq 2f
648 clz r7, r6
649 lsr r6, #24
650 lsl r6, r7
651 bic r6, #0x0080
652 lsrs r7, #1
653 orrcs r6, #0x0080
654 orr r6, r6, r7, lsl #12
655 orr r6, #0x4000
656 b 2f
657 1: add r7, r3
658 ldrh ip, [r7, #2]
659 ARM_BE8(rev16 ip, ip)
660 tst ip, #0x4000
661 and ip, #0x8f00
662 orrne ip, r6 @ mask in offset bits 31-24
663 orreq ip, r0 @ mask in offset bits 7-0
664 ARM_BE8(rev16 ip, ip)
665 strh ip, [r7, #2]
666 bne 2f
667 ldrh ip, [r7]
668 ARM_BE8(rev16 ip, ip)
669 bic ip, #0x20
670 orr ip, ip, r0, lsr #16
671 ARM_BE8(rev16 ip, ip)
672 strh ip, [r7]
673 2: cmp r4, r5
674 ldrcc r7, [r4], #4 @ use branch for delay slot
675 bcc 1b
676 bx lr
677 #else
678 #ifdef CONFIG_CPU_ENDIAN_BE8
679 moveq r0, #0x00004000 @ set bit 22, mov to mvn instruction
680 #else
681 moveq r0, #0x400000 @ set bit 22, mov to mvn instruction
682 #endif
683 b 2f
684 1: ldr ip, [r7, r3]
685 #ifdef CONFIG_CPU_ENDIAN_BE8
686 @ in BE8, we load data in BE, but instructions still in LE
687 bic ip, ip, #0xff000000
688 tst ip, #0x000f0000 @ check the rotation field
689 orrne ip, ip, r6, lsl #24 @ mask in offset bits 31-24
690 biceq ip, ip, #0x00004000 @ clear bit 22
691 orreq ip, ip, r0 @ mask in offset bits 7-0
692 #else
693 bic ip, ip, #0x000000ff
694 tst ip, #0xf00 @ check the rotation field
695 orrne ip, ip, r6 @ mask in offset bits 31-24
696 biceq ip, ip, #0x400000 @ clear bit 22
697 orreq ip, ip, r0 @ mask in offset bits 7-0
698 #endif
699 str ip, [r7, r3]
700 2: cmp r4, r5
701 ldrcc r7, [r4], #4 @ use branch for delay slot
702 bcc 1b
703 ret lr
704 #endif
705 ENDPROC(__fixup_a_pv_table)
707 .align
708 3: .long __pv_offset
710 ENTRY(fixup_pv_table)
711 stmfd sp!, {r4 - r7, lr}
712 mov r3, #0 @ no offset
713 mov r4, r0 @ r0 = table start
714 add r5, r0, r1 @ r1 = table size
715 bl __fixup_a_pv_table
716 ldmfd sp!, {r4 - r7, pc}
717 ENDPROC(fixup_pv_table)
719 .data
720 .align 2
721 .globl __pv_phys_pfn_offset
722 .type __pv_phys_pfn_offset, %object
723 __pv_phys_pfn_offset:
724 .word 0
725 .size __pv_phys_pfn_offset, . -__pv_phys_pfn_offset
727 .globl __pv_offset
728 .type __pv_offset, %object
729 __pv_offset:
730 .quad 0
731 .size __pv_offset, . -__pv_offset
732 #endif
734 #include "head-common.S"