2 * linux/arch/arm/boot/compressed/head.S
4 * Copyright (C) 1996-2002 Russell King
5 * Copyright (C) 2004 Hyok S. Choi (MPU support)
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.
11 #include <linux/linkage.h>
16 * Note that these macros must not contain any code which is not
17 * 100% relocatable. Any attempt to do so will result in a crash.
18 * Please select one of the following when turning on debugging.
22 #if defined(CONFIG_DEBUG_ICEDCC)
28 mcr p14, 0, \ch, c0, c5, 0
34 mcr p14, 0, \ch, c0, c1, 0
40 #include <asm/arch/debug-macro.S>
46 #if defined(CONFIG_ARCH_SA1100)
48 mov \rb, #0x80000000 @ physical base address
49 #ifdef CONFIG_DEBUG_LL_SER3
50 add \rb, \rb, #0x00050000 @ Ser3
52 add \rb, \rb, #0x00010000 @ Ser1
55 #elif defined(CONFIG_ARCH_S3C2410)
58 add \rb, \rb, #0x4000 * CONFIG_S3C_LOWLEVEL_UART_PORT
79 .macro debug_reloc_start
82 kphex r6, 8 /* processor id */
84 kphex r7, 8 /* architecture id */
85 #ifdef CONFIG_CPU_CP15
87 mrc p15, 0, r0, c1, c0
88 kphex r0, 8 /* control reg */
91 kphex r5, 8 /* decompressed kernel start */
93 kphex r9, 8 /* decompressed kernel end */
95 kphex r4, 8 /* kernel execution address */
100 .macro debug_reloc_end
102 kphex r5, 8 /* end of kernel */
105 bl memdump /* dump 256 bytes at start of kernel */
109 .section ".start", #alloc, #execinstr
111 * sort out different calling conventions
115 .type start,#function
121 .word 0x016f2818 @ Magic numbers to help the loader
122 .word start @ absolute load/run zImage address
123 .word _edata @ zImage end address
124 1: mov r7, r1 @ save architecture ID
125 mov r8, r2 @ save atags pointer
127 #ifndef __ARM_ARCH_2__
129 * Booting from Angel - need to enter SVC mode and disable
130 * FIQs/IRQs (numeric definitions from angel arm.h source).
131 * We only do this if we were in user mode on entry.
133 mrs r2, cpsr @ get current mode
134 tst r2, #3 @ not user?
136 mov r0, #0x17 @ angel_SWIreason_EnterSVC
137 swi 0x123456 @ angel_SWI_ARM
139 mrs r2, cpsr @ turn off interrupts to
140 orr r2, r2, #0xc0 @ prevent angel from running
143 teqp pc, #0x0c000003 @ turn off interrupts
147 * Note that some cache flushing and other stuff may
148 * be needed here - is there an Angel SWI call for this?
152 * some architecture specific code can be inserted
153 * by the linker here, but it should preserve r7, r8, and r9.
158 ldmia r0, {r1, r2, r3, r4, r5, r6, ip, sp}
159 subs r0, r0, r1 @ calculate the delta offset
161 @ if delta is zero, we are
162 beq not_relocated @ running at the address we
166 * We're running at a different address. We need to fix
167 * up various pointers:
168 * r5 - zImage base address
176 #ifndef CONFIG_ZBOOT_ROM
178 * If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
179 * we need to fix up pointers into the BSS region.
189 * Relocate all entries in the GOT table.
191 1: ldr r1, [r6, #0] @ relocate entries in the GOT
192 add r1, r1, r0 @ table. This fixes up the
193 str r1, [r6], #4 @ C references.
199 * Relocate entries in the GOT table. We only relocate
200 * the entries that are outside the (relocated) BSS region.
202 1: ldr r1, [r6, #0] @ relocate entries in the GOT
203 cmp r1, r2 @ entry < bss_start ||
204 cmphs r3, r1 @ _end < entry
205 addlo r1, r1, r0 @ table. This fixes up the
206 str r1, [r6], #4 @ C references.
211 not_relocated: mov r0, #0
212 1: str r0, [r2], #4 @ clear bss
220 * The C runtime environment should now be setup
221 * sufficiently. Turn the cache on, set up some
222 * pointers, and start decompressing.
226 mov r1, sp @ malloc space above stack
227 add r2, sp, #0x10000 @ 64k max
230 * Check to see if we will overwrite ourselves.
231 * r4 = final kernel address
232 * r5 = start of this image
233 * r2 = end of malloc space (and therefore this image)
236 * r4 + image length <= r5 -> OK
240 sub r3, sp, r5 @ > compressed kernel size
241 add r0, r4, r3, lsl #2 @ allow for 4x expansion
245 mov r5, r2 @ decompress after malloc space
250 add r0, r0, #127 + 128 @ alignment + stack
251 bic r0, r0, #127 @ align the kernel length
253 * r0 = decompressed kernel length
255 * r4 = kernel execution address
256 * r5 = decompressed kernel start
258 * r7 = architecture ID
262 add r1, r5, r0 @ end of decompressed kernel
266 1: ldmia r2!, {r9 - r14} @ copy relocation code
267 stmia r1!, {r9 - r14}
268 ldmia r2!, {r9 - r14}
269 stmia r1!, {r9 - r14}
272 add sp, r1, #128 @ relocate the stack
275 add pc, r5, r0 @ call relocation code
278 * We're not in danger of overwriting ourselves. Do this the simple way.
280 * r4 = kernel execution address
281 * r7 = architecture ID
283 wont_overwrite: mov r0, r4
290 .word __bss_start @ r2
294 .word _got_start @ r6
296 .word user_stack+4096 @ sp
297 LC1: .word reloc_end - reloc_start
300 #ifdef CONFIG_ARCH_RPC
302 params: ldr r0, =params_phys
309 * Turn on the cache. We need to setup some page tables so that we
310 * can have both the I and D caches on.
312 * We place the page tables 16k down from the kernel execution address,
313 * and we hope that nothing else is using it. If we're using it, we
317 * r4 = kernel execution address
319 * r7 = architecture number
321 * r9 = run-time address of "start" (???)
323 * r1, r2, r3, r9, r10, r12 corrupted
324 * This routine must preserve:
328 cache_on: mov r3, #8 @ cache_on function
332 * Initialize the highest priority protection region, PR7
333 * to cover all 32bit address and cacheable and bufferable.
335 __armv4_mpu_cache_on:
336 mov r0, #0x3f @ 4G, the whole
337 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
338 mcr p15, 0, r0, c6, c7, 1
341 mcr p15, 0, r0, c2, c0, 0 @ D-cache on
342 mcr p15, 0, r0, c2, c0, 1 @ I-cache on
343 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
346 mcr p15, 0, r0, c5, c0, 1 @ I-access permission
347 mcr p15, 0, r0, c5, c0, 0 @ D-access permission
350 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
351 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
352 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
353 mrc p15, 0, r0, c1, c0, 0 @ read control reg
354 @ ...I .... ..D. WC.M
355 orr r0, r0, #0x002d @ .... .... ..1. 11.1
356 orr r0, r0, #0x1000 @ ...1 .... .... ....
358 mcr p15, 0, r0, c1, c0, 0 @ write control reg
361 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
362 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
365 __armv3_mpu_cache_on:
366 mov r0, #0x3f @ 4G, the whole
367 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
370 mcr p15, 0, r0, c2, c0, 0 @ cache on
371 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
374 mcr p15, 0, r0, c5, c0, 0 @ access permission
377 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
378 mrc p15, 0, r0, c1, c0, 0 @ read control reg
379 @ .... .... .... WC.M
380 orr r0, r0, #0x000d @ .... .... .... 11.1
382 mcr p15, 0, r0, c1, c0, 0 @ write control reg
384 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
387 __setup_mmu: sub r3, r4, #16384 @ Page directory size
388 bic r3, r3, #0xff @ Align the pointer
391 * Initialise the page tables, turning on the cacheable and bufferable
392 * bits for the RAM area only.
396 mov r9, r9, lsl #18 @ start of RAM
397 add r10, r9, #0x10000000 @ a reasonable RAM size
401 1: cmp r1, r9 @ if virt > start of RAM
402 orrhs r1, r1, #0x0c @ set cacheable, bufferable
403 cmp r1, r10 @ if virt > end of RAM
404 bichs r1, r1, #0x0c @ clear cacheable, bufferable
405 str r1, [r0], #4 @ 1:1 mapping
410 * If ever we are running from Flash, then we surely want the cache
411 * to be enabled also for our execution instance... We map 2MB of it
412 * so there is no map overlap problem for up to 1 MB compressed kernel.
413 * If the execution is in RAM then we would only be duplicating the above.
418 orr r1, r1, r2, lsl #20
419 add r0, r3, r2, lsl #2
425 __armv4_mmu_cache_on:
429 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
430 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
431 mrc p15, 0, r0, c1, c0, 0 @ read control reg
432 orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
434 bl __common_mmu_cache_on
436 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
439 __armv7_mmu_cache_on:
441 mrc p15, 0, r11, c0, c1, 4 @ read ID_MMFR0
445 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
447 mcrne p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
448 mrc p15, 0, r0, c1, c0, 0 @ read control reg
449 orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
450 orr r0, r0, #0x003c @ write buffer
451 orrne r0, r0, #1 @ MMU enabled
453 mcrne p15, 0, r3, c2, c0, 0 @ load page table pointer
454 mcrne p15, 0, r1, c3, c0, 0 @ load domain access control
455 mcr p15, 0, r0, c1, c0, 0 @ load control register
456 mrc p15, 0, r0, c1, c0, 0 @ and read it back
458 mcr p15, 0, r0, c7, c5, 4 @ ISB
465 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
466 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
468 bl __common_mmu_cache_on
470 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
473 __common_mmu_cache_on:
475 orr r0, r0, #0x000d @ Write buffer, mmu
478 mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
479 mcr p15, 0, r1, c3, c0, 0 @ load domain access control
481 .align 5 @ cache line aligned
482 1: mcr p15, 0, r0, c1, c0, 0 @ load control register
483 mrc p15, 0, r0, c1, c0, 0 @ and read it back to
484 sub pc, lr, r0, lsr #32 @ properly flush pipeline
487 * All code following this line is relocatable. It is relocated by
488 * the above code to the end of the decompressed kernel image and
489 * executed there. During this time, we have no stacks.
491 * r0 = decompressed kernel length
493 * r4 = kernel execution address
494 * r5 = decompressed kernel start
496 * r7 = architecture ID
501 reloc_start: add r9, r5, r0
502 sub r9, r9, #128 @ do not copy the stack
507 ldmia r5!, {r0, r2, r3, r10 - r14} @ relocate kernel
508 stmia r1!, {r0, r2, r3, r10 - r14}
513 add sp, r1, #128 @ relocate the stack
516 call_kernel: bl cache_clean_flush
518 mov r0, #0 @ must be zero
519 mov r1, r7 @ restore architecture number
520 mov r2, r8 @ restore atags pointer
521 mov pc, r4 @ call kernel
524 * Here follow the relocatable cache support functions for the
525 * various processors. This is a generic hook for locating an
526 * entry and jumping to an instruction at the specified offset
527 * from the start of the block. Please note this is all position
537 call_cache_fn: adr r12, proc_types
538 #ifdef CONFIG_CPU_CP15
539 mrc p15, 0, r6, c0, c0 @ get processor ID
541 ldr r6, =CONFIG_PROCESSOR_ID
543 1: ldr r1, [r12, #0] @ get value
544 ldr r2, [r12, #4] @ get mask
545 eor r1, r1, r6 @ (real ^ match)
547 addeq pc, r12, r3 @ call cache function
552 * Table for cache operations. This is basically:
555 * - 'cache on' method instruction
556 * - 'cache off' method instruction
557 * - 'cache flush' method instruction
559 * We match an entry using: ((real_id ^ match) & mask) == 0
561 * Writethrough caches generally only need 'on' and 'off'
562 * methods. Writeback caches _must_ have the flush method
565 .type proc_types,#object
567 .word 0x41560600 @ ARM6/610
569 b __arm6_mmu_cache_off @ works, but slow
570 b __arm6_mmu_cache_off
572 @ b __arm6_mmu_cache_on @ untested
573 @ b __arm6_mmu_cache_off
574 @ b __armv3_mmu_cache_flush
576 .word 0x00000000 @ old ARM ID
582 .word 0x41007000 @ ARM7/710
584 b __arm7_mmu_cache_off
585 b __arm7_mmu_cache_off
588 .word 0x41807200 @ ARM720T (writethrough)
590 b __armv4_mmu_cache_on
591 b __armv4_mmu_cache_off
594 .word 0x41007400 @ ARM74x
596 b __armv3_mpu_cache_on
597 b __armv3_mpu_cache_off
598 b __armv3_mpu_cache_flush
600 .word 0x41009400 @ ARM94x
602 b __armv4_mpu_cache_on
603 b __armv4_mpu_cache_off
604 b __armv4_mpu_cache_flush
606 .word 0x00007000 @ ARM7 IDs
612 @ Everything from here on will be the new ID system.
614 .word 0x4401a100 @ sa110 / sa1100
616 b __armv4_mmu_cache_on
617 b __armv4_mmu_cache_off
618 b __armv4_mmu_cache_flush
620 .word 0x6901b110 @ sa1110
622 b __armv4_mmu_cache_on
623 b __armv4_mmu_cache_off
624 b __armv4_mmu_cache_flush
626 @ These match on the architecture ID
628 .word 0x00020000 @ ARMv4T
630 b __armv4_mmu_cache_on
631 b __armv4_mmu_cache_off
632 b __armv4_mmu_cache_flush
634 .word 0x00050000 @ ARMv5TE
636 b __armv4_mmu_cache_on
637 b __armv4_mmu_cache_off
638 b __armv4_mmu_cache_flush
640 .word 0x00060000 @ ARMv5TEJ
642 b __armv4_mmu_cache_on
643 b __armv4_mmu_cache_off
644 b __armv4_mmu_cache_flush
646 .word 0x0007b000 @ ARMv6
648 b __armv4_mmu_cache_on
649 b __armv4_mmu_cache_off
650 b __armv6_mmu_cache_flush
652 .word 0x000f0000 @ new CPU Id
654 b __armv7_mmu_cache_on
655 b __armv7_mmu_cache_off
656 b __armv7_mmu_cache_flush
658 .word 0 @ unrecognised type
664 .size proc_types, . - proc_types
667 * Turn off the Cache and MMU. ARMv3 does not support
668 * reading the control register, but ARMv4 does.
670 * On entry, r6 = processor ID
671 * On exit, r0, r1, r2, r3, r12 corrupted
672 * This routine must preserve: r4, r6, r7
675 cache_off: mov r3, #12 @ cache_off function
678 __armv4_mpu_cache_off:
679 mrc p15, 0, r0, c1, c0
681 mcr p15, 0, r0, c1, c0 @ turn MPU and cache off
683 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
684 mcr p15, 0, r0, c7, c6, 0 @ flush D-Cache
685 mcr p15, 0, r0, c7, c5, 0 @ flush I-Cache
688 __armv3_mpu_cache_off:
689 mrc p15, 0, r0, c1, c0
691 mcr p15, 0, r0, c1, c0, 0 @ turn MPU and cache off
693 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
696 __armv4_mmu_cache_off:
697 mrc p15, 0, r0, c1, c0
699 mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
701 mcr p15, 0, r0, c7, c7 @ invalidate whole cache v4
702 mcr p15, 0, r0, c8, c7 @ invalidate whole TLB v4
705 __armv7_mmu_cache_off:
706 mrc p15, 0, r0, c1, c0
708 mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
710 bl __armv7_mmu_cache_flush
712 mcr p15, 0, r0, c8, c7, 0 @ invalidate whole TLB
715 __arm6_mmu_cache_off:
716 mov r0, #0x00000030 @ ARM6 control reg.
717 b __armv3_mmu_cache_off
719 __arm7_mmu_cache_off:
720 mov r0, #0x00000070 @ ARM7 control reg.
721 b __armv3_mmu_cache_off
723 __armv3_mmu_cache_off:
724 mcr p15, 0, r0, c1, c0, 0 @ turn MMU and cache off
726 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
727 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
731 * Clean and flush the cache to maintain consistency.
736 * r1, r2, r3, r11, r12 corrupted
737 * This routine must preserve:
745 __armv4_mpu_cache_flush:
748 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
749 mov r1, #7 << 5 @ 8 segments
750 1: orr r3, r1, #63 << 26 @ 64 entries
751 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index
752 subs r3, r3, #1 << 26
753 bcs 2b @ entries 63 to 0
755 bcs 1b @ segments 7 to 0
758 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
759 mcr p15, 0, ip, c7, c10, 4 @ drain WB
763 __armv6_mmu_cache_flush:
765 mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D
766 mcr p15, 0, r1, c7, c5, 0 @ invalidate I+BTB
767 mcr p15, 0, r1, c7, c15, 0 @ clean+invalidate unified
768 mcr p15, 0, r1, c7, c10, 4 @ drain WB
771 __armv7_mmu_cache_flush:
772 mrc p15, 0, r10, c0, c1, 5 @ read ID_MMFR1
773 tst r10, #0xf << 16 @ hierarchical cache (ARMv7)
776 mcr p15, 0, r10, c7, c14, 0 @ clean+invalidate D
779 stmfd sp!, {r0-r5, r7, r9-r11}
780 mrc p15, 1, r0, c0, c0, 1 @ read clidr
781 ands r3, r0, #0x7000000 @ extract loc from clidr
782 mov r3, r3, lsr #23 @ left align loc bit field
783 beq finished @ if loc is 0, then no need to clean
784 mov r10, #0 @ start clean at cache level 0
786 add r2, r10, r10, lsr #1 @ work out 3x current cache level
787 mov r1, r0, lsr r2 @ extract cache type bits from clidr
788 and r1, r1, #7 @ mask of the bits for current cache only
789 cmp r1, #2 @ see what cache we have at this level
790 blt skip @ skip if no cache, or just i-cache
791 mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
792 mcr p15, 0, r10, c7, c5, 4 @ isb to sych the new cssr&csidr
793 mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
794 and r2, r1, #7 @ extract the length of the cache lines
795 add r2, r2, #4 @ add 4 (line length offset)
797 ands r4, r4, r1, lsr #3 @ find maximum number on the way size
798 .word 0xe16f5f14 @ clz r5, r4 - find bit position of way size increment
800 ands r7, r7, r1, lsr #13 @ extract max number of the index size
802 mov r9, r4 @ create working copy of max way size
804 orr r11, r10, r9, lsl r5 @ factor way and cache number into r11
805 orr r11, r11, r7, lsl r2 @ factor index number into r11
806 mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
807 subs r9, r9, #1 @ decrement the way
809 subs r7, r7, #1 @ decrement the index
812 add r10, r10, #2 @ increment cache number
816 mov r10, #0 @ swith back to cache level 0
817 mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
818 ldmfd sp!, {r0-r5, r7, r9-r11}
820 mcr p15, 0, r10, c7, c5, 0 @ invalidate I+BTB
821 mcr p15, 0, r10, c7, c10, 4 @ drain WB
824 __armv4_mmu_cache_flush:
825 mov r2, #64*1024 @ default: 32K dcache size (*2)
826 mov r11, #32 @ default: 32 byte line size
827 mrc p15, 0, r3, c0, c0, 1 @ read cache type
828 teq r3, r6 @ cache ID register present?
833 mov r2, r2, lsl r1 @ base dcache size *2
834 tst r3, #1 << 14 @ test M bit
835 addne r2, r2, r2, lsr #1 @ +1/2 size if M == 1
839 mov r11, r11, lsl r3 @ cache line size in bytes
841 bic r1, pc, #63 @ align to longest cache line
843 1: ldr r3, [r1], r11 @ s/w flush D cache
847 mcr p15, 0, r1, c7, c5, 0 @ flush I cache
848 mcr p15, 0, r1, c7, c6, 0 @ flush D cache
849 mcr p15, 0, r1, c7, c10, 4 @ drain WB
852 __armv3_mmu_cache_flush:
853 __armv3_mpu_cache_flush:
855 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
859 * Various debugging routines for printing hex characters and
860 * memory, which again must be relocatable.
863 .type phexbuf,#object
865 .size phexbuf, . - phexbuf
867 phex: adr r3, phexbuf
904 2: mov r0, r11, lsl #2
912 ldr r0, [r12, r11, lsl #2]
934 .section ".stack", "w"
935 user_stack: .space 4096