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_S3C2410_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 add r0, r4, #4096*1024 @ 4MB largest kernel size
244 mov r5, r2 @ decompress after malloc space
250 bic r0, r0, #127 @ align the kernel length
252 * r0 = decompressed kernel length
254 * r4 = kernel execution address
255 * r5 = decompressed kernel start
257 * r7 = architecture ID
261 add r1, r5, r0 @ end of decompressed kernel
265 1: ldmia r2!, {r9 - r14} @ copy relocation code
266 stmia r1!, {r9 - r14}
267 ldmia r2!, {r9 - r14}
268 stmia r1!, {r9 - r14}
273 add pc, r5, r0 @ call relocation code
276 * We're not in danger of overwriting ourselves. Do this the simple way.
278 * r4 = kernel execution address
279 * r7 = architecture ID
281 wont_overwrite: mov r0, r4
288 .word __bss_start @ r2
292 .word _got_start @ r6
294 .word user_stack+4096 @ sp
295 LC1: .word reloc_end - reloc_start
298 #ifdef CONFIG_ARCH_RPC
300 params: ldr r0, =params_phys
307 * Turn on the cache. We need to setup some page tables so that we
308 * can have both the I and D caches on.
310 * We place the page tables 16k down from the kernel execution address,
311 * and we hope that nothing else is using it. If we're using it, we
315 * r4 = kernel execution address
317 * r7 = architecture number
319 * r9 = run-time address of "start" (???)
321 * r1, r2, r3, r9, r10, r12 corrupted
322 * This routine must preserve:
326 cache_on: mov r3, #8 @ cache_on function
330 * Initialize the highest priority protection region, PR7
331 * to cover all 32bit address and cacheable and bufferable.
333 __armv4_mpu_cache_on:
334 mov r0, #0x3f @ 4G, the whole
335 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
336 mcr p15, 0, r0, c6, c7, 1
339 mcr p15, 0, r0, c2, c0, 0 @ D-cache on
340 mcr p15, 0, r0, c2, c0, 1 @ I-cache on
341 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
344 mcr p15, 0, r0, c5, c0, 1 @ I-access permission
345 mcr p15, 0, r0, c5, c0, 0 @ D-access permission
348 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
349 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
350 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
351 mrc p15, 0, r0, c1, c0, 0 @ read control reg
352 @ ...I .... ..D. WC.M
353 orr r0, r0, #0x002d @ .... .... ..1. 11.1
354 orr r0, r0, #0x1000 @ ...1 .... .... ....
356 mcr p15, 0, r0, c1, c0, 0 @ write control reg
359 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
360 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
363 __armv3_mpu_cache_on:
364 mov r0, #0x3f @ 4G, the whole
365 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
368 mcr p15, 0, r0, c2, c0, 0 @ cache on
369 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
372 mcr p15, 0, r0, c5, c0, 0 @ access permission
375 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
376 mrc p15, 0, r0, c1, c0, 0 @ read control reg
377 @ .... .... .... WC.M
378 orr r0, r0, #0x000d @ .... .... .... 11.1
380 mcr p15, 0, r0, c1, c0, 0 @ write control reg
382 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
385 __setup_mmu: sub r3, r4, #16384 @ Page directory size
386 bic r3, r3, #0xff @ Align the pointer
389 * Initialise the page tables, turning on the cacheable and bufferable
390 * bits for the RAM area only.
394 mov r9, r9, lsl #18 @ start of RAM
395 add r10, r9, #0x10000000 @ a reasonable RAM size
399 1: cmp r1, r9 @ if virt > start of RAM
400 orrhs r1, r1, #0x0c @ set cacheable, bufferable
401 cmp r1, r10 @ if virt > end of RAM
402 bichs r1, r1, #0x0c @ clear cacheable, bufferable
403 str r1, [r0], #4 @ 1:1 mapping
408 * If ever we are running from Flash, then we surely want the cache
409 * to be enabled also for our execution instance... We map 2MB of it
410 * so there is no map overlap problem for up to 1 MB compressed kernel.
411 * If the execution is in RAM then we would only be duplicating the above.
416 orr r1, r1, r2, lsl #20
417 add r0, r3, r2, lsl #2
423 __armv4_mmu_cache_on:
427 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
428 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
429 mrc p15, 0, r0, c1, c0, 0 @ read control reg
430 orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
432 bl __common_mmu_cache_on
434 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
441 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
442 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
444 bl __common_mmu_cache_on
446 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
449 __common_mmu_cache_on:
451 orr r0, r0, #0x000d @ Write buffer, mmu
454 mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
455 mcr p15, 0, r1, c3, c0, 0 @ load domain access control
457 .align 5 @ cache line aligned
458 1: mcr p15, 0, r0, c1, c0, 0 @ load control register
459 mrc p15, 0, r0, c1, c0, 0 @ and read it back to
460 sub pc, lr, r0, lsr #32 @ properly flush pipeline
463 * All code following this line is relocatable. It is relocated by
464 * the above code to the end of the decompressed kernel image and
465 * executed there. During this time, we have no stacks.
467 * r0 = decompressed kernel length
469 * r4 = kernel execution address
470 * r5 = decompressed kernel start
472 * r7 = architecture ID
477 reloc_start: add r9, r5, r0
482 ldmia r5!, {r0, r2, r3, r10 - r14} @ relocate kernel
483 stmia r1!, {r0, r2, r3, r10 - r14}
490 call_kernel: bl cache_clean_flush
492 mov r0, #0 @ must be zero
493 mov r1, r7 @ restore architecture number
494 mov r2, r8 @ restore atags pointer
495 mov pc, r4 @ call kernel
498 * Here follow the relocatable cache support functions for the
499 * various processors. This is a generic hook for locating an
500 * entry and jumping to an instruction at the specified offset
501 * from the start of the block. Please note this is all position
511 call_cache_fn: adr r12, proc_types
512 #ifdef CONFIG_CPU_CP15
513 mrc p15, 0, r6, c0, c0 @ get processor ID
515 ldr r6, =CONFIG_PROCESSOR_ID
517 1: ldr r1, [r12, #0] @ get value
518 ldr r2, [r12, #4] @ get mask
519 eor r1, r1, r6 @ (real ^ match)
521 addeq pc, r12, r3 @ call cache function
526 * Table for cache operations. This is basically:
529 * - 'cache on' method instruction
530 * - 'cache off' method instruction
531 * - 'cache flush' method instruction
533 * We match an entry using: ((real_id ^ match) & mask) == 0
535 * Writethrough caches generally only need 'on' and 'off'
536 * methods. Writeback caches _must_ have the flush method
539 .type proc_types,#object
541 .word 0x41560600 @ ARM6/610
543 b __arm6_mmu_cache_off @ works, but slow
544 b __arm6_mmu_cache_off
546 @ b __arm6_mmu_cache_on @ untested
547 @ b __arm6_mmu_cache_off
548 @ b __armv3_mmu_cache_flush
550 .word 0x00000000 @ old ARM ID
556 .word 0x41007000 @ ARM7/710
558 b __arm7_mmu_cache_off
559 b __arm7_mmu_cache_off
562 .word 0x41807200 @ ARM720T (writethrough)
564 b __armv4_mmu_cache_on
565 b __armv4_mmu_cache_off
568 .word 0x41007400 @ ARM74x
570 b __armv3_mpu_cache_on
571 b __armv3_mpu_cache_off
572 b __armv3_mpu_cache_flush
574 .word 0x41009400 @ ARM94x
576 b __armv4_mpu_cache_on
577 b __armv4_mpu_cache_off
578 b __armv4_mpu_cache_flush
580 .word 0x00007000 @ ARM7 IDs
586 @ Everything from here on will be the new ID system.
588 .word 0x4401a100 @ sa110 / sa1100
590 b __armv4_mmu_cache_on
591 b __armv4_mmu_cache_off
592 b __armv4_mmu_cache_flush
594 .word 0x6901b110 @ sa1110
596 b __armv4_mmu_cache_on
597 b __armv4_mmu_cache_off
598 b __armv4_mmu_cache_flush
600 @ These match on the architecture ID
602 .word 0x00020000 @ ARMv4T
604 b __armv4_mmu_cache_on
605 b __armv4_mmu_cache_off
606 b __armv4_mmu_cache_flush
608 .word 0x00050000 @ ARMv5TE
610 b __armv4_mmu_cache_on
611 b __armv4_mmu_cache_off
612 b __armv4_mmu_cache_flush
614 .word 0x00060000 @ ARMv5TEJ
616 b __armv4_mmu_cache_on
617 b __armv4_mmu_cache_off
618 b __armv4_mmu_cache_flush
620 .word 0x0007b000 @ ARMv6
622 b __armv4_mmu_cache_on
623 b __armv4_mmu_cache_off
624 b __armv6_mmu_cache_flush
626 .word 0 @ unrecognised type
632 .size proc_types, . - proc_types
635 * Turn off the Cache and MMU. ARMv3 does not support
636 * reading the control register, but ARMv4 does.
638 * On entry, r6 = processor ID
639 * On exit, r0, r1, r2, r3, r12 corrupted
640 * This routine must preserve: r4, r6, r7
643 cache_off: mov r3, #12 @ cache_off function
646 __armv4_mpu_cache_off:
647 mrc p15, 0, r0, c1, c0
649 mcr p15, 0, r0, c1, c0 @ turn MPU and cache off
651 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
652 mcr p15, 0, r0, c7, c6, 0 @ flush D-Cache
653 mcr p15, 0, r0, c7, c5, 0 @ flush I-Cache
656 __armv3_mpu_cache_off:
657 mrc p15, 0, r0, c1, c0
659 mcr p15, 0, r0, c1, c0, 0 @ turn MPU and cache off
661 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
664 __armv4_mmu_cache_off:
665 mrc p15, 0, r0, c1, c0
667 mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
669 mcr p15, 0, r0, c7, c7 @ invalidate whole cache v4
670 mcr p15, 0, r0, c8, c7 @ invalidate whole TLB v4
673 __arm6_mmu_cache_off:
674 mov r0, #0x00000030 @ ARM6 control reg.
675 b __armv3_mmu_cache_off
677 __arm7_mmu_cache_off:
678 mov r0, #0x00000070 @ ARM7 control reg.
679 b __armv3_mmu_cache_off
681 __armv3_mmu_cache_off:
682 mcr p15, 0, r0, c1, c0, 0 @ turn MMU and cache off
684 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
685 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
689 * Clean and flush the cache to maintain consistency.
694 * r1, r2, r3, r11, r12 corrupted
695 * This routine must preserve:
703 __armv4_mpu_cache_flush:
706 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
707 mov r1, #7 << 5 @ 8 segments
708 1: orr r3, r1, #63 << 26 @ 64 entries
709 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index
710 subs r3, r3, #1 << 26
711 bcs 2b @ entries 63 to 0
713 bcs 1b @ segments 7 to 0
716 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
717 mcr p15, 0, ip, c7, c10, 4 @ drain WB
721 __armv6_mmu_cache_flush:
723 mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D
724 mcr p15, 0, r1, c7, c5, 0 @ invalidate I+BTB
725 mcr p15, 0, r1, c7, c15, 0 @ clean+invalidate unified
726 mcr p15, 0, r1, c7, c10, 4 @ drain WB
729 __armv4_mmu_cache_flush:
730 mov r2, #64*1024 @ default: 32K dcache size (*2)
731 mov r11, #32 @ default: 32 byte line size
732 mrc p15, 0, r3, c0, c0, 1 @ read cache type
733 teq r3, r6 @ cache ID register present?
738 mov r2, r2, lsl r1 @ base dcache size *2
739 tst r3, #1 << 14 @ test M bit
740 addne r2, r2, r2, lsr #1 @ +1/2 size if M == 1
744 mov r11, r11, lsl r3 @ cache line size in bytes
746 bic r1, pc, #63 @ align to longest cache line
748 1: ldr r3, [r1], r11 @ s/w flush D cache
752 mcr p15, 0, r1, c7, c5, 0 @ flush I cache
753 mcr p15, 0, r1, c7, c6, 0 @ flush D cache
754 mcr p15, 0, r1, c7, c10, 4 @ drain WB
757 __armv3_mmu_cache_flush:
758 __armv3_mpu_cache_flush:
760 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
764 * Various debugging routines for printing hex characters and
765 * memory, which again must be relocatable.
768 .type phexbuf,#object
770 .size phexbuf, . - phexbuf
772 phex: adr r3, phexbuf
809 2: mov r0, r11, lsl #2
817 ldr r0, [r12, r11, lsl #2]
838 .section ".stack", "w"
839 user_stack: .space 4096