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 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
443 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
444 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
446 bl __common_mmu_cache_on
448 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
451 __common_mmu_cache_on:
453 orr r0, r0, #0x000d @ Write buffer, mmu
456 mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
457 mcr p15, 0, r1, c3, c0, 0 @ load domain access control
459 .align 5 @ cache line aligned
460 1: mcr p15, 0, r0, c1, c0, 0 @ load control register
461 mrc p15, 0, r0, c1, c0, 0 @ and read it back to
462 sub pc, lr, r0, lsr #32 @ properly flush pipeline
465 * All code following this line is relocatable. It is relocated by
466 * the above code to the end of the decompressed kernel image and
467 * executed there. During this time, we have no stacks.
469 * r0 = decompressed kernel length
471 * r4 = kernel execution address
472 * r5 = decompressed kernel start
474 * r7 = architecture ID
479 reloc_start: add r9, r5, r0
480 sub r9, r9, #128 @ do not copy the stack
485 ldmia r5!, {r0, r2, r3, r10 - r14} @ relocate kernel
486 stmia r1!, {r0, r2, r3, r10 - r14}
491 add sp, r1, #128 @ relocate the stack
494 call_kernel: bl cache_clean_flush
496 mov r0, #0 @ must be zero
497 mov r1, r7 @ restore architecture number
498 mov r2, r8 @ restore atags pointer
499 mov pc, r4 @ call kernel
502 * Here follow the relocatable cache support functions for the
503 * various processors. This is a generic hook for locating an
504 * entry and jumping to an instruction at the specified offset
505 * from the start of the block. Please note this is all position
515 call_cache_fn: adr r12, proc_types
516 #ifdef CONFIG_CPU_CP15
517 mrc p15, 0, r6, c0, c0 @ get processor ID
519 ldr r6, =CONFIG_PROCESSOR_ID
521 1: ldr r1, [r12, #0] @ get value
522 ldr r2, [r12, #4] @ get mask
523 eor r1, r1, r6 @ (real ^ match)
525 addeq pc, r12, r3 @ call cache function
530 * Table for cache operations. This is basically:
533 * - 'cache on' method instruction
534 * - 'cache off' method instruction
535 * - 'cache flush' method instruction
537 * We match an entry using: ((real_id ^ match) & mask) == 0
539 * Writethrough caches generally only need 'on' and 'off'
540 * methods. Writeback caches _must_ have the flush method
543 .type proc_types,#object
545 .word 0x41560600 @ ARM6/610
547 b __arm6_mmu_cache_off @ works, but slow
548 b __arm6_mmu_cache_off
550 @ b __arm6_mmu_cache_on @ untested
551 @ b __arm6_mmu_cache_off
552 @ b __armv3_mmu_cache_flush
554 .word 0x00000000 @ old ARM ID
560 .word 0x41007000 @ ARM7/710
562 b __arm7_mmu_cache_off
563 b __arm7_mmu_cache_off
566 .word 0x41807200 @ ARM720T (writethrough)
568 b __armv4_mmu_cache_on
569 b __armv4_mmu_cache_off
572 .word 0x41007400 @ ARM74x
574 b __armv3_mpu_cache_on
575 b __armv3_mpu_cache_off
576 b __armv3_mpu_cache_flush
578 .word 0x41009400 @ ARM94x
580 b __armv4_mpu_cache_on
581 b __armv4_mpu_cache_off
582 b __armv4_mpu_cache_flush
584 .word 0x00007000 @ ARM7 IDs
590 @ Everything from here on will be the new ID system.
592 .word 0x4401a100 @ sa110 / sa1100
594 b __armv4_mmu_cache_on
595 b __armv4_mmu_cache_off
596 b __armv4_mmu_cache_flush
598 .word 0x6901b110 @ sa1110
600 b __armv4_mmu_cache_on
601 b __armv4_mmu_cache_off
602 b __armv4_mmu_cache_flush
604 @ These match on the architecture ID
606 .word 0x00020000 @ ARMv4T
608 b __armv4_mmu_cache_on
609 b __armv4_mmu_cache_off
610 b __armv4_mmu_cache_flush
612 .word 0x00050000 @ ARMv5TE
614 b __armv4_mmu_cache_on
615 b __armv4_mmu_cache_off
616 b __armv4_mmu_cache_flush
618 .word 0x00060000 @ ARMv5TEJ
620 b __armv4_mmu_cache_on
621 b __armv4_mmu_cache_off
622 b __armv4_mmu_cache_flush
624 .word 0x0007b000 @ ARMv6
626 b __armv4_mmu_cache_on
627 b __armv4_mmu_cache_off
628 b __armv6_mmu_cache_flush
630 .word 0 @ unrecognised type
636 .size proc_types, . - proc_types
639 * Turn off the Cache and MMU. ARMv3 does not support
640 * reading the control register, but ARMv4 does.
642 * On entry, r6 = processor ID
643 * On exit, r0, r1, r2, r3, r12 corrupted
644 * This routine must preserve: r4, r6, r7
647 cache_off: mov r3, #12 @ cache_off function
650 __armv4_mpu_cache_off:
651 mrc p15, 0, r0, c1, c0
653 mcr p15, 0, r0, c1, c0 @ turn MPU and cache off
655 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
656 mcr p15, 0, r0, c7, c6, 0 @ flush D-Cache
657 mcr p15, 0, r0, c7, c5, 0 @ flush I-Cache
660 __armv3_mpu_cache_off:
661 mrc p15, 0, r0, c1, c0
663 mcr p15, 0, r0, c1, c0, 0 @ turn MPU and cache off
665 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
668 __armv4_mmu_cache_off:
669 mrc p15, 0, r0, c1, c0
671 mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
673 mcr p15, 0, r0, c7, c7 @ invalidate whole cache v4
674 mcr p15, 0, r0, c8, c7 @ invalidate whole TLB v4
677 __arm6_mmu_cache_off:
678 mov r0, #0x00000030 @ ARM6 control reg.
679 b __armv3_mmu_cache_off
681 __arm7_mmu_cache_off:
682 mov r0, #0x00000070 @ ARM7 control reg.
683 b __armv3_mmu_cache_off
685 __armv3_mmu_cache_off:
686 mcr p15, 0, r0, c1, c0, 0 @ turn MMU and cache off
688 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
689 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
693 * Clean and flush the cache to maintain consistency.
698 * r1, r2, r3, r11, r12 corrupted
699 * This routine must preserve:
707 __armv4_mpu_cache_flush:
710 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
711 mov r1, #7 << 5 @ 8 segments
712 1: orr r3, r1, #63 << 26 @ 64 entries
713 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index
714 subs r3, r3, #1 << 26
715 bcs 2b @ entries 63 to 0
717 bcs 1b @ segments 7 to 0
720 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
721 mcr p15, 0, ip, c7, c10, 4 @ drain WB
725 __armv6_mmu_cache_flush:
727 mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D
728 mcr p15, 0, r1, c7, c5, 0 @ invalidate I+BTB
729 mcr p15, 0, r1, c7, c15, 0 @ clean+invalidate unified
730 mcr p15, 0, r1, c7, c10, 4 @ drain WB
733 __armv4_mmu_cache_flush:
734 mov r2, #64*1024 @ default: 32K dcache size (*2)
735 mov r11, #32 @ default: 32 byte line size
736 mrc p15, 0, r3, c0, c0, 1 @ read cache type
737 teq r3, r6 @ cache ID register present?
742 mov r2, r2, lsl r1 @ base dcache size *2
743 tst r3, #1 << 14 @ test M bit
744 addne r2, r2, r2, lsr #1 @ +1/2 size if M == 1
748 mov r11, r11, lsl r3 @ cache line size in bytes
750 bic r1, pc, #63 @ align to longest cache line
752 1: ldr r3, [r1], r11 @ s/w flush D cache
756 mcr p15, 0, r1, c7, c5, 0 @ flush I cache
757 mcr p15, 0, r1, c7, c6, 0 @ flush D cache
758 mcr p15, 0, r1, c7, c10, 4 @ drain WB
761 __armv3_mmu_cache_flush:
762 __armv3_mpu_cache_flush:
764 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
768 * Various debugging routines for printing hex characters and
769 * memory, which again must be relocatable.
772 .type phexbuf,#object
774 .size phexbuf, . - phexbuf
776 phex: adr r3, phexbuf
813 2: mov r0, r11, lsl #2
821 ldr r0, [r12, r11, lsl #2]
842 .section ".stack", "w"
843 user_stack: .space 4096