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
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}
274 add pc, r5, r0 @ call relocation code
277 * We're not in danger of overwriting ourselves. Do this the simple way.
279 * r4 = kernel execution address
280 * r7 = architecture ID
282 wont_overwrite: mov r0, r4
289 .word __bss_start @ r2
293 .word _got_start @ r6
295 .word user_stack+4096 @ sp
296 LC1: .word reloc_end - reloc_start
299 #ifdef CONFIG_ARCH_RPC
301 params: ldr r0, =params_phys
308 * Turn on the cache. We need to setup some page tables so that we
309 * can have both the I and D caches on.
311 * We place the page tables 16k down from the kernel execution address,
312 * and we hope that nothing else is using it. If we're using it, we
316 * r4 = kernel execution address
318 * r7 = architecture number
320 * r9 = run-time address of "start" (???)
322 * r1, r2, r3, r9, r10, r12 corrupted
323 * This routine must preserve:
327 cache_on: mov r3, #8 @ cache_on function
331 * Initialize the highest priority protection region, PR7
332 * to cover all 32bit address and cacheable and bufferable.
334 __armv4_mpu_cache_on:
335 mov r0, #0x3f @ 4G, the whole
336 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
337 mcr p15, 0, r0, c6, c7, 1
340 mcr p15, 0, r0, c2, c0, 0 @ D-cache on
341 mcr p15, 0, r0, c2, c0, 1 @ I-cache on
342 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
345 mcr p15, 0, r0, c5, c0, 1 @ I-access permission
346 mcr p15, 0, r0, c5, c0, 0 @ D-access permission
349 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
350 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
351 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
352 mrc p15, 0, r0, c1, c0, 0 @ read control reg
353 @ ...I .... ..D. WC.M
354 orr r0, r0, #0x002d @ .... .... ..1. 11.1
355 orr r0, r0, #0x1000 @ ...1 .... .... ....
357 mcr p15, 0, r0, c1, c0, 0 @ write control reg
360 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
361 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
364 __armv3_mpu_cache_on:
365 mov r0, #0x3f @ 4G, the whole
366 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
369 mcr p15, 0, r0, c2, c0, 0 @ cache on
370 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
373 mcr p15, 0, r0, c5, c0, 0 @ access permission
376 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
377 mrc p15, 0, r0, c1, c0, 0 @ read control reg
378 @ .... .... .... WC.M
379 orr r0, r0, #0x000d @ .... .... .... 11.1
381 mcr p15, 0, r0, c1, c0, 0 @ write control reg
383 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
386 __setup_mmu: sub r3, r4, #16384 @ Page directory size
387 bic r3, r3, #0xff @ Align the pointer
390 * Initialise the page tables, turning on the cacheable and bufferable
391 * bits for the RAM area only.
395 mov r9, r9, lsl #18 @ start of RAM
396 add r10, r9, #0x10000000 @ a reasonable RAM size
400 1: cmp r1, r9 @ if virt > start of RAM
401 orrhs r1, r1, #0x0c @ set cacheable, bufferable
402 cmp r1, r10 @ if virt > end of RAM
403 bichs r1, r1, #0x0c @ clear cacheable, bufferable
404 str r1, [r0], #4 @ 1:1 mapping
409 * If ever we are running from Flash, then we surely want the cache
410 * to be enabled also for our execution instance... We map 2MB of it
411 * so there is no map overlap problem for up to 1 MB compressed kernel.
412 * If the execution is in RAM then we would only be duplicating the above.
417 orr r1, r1, r2, lsl #20
418 add r0, r3, r2, lsl #2
424 __armv4_mmu_cache_on:
428 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
429 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
430 mrc p15, 0, r0, c1, c0, 0 @ read control reg
431 orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
433 bl __common_mmu_cache_on
435 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
442 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
443 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
445 bl __common_mmu_cache_on
447 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
450 __common_mmu_cache_on:
452 orr r0, r0, #0x000d @ Write buffer, mmu
455 mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
456 mcr p15, 0, r1, c3, c0, 0 @ load domain access control
458 .align 5 @ cache line aligned
459 1: mcr p15, 0, r0, c1, c0, 0 @ load control register
460 mrc p15, 0, r0, c1, c0, 0 @ and read it back to
461 sub pc, lr, r0, lsr #32 @ properly flush pipeline
464 * All code following this line is relocatable. It is relocated by
465 * the above code to the end of the decompressed kernel image and
466 * executed there. During this time, we have no stacks.
468 * r0 = decompressed kernel length
470 * r4 = kernel execution address
471 * r5 = decompressed kernel start
473 * r7 = architecture ID
478 reloc_start: add r9, r5, r0
483 ldmia r5!, {r0, r2, r3, r10 - r14} @ relocate kernel
484 stmia r1!, {r0, r2, r3, r10 - r14}
491 call_kernel: bl cache_clean_flush
493 mov r0, #0 @ must be zero
494 mov r1, r7 @ restore architecture number
495 mov r2, r8 @ restore atags pointer
496 mov pc, r4 @ call kernel
499 * Here follow the relocatable cache support functions for the
500 * various processors. This is a generic hook for locating an
501 * entry and jumping to an instruction at the specified offset
502 * from the start of the block. Please note this is all position
512 call_cache_fn: adr r12, proc_types
513 #ifdef CONFIG_CPU_CP15
514 mrc p15, 0, r6, c0, c0 @ get processor ID
516 ldr r6, =CONFIG_PROCESSOR_ID
518 1: ldr r1, [r12, #0] @ get value
519 ldr r2, [r12, #4] @ get mask
520 eor r1, r1, r6 @ (real ^ match)
522 addeq pc, r12, r3 @ call cache function
527 * Table for cache operations. This is basically:
530 * - 'cache on' method instruction
531 * - 'cache off' method instruction
532 * - 'cache flush' method instruction
534 * We match an entry using: ((real_id ^ match) & mask) == 0
536 * Writethrough caches generally only need 'on' and 'off'
537 * methods. Writeback caches _must_ have the flush method
540 .type proc_types,#object
542 .word 0x41560600 @ ARM6/610
544 b __arm6_mmu_cache_off @ works, but slow
545 b __arm6_mmu_cache_off
547 @ b __arm6_mmu_cache_on @ untested
548 @ b __arm6_mmu_cache_off
549 @ b __armv3_mmu_cache_flush
551 .word 0x00000000 @ old ARM ID
557 .word 0x41007000 @ ARM7/710
559 b __arm7_mmu_cache_off
560 b __arm7_mmu_cache_off
563 .word 0x41807200 @ ARM720T (writethrough)
565 b __armv4_mmu_cache_on
566 b __armv4_mmu_cache_off
569 .word 0x41007400 @ ARM74x
571 b __armv3_mpu_cache_on
572 b __armv3_mpu_cache_off
573 b __armv3_mpu_cache_flush
575 .word 0x41009400 @ ARM94x
577 b __armv4_mpu_cache_on
578 b __armv4_mpu_cache_off
579 b __armv4_mpu_cache_flush
581 .word 0x00007000 @ ARM7 IDs
587 @ Everything from here on will be the new ID system.
589 .word 0x4401a100 @ sa110 / sa1100
591 b __armv4_mmu_cache_on
592 b __armv4_mmu_cache_off
593 b __armv4_mmu_cache_flush
595 .word 0x6901b110 @ sa1110
597 b __armv4_mmu_cache_on
598 b __armv4_mmu_cache_off
599 b __armv4_mmu_cache_flush
601 @ These match on the architecture ID
603 .word 0x00020000 @ ARMv4T
605 b __armv4_mmu_cache_on
606 b __armv4_mmu_cache_off
607 b __armv4_mmu_cache_flush
609 .word 0x00050000 @ ARMv5TE
611 b __armv4_mmu_cache_on
612 b __armv4_mmu_cache_off
613 b __armv4_mmu_cache_flush
615 .word 0x00060000 @ ARMv5TEJ
617 b __armv4_mmu_cache_on
618 b __armv4_mmu_cache_off
619 b __armv4_mmu_cache_flush
621 .word 0x0007b000 @ ARMv6
623 b __armv4_mmu_cache_on
624 b __armv4_mmu_cache_off
625 b __armv6_mmu_cache_flush
627 .word 0 @ unrecognised type
633 .size proc_types, . - proc_types
636 * Turn off the Cache and MMU. ARMv3 does not support
637 * reading the control register, but ARMv4 does.
639 * On entry, r6 = processor ID
640 * On exit, r0, r1, r2, r3, r12 corrupted
641 * This routine must preserve: r4, r6, r7
644 cache_off: mov r3, #12 @ cache_off function
647 __armv4_mpu_cache_off:
648 mrc p15, 0, r0, c1, c0
650 mcr p15, 0, r0, c1, c0 @ turn MPU and cache off
652 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
653 mcr p15, 0, r0, c7, c6, 0 @ flush D-Cache
654 mcr p15, 0, r0, c7, c5, 0 @ flush I-Cache
657 __armv3_mpu_cache_off:
658 mrc p15, 0, r0, c1, c0
660 mcr p15, 0, r0, c1, c0, 0 @ turn MPU and cache off
662 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
665 __armv4_mmu_cache_off:
666 mrc p15, 0, r0, c1, c0
668 mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
670 mcr p15, 0, r0, c7, c7 @ invalidate whole cache v4
671 mcr p15, 0, r0, c8, c7 @ invalidate whole TLB v4
674 __arm6_mmu_cache_off:
675 mov r0, #0x00000030 @ ARM6 control reg.
676 b __armv3_mmu_cache_off
678 __arm7_mmu_cache_off:
679 mov r0, #0x00000070 @ ARM7 control reg.
680 b __armv3_mmu_cache_off
682 __armv3_mmu_cache_off:
683 mcr p15, 0, r0, c1, c0, 0 @ turn MMU and cache off
685 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
686 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
690 * Clean and flush the cache to maintain consistency.
695 * r1, r2, r3, r11, r12 corrupted
696 * This routine must preserve:
704 __armv4_mpu_cache_flush:
707 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
708 mov r1, #7 << 5 @ 8 segments
709 1: orr r3, r1, #63 << 26 @ 64 entries
710 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index
711 subs r3, r3, #1 << 26
712 bcs 2b @ entries 63 to 0
714 bcs 1b @ segments 7 to 0
717 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
718 mcr p15, 0, ip, c7, c10, 4 @ drain WB
722 __armv6_mmu_cache_flush:
724 mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D
725 mcr p15, 0, r1, c7, c5, 0 @ invalidate I+BTB
726 mcr p15, 0, r1, c7, c15, 0 @ clean+invalidate unified
727 mcr p15, 0, r1, c7, c10, 4 @ drain WB
730 __armv4_mmu_cache_flush:
731 mov r2, #64*1024 @ default: 32K dcache size (*2)
732 mov r11, #32 @ default: 32 byte line size
733 mrc p15, 0, r3, c0, c0, 1 @ read cache type
734 teq r3, r6 @ cache ID register present?
739 mov r2, r2, lsl r1 @ base dcache size *2
740 tst r3, #1 << 14 @ test M bit
741 addne r2, r2, r2, lsr #1 @ +1/2 size if M == 1
745 mov r11, r11, lsl r3 @ cache line size in bytes
747 bic r1, pc, #63 @ align to longest cache line
749 1: ldr r3, [r1], r11 @ s/w flush D cache
753 mcr p15, 0, r1, c7, c5, 0 @ flush I cache
754 mcr p15, 0, r1, c7, c6, 0 @ flush D cache
755 mcr p15, 0, r1, c7, c10, 4 @ drain WB
758 __armv3_mmu_cache_flush:
759 __armv3_mpu_cache_flush:
761 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
765 * Various debugging routines for printing hex characters and
766 * memory, which again must be relocatable.
769 .type phexbuf,#object
771 .size phexbuf, . - phexbuf
773 phex: adr r3, phexbuf
810 2: mov r0, r11, lsl #2
818 ldr r0, [r12, r11, lsl #2]
839 .section ".stack", "w"
840 user_stack: .space 4096