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 */
86 mrc p15, 0, r0, c1, c0
87 kphex r0, 8 /* control reg */
89 kphex r5, 8 /* decompressed kernel start */
91 kphex r9, 8 /* decompressed kernel end */
93 kphex r4, 8 /* kernel execution address */
98 .macro debug_reloc_end
100 kphex r5, 8 /* end of kernel */
103 bl memdump /* dump 256 bytes at start of kernel */
107 .section ".start", #alloc, #execinstr
109 * sort out different calling conventions
113 .type start,#function
119 .word 0x016f2818 @ Magic numbers to help the loader
120 .word start @ absolute load/run zImage address
121 .word _edata @ zImage end address
122 1: mov r7, r1 @ save architecture ID
123 mov r8, r2 @ save atags pointer
125 #ifndef __ARM_ARCH_2__
127 * Booting from Angel - need to enter SVC mode and disable
128 * FIQs/IRQs (numeric definitions from angel arm.h source).
129 * We only do this if we were in user mode on entry.
131 mrs r2, cpsr @ get current mode
132 tst r2, #3 @ not user?
134 mov r0, #0x17 @ angel_SWIreason_EnterSVC
135 swi 0x123456 @ angel_SWI_ARM
137 mrs r2, cpsr @ turn off interrupts to
138 orr r2, r2, #0xc0 @ prevent angel from running
141 teqp pc, #0x0c000003 @ turn off interrupts
145 * Note that some cache flushing and other stuff may
146 * be needed here - is there an Angel SWI call for this?
150 * some architecture specific code can be inserted
151 * by the linker here, but it should preserve r7, r8, and r9.
156 ldmia r0, {r1, r2, r3, r4, r5, r6, ip, sp}
157 subs r0, r0, r1 @ calculate the delta offset
159 @ if delta is zero, we are
160 beq not_relocated @ running at the address we
164 * We're running at a different address. We need to fix
165 * up various pointers:
166 * r5 - zImage base address
174 #ifndef CONFIG_ZBOOT_ROM
176 * If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
177 * we need to fix up pointers into the BSS region.
187 * Relocate all entries in the GOT table.
189 1: ldr r1, [r6, #0] @ relocate entries in the GOT
190 add r1, r1, r0 @ table. This fixes up the
191 str r1, [r6], #4 @ C references.
197 * Relocate entries in the GOT table. We only relocate
198 * the entries that are outside the (relocated) BSS region.
200 1: ldr r1, [r6, #0] @ relocate entries in the GOT
201 cmp r1, r2 @ entry < bss_start ||
202 cmphs r3, r1 @ _end < entry
203 addlo r1, r1, r0 @ table. This fixes up the
204 str r1, [r6], #4 @ C references.
209 not_relocated: mov r0, #0
210 1: str r0, [r2], #4 @ clear bss
218 * The C runtime environment should now be setup
219 * sufficiently. Turn the cache on, set up some
220 * pointers, and start decompressing.
224 mov r1, sp @ malloc space above stack
225 add r2, sp, #0x10000 @ 64k max
228 * Check to see if we will overwrite ourselves.
229 * r4 = final kernel address
230 * r5 = start of this image
231 * r2 = end of malloc space (and therefore this image)
234 * r4 + image length <= r5 -> OK
238 add r0, r4, #4096*1024 @ 4MB largest kernel size
242 mov r5, r2 @ decompress after malloc space
248 bic r0, r0, #127 @ align the kernel length
250 * r0 = decompressed kernel length
252 * r4 = kernel execution address
253 * r5 = decompressed kernel start
255 * r7 = architecture ID
259 add r1, r5, r0 @ end of decompressed kernel
263 1: ldmia r2!, {r9 - r14} @ copy relocation code
264 stmia r1!, {r9 - r14}
265 ldmia r2!, {r9 - r14}
266 stmia r1!, {r9 - r14}
271 add pc, r5, r0 @ call relocation code
274 * We're not in danger of overwriting ourselves. Do this the simple way.
276 * r4 = kernel execution address
277 * r7 = architecture ID
279 wont_overwrite: mov r0, r4
286 .word __bss_start @ r2
290 .word _got_start @ r6
292 .word user_stack+4096 @ sp
293 LC1: .word reloc_end - reloc_start
296 #ifdef CONFIG_ARCH_RPC
298 params: ldr r0, =params_phys
305 * Turn on the cache. We need to setup some page tables so that we
306 * can have both the I and D caches on.
308 * We place the page tables 16k down from the kernel execution address,
309 * and we hope that nothing else is using it. If we're using it, we
313 * r4 = kernel execution address
315 * r7 = architecture number
317 * r9 = run-time address of "start" (???)
319 * r1, r2, r3, r9, r10, r12 corrupted
320 * This routine must preserve:
324 cache_on: mov r3, #8 @ cache_on function
328 * Initialize the highest priority protection region, PR7
329 * to cover all 32bit address and cacheable and bufferable.
331 __armv4_mpu_cache_on:
332 mov r0, #0x3f @ 4G, the whole
333 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
334 mcr p15, 0, r0, c6, c7, 1
337 mcr p15, 0, r0, c2, c0, 0 @ D-cache on
338 mcr p15, 0, r0, c2, c0, 1 @ I-cache on
339 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
342 mcr p15, 0, r0, c5, c0, 1 @ I-access permission
343 mcr p15, 0, r0, c5, c0, 0 @ D-access permission
346 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
347 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
348 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
349 mrc p15, 0, r0, c1, c0, 0 @ read control reg
350 @ ...I .... ..D. WC.M
351 orr r0, r0, #0x002d @ .... .... ..1. 11.1
352 orr r0, r0, #0x1000 @ ...1 .... .... ....
354 mcr p15, 0, r0, c1, c0, 0 @ write control reg
357 mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
358 mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
361 __armv3_mpu_cache_on:
362 mov r0, #0x3f @ 4G, the whole
363 mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
366 mcr p15, 0, r0, c2, c0, 0 @ cache on
367 mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
370 mcr p15, 0, r0, c5, c0, 0 @ access permission
373 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
374 mrc p15, 0, r0, c1, c0, 0 @ read control reg
375 @ .... .... .... WC.M
376 orr r0, r0, #0x000d @ .... .... .... 11.1
378 mcr p15, 0, r0, c1, c0, 0 @ write control reg
380 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
383 __setup_mmu: sub r3, r4, #16384 @ Page directory size
384 bic r3, r3, #0xff @ Align the pointer
387 * Initialise the page tables, turning on the cacheable and bufferable
388 * bits for the RAM area only.
392 mov r9, r9, lsl #18 @ start of RAM
393 add r10, r9, #0x10000000 @ a reasonable RAM size
397 1: cmp r1, r9 @ if virt > start of RAM
398 orrhs r1, r1, #0x0c @ set cacheable, bufferable
399 cmp r1, r10 @ if virt > end of RAM
400 bichs r1, r1, #0x0c @ clear cacheable, bufferable
401 str r1, [r0], #4 @ 1:1 mapping
406 * If ever we are running from Flash, then we surely want the cache
407 * to be enabled also for our execution instance... We map 2MB of it
408 * so there is no map overlap problem for up to 1 MB compressed kernel.
409 * If the execution is in RAM then we would only be duplicating the above.
414 orr r1, r1, r2, lsl #20
415 add r0, r3, r2, lsl #2
421 __armv4_mmu_cache_on:
425 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
426 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
427 mrc p15, 0, r0, c1, c0, 0 @ read control reg
428 orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
430 bl __common_mmu_cache_on
432 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
439 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
440 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
442 bl __common_mmu_cache_on
444 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
447 __common_mmu_cache_on:
449 orr r0, r0, #0x000d @ Write buffer, mmu
452 mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
453 mcr p15, 0, r1, c3, c0, 0 @ load domain access control
455 .align 5 @ cache line aligned
456 1: mcr p15, 0, r0, c1, c0, 0 @ load control register
457 mrc p15, 0, r0, c1, c0, 0 @ and read it back to
458 sub pc, lr, r0, lsr #32 @ properly flush pipeline
461 * All code following this line is relocatable. It is relocated by
462 * the above code to the end of the decompressed kernel image and
463 * executed there. During this time, we have no stacks.
465 * r0 = decompressed kernel length
467 * r4 = kernel execution address
468 * r5 = decompressed kernel start
470 * r7 = architecture ID
475 reloc_start: add r9, r5, r0
480 ldmia r5!, {r0, r2, r3, r10 - r14} @ relocate kernel
481 stmia r1!, {r0, r2, r3, r10 - r14}
488 call_kernel: bl cache_clean_flush
490 mov r0, #0 @ must be zero
491 mov r1, r7 @ restore architecture number
492 mov r2, r8 @ restore atags pointer
493 mov pc, r4 @ call kernel
496 * Here follow the relocatable cache support functions for the
497 * various processors. This is a generic hook for locating an
498 * entry and jumping to an instruction at the specified offset
499 * from the start of the block. Please note this is all position
509 call_cache_fn: adr r12, proc_types
510 mrc p15, 0, r6, c0, c0 @ get processor ID
511 1: ldr r1, [r12, #0] @ get value
512 ldr r2, [r12, #4] @ get mask
513 eor r1, r1, r6 @ (real ^ match)
515 addeq pc, r12, r3 @ call cache function
520 * Table for cache operations. This is basically:
523 * - 'cache on' method instruction
524 * - 'cache off' method instruction
525 * - 'cache flush' method instruction
527 * We match an entry using: ((real_id ^ match) & mask) == 0
529 * Writethrough caches generally only need 'on' and 'off'
530 * methods. Writeback caches _must_ have the flush method
533 .type proc_types,#object
535 .word 0x41560600 @ ARM6/610
537 b __arm6_mmu_cache_off @ works, but slow
538 b __arm6_mmu_cache_off
540 @ b __arm6_mmu_cache_on @ untested
541 @ b __arm6_mmu_cache_off
542 @ b __armv3_mmu_cache_flush
544 .word 0x00000000 @ old ARM ID
550 .word 0x41007000 @ ARM7/710
552 b __arm7_mmu_cache_off
553 b __arm7_mmu_cache_off
556 .word 0x41807200 @ ARM720T (writethrough)
558 b __armv4_mmu_cache_on
559 b __armv4_mmu_cache_off
562 .word 0x41007400 @ ARM74x
564 b __armv3_mpu_cache_on
565 b __armv3_mpu_cache_off
566 b __armv3_mpu_cache_flush
568 .word 0x41009400 @ ARM94x
570 b __armv4_mpu_cache_on
571 b __armv4_mpu_cache_off
572 b __armv4_mpu_cache_flush
574 .word 0x00007000 @ ARM7 IDs
580 @ Everything from here on will be the new ID system.
582 .word 0x4401a100 @ sa110 / sa1100
584 b __armv4_mmu_cache_on
585 b __armv4_mmu_cache_off
586 b __armv4_mmu_cache_flush
588 .word 0x6901b110 @ sa1110
590 b __armv4_mmu_cache_on
591 b __armv4_mmu_cache_off
592 b __armv4_mmu_cache_flush
594 @ These match on the architecture ID
596 .word 0x00020000 @ ARMv4T
598 b __armv4_mmu_cache_on
599 b __armv4_mmu_cache_off
600 b __armv4_mmu_cache_flush
602 .word 0x00050000 @ ARMv5TE
604 b __armv4_mmu_cache_on
605 b __armv4_mmu_cache_off
606 b __armv4_mmu_cache_flush
608 .word 0x00060000 @ ARMv5TEJ
610 b __armv4_mmu_cache_on
611 b __armv4_mmu_cache_off
612 b __armv4_mmu_cache_flush
614 .word 0x0007b000 @ ARMv6
616 b __armv4_mmu_cache_on
617 b __armv4_mmu_cache_off
618 b __armv6_mmu_cache_flush
620 .word 0 @ unrecognised type
626 .size proc_types, . - proc_types
629 * Turn off the Cache and MMU. ARMv3 does not support
630 * reading the control register, but ARMv4 does.
632 * On entry, r6 = processor ID
633 * On exit, r0, r1, r2, r3, r12 corrupted
634 * This routine must preserve: r4, r6, r7
637 cache_off: mov r3, #12 @ cache_off function
640 __armv4_mpu_cache_off:
641 mrc p15, 0, r0, c1, c0
643 mcr p15, 0, r0, c1, c0 @ turn MPU and cache off
645 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
646 mcr p15, 0, r0, c7, c6, 0 @ flush D-Cache
647 mcr p15, 0, r0, c7, c5, 0 @ flush I-Cache
650 __armv3_mpu_cache_off:
651 mrc p15, 0, r0, c1, c0
653 mcr p15, 0, r0, c1, c0, 0 @ turn MPU and cache off
655 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
658 __armv4_mmu_cache_off:
659 mrc p15, 0, r0, c1, c0
661 mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
663 mcr p15, 0, r0, c7, c7 @ invalidate whole cache v4
664 mcr p15, 0, r0, c8, c7 @ invalidate whole TLB v4
667 __arm6_mmu_cache_off:
668 mov r0, #0x00000030 @ ARM6 control reg.
669 b __armv3_mmu_cache_off
671 __arm7_mmu_cache_off:
672 mov r0, #0x00000070 @ ARM7 control reg.
673 b __armv3_mmu_cache_off
675 __armv3_mmu_cache_off:
676 mcr p15, 0, r0, c1, c0, 0 @ turn MMU and cache off
678 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
679 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
683 * Clean and flush the cache to maintain consistency.
688 * r1, r2, r3, r11, r12 corrupted
689 * This routine must preserve:
697 __armv4_mpu_cache_flush:
700 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
701 mov r1, #7 << 5 @ 8 segments
702 1: orr r3, r1, #63 << 26 @ 64 entries
703 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index
704 subs r3, r3, #1 << 26
705 bcs 2b @ entries 63 to 0
707 bcs 1b @ segments 7 to 0
710 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
711 mcr p15, 0, ip, c7, c10, 4 @ drain WB
715 __armv6_mmu_cache_flush:
717 mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D
718 mcr p15, 0, r1, c7, c5, 0 @ invalidate I+BTB
719 mcr p15, 0, r1, c7, c15, 0 @ clean+invalidate unified
720 mcr p15, 0, r1, c7, c10, 4 @ drain WB
723 __armv4_mmu_cache_flush:
724 mov r2, #64*1024 @ default: 32K dcache size (*2)
725 mov r11, #32 @ default: 32 byte line size
726 mrc p15, 0, r3, c0, c0, 1 @ read cache type
727 teq r3, r6 @ cache ID register present?
732 mov r2, r2, lsl r1 @ base dcache size *2
733 tst r3, #1 << 14 @ test M bit
734 addne r2, r2, r2, lsr #1 @ +1/2 size if M == 1
738 mov r11, r11, lsl r3 @ cache line size in bytes
740 bic r1, pc, #63 @ align to longest cache line
742 1: ldr r3, [r1], r11 @ s/w flush D cache
746 mcr p15, 0, r1, c7, c5, 0 @ flush I cache
747 mcr p15, 0, r1, c7, c6, 0 @ flush D cache
748 mcr p15, 0, r1, c7, c10, 4 @ drain WB
751 __armv3_mmu_cache_flush:
752 __armv3_mpu_cache_flush:
754 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
758 * Various debugging routines for printing hex characters and
759 * memory, which again must be relocatable.
762 .type phexbuf,#object
764 .size phexbuf, . - phexbuf
766 phex: adr r3, phexbuf
803 2: mov r0, r11, lsl #2
811 ldr r0, [r12, r11, lsl #2]
832 .section ".stack", "w"
833 user_stack: .space 4096