2 * linux/arch/arm/boot/compressed/head.S
4 * Copyright (C) 1996-2002 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 #include <linux/config.h>
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)
26 mcr p14, 0, \ch, c0, c1, 0
30 #include <asm/arch/debug-macro.S>
36 #if defined(CONFIG_ARCH_SA1100)
38 mov \rb, #0x80000000 @ physical base address
39 #ifdef CONFIG_DEBUG_LL_SER3
40 add \rb, \rb, #0x00050000 @ Ser3
42 add \rb, \rb, #0x00010000 @ Ser1
45 #elif defined(CONFIG_ARCH_IOP331)
48 orr \rb, \rb, #0x00ff0000
49 orr \rb, \rb, #0x0000f700 @ location of the UART
51 #elif defined(CONFIG_ARCH_S3C2410)
54 add \rb, \rb, #0x4000 * CONFIG_S3C2410_LOWLEVEL_UART_PORT
75 .macro debug_reloc_start
78 kphex r6, 8 /* processor id */
80 kphex r7, 8 /* architecture id */
82 mrc p15, 0, r0, c1, c0
83 kphex r0, 8 /* control reg */
85 kphex r5, 8 /* decompressed kernel start */
87 kphex r9, 8 /* decompressed kernel end */
89 kphex r4, 8 /* kernel execution address */
94 .macro debug_reloc_end
96 kphex r5, 8 /* end of kernel */
99 bl memdump /* dump 256 bytes at start of kernel */
103 .section ".start", #alloc, #execinstr
105 * sort out different calling conventions
109 .type start,#function
115 .word 0x016f2818 @ Magic numbers to help the loader
116 .word start @ absolute load/run zImage address
117 .word _edata @ zImage end address
118 1: mov r7, r1 @ save architecture ID
119 mov r8, r2 @ save atags pointer
121 #ifndef __ARM_ARCH_2__
123 * Booting from Angel - need to enter SVC mode and disable
124 * FIQs/IRQs (numeric definitions from angel arm.h source).
125 * We only do this if we were in user mode on entry.
127 mrs r2, cpsr @ get current mode
128 tst r2, #3 @ not user?
130 mov r0, #0x17 @ angel_SWIreason_EnterSVC
131 swi 0x123456 @ angel_SWI_ARM
133 mrs r2, cpsr @ turn off interrupts to
134 orr r2, r2, #0xc0 @ prevent angel from running
137 teqp pc, #0x0c000003 @ turn off interrupts
141 * Note that some cache flushing and other stuff may
142 * be needed here - is there an Angel SWI call for this?
146 * some architecture specific code can be inserted
147 * by the linker here, but it should preserve r7, r8, and r9.
152 ldmia r0, {r1, r2, r3, r4, r5, r6, ip, sp}
153 subs r0, r0, r1 @ calculate the delta offset
155 @ if delta is zero, we are
156 beq not_relocated @ running at the address we
160 * We're running at a different address. We need to fix
161 * up various pointers:
162 * r5 - zImage base address
170 #ifndef CONFIG_ZBOOT_ROM
172 * If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
173 * we need to fix up pointers into the BSS region.
183 * Relocate all entries in the GOT table.
185 1: ldr r1, [r6, #0] @ relocate entries in the GOT
186 add r1, r1, r0 @ table. This fixes up the
187 str r1, [r6], #4 @ C references.
193 * Relocate entries in the GOT table. We only relocate
194 * the entries that are outside the (relocated) BSS region.
196 1: ldr r1, [r6, #0] @ relocate entries in the GOT
197 cmp r1, r2 @ entry < bss_start ||
198 cmphs r3, r1 @ _end < entry
199 addlo r1, r1, r0 @ table. This fixes up the
200 str r1, [r6], #4 @ C references.
205 not_relocated: mov r0, #0
206 1: str r0, [r2], #4 @ clear bss
214 * The C runtime environment should now be setup
215 * sufficiently. Turn the cache on, set up some
216 * pointers, and start decompressing.
220 mov r1, sp @ malloc space above stack
221 add r2, sp, #0x10000 @ 64k max
224 * Check to see if we will overwrite ourselves.
225 * r4 = final kernel address
226 * r5 = start of this image
227 * r2 = end of malloc space (and therefore this image)
230 * r4 + image length <= r5 -> OK
234 add r0, r4, #4096*1024 @ 4MB largest kernel size
238 mov r5, r2 @ decompress after malloc space
244 bic r0, r0, #127 @ align the kernel length
246 * r0 = decompressed kernel length
248 * r4 = kernel execution address
249 * r5 = decompressed kernel start
251 * r7 = architecture ID
255 add r1, r5, r0 @ end of decompressed kernel
259 1: ldmia r2!, {r9 - r14} @ copy relocation code
260 stmia r1!, {r9 - r14}
261 ldmia r2!, {r9 - r14}
262 stmia r1!, {r9 - r14}
267 add pc, r5, r0 @ call relocation code
270 * We're not in danger of overwriting ourselves. Do this the simple way.
272 * r4 = kernel execution address
273 * r7 = architecture ID
275 wont_overwrite: mov r0, r4
282 .word __bss_start @ r2
286 .word _got_start @ r6
288 .word user_stack+4096 @ sp
289 LC1: .word reloc_end - reloc_start
292 #ifdef CONFIG_ARCH_RPC
294 params: ldr r0, =params_phys
301 * Turn on the cache. We need to setup some page tables so that we
302 * can have both the I and D caches on.
304 * We place the page tables 16k down from the kernel execution address,
305 * and we hope that nothing else is using it. If we're using it, we
309 * r4 = kernel execution address
311 * r7 = architecture number
313 * r9 = run-time address of "start" (???)
315 * r1, r2, r3, r9, r10, r12 corrupted
316 * This routine must preserve:
320 cache_on: mov r3, #8 @ cache_on function
323 __setup_mmu: sub r3, r4, #16384 @ Page directory size
324 bic r3, r3, #0xff @ Align the pointer
327 * Initialise the page tables, turning on the cacheable and bufferable
328 * bits for the RAM area only.
332 mov r9, r9, lsl #18 @ start of RAM
333 add r10, r9, #0x10000000 @ a reasonable RAM size
337 1: cmp r1, r9 @ if virt > start of RAM
338 orrhs r1, r1, #0x0c @ set cacheable, bufferable
339 cmp r1, r10 @ if virt > end of RAM
340 bichs r1, r1, #0x0c @ clear cacheable, bufferable
341 str r1, [r0], #4 @ 1:1 mapping
346 * If ever we are running from Flash, then we surely want the cache
347 * to be enabled also for our execution instance... We map 2MB of it
348 * so there is no map overlap problem for up to 1 MB compressed kernel.
349 * If the execution is in RAM then we would only be duplicating the above.
354 orr r1, r1, r2, lsl #20
355 add r0, r3, r2, lsl #2
361 __armv4_mmu_cache_on:
365 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
366 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
367 mrc p15, 0, r0, c1, c0, 0 @ read control reg
368 orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
370 bl __common_mmu_cache_on
372 mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
379 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
380 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
382 bl __common_mmu_cache_on
384 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
387 __common_mmu_cache_on:
389 orr r0, r0, #0x000d @ Write buffer, mmu
392 mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
393 mcr p15, 0, r1, c3, c0, 0 @ load domain access control
394 mcr p15, 0, r0, c1, c0, 0 @ load control register
398 * All code following this line is relocatable. It is relocated by
399 * the above code to the end of the decompressed kernel image and
400 * executed there. During this time, we have no stacks.
402 * r0 = decompressed kernel length
404 * r4 = kernel execution address
405 * r5 = decompressed kernel start
407 * r7 = architecture ID
412 reloc_start: add r9, r5, r0
417 ldmia r5!, {r0, r2, r3, r10 - r14} @ relocate kernel
418 stmia r1!, {r0, r2, r3, r10 - r14}
425 call_kernel: bl cache_clean_flush
427 mov r0, #0 @ must be zero
428 mov r1, r7 @ restore architecture number
429 mov r2, r8 @ restore atags pointer
430 mov pc, r4 @ call kernel
433 * Here follow the relocatable cache support functions for the
434 * various processors. This is a generic hook for locating an
435 * entry and jumping to an instruction at the specified offset
436 * from the start of the block. Please note this is all position
446 call_cache_fn: adr r12, proc_types
447 mrc p15, 0, r6, c0, c0 @ get processor ID
448 1: ldr r1, [r12, #0] @ get value
449 ldr r2, [r12, #4] @ get mask
450 eor r1, r1, r6 @ (real ^ match)
452 addeq pc, r12, r3 @ call cache function
457 * Table for cache operations. This is basically:
460 * - 'cache on' method instruction
461 * - 'cache off' method instruction
462 * - 'cache flush' method instruction
464 * We match an entry using: ((real_id ^ match) & mask) == 0
466 * Writethrough caches generally only need 'on' and 'off'
467 * methods. Writeback caches _must_ have the flush method
470 .type proc_types,#object
472 .word 0x41560600 @ ARM6/610
474 b __arm6_mmu_cache_off @ works, but slow
475 b __arm6_mmu_cache_off
477 @ b __arm6_mmu_cache_on @ untested
478 @ b __arm6_mmu_cache_off
479 @ b __armv3_mmu_cache_flush
481 .word 0x00000000 @ old ARM ID
487 .word 0x41007000 @ ARM7/710
489 b __arm7_mmu_cache_off
490 b __arm7_mmu_cache_off
493 .word 0x41807200 @ ARM720T (writethrough)
495 b __armv4_mmu_cache_on
496 b __armv4_mmu_cache_off
499 .word 0x00007000 @ ARM7 IDs
505 @ Everything from here on will be the new ID system.
507 .word 0x4401a100 @ sa110 / sa1100
509 b __armv4_mmu_cache_on
510 b __armv4_mmu_cache_off
511 b __armv4_mmu_cache_flush
513 .word 0x6901b110 @ sa1110
515 b __armv4_mmu_cache_on
516 b __armv4_mmu_cache_off
517 b __armv4_mmu_cache_flush
519 @ These match on the architecture ID
521 .word 0x00020000 @ ARMv4T
523 b __armv4_mmu_cache_on
524 b __armv4_mmu_cache_off
525 b __armv4_mmu_cache_flush
527 .word 0x00050000 @ ARMv5TE
529 b __armv4_mmu_cache_on
530 b __armv4_mmu_cache_off
531 b __armv4_mmu_cache_flush
533 .word 0x00060000 @ ARMv5TEJ
535 b __armv4_mmu_cache_on
536 b __armv4_mmu_cache_off
537 b __armv4_mmu_cache_flush
539 .word 0x00070000 @ ARMv6
541 b __armv4_mmu_cache_on
542 b __armv4_mmu_cache_off
543 b __armv6_mmu_cache_flush
545 .word 0 @ unrecognised type
551 .size proc_types, . - proc_types
554 * Turn off the Cache and MMU. ARMv3 does not support
555 * reading the control register, but ARMv4 does.
557 * On entry, r6 = processor ID
558 * On exit, r0, r1, r2, r3, r12 corrupted
559 * This routine must preserve: r4, r6, r7
562 cache_off: mov r3, #12 @ cache_off function
565 __armv4_mmu_cache_off:
566 mrc p15, 0, r0, c1, c0
568 mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
570 mcr p15, 0, r0, c7, c7 @ invalidate whole cache v4
571 mcr p15, 0, r0, c8, c7 @ invalidate whole TLB v4
574 __arm6_mmu_cache_off:
575 mov r0, #0x00000030 @ ARM6 control reg.
576 b __armv3_mmu_cache_off
578 __arm7_mmu_cache_off:
579 mov r0, #0x00000070 @ ARM7 control reg.
580 b __armv3_mmu_cache_off
582 __armv3_mmu_cache_off:
583 mcr p15, 0, r0, c1, c0, 0 @ turn MMU and cache off
585 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
586 mcr p15, 0, r0, c5, c0, 0 @ invalidate whole TLB v3
590 * Clean and flush the cache to maintain consistency.
595 * r1, r2, r3, r11, r12 corrupted
596 * This routine must preserve:
604 __armv6_mmu_cache_flush:
606 mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D
607 mcr p15, 0, r1, c7, c5, 0 @ invalidate I+BTB
608 mcr p15, 0, r1, c7, c15, 0 @ clean+invalidate unified
609 mcr p15, 0, r1, c7, c10, 4 @ drain WB
612 __armv4_mmu_cache_flush:
613 mov r2, #64*1024 @ default: 32K dcache size (*2)
614 mov r11, #32 @ default: 32 byte line size
615 mrc p15, 0, r3, c0, c0, 1 @ read cache type
616 teq r3, r6 @ cache ID register present?
621 mov r2, r2, lsl r1 @ base dcache size *2
622 tst r3, #1 << 14 @ test M bit
623 addne r2, r2, r2, lsr #1 @ +1/2 size if M == 1
627 mov r11, r11, lsl r3 @ cache line size in bytes
629 bic r1, pc, #63 @ align to longest cache line
631 1: ldr r3, [r1], r11 @ s/w flush D cache
635 mcr p15, 0, r1, c7, c5, 0 @ flush I cache
636 mcr p15, 0, r1, c7, c6, 0 @ flush D cache
637 mcr p15, 0, r1, c7, c10, 4 @ drain WB
640 __armv3_mmu_cache_flush:
642 mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
646 * Various debugging routines for printing hex characters and
647 * memory, which again must be relocatable.
650 .type phexbuf,#object
652 .size phexbuf, . - phexbuf
654 phex: adr r3, phexbuf
691 2: mov r0, r11, lsl #2
699 ldr r0, [r12, r11, lsl #2]
720 .section ".stack", "w"
721 user_stack: .space 4096