diff options
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 239 |
1 files changed, 110 insertions, 129 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 920f4dbd488..39859216af0 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -174,9 +174,7 @@ not_angel: */ .text - adr r0, LC0 - ldmia r0, {r1, r2, r3, r5, r6, r11, ip} - ldr sp, [r0, #28] + #ifdef CONFIG_AUTO_ZRELADDR @ determine final kernel image address mov r4, pc @@ -185,35 +183,108 @@ not_angel: #else ldr r4, =zreladdr #endif - subs r0, r0, r1 @ calculate the delta offset - @ if delta is zero, we are - beq not_relocated @ running at the address we - @ were linked at. + bl cache_on + +restart: adr r0, LC0 + ldmia r0, {r1, r2, r3, r5, r6, r9, r11, r12} + ldr sp, [r0, #32] + + /* + * We might be running at a different address. We need + * to fix up various pointers. + */ + sub r0, r0, r1 @ calculate the delta offset + add r5, r5, r0 @ _start + add r6, r6, r0 @ _edata +#ifndef CONFIG_ZBOOT_ROM + /* malloc space is above the relocated stack (64k max) */ + add sp, sp, r0 + add r10, sp, #0x10000 +#else /* - * We're running at a different address. We need to fix - * up various pointers: - * r5 - zImage base address (_start) - * r6 - size of decompressed image - * r11 - GOT start - * ip - GOT end + * With ZBOOT_ROM the bss/stack is non relocatable, + * but someone could still run this code from RAM, + * in which case our reference is _edata. */ - add r5, r5, r0 + mov r10, r6 +#endif + +/* + * Check to see if we will overwrite ourselves. + * r4 = final kernel address + * r5 = start of this image + * r9 = size of decompressed image + * r10 = end of this image, including bss/stack/malloc space if non XIP + * We basically want: + * r4 >= r10 -> OK + * r4 + image length <= r5 -> OK + */ + cmp r4, r10 + bhs wont_overwrite + add r10, r4, r9 + cmp r10, r5 + bls wont_overwrite + +/* + * Relocate ourselves past the end of the decompressed kernel. + * r5 = start of this image + * r6 = _edata + * r10 = end of the decompressed kernel + * Because we always copy ahead, we need to do it from the end and go + * backward in case the source and destination overlap. + */ + /* Round up to next 256-byte boundary. */ + add r10, r10, #256 + bic r10, r10, #255 + + sub r9, r6, r5 @ size to copy + add r9, r9, #31 @ rounded up to a multiple + bic r9, r9, #31 @ ... of 32 bytes + add r6, r9, r5 + add r9, r9, r10 + +1: ldmdb r6!, {r0 - r3, r10 - r12, lr} + cmp r6, r5 + stmdb r9!, {r0 - r3, r10 - r12, lr} + bhi 1b + + /* Preserve offset to relocated code. */ + sub r6, r9, r6 + + bl cache_clean_flush + + adr r0, BSYM(restart) + add r0, r0, r6 + mov pc, r0 + +wont_overwrite: +/* + * If delta is zero, we are running at the address we were linked at. + * r0 = delta + * r2 = BSS start + * r3 = BSS end + * r4 = kernel execution address + * r7 = architecture ID + * r8 = atags pointer + * r11 = GOT start + * r12 = GOT end + * sp = stack pointer + */ + teq r0, #0 + beq not_relocated add r11, r11, r0 - add ip, ip, r0 + add r12, r12, r0 #ifndef CONFIG_ZBOOT_ROM /* * If we're running fully PIC === CONFIG_ZBOOT_ROM = n, * we need to fix up pointers into the BSS region. - * r2 - BSS start - * r3 - BSS end - * sp - stack pointer + * Note that the stack pointer has already been fixed up. */ add r2, r2, r0 add r3, r3, r0 - add sp, sp, r0 /* * Relocate all entries in the GOT table. @@ -221,7 +292,7 @@ not_angel: 1: ldr r1, [r11, #0] @ relocate entries in the GOT add r1, r1, r0 @ table. This fixes up the str r1, [r11], #4 @ C references. - cmp r11, ip + cmp r11, r12 blo 1b #else @@ -234,7 +305,7 @@ not_angel: cmphs r3, r1 @ _end < entry addlo r1, r1, r0 @ table. This fixes up the str r1, [r11], #4 @ C references. - cmp r11, ip + cmp r11, r12 blo 1b #endif @@ -246,76 +317,24 @@ not_relocated: mov r0, #0 cmp r2, r3 blo 1b - /* - * The C runtime environment should now be setup - * sufficiently. Turn the cache on, set up some - * pointers, and start decompressing. - */ - bl cache_on - - mov r1, sp @ malloc space above stack - add r2, sp, #0x10000 @ 64k max - /* - * Check to see if we will overwrite ourselves. - * r4 = final kernel address - * r5 = start of this image - * r6 = size of decompressed image - * r2 = end of malloc space (and therefore this image) - * We basically want: - * r4 >= r2 -> OK - * r4 + image length <= r5 -> OK + * The C runtime environment should now be setup sufficiently. + * Set up some pointers, and start decompressing. + * r4 = kernel execution address + * r7 = architecture ID + * r8 = atags pointer */ - cmp r4, r2 - bhs wont_overwrite - add r0, r4, r6 - cmp r0, r5 - bls wont_overwrite - - mov r5, r2 @ decompress after malloc space - mov r0, r5 + mov r0, r4 + mov r1, sp @ malloc space above stack + add r2, sp, #0x10000 @ 64k max mov r3, r7 bl decompress_kernel - - add r0, r0, #127 + 128 @ alignment + stack - bic r0, r0, #127 @ align the kernel length -/* - * r0 = decompressed kernel length - * r1-r3 = unused - * r4 = kernel execution address - * r5 = decompressed kernel start - * r7 = architecture ID - * r8 = atags pointer - * r9-r12,r14 = corrupted - */ - add r1, r5, r0 @ end of decompressed kernel - adr r2, reloc_start - ldr r3, LC1 - add r3, r2, r3 -1: ldmia r2!, {r9 - r12, r14} @ copy relocation code - stmia r1!, {r9 - r12, r14} - ldmia r2!, {r9 - r12, r14} - stmia r1!, {r9 - r12, r14} - cmp r2, r3 - blo 1b - mov sp, r1 - add sp, sp, #128 @ relocate the stack - bl cache_clean_flush - ARM( add pc, r5, r0 ) @ call relocation code - THUMB( add r12, r5, r0 ) - THUMB( mov pc, r12 ) @ call relocation code - -/* - * We're not in danger of overwriting ourselves. Do this the simple way. - * - * r4 = kernel execution address - * r7 = architecture ID - */ -wont_overwrite: mov r0, r4 - mov r3, r7 - bl decompress_kernel - b call_kernel + bl cache_off + mov r0, #0 @ must be zero + mov r1, r7 @ restore architecture number + mov r2, r8 @ restore atags pointer + mov pc, r4 @ call kernel .align 2 .type LC0, #object @@ -323,11 +342,11 @@ LC0: .word LC0 @ r1 .word __bss_start @ r2 .word _end @ r3 .word _start @ r5 - .word _image_size @ r6 + .word _edata @ r6 + .word _image_size @ r9 .word _got_start @ r11 .word _got_end @ ip .word user_stack_end @ sp -LC1: .word reloc_end - reloc_start .size LC0, . - LC0 #ifdef CONFIG_ARCH_RPC @@ -353,7 +372,7 @@ params: ldr r0, =0x10000100 @ params_phys for RPC * On exit, * r0, r1, r2, r3, r9, r10, r12 corrupted * This routine must preserve: - * r4, r5, r6, r7, r8 + * r4, r7, r8 */ .align 5 cache_on: mov r3, #8 @ cache_on function @@ -551,43 +570,6 @@ __common_mmu_cache_on: #endif /* - * All code following this line is relocatable. It is relocated by - * the above code to the end of the decompressed kernel image and - * executed there. During this time, we have no stacks. - * - * r0 = decompressed kernel length - * r1-r3 = unused - * r4 = kernel execution address - * r5 = decompressed kernel start - * r7 = architecture ID - * r8 = atags pointer - * r9-r12,r14 = corrupted - */ - .align 5 -reloc_start: add r9, r5, r0 - sub r9, r9, #128 @ do not copy the stack - debug_reloc_start - mov r1, r4 -1: - .rept 4 - ldmia r5!, {r0, r2, r3, r10 - r12, r14} @ relocate kernel - stmia r1!, {r0, r2, r3, r10 - r12, r14} - .endr - - cmp r5, r9 - blo 1b - mov sp, r1 - add sp, sp, #128 @ relocate the stack - debug_reloc_end - -call_kernel: bl cache_clean_flush - bl cache_off - mov r0, #0 @ must be zero - mov r1, r7 @ restore architecture number - mov r2, r8 @ restore atags pointer - mov pc, r4 @ call kernel - -/* * Here follow the relocatable cache support functions for the * various processors. This is a generic hook for locating an * entry and jumping to an instruction at the specified offset @@ -791,7 +773,7 @@ proc_types: * On exit, * r0, r1, r2, r3, r9, r12 corrupted * This routine must preserve: - * r4, r6, r7 + * r4, r7, r8 */ .align 5 cache_off: mov r3, #12 @ cache_off function @@ -866,7 +848,7 @@ __armv3_mmu_cache_off: * On exit, * r1, r2, r3, r9, r10, r11, r12 corrupted * This routine must preserve: - * r0, r4, r5, r6, r7 + * r4, r6, r7, r8 */ .align 5 cache_clean_flush: @@ -1088,7 +1070,6 @@ memdump: mov r12, r0 #endif .ltorg -reloc_end: .align .section ".stack", "aw", %nobits |