diff options
Diffstat (limited to 'arch/powerpc/boot/crt0.S')
| -rw-r--r-- | arch/powerpc/boot/crt0.S | 290 |
1 files changed, 247 insertions, 43 deletions
diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S index f1c4dfc635b..14de4f8778a 100644 --- a/arch/powerpc/boot/crt0.S +++ b/arch/powerpc/boot/crt0.S @@ -1,21 +1,51 @@ /* * Copyright (C) Paul Mackerras 1997. * + * Adapted for 64 bit LE PowerPC by Andrew Tauferner + * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * - * NOTE: this code runs in 32 bit mode and is packaged as ELF32. */ #include "ppc_asm.h" +RELA = 7 +RELACOUNT = 0x6ffffff9 + .text - /* a procedure descriptor used when booting this as a COFF file */ + /* A procedure descriptor used when booting this as a COFF file. + * When making COFF, this comes first in the link and we're + * linked at 0x500000. + */ .globl _zimage_start_opd _zimage_start_opd: - .long _zimage_start, 0, 0, 0 + .long 0x500000, 0, 0, 0 + +#ifdef __powerpc64__ +.balign 8 +p_start: .llong _start +p_etext: .llong _etext +p_bss_start: .llong __bss_start +p_end: .llong _end + +p_toc: .llong __toc_start + 0x8000 - p_base +p_dyn: .llong __dynamic_start - p_base +p_rela: .llong __rela_dyn_start - p_base +p_prom: .llong 0 + .weak _platform_stack_top +p_pstack: .llong _platform_stack_top +#else +p_start: .long _start +p_etext: .long _etext +p_bss_start: .long __bss_start +p_end: .long _end + + .weak _platform_stack_top +p_pstack: .long _platform_stack_top +#endif .weak _zimage_start .globl _zimage_start @@ -24,37 +54,64 @@ _zimage_start: _zimage_start_lib: /* Work out the offset between the address we were linked at and the address where we're running. */ - bl 1f -1: mflr r0 - lis r9,1b@ha - addi r9,r9,1b@l - subf. r0,r9,r0 - beq 3f /* if running at same address as linked */ - - /* The .got2 section contains a list of addresses, so add - the address offset onto each entry. */ - lis r9,__got2_start@ha - addi r9,r9,__got2_start@l - lis r8,__got2_end@ha - addi r8,r8,__got2_end@l - subf. r8,r9,r8 + bl .+4 +p_base: mflr r10 /* r10 now points to runtime addr of p_base */ +#ifndef __powerpc64__ + /* grab the link address of the dynamic section in r11 */ + addis r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha + lwz r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11) + cmpwi r11,0 + beq 3f /* if not linked -pie */ + /* get the runtime address of the dynamic section in r12 */ + .weak __dynamic_start + addis r12,r10,(__dynamic_start-p_base)@ha + addi r12,r12,(__dynamic_start-p_base)@l + subf r11,r11,r12 /* runtime - linktime offset */ + + /* The dynamic section contains a series of tagged entries. + * We need the RELA and RELACOUNT entries. */ + li r9,0 + li r0,0 +9: lwz r8,0(r12) /* get tag */ + cmpwi r8,0 + beq 10f /* end of list */ + cmpwi r8,RELA + bne 11f + lwz r9,4(r12) /* get RELA pointer in r9 */ + b 12f +11: addis r8,r8,(-RELACOUNT)@ha + cmpwi r8,RELACOUNT@l + bne 12f + lwz r0,4(r12) /* get RELACOUNT value in r0 */ +12: addi r12,r12,8 + b 9b + + /* The relocation section contains a list of relocations. + * We now do the R_PPC_RELATIVE ones, which point to words + * which need to be initialized with addend + offset. + * The R_PPC_RELATIVE ones come first and there are RELACOUNT + * of them. */ +10: /* skip relocation if we don't have both */ + cmpwi r0,0 beq 3f - srwi. r8,r8,2 - mtctr r8 - add r9,r0,r9 -2: lwz r8,0(r9) - add r8,r8,r0 - stw r8,0(r9) - addi r9,r9,4 + cmpwi r9,0 + beq 3f + + add r9,r9,r11 /* Relocate RELA pointer */ + mtctr r0 +2: lbz r0,4+3(r9) /* ELF32_R_INFO(reloc->r_info) */ + cmpwi r0,22 /* R_PPC_RELATIVE */ + bne 3f + lwz r12,0(r9) /* reloc->r_offset */ + lwz r0,8(r9) /* reloc->r_addend */ + add r0,r0,r11 + stwx r0,r11,r12 + addi r9,r9,12 bdnz 2b /* Do a cache flush for our text, in case the loader didn't */ -3: lis r9,_start@ha - addi r9,r9,_start@l - add r9,r0,r9 - lis r8,_etext@ha - addi r8,r8,_etext@l - add r8,r0,r8 +3: lwz r9,p_start-p_base(r10) /* note: these are relocated now */ + lwz r8,p_etext-p_base(r10) 4: dcbf r0,r9 icbi r0,r9 addi r9,r9,0x20 @@ -64,33 +121,180 @@ _zimage_start_lib: isync /* Clear the BSS */ - lis r9,__bss_start@ha - addi r9,r9,__bss_start@l - add r9,r0,r9 - lis r8,_end@ha - addi r8,r8,_end@l - add r8,r0,r8 - li r10,0 -5: stw r10,0(r9) + lwz r9,p_bss_start-p_base(r10) + lwz r8,p_end-p_base(r10) + li r0,0 +5: stw r0,0(r9) addi r9,r9,4 cmplw cr0,r9,r8 blt 5b /* Possibly set up a custom stack */ -.weak _platform_stack_top - lis r8,_platform_stack_top@ha - addi r8,r8,_platform_stack_top@l + lwz r8,p_pstack-p_base(r10) cmpwi r8,0 beq 6f - add r8,r0,r8 lwz r1,0(r8) - add r1,r0,r1 li r0,0 stwu r0,-16(r1) /* establish a stack frame */ 6: +#else /* __powerpc64__ */ + /* Save the prom pointer at p_prom. */ + std r5,(p_prom-p_base)(r10) + + /* Set r2 to the TOC. */ + ld r2,(p_toc-p_base)(r10) + add r2,r2,r10 + + /* Grab the link address of the dynamic section in r11. */ + ld r11,-32768(r2) + cmpwi r11,0 + beq 3f /* if not linked -pie then no dynamic section */ + + ld r11,(p_dyn-p_base)(r10) + add r11,r11,r10 + ld r9,(p_rela-p_base)(r10) + add r9,r9,r10 + + li r7,0 + li r8,0 +9: ld r6,0(r11) /* get tag */ + cmpdi r6,0 + beq 12f /* end of list */ + cmpdi r6,RELA + bne 10f + ld r7,8(r11) /* get RELA pointer in r7 */ + b 11f +10: addis r6,r6,(-RELACOUNT)@ha + cmpdi r6,RELACOUNT@l + bne 11f + ld r8,8(r11) /* get RELACOUNT value in r8 */ +11: addi r11,r11,16 + b 9b +12: + cmpdi r7,0 /* check we have both RELA and RELACOUNT */ + cmpdi cr1,r8,0 + beq 3f + beq cr1,3f + + /* Calcuate the runtime offset. */ + subf r7,r7,r9 + + /* Run through the list of relocations and process the + * R_PPC64_RELATIVE ones. */ + mtctr r8 +13: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */ + cmpdi r0,22 /* R_PPC64_RELATIVE */ + bne 3f + ld r6,0(r9) /* reloc->r_offset */ + ld r0,16(r9) /* reloc->r_addend */ + add r0,r0,r7 + stdx r0,r7,r6 + addi r9,r9,24 + bdnz 13b + + /* Do a cache flush for our text, in case the loader didn't */ +3: ld r9,p_start-p_base(r10) /* note: these are relocated now */ + ld r8,p_etext-p_base(r10) +4: dcbf r0,r9 + icbi r0,r9 + addi r9,r9,0x20 + cmpld cr0,r9,r8 + blt 4b + sync + isync + /* Clear the BSS */ + ld r9,p_bss_start-p_base(r10) + ld r8,p_end-p_base(r10) + li r0,0 +5: std r0,0(r9) + addi r9,r9,8 + cmpld cr0,r9,r8 + blt 5b + + /* Possibly set up a custom stack */ + ld r8,p_pstack-p_base(r10) + cmpdi r8,0 + beq 6f + ld r1,0(r8) + li r0,0 + stdu r0,-16(r1) /* establish a stack frame */ +6: +#endif /* __powerpc64__ */ /* Call platform_init() */ bl platform_init /* Call start */ b start + +#ifdef __powerpc64__ + +#define PROM_FRAME_SIZE 512 +#define SAVE_GPR(n, base) std n,8*(n)(base) +#define REST_GPR(n, base) ld n,8*(n)(base) +#define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base) +#define SAVE_4GPRS(n, base) SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base) +#define SAVE_8GPRS(n, base) SAVE_4GPRS(n, base); SAVE_4GPRS(n+4, base) +#define SAVE_10GPRS(n, base) SAVE_8GPRS(n, base); SAVE_2GPRS(n+8, base) +#define REST_2GPRS(n, base) REST_GPR(n, base); REST_GPR(n+1, base) +#define REST_4GPRS(n, base) REST_2GPRS(n, base); REST_2GPRS(n+2, base) +#define REST_8GPRS(n, base) REST_4GPRS(n, base); REST_4GPRS(n+4, base) +#define REST_10GPRS(n, base) REST_8GPRS(n, base); REST_2GPRS(n+8, base) + +/* prom handles the jump into and return from firmware. The prom args pointer + is loaded in r3. */ +.globl prom +prom: + mflr r0 + std r0,16(r1) + stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */ + + SAVE_GPR(2, r1) + SAVE_GPR(13, r1) + SAVE_8GPRS(14, r1) + SAVE_10GPRS(22, r1) + mfcr r10 + std r10,8*32(r1) + mfmsr r10 + std r10,8*33(r1) + + /* remove MSR_LE from msr but keep MSR_SF */ + mfmsr r10 + rldicr r10,r10,0,62 + mtsrr1 r10 + + /* Load FW address, set LR to label 1, and jump to FW */ + bl 0f +0: mflr r10 + addi r11,r10,(1f-0b) + mtlr r11 + + ld r10,(p_prom-0b)(r10) + mtsrr0 r10 + + rfid + +1: /* Return from OF */ + FIXUP_ENDIAN + + /* Restore registers and return. */ + rldicl r1,r1,0,32 + + /* Restore the MSR (back to 64 bits) */ + ld r10,8*(33)(r1) + mtmsr r10 + isync + + /* Restore other registers */ + REST_GPR(2, r1) + REST_GPR(13, r1) + REST_8GPRS(14, r1) + REST_10GPRS(22, r1) + ld r10,8*32(r1) + mtcr r10 + + addi r1,r1,PROM_FRAME_SIZE + ld r0,16(r1) + mtlr r0 + blr +#endif |