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296 lines
6.7 KiB
296 lines
6.7 KiB
/* SPDX-License-Identifier: GPL-2.0-or-later */ |
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/* |
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* Copyright (C) Paul Mackerras 1997. |
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* |
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* Adapted for 64 bit LE PowerPC by Andrew Tauferner |
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*/ |
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#include "ppc_asm.h" |
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RELA = 7 |
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RELACOUNT = 0x6ffffff9 |
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.data |
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/* A procedure descriptor used when booting this as a COFF file. |
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* When making COFF, this comes first in the link and we're |
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* linked at 0x500000. |
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*/ |
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.globl _zimage_start_opd |
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_zimage_start_opd: |
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.long 0x500000, 0, 0, 0 |
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.text |
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b _zimage_start |
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#ifdef __powerpc64__ |
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.balign 8 |
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p_start: .8byte _start |
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p_etext: .8byte _etext |
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p_bss_start: .8byte __bss_start |
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p_end: .8byte _end |
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p_toc: .8byte __toc_start + 0x8000 - p_base |
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p_dyn: .8byte __dynamic_start - p_base |
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p_rela: .8byte __rela_dyn_start - p_base |
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p_prom: .8byte 0 |
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.weak _platform_stack_top |
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p_pstack: .8byte _platform_stack_top |
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#else |
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p_start: .long _start |
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p_etext: .long _etext |
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p_bss_start: .long __bss_start |
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p_end: .long _end |
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.weak _platform_stack_top |
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p_pstack: .long _platform_stack_top |
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#endif |
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.weak _zimage_start |
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_zimage_start: |
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.globl _zimage_start_lib |
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_zimage_start_lib: |
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/* Work out the offset between the address we were linked at |
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and the address where we're running. */ |
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bl .+4 |
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p_base: mflr r10 /* r10 now points to runtime addr of p_base */ |
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#ifndef __powerpc64__ |
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/* grab the link address of the dynamic section in r11 */ |
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addis r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha |
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lwz r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11) |
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cmpwi r11,0 |
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beq 3f /* if not linked -pie */ |
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/* get the runtime address of the dynamic section in r12 */ |
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.weak __dynamic_start |
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addis r12,r10,(__dynamic_start-p_base)@ha |
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addi r12,r12,(__dynamic_start-p_base)@l |
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subf r11,r11,r12 /* runtime - linktime offset */ |
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/* The dynamic section contains a series of tagged entries. |
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* We need the RELA and RELACOUNT entries. */ |
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li r9,0 |
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li r0,0 |
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9: lwz r8,0(r12) /* get tag */ |
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cmpwi r8,0 |
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beq 10f /* end of list */ |
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cmpwi r8,RELA |
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bne 11f |
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lwz r9,4(r12) /* get RELA pointer in r9 */ |
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b 12f |
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11: addis r8,r8,(-RELACOUNT)@ha |
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cmpwi r8,RELACOUNT@l |
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bne 12f |
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lwz r0,4(r12) /* get RELACOUNT value in r0 */ |
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12: addi r12,r12,8 |
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b 9b |
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/* The relocation section contains a list of relocations. |
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* We now do the R_PPC_RELATIVE ones, which point to words |
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* which need to be initialized with addend + offset. |
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* The R_PPC_RELATIVE ones come first and there are RELACOUNT |
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* of them. */ |
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10: /* skip relocation if we don't have both */ |
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cmpwi r0,0 |
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beq 3f |
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cmpwi r9,0 |
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beq 3f |
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add r9,r9,r11 /* Relocate RELA pointer */ |
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mtctr r0 |
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2: lbz r0,4+3(r9) /* ELF32_R_INFO(reloc->r_info) */ |
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cmpwi r0,22 /* R_PPC_RELATIVE */ |
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bne 3f |
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lwz r12,0(r9) /* reloc->r_offset */ |
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lwz r0,8(r9) /* reloc->r_addend */ |
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add r0,r0,r11 |
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stwx r0,r11,r12 |
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addi r9,r9,12 |
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bdnz 2b |
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/* Do a cache flush for our text, in case the loader didn't */ |
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3: lwz r9,p_start-p_base(r10) /* note: these are relocated now */ |
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lwz r8,p_etext-p_base(r10) |
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4: dcbf r0,r9 |
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icbi r0,r9 |
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addi r9,r9,0x20 |
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cmplw cr0,r9,r8 |
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blt 4b |
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sync |
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isync |
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/* Clear the BSS */ |
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lwz r9,p_bss_start-p_base(r10) |
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lwz r8,p_end-p_base(r10) |
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li r0,0 |
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5: stw r0,0(r9) |
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addi r9,r9,4 |
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cmplw cr0,r9,r8 |
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blt 5b |
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/* Possibly set up a custom stack */ |
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lwz r8,p_pstack-p_base(r10) |
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cmpwi r8,0 |
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beq 6f |
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lwz r1,0(r8) |
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li r0,0 |
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stwu r0,-16(r1) /* establish a stack frame */ |
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6: |
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#else /* __powerpc64__ */ |
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/* Save the prom pointer at p_prom. */ |
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std r5,(p_prom-p_base)(r10) |
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/* Set r2 to the TOC. */ |
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ld r2,(p_toc-p_base)(r10) |
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add r2,r2,r10 |
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/* Grab the link address of the dynamic section in r11. */ |
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ld r11,-32768(r2) |
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cmpwi r11,0 |
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beq 3f /* if not linked -pie then no dynamic section */ |
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ld r11,(p_dyn-p_base)(r10) |
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add r11,r11,r10 |
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ld r9,(p_rela-p_base)(r10) |
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add r9,r9,r10 |
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li r13,0 |
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li r8,0 |
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9: ld r12,0(r11) /* get tag */ |
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cmpdi r12,0 |
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beq 12f /* end of list */ |
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cmpdi r12,RELA |
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bne 10f |
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ld r13,8(r11) /* get RELA pointer in r13 */ |
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b 11f |
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10: addis r12,r12,(-RELACOUNT)@ha |
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cmpdi r12,RELACOUNT@l |
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bne 11f |
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ld r8,8(r11) /* get RELACOUNT value in r8 */ |
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11: addi r11,r11,16 |
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b 9b |
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12: |
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cmpdi r13,0 /* check we have both RELA and RELACOUNT */ |
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cmpdi cr1,r8,0 |
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beq 3f |
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beq cr1,3f |
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/* Calcuate the runtime offset. */ |
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subf r13,r13,r9 |
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/* Run through the list of relocations and process the |
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* R_PPC64_RELATIVE ones. */ |
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mtctr r8 |
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13: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */ |
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cmpdi r0,22 /* R_PPC64_RELATIVE */ |
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bne 3f |
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ld r12,0(r9) /* reloc->r_offset */ |
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ld r0,16(r9) /* reloc->r_addend */ |
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add r0,r0,r13 |
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stdx r0,r13,r12 |
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addi r9,r9,24 |
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bdnz 13b |
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/* Do a cache flush for our text, in case the loader didn't */ |
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3: ld r9,p_start-p_base(r10) /* note: these are relocated now */ |
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ld r8,p_etext-p_base(r10) |
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4: dcbf r0,r9 |
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icbi r0,r9 |
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addi r9,r9,0x20 |
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cmpld cr0,r9,r8 |
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blt 4b |
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sync |
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isync |
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/* Clear the BSS */ |
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ld r9,p_bss_start-p_base(r10) |
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ld r8,p_end-p_base(r10) |
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li r0,0 |
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5: std r0,0(r9) |
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addi r9,r9,8 |
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cmpld cr0,r9,r8 |
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blt 5b |
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/* Possibly set up a custom stack */ |
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ld r8,p_pstack-p_base(r10) |
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cmpdi r8,0 |
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beq 6f |
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ld r1,0(r8) |
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li r0,0 |
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stdu r0,-112(r1) /* establish a stack frame */ |
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6: |
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#endif /* __powerpc64__ */ |
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/* Call platform_init() */ |
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bl platform_init |
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/* Call start */ |
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b start |
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#ifdef __powerpc64__ |
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#define PROM_FRAME_SIZE 512 |
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#define SAVE_GPR(n, base) std n,8*(n)(base) |
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#define REST_GPR(n, base) ld n,8*(n)(base) |
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#define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base) |
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#define SAVE_4GPRS(n, base) SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base) |
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#define SAVE_8GPRS(n, base) SAVE_4GPRS(n, base); SAVE_4GPRS(n+4, base) |
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#define SAVE_10GPRS(n, base) SAVE_8GPRS(n, base); SAVE_2GPRS(n+8, base) |
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#define REST_2GPRS(n, base) REST_GPR(n, base); REST_GPR(n+1, base) |
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#define REST_4GPRS(n, base) REST_2GPRS(n, base); REST_2GPRS(n+2, base) |
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#define REST_8GPRS(n, base) REST_4GPRS(n, base); REST_4GPRS(n+4, base) |
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#define REST_10GPRS(n, base) REST_8GPRS(n, base); REST_2GPRS(n+8, base) |
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/* prom handles the jump into and return from firmware. The prom args pointer |
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is loaded in r3. */ |
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.globl prom |
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prom: |
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mflr r0 |
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std r0,16(r1) |
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stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */ |
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SAVE_GPR(2, r1) |
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SAVE_GPR(13, r1) |
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SAVE_8GPRS(14, r1) |
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SAVE_10GPRS(22, r1) |
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mfcr r10 |
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std r10,8*32(r1) |
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mfmsr r10 |
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std r10,8*33(r1) |
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/* remove MSR_LE from msr but keep MSR_SF */ |
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mfmsr r10 |
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rldicr r10,r10,0,62 |
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mtsrr1 r10 |
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/* Load FW address, set LR to label 1, and jump to FW */ |
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bl 0f |
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0: mflr r10 |
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addi r11,r10,(1f-0b) |
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mtlr r11 |
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ld r10,(p_prom-0b)(r10) |
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mtsrr0 r10 |
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rfid |
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1: /* Return from OF */ |
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FIXUP_ENDIAN |
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/* Restore registers and return. */ |
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rldicl r1,r1,0,32 |
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/* Restore the MSR (back to 64 bits) */ |
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ld r10,8*(33)(r1) |
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mtmsr r10 |
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isync |
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/* Restore other registers */ |
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REST_GPR(2, r1) |
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REST_GPR(13, r1) |
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REST_8GPRS(14, r1) |
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REST_10GPRS(22, r1) |
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ld r10,8*32(r1) |
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mtcr r10 |
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addi r1,r1,PROM_FRAME_SIZE |
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ld r0,16(r1) |
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mtlr r0 |
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blr |
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#endif
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