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| /* SPDX-License-Identifier: GPL-2.0-or-later */
| /*
| * Copyright (C) Paul Mackerras 1997.
| *
| * Adapted for 64 bit LE PowerPC by Andrew Tauferner
| */
|
| #include "ppc_asm.h"
|
| RELA = 7
| RELACOUNT = 0x6ffffff9
|
| .data
| /* 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 0x500000, 0, 0, 0
| .text
| b _zimage_start
|
| #ifdef __powerpc64__
| .balign 8
| p_start: .8byte _start
| p_etext: .8byte _etext
| p_bss_start: .8byte __bss_start
| p_end: .8byte _end
|
| p_toc: .8byte __toc_start + 0x8000 - p_base
| p_dyn: .8byte __dynamic_start - p_base
| p_rela: .8byte __rela_dyn_start - p_base
| p_prom: .8byte 0
| .weak _platform_stack_top
| p_pstack: .8byte _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
| _zimage_start:
| .globl _zimage_start_lib
| _zimage_start_lib:
| /* Work out the offset between the address we were linked at
| and the address where we're running. */
| 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
| 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: 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
| cmplw cr0,r9,r8
| blt 4b
| sync
| isync
|
| /* Clear the BSS */
| 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 */
| lwz r8,p_pstack-p_base(r10)
| cmpwi r8,0
| beq 6f
| lwz r1,0(r8)
| 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 r13,0
| li r8,0
| 9: ld r12,0(r11) /* get tag */
| cmpdi r12,0
| beq 12f /* end of list */
| cmpdi r12,RELA
| bne 10f
| ld r13,8(r11) /* get RELA pointer in r13 */
| b 11f
| 10: addis r12,r12,(-RELACOUNT)@ha
| cmpdi r12,RELACOUNT@l
| bne 11f
| ld r8,8(r11) /* get RELACOUNT value in r8 */
| 11: addi r11,r11,16
| b 9b
| 12:
| cmpdi r13,0 /* check we have both RELA and RELACOUNT */
| cmpdi cr1,r8,0
| beq 3f
| beq cr1,3f
|
| /* Calcuate the runtime offset. */
| subf r13,r13,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 r12,0(r9) /* reloc->r_offset */
| ld r0,16(r9) /* reloc->r_addend */
| add r0,r0,r13
| stdx r0,r13,r12
| 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,-112(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
|
|
