From: Cédric Le Goater Date: Thu, 24 Apr 2014 07:23:37 +0000 (+0200) Subject: powerpc/boot: Modify entry point for 64bit X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=f16e9684996188c12e1f460589003e99086ce36e;p=openwrt%2Fstaging%2Fblogic.git powerpc/boot: Modify entry point for 64bit This patch adds support a 64bit wrapper entry point. As in 32bit, the entry point does its own relocation and can be loaded at any address by the firmware. Signed-off-by: Cédric Le Goater Signed-off-by: Benjamin Herrenschmidt --- diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S index dbd99d064828..689290561e69 100644 --- a/arch/powerpc/boot/crt0.S +++ b/arch/powerpc/boot/crt0.S @@ -1,17 +1,20 @@ /* * 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, is position-independent, - * 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. * When making COFF, this comes first in the link and we're @@ -21,6 +24,20 @@ _zimage_start_opd: .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 @@ -28,6 +45,7 @@ p_end: .long _end .weak _platform_stack_top p_pstack: .long _platform_stack_top +#endif .weak _zimage_start .globl _zimage_start @@ -38,6 +56,7 @@ _zimage_start_lib: 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) @@ -51,8 +70,6 @@ p_base: mflr r10 /* r10 now points to runtime addr of p_base */ /* The dynamic section contains a series of tagged entries. * We need the RELA and RELACOUNT entries. */ -RELA = 7 -RELACOUNT = 0x6ffffff9 li r9,0 li r0,0 9: lwz r8,0(r12) /* get tag */ @@ -120,7 +137,90 @@ RELACOUNT = 0x6ffffff9 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