Commit f16e9684 authored by Cédric Le Goater's avatar Cédric Le Goater Committed by Benjamin Herrenschmidt

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: default avatarCédric Le Goater <clg@fr.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 93d39210
/*
* 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
......
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