linux/arch/ppc/kernel/relocate_kernel.S

124 lines
2.5 KiB
ArmAsm

/*
* relocate_kernel.S - put the kernel image in place to boot
* Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
*
* GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <asm/reg.h>
#include <asm/ppc_asm.h>
#include <asm/processor.h>
#include <asm/kexec.h>
#define PAGE_SIZE 4096 /* must be same value as in <asm/page.h> */
/*
* Must be relocatable PIC code callable as a C function.
*/
.globl relocate_new_kernel
relocate_new_kernel:
/* r3 = page_list */
/* r4 = reboot_code_buffer */
/* r5 = start_address */
li r0, 0
/*
* Set Machine Status Register to a known status,
* switch the MMU off and jump to 1: in a single step.
*/
mr r8, r0
ori r8, r8, MSR_RI|MSR_ME
mtspr SPRN_SRR1, r8
addi r8, r4, 1f - relocate_new_kernel
mtspr SPRN_SRR0, r8
sync
rfi
1:
/* from this point address translation is turned off */
/* and interrupts are disabled */
/* set a new stack at the bottom of our page... */
/* (not really needed now) */
addi r1, r4, KEXEC_CONTROL_CODE_SIZE - 8 /* for LR Save+Back Chain */
stw r0, 0(r1)
/* Do the copies */
li r6, 0 /* checksum */
mr r0, r3
b 1f
0: /* top, read another word for the indirection page */
lwzu r0, 4(r3)
1:
/* is it a destination page? (r8) */
rlwinm. r7, r0, 0, 31, 31 /* IND_DESTINATION (1<<0) */
beq 2f
rlwinm r8, r0, 0, 0, 19 /* clear kexec flags, page align */
b 0b
2: /* is it an indirection page? (r3) */
rlwinm. r7, r0, 0, 30, 30 /* IND_INDIRECTION (1<<1) */
beq 2f
rlwinm r3, r0, 0, 0, 19 /* clear kexec flags, page align */
subi r3, r3, 4
b 0b
2: /* are we done? */
rlwinm. r7, r0, 0, 29, 29 /* IND_DONE (1<<2) */
beq 2f
b 3f
2: /* is it a source page? (r9) */
rlwinm. r7, r0, 0, 28, 28 /* IND_SOURCE (1<<3) */
beq 0b
rlwinm r9, r0, 0, 0, 19 /* clear kexec flags, page align */
li r7, PAGE_SIZE / 4
mtctr r7
subi r9, r9, 4
subi r8, r8, 4
9:
lwzu r0, 4(r9) /* do the copy */
xor r6, r6, r0
stwu r0, 4(r8)
dcbst 0, r8
sync
icbi 0, r8
bdnz 9b
addi r9, r9, 4
addi r8, r8, 4
b 0b
3:
/* To be certain of avoiding problems with self-modifying code
* execute a serializing instruction here.
*/
isync
sync
/* jump to the entry point, usually the setup routine */
mtlr r5
blrl
1: b 1b
relocate_new_kernel_end:
.globl relocate_new_kernel_size
relocate_new_kernel_size:
.long relocate_new_kernel_end - relocate_new_kernel