/* SPDX-License-Identifier: GPL-2.0-only */
/*
* kexec trampoline
*
* Based on code taken from kexec-tools and kexec-lite.
*
* Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation
* Copyright (C) 2006, Mohan Kumar M, IBM Corporation
* Copyright (C) 2013, Anton Blanchard, IBM Corporation
*/
#include <asm/asm-compat.h>
#include <asm/crashdump-ppc64.h>
.balign 256
.globl purgatory_start
purgatory_start:
b master
/* ABI: possible run_at_load flag at 0x5c */
.org purgatory_start + 0x5c
.globl run_at_load
run_at_load:
.long 0
.size run_at_load, . - run_at_load
/* ABI: slaves start at 60 with r3=phys */
.org purgatory_start + 0x60
slave:
b .
/* ABI: end of copied region */
.org purgatory_start + 0x100
.size purgatory_start, . - purgatory_start
/*
* The above 0x100 bytes at purgatory_start are replaced with the
* code from the kernel (or next stage) by setup_purgatory().
*/
master:
or %r1,%r1,%r1 /* low priority to let other threads catchup */
isync
mr %r17,%r3 /* save cpu id to r17 */
mr %r15,%r4 /* save physical address in reg15 */
/* Work out where we're running */
bcl 20, 31, 0f
0: mflr %r18
/*
* Copy BACKUP_SRC_SIZE bytes from BACKUP_SRC_START to
* backup_start 8 bytes at a time.
*
* Use r3 = dest, r4 = src, r5 = size, r6 = count
*/
ld %r3, (backup_start - 0b)(%r18)
cmpdi %cr0, %r3, 0
beq .Lskip_copy /* skip if there is no backup region */
lis %r5, BACKUP_SRC_SIZE@h
ori %r5, %r5, BACKUP_SRC_SIZE@l
cmpdi %cr0, %r5, 0
beq .Lskip_copy /* skip if copy size is zero */
lis %r4, BACKUP_SRC_START@h
ori %r4, %r4, BACKUP_SRC_START@l
li %r6, 0
.Lcopy_loop:
ldx %r0, %r6, %r4
stdx %r0, %r6, %r3
addi %r6, %r6, 8
cmpld %cr0, %r6, %r5
blt .Lcopy_loop
.Lskip_copy:
or %r3,%r3,%r3 /* ok now to high priority, lets boot */
lis %r6,0x1
mtctr %r6 /* delay a bit for slaves to catch up */
bdnz . /* before we overwrite 0-100 again */
/* load device-tree address */
ld %r3, (dt_offset - 0b)(%r18)
mr %r16,%r3 /* save dt address in reg16 */
li %r4,20
LWZX_BE %r6,%r3,%r4 /* fetch __be32 version number at byte 20 */
cmpwi %cr0,%r6,2 /* v2 or later? */
blt 1f
li %r4,28
STWX_BE %r17,%r3,%r4 /* Store my cpu as __be32 at byte 28 */
1:
/* Load opal base and entry values in r8 & r9 respectively */
ld %r8,(opal_base - 0b)(%r18)
ld %r9,(opal_entry - 0b)(%r18)
/* load the kernel address */
ld %r4,(kernel - 0b)(%r18)
/* load the run_at_load flag */
/* possibly patched by kexec */
ld %r6,(run_at_load - 0b)(%r18)
/* and patch it into the kernel */
stw %r6,(0x5c)(%r4)
mr %r3,%r16 /* restore dt address */
li %r5,0 /* r5 will be 0 for kernel */
mfmsr %r11
andi. %r10,%r11,1 /* test MSR_LE */
bne .Little_endian
mtctr %r4 /* prepare branch to */
bctr /* start kernel */
.Little_endian:
mtsrr0 %r4 /* prepare branch to */
clrrdi %r11,%r11,1 /* clear MSR_LE */
mtsrr1 %r11
rfid /* update MSR and start kernel */
.balign 8
.globl kernel
kernel:
.8byte 0x0
.size kernel, . - kernel
.balign 8
.globl dt_offset
dt_offset:
.8byte 0x0
.size dt_offset, . - dt_offset
.balign 8
.globl backup_start
backup_start:
.8byte 0x0
.size backup_start, . - backup_start
.balign 8
.globl opal_base
opal_base:
.8byte 0x0
.size opal_base, . - opal_base
.balign 8
.globl opal_entry
opal_entry:
.8byte 0x0
.size opal_entry, . - opal_entry
.data
.balign 8
.globl purgatory_sha256_digest
purgatory_sha256_digest:
.skip 32
.size purgatory_sha256_digest, . - purgatory_sha256_digest
.balign 8
.globl purgatory_sha_regions
purgatory_sha_regions:
.skip 8 * 2 * 16
.size purgatory_sha_regions, . - purgatory_sha_regions
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