/* SPDX-License-Identifier: GPL-2.0
*
* relocate_kernel.S - put the kernel image in place to boot
* 2005.9.17 kogiidena@eggplant.ddo.jp
*
* LANDISK/sh4 is supported. Maybe, SH archtecture works well.
*
* 2009-03-18 Magnus Damm - Added Kexec Jump support
*/
#include <linux/linkage.h>
#include <asm/addrspace.h>
#include <asm/page.h>
.globl relocate_new_kernel
relocate_new_kernel:
/* r4 = indirection_page */
/* r5 = reboot_code_buffer */
/* r6 = start_address */
mov.l 10f, r0 /* PAGE_SIZE */
add r5, r0 /* setup new stack at end of control page */
/* save r15->r8 to new stack */
mov.l r15, @-r0
mov r0, r15
mov.l r14, @-r15
mov.l r13, @-r15
mov.l r12, @-r15
mov.l r11, @-r15
mov.l r10, @-r15
mov.l r9, @-r15
mov.l r8, @-r15
/* save other random registers */
sts.l macl, @-r15
sts.l mach, @-r15
stc.l gbr, @-r15
stc.l ssr, @-r15
stc.l sr, @-r15
sts.l pr, @-r15
stc.l spc, @-r15
/* switch to bank1 and save r7->r0 */
mov.l 12f, r9
stc sr, r8
or r9, r8
ldc r8, sr
mov.l r7, @-r15
mov.l r6, @-r15
mov.l r5, @-r15
mov.l r4, @-r15
mov.l r3, @-r15
mov.l r2, @-r15
mov.l r1, @-r15
mov.l r0, @-r15
/* switch to bank0 and save r7->r0 */
mov.l 12f, r9
not r9, r9
stc sr, r8
and r9, r8
ldc r8, sr
mov.l r7, @-r15
mov.l r6, @-r15
mov.l r5, @-r15
mov.l r4, @-r15
mov.l r3, @-r15
mov.l r2, @-r15
mov.l r1, @-r15
mov.l r0, @-r15
mov.l r4, @-r15 /* save indirection page again */
bsr swap_pages /* swap pages before jumping to new kernel */
nop
mova 11f, r0
mov.l r15, @r0 /* save pointer to stack */
jsr @r6 /* hand over control to new kernel */
nop
mov.l 11f, r15 /* get pointer to stack */
mov.l @r15+, r4 /* restore r4 to get indirection page */
bsr swap_pages /* swap pages back to previous state */
nop
/* make sure bank0 is active and restore r0->r7 */
mov.l 12f, r9
not r9, r9
stc sr, r8
and r9, r8
ldc r8, sr
mov.l @r15+, r0
mov.l @r15+, r1
mov.l @r15+, r2
mov.l @r15+, r3
mov.l @r15+, r4
mov.l @r15+, r5
mov.l @r15+, r6
mov.l @r15+, r7
/* switch to bank1 and restore r0->r7 */
mov.l 12f, r9
stc sr, r8
or r9, r8
ldc r8, sr
mov.l @r15+, r0
mov.l @r15+, r1
mov.l @r15+, r2
mov.l @r15+, r3
mov.l @r15+, r4
mov.l @r15+, r5
mov.l @r15+, r6
mov.l @r15+, r7
/* switch back to bank0 */
mov.l 12f, r9
not r9, r9
stc sr, r8
and r9, r8
ldc r8, sr
/* restore other random registers */
ldc.l @r15+, spc
lds.l @r15+, pr
ldc.l @r15+, sr
ldc.l @r15+, ssr
ldc.l @r15+, gbr
lds.l @r15+, mach
lds.l @r15+, macl
/* restore r8->r15 */
mov.l @r15+, r8
mov.l @r15+, r9
mov.l @r15+, r10
mov.l @r15+, r11
mov.l @r15+, r12
mov.l @r15+, r13
mov.l @r15+, r14
mov.l @r15+, r15
rts
nop
swap_pages:
bra 1f
mov r4,r0 /* cmd = indirection_page */
0:
mov.l @r4+,r0 /* cmd = *ind++ */
1: /* addr = cmd & 0xfffffff0 */
mov r0,r2
mov #-16,r1
and r1,r2
/* if(cmd & IND_DESTINATION) dst = addr */
tst #1,r0
bt 2f
bra 0b
mov r2,r5
2: /* else if(cmd & IND_INDIRECTION) ind = addr */
tst #2,r0
bt 3f
bra 0b
mov r2,r4
3: /* else if(cmd & IND_DONE) return */
tst #4,r0
bt 4f
rts
nop
4: /* else if(cmd & IND_SOURCE) memcpy(dst,addr,PAGE_SIZE) */
tst #8,r0
bt 0b
mov.l 10f,r3 /* PAGE_SIZE */
shlr2 r3
shlr2 r3
5:
dt r3
/* regular kexec just overwrites the destination page
* with the contents of the source page.
* for the kexec jump case we need to swap the contents
* of the pages.
* to keep it simple swap the contents for both cases.
*/
mov.l @(0, r2), r8
mov.l @(0, r5), r1
mov.l r8, @(0, r5)
mov.l r1, @(0, r2)
mov.l @(4, r2), r8
mov.l @(4, r5), r1
mov.l r8, @(4, r5)
mov.l r1, @(4, r2)
mov.l @(8, r2), r8
mov.l @(8, r5), r1
mov.l r8, @(8, r5)
mov.l r1, @(8, r2)
mov.l @(12, r2), r8
mov.l @(12, r5), r1
mov.l r8, @(12, r5)
mov.l r1, @(12, r2)
add #16,r5
add #16,r2
bf 5b
bra 0b
nop
.align 2
10:
.long PAGE_SIZE
11:
.long 0
12:
.long 0x20000000 ! RB=1
relocate_new_kernel_end:
.globl relocate_new_kernel_size
relocate_new_kernel_size:
.long relocate_new_kernel_end - relocate_new_kernel