linux/arch/arm/kernel/relocate_kernel.S
Will Deacon 552e0c8da8 ARM: 7065/1: kexec: ensure new kernel is entered in ARM state
Commit 540b5738 ("ARM: 6999/1: head, zImage: Always Enter the kernel in
ARM state") mandates that the kernel should be entered in ARM state.

If a Thumb-2 kernel kexecs a new kernel image, we need to ensure that
we change state when branching to the new code. This patch replaces a
mov pc, lr with a bx lr on Thumb-2 kernels so that we transition to ARM
state if need be.

Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-28 10:39:41 +01:00

88 lines
1.3 KiB
ArmAsm

/*
* relocate_kernel.S - put the kernel image in place to boot
*/
#include <asm/kexec.h>
.globl relocate_new_kernel
relocate_new_kernel:
ldr r0,kexec_indirection_page
ldr r1,kexec_start_address
/*
* If there is no indirection page (we are doing crashdumps)
* skip any relocation.
*/
cmp r0, #0
beq 2f
0: /* top, read another word for the indirection page */
ldr r3, [r0],#4
/* Is it a destination page. Put destination address to r4 */
tst r3,#1,0
beq 1f
bic r4,r3,#1
b 0b
1:
/* Is it an indirection page */
tst r3,#2,0
beq 1f
bic r0,r3,#2
b 0b
1:
/* are we done ? */
tst r3,#4,0
beq 1f
b 2f
1:
/* is it source ? */
tst r3,#8,0
beq 0b
bic r3,r3,#8
mov r6,#1024
9:
ldr r5,[r3],#4
str r5,[r4],#4
subs r6,r6,#1
bne 9b
b 0b
2:
/* Jump to relocated kernel */
mov lr,r1
mov r0,#0
ldr r1,kexec_mach_type
ldr r2,kexec_boot_atags
ARM( mov pc, lr )
THUMB( bx lr )
.align
.globl kexec_start_address
kexec_start_address:
.long 0x0
.globl kexec_indirection_page
kexec_indirection_page:
.long 0x0
.globl kexec_mach_type
kexec_mach_type:
.long 0x0
/* phy addr of the atags for the new kernel */
.globl kexec_boot_atags
kexec_boot_atags:
.long 0x0
relocate_new_kernel_end:
.globl relocate_new_kernel_size
relocate_new_kernel_size:
.long relocate_new_kernel_end - relocate_new_kernel