linux/arch/arm/kernel/relocate_kernel.S
Dave Martin e2ccba4908 ARM: 7897/1: kexec: Use the right ISA for relocate_new_kernel
Copying a function with memcpy() and then trying to execute the
result isn't trivially portable to Thumb.

This patch modifies the kexec soft restart code to copy its
assembler trampoline relocate_new_kernel() using fncpy() instead,
so that relocate_new_kernel can be in the same ISA as the rest of
the kernel without problems.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reported-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
Tested-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-11-30 22:21:02 +00:00

93 lines
1.4 KiB
ArmAsm

/*
* relocate_kernel.S - put the kernel image in place to boot
*/
#include <linux/linkage.h>
#include <asm/kexec.h>
.align 3 /* not needed for this code, but keeps fncpy() happy */
ENTRY(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
ENDPROC(relocate_new_kernel)
relocate_new_kernel_end:
.globl relocate_new_kernel_size
relocate_new_kernel_size:
.long relocate_new_kernel_end - relocate_new_kernel