mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 12:43:55 +08:00
bc8b57f08c
Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
88 lines
1.3 KiB
ArmAsm
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
|
|
mov pc,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
|
|
|
|
|