[ARM] 4736/1: Export atags to userspace and allow kexec to use customised atags
Currently, the atags used by kexec are fixed to the ones originally used
to boot the kernel. This is less than ideal as changing the commandline,
initrd and other options would be a useful feature.
This patch exports the atags used for the current kernel to userspace
through an "atags" file in procfs. The presence of the file is
controlled by its own Kconfig option and cleans up several ifdef blocks
into a separate file. The tags for the new kernel are assumed to be at
a fixed location before the kernel image itself. The location of the
tags used to boot the original kernel is unimportant and no longer
saved.
Based on a patch from Uli Luckas <u.luckas@road.de>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Uli Luckas <u.luckas@road.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S
index 062c111..61930eb0 100644
--- a/arch/arm/kernel/relocate_kernel.S
+++ b/arch/arm/kernel/relocate_kernel.S
@@ -7,23 +7,6 @@
.globl relocate_new_kernel
relocate_new_kernel:
- /* Move boot params back to where the kernel expects them */
-
- ldr r0,kexec_boot_params_address
- teq r0,#0
- beq 8f
-
- ldr r1,kexec_boot_params_copy
- mov r6,#KEXEC_BOOT_PARAMS_SIZE/4
-7:
- ldr r5,[r1],#4
- str r5,[r0],#4
- subs r6,r6,#1
- bne 7b
-
-8:
- /* Boot params moved, now go on with the kernel */
-
ldr r0,kexec_indirection_page
ldr r1,kexec_start_address
@@ -67,7 +50,7 @@
mov lr,r1
mov r0,#0
ldr r1,kexec_mach_type
- ldr r2,kexec_boot_params_address
+ ldr r2,kexec_boot_atags
mov pc,lr
.globl kexec_start_address
@@ -82,14 +65,9 @@
kexec_mach_type:
.long 0x0
- /* phy addr where new kernel will expect to find boot params */
- .globl kexec_boot_params_address
-kexec_boot_params_address:
- .long 0x0
-
- /* phy addr where old kernel put a copy of orig boot params */
- .globl kexec_boot_params_copy
-kexec_boot_params_copy:
+ /* phy addr of the atags for the new kernel */
+ .globl kexec_boot_atags
+kexec_boot_atags:
.long 0x0
relocate_new_kernel_end: