[PATCH 3.12 113/212] avr32: setup crt for early panic()

From: Greg Kroah-Hartman
Date: Mon Dec 02 2013 - 14:56:48 EST


3.12-stable review patch. If anyone has any objections, please let me know.

------------------

From: Andreas BieÃmann <andreas@xxxxxxxxxxxx>

commit 7a2a74f4b856993218aa7cdeeb6c3103101340db upstream.

Before the CRT was (fully) set up in kernel_entry (bss cleared before in
_start, but also not before jump to panic() in no_tag_table case).

This patch fixes this up to have a fully working CRT when branching to panic()
in no_tag_table.

Signed-off-by: Andreas BieÃmann <andreas@xxxxxxxxxxxx>
Acked-by: Hans-Christian Egtvedt <egtvedt@xxxxxxxxxxxx>
Cc: Haavard Skinnemoen <hskinnemoen@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/avr32/boot/u-boot/head.S | 30 +++++++++++++++++++++++++-----
arch/avr32/kernel/head.S | 20 --------------------
2 files changed, 25 insertions(+), 25 deletions(-)

--- a/arch/avr32/boot/u-boot/head.S
+++ b/arch/avr32/boot/u-boot/head.S
@@ -8,6 +8,8 @@
* published by the Free Software Foundation.
*/
#include <asm/setup.h>
+#include <asm/thread_info.h>
+#include <asm/sysreg.h>

/*
* The kernel is loaded where we want it to be and all caches
@@ -20,11 +22,6 @@
.section .init.text,"ax"
.global _start
_start:
- /* Check if the boot loader actually provided a tag table */
- lddpc r0, magic_number
- cp.w r12, r0
- brne no_tag_table
-
/* Initialize .bss */
lddpc r2, bss_start_addr
lddpc r3, end_addr
@@ -34,6 +31,25 @@ _start:
cp r2, r3
brlo 1b

+ /* Initialize status register */
+ lddpc r0, init_sr
+ mtsr SYSREG_SR, r0
+
+ /* Set initial stack pointer */
+ lddpc sp, stack_addr
+ sub sp, -THREAD_SIZE
+
+#ifdef CONFIG_FRAME_POINTER
+ /* Mark last stack frame */
+ mov lr, 0
+ mov r7, 0
+#endif
+
+ /* Check if the boot loader actually provided a tag table */
+ lddpc r0, magic_number
+ cp.w r12, r0
+ brne no_tag_table
+
/*
* Save the tag table address for later use. This must be done
* _after_ .bss has been initialized...
@@ -53,6 +69,10 @@ bss_start_addr:
.long __bss_start
end_addr:
.long _end
+init_sr:
+ .long 0x007f0000 /* Supervisor mode, everything masked */
+stack_addr:
+ .long init_thread_union

no_tag_table:
sub r12, pc, (. - 2f)
--- a/arch/avr32/kernel/head.S
+++ b/arch/avr32/kernel/head.S
@@ -10,33 +10,13 @@
#include <linux/linkage.h>

#include <asm/page.h>
-#include <asm/thread_info.h>
-#include <asm/sysreg.h>

.section .init.text,"ax"
.global kernel_entry
kernel_entry:
- /* Initialize status register */
- lddpc r0, init_sr
- mtsr SYSREG_SR, r0
-
- /* Set initial stack pointer */
- lddpc sp, stack_addr
- sub sp, -THREAD_SIZE
-
-#ifdef CONFIG_FRAME_POINTER
- /* Mark last stack frame */
- mov lr, 0
- mov r7, 0
-#endif
-
/* Start the show */
lddpc pc, kernel_start_addr

.align 2
-init_sr:
- .long 0x007f0000 /* Supervisor mode, everything masked */
-stack_addr:
- .long init_thread_union
kernel_start_addr:
.long start_kernel


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