diff options
| author | Vitaly Kuzmichev <vkuzmichev@mvista.com> | 2010-06-15 22:18:11 +0400 |
|---|---|---|
| committer | Wolfgang Denk <wd@denx.de> | 2010-06-22 21:41:06 +0200 |
| commit | 1a27f7d9c27671e7ae3cd0a3ee316149fa0824dc (patch) | |
| tree | 4956c3b08860ad3467ac68d51ec2d2c1f190ab6d /arch/arm/cpu/pxa/start.S | |
| parent | 96b35730a43160afa025ac405961737dbb0682b4 (diff) | |
ARM: Align stack to 8 bytes
The ARM ABI requires that the stack be aligned to 8 bytes as it is noted
in Procedure Call Standard for the ARM Architecture:
http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042d/index.html
Unaligned SP also causes the problem with variable-length arrays
allocation when VLA address becomes less than stack pointer during
aligning of this address, so the next 'push' in the stack overwrites
first 4 bytes of VLA.
Signed-off-by: Vitaly Kuzmichev <vkuzmichev@mvista.com>
Diffstat (limited to 'arch/arm/cpu/pxa/start.S')
| -rw-r--r-- | arch/arm/cpu/pxa/start.S | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm/cpu/pxa/start.S b/arch/arm/cpu/pxa/start.S index 3989fa61bc..e07c8c2e0e 100644 --- a/arch/arm/cpu/pxa/start.S +++ b/arch/arm/cpu/pxa/start.S @@ -140,10 +140,8 @@ stack_setup: #ifdef CONFIG_USE_IRQ sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ) #endif /* CONFIG_USE_IRQ */ - sub r0, r0, #12 /* leave 3 words for abort-stack */ - bic sp, r0, #7 /* NOTE: stack MUST be aligned to */ - /* 8 bytes in case we want to use */ - /* 64bit datatypes (eg. VSPRINTF64) */ + sub sp, r0, #12 /* leave 3 words for abort-stack */ + bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ clear_bss: ldr r0, _bss_start /* find start of bss segment */ |