From 1a27f7d9c27671e7ae3cd0a3ee316149fa0824dc Mon Sep 17 00:00:00 2001 From: Vitaly Kuzmichev Date: Tue, 15 Jun 2010 22:18:11 +0400 Subject: 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 --- arch/arm/cpu/arm720t/start.S | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/cpu/arm720t') diff --git a/arch/arm/cpu/arm720t/start.S b/arch/arm/cpu/arm720t/start.S index 022b873..d6f2c16 100644 --- a/arch/arm/cpu/arm720t/start.S +++ b/arch/arm/cpu/arm720t/start.S @@ -172,6 +172,7 @@ stack_setup: sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ) #endif 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 */ -- cgit v1.1