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>
Part of this patch is by: Mikhail Kshevetskiy.
Stack must be aligned to 8 bytes on PXA (possibly all armv5te) for LDRD/STRD
instructions. In case LDRD/STRD is issued on an unaligned address, the behaviour
is undefined.
The issue was observed when working with the NAND code, which was rendered
disfunctional. Also, the vsprintf() function had serious problems with printing
64bit wide long longs. After aligning the stack, this wrong behaviour is no
longer present.
Tested on:
Marvell Littleton PXA310 board
Toradex Colibri PXA320 board
Aeronix Zipit Z2 PXA270 handheld
Voipac PXA270 board
Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
