On Mon, 05 Oct 2009 13:37:36 -0500 Tom Tom.Rix@windriver.com wrote:
Simon Kagstrom wrote:
U-boot for Marvell Kirkwood boards no longer work after the EABI changes introduced in commit f772acf8a584067033eff1e231fcd1fb3a00d3d9. This turns out to be caused by a stack alignment issue. The armv5te instructions ldrd/strd instructions require 8-byte alignment to work properly (otherwise undefined behavior), and start.S gave the stack a 12-byte alignment.
Tested on an OpenRD base board, where both printouts and ubifs stuff now works.
Has this patch been tested on any other boards ? This patch looks ok, I am just concerned about regressions.
It would probably be good to have it tested on non-Kirkwood boards as well. I can't see that it should do any harm to other boards though - it's just aligning the stack to 8 bytes (disregard the Subject for now and see v3 of the patch :-)).
The strange thing is really why it worked before on other boards. Perhaps the stack by change was already 8-byte aligned there, or perhaps ldrd/strd with non-8-byte alignment is handled. The architecture manual says that the behavior of ldrd/strd is undefined unless the address is 8-byte aligned, but I suppose that allows for it to actually work.
// Simon