arm926ejs: 8-byte align stack to avoid LDRD/STRD problems
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).
Tested on an OpenRD base board, where both printouts and ubifs stuff now
works.
Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
diff --git a/cpu/arm926ejs/start.S b/cpu/arm926ejs/start.S
index 8043322..4421b6a 100644
--- a/cpu/arm926ejs/start.S
+++ b/cpu/arm926ejs/start.S
@@ -172,6 +172,7 @@
sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
#endif
sub sp, r0, #12 /* leave 3 words for abort-stack */
+ bic sp, r0, #7 /* 8-byte align stack for ABI compliance */
clear_bss:
ldr r0, _bss_start /* find start of bss segment */