lantiq: lzma-loader: fix O32 ABI conformance

According to the calling convention of the o32 ABI the
caller function must reserve stack space for $a0-$a3
registers in case the callee needs to save its arguments.

The assembly startup code does not reserve stack space
for these registers thus when the main C function needs
to save its arguments, that will cause a stack overflow.

Fix the assembly code to reserve stack space for the
registers to avoid that.

Compile tested only.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@49061 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/target/linux/lantiq/image/lzma-loader/src/head.S b/target/linux/lantiq/image/lzma-loader/src/head.S
index 543996a0da4701cca80481aa181cd7bddc6df5c6..47a7c9bd6300ad92e6a0d426c5f44bc0f3e7e85f 100644 (file)
--- a/target/linux/lantiq/image/lzma-loader/src/head.S
+++ b/target/linux/lantiq/image/lzma-loader/src/head.S
@@ -109,6 +109,9 @@ __bss_check:
        /* Setup new "C" stack */
        la      sp, _stack
 
+       /* reserve stack space for a0-a3 registers */
+       subu    sp, 16
+
        /* jump to the decompressor routine */
        la      t0, loader_main
        jr      t0