| Message ID | 303546e60924ac702fb6e1c1976b363ab58db930.1456800208.git.mschiffer@universe-factory.net |
|---|---|
| State | Accepted |
| Headers | show |
diff --git a/target/linux/ar71xx/image/lzma-loader/src/head.S b/target/linux/ar71xx/image/lzma-loader/src/head.S index 543996a..47a7c9b 100644 --- a/target/linux/ar71xx/image/lzma-loader/src/head.S +++ b/target/linux/ar71xx/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
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 code of the loader does not reserve stack space for these registers thus when the 'loader_main' function needs to save its arguments, those will be stored in the 'workspace' area instead of the stack. Because the workspace area is also used by other part of the code, the saved register values gets overwritten and this often leads to failed kernel boots. Fix the code to reserve stack space for the registers to avoid this error. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Backport of r48279 --- target/linux/ar71xx/image/lzma-loader/src/head.S | 3 +++ 1 file changed, 3 insertions(+)