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authorJohn Crispin <blogic@openwrt.org>2016-03-01 08:14:52 +0000
committerJohn Crispin <blogic@openwrt.org>2016-03-01 08:14:52 +0000
commit708f8c1ca71f840b6a059b2af95e6efa57243abf (patch)
tree39d349d63033e003963869ed14a37cd35879e831 /target/linux/ar71xx
parent76b79b5635abd16bd466e7add3eaf98be9b7d1a3 (diff)
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ar71xx/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 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 git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@48852 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/ar71xx')
-rw-r--r--target/linux/ar71xx/image/lzma-loader/src/head.S3
1 files changed, 3 insertions, 0 deletions
diff --git a/target/linux/ar71xx/image/lzma-loader/src/head.S b/target/linux/ar71xx/image/lzma-loader/src/head.S
index 543996a0da..47a7c9bd63 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