x86, setup: Allow global variables and functions in the decompressor
In order for global variables and functions to work in the
decompressor, we need to fix up the GOT in assembly code.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4C57382E.8050501@zytor.com>
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index faff0dc..52f85a1 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -280,6 +280,19 @@
rep stosq
/*
+ * Adjust our own GOT
+ */
+ leaq _got(%rip), %rdx
+ leaq _egot(%rip), %rcx
+1:
+ cmpq %rcx, %rdx
+ jae 2f
+ addq %rbx, (%rdx)
+ addq $8, %rdx
+ jmp 1b
+2:
+
+/*
* Do the decompression, and jump to the new kernel..
*/
pushq %rsi /* Save the real mode argument */