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authorIru Cai <mytbk920423@gmail.com>2021-06-29 21:16:26 +0800
committerPatrick Georgi <pgeorgi@google.com>2021-07-07 14:54:56 +0000
commit88eb16786872404c9279ac6b0decbd98dac7ca8d (patch)
tree00254cb216ff13594d90e164a58ee4cf1001afdf /src/arch/x86
parentd109354c0f1d4b155c60701cd42e632213350d72 (diff)
arch/x86: Save resume vector to stack in x86_64 mode
In x86_64, the first function parameter is passed in rdi register, and the 32-bit code after exiting long mode reads the resume vector in 4(%esp), so it's needed to save the resume vector from rdi to 4(%rsp). Also note that the function attribute "regparm" only works on x86-32 targets according to the GCC manual, so "asmlinkage" doesn't change the ABI of an x86_64 function. Tested on HP EliteBook 2560p. The laptop can resume from S3 in x86_64 mode after this change. Change-Id: I45f2678071b2511c0af5dce9d9b73ac70dfd7252 Signed-off-by: Iru Cai <mytbk920423@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/55947 Reviewed-by: Arthur Heymans <arthur@aheymans.xyz> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/arch/x86')
-rw-r--r--src/arch/x86/wakeup.S7
1 files changed, 7 insertions, 0 deletions
diff --git a/src/arch/x86/wakeup.S b/src/arch/x86/wakeup.S
index dc9510bb90..7462dadbe8 100644
--- a/src/arch/x86/wakeup.S
+++ b/src/arch/x86/wakeup.S
@@ -15,6 +15,13 @@
.globl __wakeup
__wakeup:
#if ENV_X86_64
+ /* When called in x86_64 mode, the resume vector is in %rdi
+ * instead of the stack, save it in 4(%rsp) for the 32-bit code.
+ * It's OK to overwrite the return address at (%rsp) because this
+ * function doesn't return.
+ */
+ mov %edi, 4(%rsp)
+
xor %rax,%rax
mov %ss, %ax
push %rax