[PATCH 12/23] x86, realmode: Remove indirect jumps in trampoline_64.S

From: Jarkko Sakkinen
Date: Tue May 08 2012 - 14:26:49 EST


From: "H. Peter Anvin" <hpa@xxxxxxxxxxxxxxx>

Remove indirect jumps in trampoline_64.S which are no longer
necessary: the realmode code can relocate the absolute jumps
correctly from the start.

Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/realmode/rm/trampoline_64.S | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S
index 66c58cf..77b72b4 100644
--- a/arch/x86/realmode/rm/trampoline_64.S
+++ b/arch/x86/realmode/rm/trampoline_64.S
@@ -73,7 +73,7 @@ ENTRY(trampoline_data)
lmsw %ax # into protected mode

# flush prefetch and jump to startup_32
- ljmpl *(startup_32_vector)
+ ljmpl $__KERNEL32_CS, $pa_startup_32

no_longmode:
hlt
@@ -113,7 +113,7 @@ ENTRY(startup_32)
* EFER.LMA = 1). Now we want to jump in 64bit mode, to do that we use
* the new gdt/idt that has __KERNEL_CS with CS.L = 1.
*/
- ljmpl *(pa_startup_64_vector)
+ ljmpl $__KERNEL_CS, $pa_startup_64

.section ".text64","ax"
.code64
@@ -144,17 +144,6 @@ tgdt:
.quad 0x00cf93000000ffff # __KERNEL_DS
tgdt_end:

- .balign 4
-startup_32_vector:
- .long pa_startup_32
- .word __KERNEL32_CS, 0
-
- .balign 4
- .globl startup_64_vector
-startup_64_vector:
- .long pa_startup_64
- .word __KERNEL_CS, 0
-
.data
.balign 4
GLOBAL(trampoline_status)
--
1.7.9.5

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