Commit-ID: 9e085cefc61155e45b87a277440f96682e7921f1
Gitweb: http://git.kernel.org/tip/9e085cefc61155e45b87a277440f96682e7921f1
Author: Jiri Slaby <jslaby@xxxxxxx>
AuthorDate: Thu, 24 Aug 2017 09:33:27 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 29 Aug 2017 13:23:29 +0200
x86/boot/64: Extract efi_pe_entry() from startup_64()
Similarly to the 32-bit code, efi_pe_entry body() is somehow squashed into
startup_64().
In the old days, we forced startup_64() to start at offset 0x200 and efi_pe_entry()
to start at 0x210. But this requirement was removed long time ago, in:
99f857db8857 ("x86, build: Dynamically find entry points in compressed startup code")
The way it is now makes the code less readable and illogical. Given
we can now safely extract the inlined efi_pe_entry() body from
startup_64() into a separate function, we do so.
We also annotate the function appropriatelly by ENTRY+ENDPROC.
ABI offsets are preserved:
0000000000000000 T startup_32
0000000000000200 T startup_64
0000000000000390 T efi64_stub_entry
On the top-level, it looked like:
.org 0x200
ENTRY(startup_64)
#ifdef CONFIG_EFI_STUB ; start of inlined
jmp preferred_addr
GLOBAL(efi_pe_entry)
... ; a lot of assembly (efi_pe_entry)
leaq preferred_addr(%rax), %rax
jmp *%rax
preferred_addr:
#endif ; end of inlined
... ; a lot of assembly (startup_64)
ENDPROC(startup_64)
And it is now converted into:
.org 0x200
ENTRY(startup_64)
... ; a lot of assembly (startup_64)
ENDPROC(startup_64)
#ifdef CONFIG_EFI_STUB
ENTRY(efi_pe_entry)
... ; a lot of assembly (efi_pe_entry)
leaq startup_64(%rax), %rax
jmp *%rax
ENDPROC(efi_pe_entry)
#endif
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: ard.biesheuvel@xxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20170824073327.4129-2-jslaby@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/boot/compressed/head_64.S | 112 ++++++++++++++++++-------------------
1 file changed, 53 insertions(+), 59 deletions(-)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index fbf4c32..b4a5d28 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -243,65 +243,6 @@ ENTRY(startup_64)
* that maps our entire kernel(text+data+bss+brk), zero page
* and command line.
*/
-#ifdef CONFIG_EFI_STUB
- /*
- * The entry point for the PE/COFF executable is efi_pe_entry, so
- * only legacy boot loaders will execute this jmp.
- */
- jmp preferred_addr
-
-ENTRY(efi_pe_entry)
- movq %rcx, efi64_config(%rip) /* Handle */
- movq %rdx, efi64_config+8(%rip) /* EFI System table pointer */
-
- leaq efi64_config(%rip), %rax
- movq %rax, efi_config(%rip)
-
- call 1f
-1: popq %rbp
- subq $1b, %rbp
-
- /*
- * Relocate efi_config->call().
- */
- addq %rbp, efi64_config+40(%rip)
-
- movq %rax, %rdi
- call make_boot_params
- cmpq $0,%rax
- je fail
- mov %rax, %rsi
- leaq startup_32(%rip), %rax
- movl %eax, BP_code32_start(%rsi)
- jmp 2f /* Skip the relocation */
-
-handover_entry:
- call 1f
-1: popq %rbp
- subq $1b, %rbp
-
- /*
- * Relocate efi_config->call().
- */
- movq efi_config(%rip), %rax
- addq %rbp, 40(%rax)
-2:
- movq efi_config(%rip), %rdi
- call efi_main
- movq %rax,%rsi
- cmpq $0,%rax
- jne 2f
-fail:
- /* EFI init failed, so hang. */
- hlt
- jmp fail
-2:
- movl BP_code32_start(%esi), %eax
- leaq preferred_addr(%rax), %rax
- jmp *%rax
-
-preferred_addr:
-#endif
/* Setup data segments. */
xorl %eax, %eax
@@ -413,6 +354,59 @@ lvl5:
jmp *%rax
#ifdef CONFIG_EFI_STUB
+
+/* The entry point for the PE/COFF executable is efi_pe_entry. */
+ENTRY(efi_pe_entry)
+ movq %rcx, efi64_config(%rip) /* Handle */
+ movq %rdx, efi64_config+8(%rip) /* EFI System table pointer */
+
+ leaq efi64_config(%rip), %rax
+ movq %rax, efi_config(%rip)
+
+ call 1f
+1: popq %rbp
+ subq $1b, %rbp
+
+ /*
+ * Relocate efi_config->call().
+ */
+ addq %rbp, efi64_config+40(%rip)
+
+ movq %rax, %rdi
+ call make_boot_params
+ cmpq $0,%rax
+ je fail
+ mov %rax, %rsi
+ leaq startup_32(%rip), %rax
+ movl %eax, BP_code32_start(%rsi)
+ jmp 2f /* Skip the relocation */
+
+handover_entry:
+ call 1f
+1: popq %rbp
+ subq $1b, %rbp
+
+ /*
+ * Relocate efi_config->call().
+ */
+ movq efi_config(%rip), %rax
+ addq %rbp, 40(%rax)
+2:
+ movq efi_config(%rip), %rdi
+ call efi_main
+ movq %rax,%rsi
+ cmpq $0,%rax
+ jne 2f
+fail:
+ /* EFI init failed, so hang. */
+ hlt
+ jmp fail
+2:
+ movl BP_code32_start(%esi), %eax
+ leaq startup_64(%rax), %rax
+ jmp *%rax
+ENDPROC(efi_pe_entry)
+
.org 0x390
ENTRY(efi64_stub_entry)
movq %rdi, efi64_config(%rip) /* Handle */
--
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