aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/boot/compressed/efi_thunk_64.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/boot/compressed/efi_thunk_64.S')
-rw-r--r--arch/x86/boot/compressed/efi_thunk_64.S65
1 files changed, 17 insertions, 48 deletions
diff --git a/arch/x86/boot/compressed/efi_thunk_64.S b/arch/x86/boot/compressed/efi_thunk_64.S
index 593913692d16..8fb7f6799c52 100644
--- a/arch/x86/boot/compressed/efi_thunk_64.S
+++ b/arch/x86/boot/compressed/efi_thunk_64.S
@@ -10,7 +10,7 @@
* needs to be able to service interrupts.
*
* On the plus side, we don't have to worry about mangling 64-bit
- * addresses into 32-bits because we're executing with an identify
+ * addresses into 32-bits because we're executing with an identity
* mapped pagetable and haven't transitioned to 64-bit virtual addresses
* yet.
*/
@@ -23,16 +23,13 @@
.code64
.text
-SYM_FUNC_START(efi64_thunk)
+SYM_FUNC_START(__efi64_thunk)
push %rbp
push %rbx
- subq $8, %rsp
- leaq efi_exit32(%rip), %rax
- movl %eax, 4(%rsp)
- leaq efi_gdt64(%rip), %rax
- movl %eax, (%rsp)
- movl %eax, 2(%rax) /* Fixup the gdt base address */
+ leaq 1f(%rip), %rbp
+ leaq efi_gdt64(%rip), %rbx
+ movl %ebx, 2(%rbx) /* Fixup the gdt base address */
movl %ds, %eax
push %rax
@@ -48,15 +45,10 @@ SYM_FUNC_START(efi64_thunk)
movl %esi, 0x0(%rsp)
movl %edx, 0x4(%rsp)
movl %ecx, 0x8(%rsp)
- movq %r8, %rsi
- movl %esi, 0xc(%rsp)
- movq %r9, %rsi
- movl %esi, 0x10(%rsp)
+ movl %r8d, 0xc(%rsp)
+ movl %r9d, 0x10(%rsp)
- sgdt save_gdt(%rip)
-
- leaq 1f(%rip), %rbx
- movq %rbx, func_rt_ptr(%rip)
+ sgdt 0x14(%rsp)
/*
* Switch to gdt with 32-bit segments. This is the firmware GDT
@@ -71,9 +63,9 @@ SYM_FUNC_START(efi64_thunk)
pushq %rax
lretq
-1: addq $32, %rsp
-
- lgdt save_gdt(%rip)
+1: lgdt 0x14(%rsp)
+ addq $32, %rsp
+ movq %rdi, %rax
pop %rbx
movl %ebx, %ss
@@ -85,26 +77,13 @@ SYM_FUNC_START(efi64_thunk)
/*
* Convert 32-bit status code into 64-bit.
*/
- test %rax, %rax
- jz 1f
- movl %eax, %ecx
- andl $0x0fffffff, %ecx
- andl $0xf0000000, %eax
- shl $32, %rax
- or %rcx, %rax
-1:
- addq $8, %rsp
+ roll $1, %eax
+ rorq $1, %rax
+
pop %rbx
pop %rbp
ret
-SYM_FUNC_END(efi64_thunk)
-
-SYM_FUNC_START_LOCAL(efi_exit32)
- movq func_rt_ptr(%rip), %rax
- push %rax
- mov %rdi, %rax
- ret
-SYM_FUNC_END(efi_exit32)
+SYM_FUNC_END(__efi64_thunk)
.code32
/*
@@ -144,9 +123,7 @@ SYM_FUNC_START_LOCAL(efi_enter32)
*/
cli
- movl 56(%esp), %eax
- movl %eax, 2(%eax)
- lgdtl (%eax)
+ lgdtl (%ebx)
movl %cr4, %eax
btsl $(X86_CR4_PAE_BIT), %eax
@@ -163,9 +140,8 @@ SYM_FUNC_START_LOCAL(efi_enter32)
xorl %eax, %eax
lldt %ax
- movl 60(%esp), %eax
pushl $__KERNEL_CS
- pushl %eax
+ pushl %ebp
/* Enable paging */
movl %cr0, %eax
@@ -181,13 +157,6 @@ SYM_DATA_START(efi32_boot_gdt)
.quad 0
SYM_DATA_END(efi32_boot_gdt)
-SYM_DATA_START_LOCAL(save_gdt)
- .word 0
- .quad 0
-SYM_DATA_END(save_gdt)
-
-SYM_DATA_LOCAL(func_rt_ptr, .quad 0)
-
SYM_DATA_START(efi_gdt64)
.word efi_gdt64_end - efi_gdt64
.long 0 /* Filled out by user */