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/*
* Copyright (C) 2014 Intel Corporation; author Matt Fleming
*/
#include <linux/linkage.h>
#include <asm/page_types.h>
.text
.code64
ENTRY(efi64_thunk)
push %rbp
push %rbx
/*
* Switch to 1:1 mapped 32-bit stack pointer.
*/
movq %rsp, efi_saved_sp(%rip)
movq efi_scratch+25(%rip), %rsp
/*
* Calculate the physical address of the kernel text.
*/
movq $__START_KERNEL_map, %rax
subq phys_base(%rip), %rax
/*
* Push some physical addresses onto the stack. This is easier
* to do now in a code64 section while the assembler can address
* 64-bit values. Note that all the addresses on the stack are
* 32-bit.
*/
subq $16, %rsp
leaq efi_exit32(%rip), %rbx
subq %rax, %rbx
movl %ebx, 8(%rsp)
leaq efi_gdt64(%rip), %rbx
subq %rax, %rbx
movl %ebx, 2(%ebx)
movl %ebx, 4(%rsp)
leaq efi_gdt32(%rip), %rbx
subq %rax, %rbx
movl %ebx, 2(%ebx)
movl %ebx, (%rsp)
leaq __efi64_thunk(%rip), %rbx
subq %rax, %rbx
call *%rbx
movq efi_saved_sp(%rip), %rsp
pop %rbx
pop %rbp
retq
ENDPROC(efi64_thunk)
.data
efi_gdt32:
.word efi_gdt32_end - efi_gdt32
.long 0 /* Filled out above */
.word 0
.quad 0x0000000000000000 /* NULL descriptor */
.quad 0x00cf9a000000ffff /* __KERNEL_CS */
.quad 0x00cf93000000ffff /* __KERNEL_DS */
efi_gdt32_end:
efi_saved_sp: .quad 0
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