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