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bits 64
section .text
org 0x0
_start:
; EFI System Table magic
mov rax, 0x5453595320494249
cmp rax, [rdx]
mov rdi, 0x1
jne fail ; Invalid magic
; mov r8, rax
; add r8, 0x1c
; mov word [rax+0x10], 0xfff
; mov qword [rax+0x12], r8
;
; xor rcx, rcx
;zero:
; mov qword [r8+rcx], 0x0
; add rcx, 0x8
; cmp rcx, 0xfff
; jle zero
;
; lea r8, [rel int]
; mov word [rax+0x1c], r8w ; offset_1
; shr r8, 16
; mov word [rax+0x1e], 0 ; selector
; mov byte [rax+0x20], 0 ; ist
; mov byte [rax+0x21], 0xff ; type_attr
; mov word [rax+0x22], r8w ; offset_2
; shr r8, 16
; mov dword [rax+0x24], r8d ; offset_3
; mov dword [rax+0x28], 0 ; reserved, SBZ
;
; cli
; lidt [rax+16]
; sti
;int 0x0
push rbp
mov rbp, rsp
sub rsp, 0x30
mov rbx, rdx
hello:
mov rcx, qword [rdx+0x40] ; arg0=ConOut
lea rdx, [rel msg] ; arg1=msg
call qword [rcx+0x8] ; OutputString
mov rdi, 0x0 ; EFI_SUCCESS
fail: ; error in rdi
mov rax, rdi
mov rsp, rbp
pop rbp
retn
msg: db __utf16__ 'Hello, World',0xd,0,0xa,0,0,0
; int:
; lea rax, [rel end]
; mov rdx, qword [rax+8]
;
; mov rcx, qword [rdx+0x40] ; arg0=ConOut
; lea rdx, [rel err] ; arg1=err
; call qword [rcx+0x8] ; OutputString
;
; iretq
align 0x20
end:
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