mirror of https://github.com/k3s-io/k3s
58 lines
1.6 KiB
NASM
58 lines
1.6 KiB
NASM
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; This is heavily based on https://github.com/tianon/dockerfiles/tree/master/true
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; which is in turn especially thanks to:
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; http://blog.markloiseau.com/2012/05/tiny-64-bit-elf-executables/
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BITS 64
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org 0x00400000 ; Program load offset
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; 64-bit ELF header
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ehdr:
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; 1), 0 (ABI ver.)
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db 0x7F, "ELF", 2, 1, 1, 0 ; e_ident
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times 8 db 0 ; reserved (zeroes)
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dw 2 ; e_type: Executable file
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dw 0x3e ; e_machine: AMD64
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dd 1 ; e_version: current version
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dq _start ; e_entry: program entry address (0x78)
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dq phdr - $$ ; e_phoff program header offset (0x40)
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dq 0 ; e_shoff no section headers
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dd 0 ; e_flags no flags
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dw ehdrsize ; e_ehsize: ELF header size (0x40)
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dw phdrsize ; e_phentsize: program header size (0x38)
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dw 1 ; e_phnum: one program header
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dw 0 ; e_shentsize
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dw 0 ; e_shnum
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dw 0 ; e_shstrndx
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ehdrsize equ $ - ehdr
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; 64-bit ELF program header
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phdr:
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dd 1 ; p_type: loadable segment
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dd 5 ; p_flags read and execute
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dq 0 ; p_offset
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dq $$ ; p_vaddr: start of the current section
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dq $$ ; p_paddr: " "
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dq filesize ; p_filesz
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dq filesize ; p_memsz
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dq 0x200000 ; p_align: 2^11=200000 = section alignment
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; program header size
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phdrsize equ $ - phdr
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_start:
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; pause()
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mov al, 34 ; pause syscall number
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syscall
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; sys_exit(return_code)
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mov al, 60 ; sys_exit syscall number
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cdq ; Sign-extend eax into edi to return 0 (success)
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syscall
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; File size calculation
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filesize equ $ - $$
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