46 lines
1.7 KiB
ArmAsm
46 lines
1.7 KiB
ArmAsm
;; Hello World Program #2
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;; Compile with: nasm -f elf64 hello.s
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;; Link with: ld -m elf_x86_64 -o hello hello.o
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;; Run with: ./hello
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;; The following includes are derived from:
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;; sys/unistd_64.h
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%define SYS_write 1
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%define SYS_exit 60
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;; The following includes are derived from:
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;; unistd.h
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%define STDOUT 1
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;;; 'global' is the directive that tells the NASM the address of the
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;;; first instruction to run.
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global _start
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section .data
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msg db "Hello You Beautiful Human", 0Ah
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len equ $-msg ; The $ is a NASM helper that means
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; "The address of the current
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; instruction. 'equ' is a NASM
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; macro that performs the math and
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; places in the 'len' constant the
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; difference between the start of the
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; current instruction and the 'msg'.
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section .text
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_start:
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mov rdx, len ; Mov the address of 'len' to register RDX
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mov rsi, msg ; Mov the address of the message to RSI (Source Index)
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mov rdi, STDOUT ; using STDOUT (see definition above)
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mov rax, SYS_write ; Access WRITE in 64-bit linux
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syscall ; Call the kernel to run the WRITE command.
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;; Note that it's always register AX that we use to tell the kernel
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;; what we want it to do. Depending on the kernel instruction, other
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;; registers may be used to fill out the command.
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mov rdi, 0 ; Mov '0' to be our exit code
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mov rax, SYS_exit ; Access the exit command
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syscall ; Call the kernel to run the EXIT command.
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