131 lines
1.8 KiB
ArmAsm
131 lines
1.8 KiB
ArmAsm
.intel_syntax noprefix
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.data
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error_msg_closefd: .ascii "Cannot close STD IO!\n\0"
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error_msg_openfd_noexist: .ascii "The file does not exist or can't be opened!\n\0"
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code_max_size: .quad 65536
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max_size: .quad 16384
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.text
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# ===================
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# Memory Allocs
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# ===================
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# rdi = address
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# rsi = size
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clear_heap_block:
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xor rcx, rcx
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clear_heap_block_loop:
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mov byte ptr [rdi+rcx], 0
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inc rcx
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cmp rcx, rsi
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jl clear_heap_block_loop
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ret
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# rdi = size in octets
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brk_alloc:
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push rbx
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push r12
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mov rbx, rdi
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mov rax, 12
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xor rdi, rdi
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syscall
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mov rdi, rax # To push brk
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add rdi, rbx
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mov r12, rax # To return
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# Pushed
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mov rax, 12
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syscall
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mov rax, r12
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# Gotta return
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pop r12
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pop rbx
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ret
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# ===================
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# File I/O
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# ===================
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# rdi = FD
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# rsi = char*
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# rdx = size
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read:
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push r11 # read uses r11
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xor rax, rax
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syscall
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pop r11
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ret
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# rdi = FD
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# rsi = char*
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write:
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push r15
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mov r15, rdi
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mov rdi, rsi # no need to touch rsi
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call count
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mov rdx, rax # Lenght
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mov rax, 1
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mov rdi, r15
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syscall
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pop r15
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ret
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# rdi = String to count
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count:
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mov rax, rdi
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count_loop:
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mov r8b, [rax]
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inc rax
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cmp r8b, 0
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jnz count_loop
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dec rax
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sub rax, rdi
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ret
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# ===================
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# File Handling
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# ===================
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# rdi = Path
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open_fd:
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mov rax, 2
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xor rsi, rsi # RO
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mov rdx, 644
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syscall
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cmp rax, 0
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jl error_out_open
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ret
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# rdi = FD
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close_fd:
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cmp rdi, 0
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je error_out_close
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mov rax, 3
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syscall
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ret
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# ===================
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# Exit & Errors
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# ===================
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# rdi = Exit code
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exit:
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mov rax, 60
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syscall
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error_out_close:
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mov rdi, 1
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mov rsi, offset error_msg_closefd
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call write
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call exit
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error_out_open:
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mov rdi, 1
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mov rsi, offset error_msg_openfd_noexist
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call write
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call exit
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