150 lines
2.3 KiB
NASM
Executable File
150 lines
2.3 KiB
NASM
Executable File
; SI = pointer to start of string to be printed
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os_print_string:
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pusha
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mov ah, 0Eh ; int 10h teletype function, we're telling the BIOS we will print something
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.repeat:
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lodsb ; Get char from si into al
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cmp al, 0 ; Compare al to 0
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je .done ; If char is zero, end of string
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int 10h ; Otherwise, print it
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jmp .repeat ; And move on to next char
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.done:
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popa
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ret
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; Exact same as the above procedure, but this adds a newline
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; after priting, similar to the difference between Rust's print! and println!
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os_print_string_nl:
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pusha
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mov ah, 0Eh ; int 10h teletype function, we're telling the BIOS we will print something
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.repeat:
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lodsb ; Get char from si into al
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cmp al, 0 ; Compare al to 0
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je .done ; If char is zero, end of string
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int 10h ; Otherwise, print it
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jmp .repeat ; And move on to next char
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.done:
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call os_print_newline
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popa
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ret
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; --------------------------------------------
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os_print_newline:
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pusha
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mov ah, 0Eh
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mov al, 13
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int 10h
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mov al, 10
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int 10h
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popa
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ret
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; -------------------------------------------
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os_set_text_mode:
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pusha
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; Set mode = 80x25 (text mode)
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mov ah, 00h
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mov al, 03h
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int 10h
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; Move cursor to the top left
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mov ah, 02h
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mov dh, 0
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mov dl, 0
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int 10h
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popa
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ret
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; -------------------------------------------
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; AX = key pressed
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os_read_input:
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mov ah, 11h ; BIOS call to check for key
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int 16h ; Interrupt
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jnz .key_pressed ; Jump if input isn't 0
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hlt
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jmp os_read_input
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.key_pressed:
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mov ah, 10h
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int 16h
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ret
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; -------------------------------------------
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os_display_input:
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pusha
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mov cx, [prompt_length]
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.loop:
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call .check_key_pressed
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jmp .loop
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.check_key_pressed:
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call os_read_input
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cmp al, 08h
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je .backspace
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cmp al, 0Dh
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je .enter_key
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cmp al, 1Bh
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je .esc_key
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cmp cx, 0
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jb .check_key_pressed
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call .print_current_input
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dec cx
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jmp .check_key_pressed
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.esc_key:
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call os_reboot
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.enter_key:
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mov al, 0
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stosb
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popa
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call os_read_cli
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.backspace:
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call .move_cursor_back ; then .move_cursor_back
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call .loop ; Else .loop
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.move_cursor_back:
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mov ah, 0Eh
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mov al, 08h
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int 10h
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mov al, 20h
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int 10h
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mov al, 08h
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int 10h
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dec di
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jmp os_display_input
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.print_current_input:
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stosb
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mov ah, 0Eh
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int 10h
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ret
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