153 lines
2.7 KiB
NASM
Executable File
153 lines
2.7 KiB
NASM
Executable File
; ==================================================================
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; MikeOS -- The Mike Operating System kernel
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; Copyright (C) 2006 - 2021 MikeOS Developers -- see doc/LICENSE.TXT
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;
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; SCREEN HANDLING SYSTEM CALLS
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; ==================================================================
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; ------------------------------------------------------------------
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; os_print_string -- Displays text
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; IN: SI = message location (zero-terminated string)
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; OUT: Nothing (registers preserved)
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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: 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, 03h
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int 10h
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mov ah, 02h
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add dh, 1
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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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os_clear_screen:
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pusha
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mov ah, 00h
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mov al, 03h ; Set video mode to textmode (80x25). 16 colors, 8 pages
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int 10h
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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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call .check_key_pressed
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jmp os_display_input
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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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call .print_current_input
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ret
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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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mov di, user_input
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call os_read_cli
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.backspace:
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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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