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73 lines
1.5 KiB
73 lines
1.5 KiB
// VGA Graphics Library
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#include "../kernel/io.h"
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// VGA base address: 0xb8000
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// Charpos = 0xb8000 + 2(row*80 + col)
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// Memory
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#define VGA_ADDRESS (char*)0xb8000
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#define VGA_ADDRESS_MAX (char*)0xb8fa0
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#define MAX_ROWS 25
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#define MAX_COLS 80
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// Global
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static unsigned int cursor_row = 0;
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static unsigned int cursor_col = 0;
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/*
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VGA & Memory Functions
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*/
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char* get_vga_charpos_pointer(unsigned int col, unsigned int row) {
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return (char*)(VGA_ADDRESS + 2*((row*80) + col));
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}
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void writechar(char c, unsigned int col, unsigned int row, int attribute_byte) {
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if( !attribute_byte )
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attribute_byte = 0x0f;
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char* mem = get_vga_charpos_pointer(col, row);
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*mem = c; // Write the character
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*(mem+1) = attribute_byte; // Write the attribute_byte
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}
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/*
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Graphics Functions
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*/
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void clear_screen() {
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for( int c = 0; c < MAX_COLS; c++ )
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for( int r = 0; r < MAX_ROWS; r++ )
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writechar(0x20, c, r, 0xf0);
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}
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void disable_vga_cursor() {
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port_outb(0x0a, 0x3d4);
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port_outb(0x20, 0x3d5);
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}
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/*
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General Printing Functions
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*/
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void set_cursor_pos(unsigned int x, unsigned int y) {
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cursor_col = x;
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cursor_row = y;
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}
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void print(char* str, int attribute_byte) {
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for( char* c = str; *c != '\0'; c++ )
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writechar(*c, (unsigned int)(c - str) + cursor_col, cursor_row, attribute_byte);
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}
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void println(char* str, int attribute_byte) {
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print(str, attribute_byte);
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cursor_row++; // Increment to next y-pos (newline)
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}
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// VGA Initialization Function
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void vga_init() {
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disable_vga_cursor();
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clear_screen();
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}
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