#include /* * Text pointer, background, foreground */ unsigned short * textmemptr; int attrib = 0x0F; int csr_x = 0, csr_y = 0, use_serial = 1, use_csr = 1; int old_x = 0, old_y = 0, old_s = 1, old_csr = 1; /* * scroll * Scroll the screen */ void scroll() { unsigned blank, temp; blank = 0x20 | (attrib << 8); if (csr_y >= 25) { /* * Move the current text chunk that makes up the screen * back in the buffer by one line. */ temp = csr_y - 25 + 1; memcpy(textmemptr, textmemptr + temp * 80, (25 - temp) * 80 * 2); /* * Set the chunk of memory that occupies * the last line of text to the blank character */ memsetw(textmemptr + (25 - temp) * 80, blank, 80); csr_y = 25 - 1; } } void set_serial(int on) { use_serial = on; } void set_csr(int on) { use_csr = on; } void store_csr() { old_x = csr_x; old_y = csr_y; old_s = use_serial; old_csr = use_csr; } void restore_csr() { csr_x = old_x; csr_y = old_y; use_serial = old_s; use_csr = old_csr; } /* * move_csr * Update the hardware cursor */ void move_csr() { if (!use_csr) return; unsigned temp; temp = csr_y * 80 + csr_x; /* * Write stuff out. */ outportb(0x3D4, 14); outportb(0x3D5, temp >> 8); outportb(0x3D4, 15); outportb(0x3D5, temp); } /* * place_csr(x, y) */ void place_csr( uint32_t x, uint32_t y ) { csr_x = x; csr_y = y; move_csr(); } /* * cls * Clear the screen */ void cls() { unsigned blank; int i; blank = 0x20 | (attrib << 8); for (i = 0; i < 25; ++i) { memsetw(textmemptr + i * 80, blank, 80); } csr_x = 0; csr_y = 0; move_csr(); } /* * placech * Put a character in a particular cell with the given attributes. */ void placech( unsigned char c, int x, int y, int attr ) { unsigned short *where; unsigned att = attr << 8; where = textmemptr + (y * 80 + x); *where = c | att; } /* * writechf * Force write the given character. */ void writechf( unsigned char c ) { placech(c, csr_x, csr_y, attrib); csr_x++; if (csr_x >= 80) { csr_x = 0; ++csr_y; } scroll(); move_csr(); } /* * writech * Write a character to the screen. */ void writech( unsigned char c ) { unsigned short *where; unsigned att = attrib << 8; if (c == 0x08) { /* Backspace */ if (csr_x != 0) csr_x--; } else if (c == 0x09) { /* Tab */ csr_x = (csr_x + 8) & ~(8 - 1); } else if (c == '\r') { /* Carriage return */ csr_x = 0; } else if (c == '\n') { /* New line */ csr_x = 0; csr_y++; } else if (c >= ' ') { where = textmemptr + (csr_y * 80 + csr_x); *where = c | att; csr_x++; } if (use_serial) { serial_send(c); } if (csr_x >= 80) { csr_x = 0; csr_y++; } scroll(); move_csr(); } /* * puts * Put string to screen */ void puts( char * text ){ int i; int len = strlen(text); for (i = 0; i < len; ++i) { writech(text[i]); } } /* * settextcolor * Sets the foreground and background color */ void settextcolor( unsigned char forecolor, unsigned char backcolor ) { attrib = (backcolor << 4) | (forecolor & 0x0F); } /* * resettextcolor * Reset the text color to white on black */ void resettextcolor() { settextcolor(7,0); } void brighttextcolor() { settextcolor(15,0); } /* * init_video * Initialize the VGA driver. */ void init_video() { textmemptr = (unsigned short *)0xB8000; csr_y = 10; move_csr(); }