1991/0724/pc/vga.c (diff list | history)

pc/vga.c on 1991/0723
1991/0723		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" enum { GRX= 0x3CE, /* index to graphics registers */ GR= 0x3CF, /* graphics registers 0-8 */
1991/0724		SRX= 0x3C4, /* index to sequence registers */ SR= 0x3C5, /* sequence registers 0-7 */
1991/0723		};
1991/0724		void srout(int reg, int val) { outb(SRX, reg); outb(SR, val); } void grout(int reg, int val) { outb(GRX, reg); outb(GR, val); }
1991/0723		/* * look at VGA registers */ void vgainit(void) {
1991/0724		uchar *display;
1991/0723		int i;
1991/0724		srout(2, 0x0f); /* enable all 4 color planes */ srout(4, 0x08); /* quad mode */ grout(5, 0x40); /* pixel bits are sequential */ grout(6, 0x01); /* graphics mode - display starts at 0xA0000 */ for(;;); display = (uchar*)(0xA0000 | KZERO); for(i = 0; i < 128*1024; i++) display[i] = 0x00; for(i = 0; i < 4*640; i++) display[i] = 0xff;
1991/0723		}