nuclear@0: #include <string.h>
nuclear@0: #include "vid.h"
nuclear@35: #include "intr.h"
nuclear@2: #include "asmops.h"
nuclear@2: 
nuclear@2: /* height of our virtual console text buffer */
nuclear@12: #define VIRT_HEIGHT	200
nuclear@2: 
nuclear@2: /* CRTC ports */
nuclear@2: #define CRTC_ADDR	0x3d4
nuclear@2: #define CRTC_DATA	0x3d5
nuclear@2: 
nuclear@2: /* CRTC registers */
nuclear@2: #define CRTC_START_HIGH		0xc
nuclear@2: #define CRTC_START_LOW		0xd
nuclear@2: #define CRTC_CURSOR_HIGH	0xe
nuclear@2: #define CRTC_CURSOR_LOW		0xf
nuclear@2: 
nuclear@2: /* construct a character with its attributes */
nuclear@2: #define VMEM_CHAR(c, fg, bg) \
nuclear@2: 	((uint16_t)(c) | (((uint16_t)(fg) & 0xf) << 8) | (((uint16_t)(bg) & 0xf) << 12))
nuclear@2: 
nuclear@2: static void set_start_line(int line);
nuclear@0: 
nuclear@0: static uint16_t *vmem = (uint16_t*)0xb8000;
nuclear@2: static int start_line;
nuclear@0: 
nuclear@2: 
nuclear@2: void clear_scr(void)
nuclear@0: {
nuclear@35: 	int istate = get_intr_state();
nuclear@35: 	disable_intr();
nuclear@35: 
nuclear@2: 	memset16(vmem, VMEM_CHAR(' ', LTGRAY, BLACK), WIDTH * HEIGHT);
nuclear@2: 	start_line = 0;
nuclear@2: 	set_start_line(0);
nuclear@2: 	set_cursor(0, 0);
nuclear@35: 
nuclear@35: 	set_intr_state(istate);
nuclear@0: }
nuclear@0: 
nuclear@1: void set_char(char c, int x, int y, int fg, int bg)
nuclear@0: {
nuclear@2: 	vmem[(y + start_line) * WIDTH + x] = VMEM_CHAR(c, fg, bg);
nuclear@2: }
nuclear@2: 
nuclear@2: void set_cursor(int x, int y)
nuclear@2: {
nuclear@2: 	int loc;
nuclear@35: 	int istate = get_intr_state();
nuclear@35: 	disable_intr();
nuclear@2: 
nuclear@2: 	if(x < 0 || x >= WIDTH || y < 0 || y >= HEIGHT) {
nuclear@2: 		loc = 0xffff;
nuclear@2: 	} else {
nuclear@2: 		loc = (y + start_line) * WIDTH + x;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	outb(CRTC_CURSOR_LOW, CRTC_ADDR);
nuclear@2: 	outb(loc, CRTC_DATA);
nuclear@2: 	outb(CRTC_CURSOR_HIGH, CRTC_ADDR);
nuclear@2: 	outb(loc >> 8, CRTC_DATA);
nuclear@35: 
nuclear@35: 	set_intr_state(istate);
nuclear@0: }
nuclear@0: 
nuclear@1: void scroll_scr(void)
nuclear@0: {
nuclear@35: 	int new_line, istate = get_intr_state();
nuclear@35: 	disable_intr();
nuclear@35: 
nuclear@2: 	if(++start_line > VIRT_HEIGHT - HEIGHT) {
nuclear@2: 		/* The bottom of the visible range reached the end of our text buffer.
nuclear@2: 		 * Copy the rest of the lines to the top and reset start_line.
nuclear@2: 		 */
nuclear@12: 		memcpy(vmem, vmem + start_line * WIDTH, (HEIGHT - 1) * WIDTH * 2);
nuclear@2: 		start_line = 0;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	/* clear the next line that will be revealed by scrolling */
nuclear@35: 	new_line = start_line + HEIGHT - 1;
nuclear@2: 	memset16(vmem + new_line * WIDTH, VMEM_CHAR(' ', LTGRAY, BLACK), WIDTH);
nuclear@35: 	set_start_line(start_line);
nuclear@2: 
nuclear@35: 	set_intr_state(istate);
nuclear@0: }
nuclear@2: 
nuclear@2: static void set_start_line(int line)
nuclear@2: {
nuclear@2: 	int start_addr = line * WIDTH;
nuclear@2: 
nuclear@2: 	outb(CRTC_START_LOW, CRTC_ADDR);
nuclear@2: 	outb(start_addr & 0xff, CRTC_DATA);
nuclear@2: 	outb(CRTC_START_HIGH, CRTC_ADDR);
nuclear@2: 	outb((start_addr >> 8) & 0xff, CRTC_DATA);
nuclear@2: }