X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=3sys;a=blobdiff_plain;f=sys1%2Fkern%2Fsrc%2Fcon.c;fp=sys1%2Fkern%2Fsrc%2Fcon.c;h=b1102723aab1d5b3c7ff57b14210a9648a8236ab;hp=0000000000000000000000000000000000000000;hb=f28bc61c31cc95d9a0496a6f40a2fcdfd79f782d;hpb=3029144412cf13580e11bc1dffca8b14e05014d0

diff --git a/sys1/kern/src/con.c b/sys1/kern/src/con.c
new file mode 100644
index 0000000..b110272
--- /dev/null
+++ b/sys1/kern/src/con.c
@@ -0,0 +1,90 @@
+#include <string.h>
+#include "con.h"
+#include "vga.h"
+
+#define NCOLS			80
+#define NROWS			25
+
+/* must be pow2 */
+#define TEXTBUF_SIZE	256
+
+static char textbuf[TEXTBUF_SIZE][NCOLS];
+static int tbuf_first, tbuf_last;
+
+static int curx, cury, scroll;
+
+
+static void newline(void);
+
+
+void con_init(void)
+{
+	con_reset();
+}
+
+void con_reset(void)
+{
+	vga_reset();
+
+	curx = cury = scroll = 0;
+	tbuf_first = tbuf_last = 0;
+	memset(textbuf[0], 0, sizeof textbuf[0]);
+}
+
+void con_putchar(int c)
+{
+	switch(c) {
+	case '\t':
+		curx = (curx + 8) & 0xfffffff8;
+		if(curx >= NCOLS) {
+			newline();
+		}
+		break;
+
+	case '\r':
+		curx = 0;
+		break;
+
+	case '\n':
+		newline();
+		break;
+
+	case '\b':
+		if(curx > 0) {
+			textbuf[tbuf_last][--curx] = 0;
+			vga_drawchar(curx, cury, 0);
+		}
+		break;
+
+	default:
+		textbuf[tbuf_last][curx] = c;
+		vga_drawchar(curx, cury, c);
+		if(++curx >= NCOLS) {
+			newline();
+		}
+		break;
+	}
+
+	if(cury >= NROWS) {
+		cury--;
+		vga_scroll(++scroll);
+		vga_clearline(NROWS - 1);
+	}
+
+	vga_setcursor(curx, cury);
+}
+
+static void newline(void)
+{
+	int num;
+
+	curx = 0;
+	cury++;
+
+	num = (tbuf_last + 1) & (TEXTBUF_SIZE - 1);
+
+	if(tbuf_last == tbuf_first) {
+		tbuf_first = num;
+	}
+	tbuf_last = num;
+}