From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 13 Jun 2021 21:35:31 +0000 (+0300)
Subject: rudimentary console
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=3sys;a=commitdiff_plain;h=f28bc61c31cc95d9a0496a6f40a2fcdfd79f782d

rudimentary console
---

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;
+}
diff --git a/sys1/kern/src/con.h b/sys1/kern/src/con.h
index 9eb776a..5beb167 100644
--- a/sys1/kern/src/con.h
+++ b/sys1/kern/src/con.h
@@ -1,8 +1,13 @@
 #ifndef CON_H_
 #define CON_H_
 
+#include "vga.h"
+
 void con_init(void);
 
+void con_reset(void);
+#define con_color(fg, bg)	vga_setcolor(fg, bg)
+
 void con_putchar(int c);
 
 #endif	/* CON_H_ */
diff --git a/sys1/kern/src/libc/stdio.c b/sys1/kern/src/libc/stdio.c
index 2035cf8..3c2d61e 100644
--- a/sys1/kern/src/libc/stdio.c
+++ b/sys1/kern/src/libc/stdio.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <ctype.h>
+#include "con.h"
 
 enum {
 	OUT_DEF,
@@ -13,7 +14,7 @@ static void bwrite(int out, char *buf, size_t buf_sz, char *str, int sz);
 
 int putchar(int c)
 {
-	/*con_putchar(c);*/
+	con_putchar(c);
 	return c;
 }
 
diff --git a/sys1/kern/src/main.c b/sys1/kern/src/main.c
index 1a84caf..e45e929 100644
--- a/sys1/kern/src/main.c
+++ b/sys1/kern/src/main.c
@@ -1,47 +1,29 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdint.h>
+#include "con.h"
 #include "vga.h"
 #include "mem.h"
 #include "intr.h"
 
-void drawtext(int x, int y, const char *s)
-{
-	while(*s) {
-		vga_drawchar(x++, y, *s++);
-	}
-}
-
 void kmain(void)
 {
-	int i, row;
-	int line, scroll;
-	char buf[64];
-	char twirl[] = "-\\|/";
+	int i, line;
 
-	vga_reset();
+	con_init();
 
 	mem_init();
 	intr_init();
 
 	line = 0;
 	for(;;) {
-		scroll = line <= 24 ? 0 : line - 24;
-		row = line <= 24 ? line : 24;
-		sprintf(buf, "line %d  (scroll %d [%d])", line, scroll, scroll % 25);
-		vga_scroll(scroll);
-		if(scroll) {
-			vga_clearline(24);
-		}
-		vga_setcolor(VGA_YELLOW | VGA_BRIGHT, VGA_BLACK);
-		drawtext(line & 7, row, buf);
+		printf("line %d", line++);
 
-		for(i=0; i<65536 * 16; i++) {
-			buf[0] = twirl[(i >> 15) & 3];
-			buf[1] = 0;
-			vga_setcolor(VGA_WHITE, VGA_BLACK);
-			drawtext(50, row, buf);
+		for(i=0; i<65536 * 128; i++) {
+			if((i & 0x3ffff) == 0) {
+				con_putchar('.');
+			}
 		}
-		line++;
+		con_putchar('\n');
 	}
 }