altos: Add console driver using VGA and PS/2

Provides an interactive text console.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/src/drivers/ao_console.c b/src/drivers/ao_console.c
new file mode 100644
index 00000000..cbde38c9
--- /dev/null
+++ b/src/drivers/ao_console.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright © 2016 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include "ao.h"
+#include "ao_console.h"
+#include "ao_ps2.h"
+#include "ao_vga.h"
+
+static uint8_t	console_row, console_col;
+
+#define ao_console_bitmap	ao_vga_bitmap
+
+static uint8_t	console_rows, console_cols;
+
+static void
+ao_console_scroll(void)
+{
+	ao_copy(&ao_console_bitmap,
+		0, 0,
+		ao_console_bitmap.width,
+		ao_console_bitmap.height - ao_font.height,
+		&ao_console_bitmap,
+		0, ao_font.height,
+		AO_COPY);
+	ao_rect(&ao_console_bitmap,
+		0,
+		(console_rows - 1) * ao_font.height,
+		ao_console_bitmap.width,
+		ao_font.height,
+		1,
+		AO_COPY);
+}
+
+static void
+ao_console_cursor(void)
+{
+	ao_rect(&ao_console_bitmap,
+		console_col * ao_font.width,
+		console_row * ao_font.height,
+		ao_font.width,
+		ao_font.height,
+		1,
+		AO_XOR);
+}
+
+static void
+ao_console_clear(void)
+{
+	ao_rect(&ao_console_bitmap,
+		0, 0,
+		ao_console_bitmap.width,
+		ao_console_bitmap.height,
+		1,
+		AO_COPY);
+}
+
+static void
+ao_console_space(void)
+{
+	ao_rect(&ao_console_bitmap,
+		console_col * ao_font.width,
+		console_row * ao_font.height,
+		ao_font.width,
+		ao_font.height,
+		1,
+		AO_COPY);
+}
+
+static void
+ao_console_newline(void)
+{
+	if (++console_row == console_rows) {
+		ao_console_scroll();
+		console_row--;
+	}
+}
+
+void
+ao_console_putchar(char c)
+{
+	if (' ' <= c && c < 0x7f) {
+		char	text[2];
+		ao_console_space();
+		text[0] = c;
+		text[1] = '\0';
+		ao_text(&ao_console_bitmap,
+			console_col * ao_font.width,
+			console_row * ao_font.height + ao_font.ascent,
+			text,
+			0,
+			AO_COPY);
+		if (++console_col == console_cols) {
+			console_col = 0;
+			ao_console_newline();
+		}
+	} else {
+		ao_console_cursor();
+		switch (c) {
+		case '\r':
+			console_col = 0;
+			break;
+		case '\t':
+			console_col += 8 - (console_col & 7);
+			if (console_col >= console_cols) {
+				console_col = 0;
+				ao_console_newline();
+			}
+			break;
+		case '\n':
+			ao_console_newline();
+			break;
+		case '\f':
+			console_col = console_row = 0;
+			ao_console_clear();
+			break;
+		case '\177':
+		case '\010':
+			if (console_col)
+				console_col--;
+			break;
+		}
+	}
+	ao_console_cursor();
+}
+
+void
+ao_console_init(void)
+{
+	console_cols = ao_console_bitmap.width / ao_font.width;
+	console_rows = ao_console_bitmap.height / ao_font.height;
+#if CONSOLE_STDIN
+	ao_ps2_stdin = 1;
+	ao_add_stdio(_ao_ps2_pollchar,
+		     ao_console_putchar,
+		     NULL);
+#endif
+	ao_console_clear();
+	ao_console_cursor();
+	ao_vga_enable(1);
+}