misc: changes from a long time ago

arch/x86_64/vga.c

@@ -0,0 +1,126 @@
+#include <arch/irq.h>
+#include <arch/ports.h>
+#include <arch/serial.h>
+#include <mango/libc/stdio.h>
+#include <mango/machine/vm.h>
+#include <mango/printk.h>
+
+struct vga_console {
+	uint16_t *vga_framebuffer;
+	unsigned int vga_cursor_x, vga_cursor_y;
+	unsigned int vga_screen_width, vga_screen_height;
+	uint8_t vga_attrib;
+};
+
+static struct vga_console vga_con = {
+	.vga_attrib = 0x0F,
+	.vga_screen_width = 80,
+	.vga_screen_height = 25,
+	.vga_framebuffer = (uint16_t *)0xffffffff800b8000,
+};
+
+static void vga_console_clear(struct vga_console *con)
+{
+	size_t len = con->vga_screen_width * con->vga_screen_height;
+
+	for (size_t i = 0; i < len; i++) {
+		con->vga_framebuffer[i] = (uint16_t)con->vga_attrib << 8;
+	}
+
+	con->vga_cursor_x = 0;
+	con->vga_cursor_y = 0;
+}
+
+static void vga_console_show_cursor(struct vga_console *con)
+{
+	size_t start = 0, end = 15;
+
+	outportb(0x3D4, 0x0A);
+	outportb(0x3D5, (inportb(0x3D5) & 0xC0) | start);
+
+	outportb(0x3D4, 0x0B);
+	outportb(0x3D5, (inportb(0x3D5) & 0xE0) | end);
+}
+
+static void vga_console_update_cursor(struct vga_console *con)
+{
+	uint16_t pos
+		= con->vga_cursor_y * con->vga_screen_width + con->vga_cursor_x;
+
+	outportb(0x3D4, 0x0F);
+	outportb(0x3D5, (uint8_t)(pos & 0xFF));
+	outportb(0x3D4, 0x0E);
+	outportb(0x3D5, (uint8_t)((pos >> 8) & 0xFF));
+}
+
+static void vga_console_scroll(struct vga_console *con)
+{
+	uint16_t *src = &con->vga_framebuffer[con->vga_screen_width];
+	uint16_t *dest = &con->vga_framebuffer[0];
+	size_t len = (con->vga_screen_height - 1) * con->vga_screen_width
+	           * sizeof *con->vga_framebuffer;
+
+	memcpy(dest, src, len);
+
+	dest = &con->vga_framebuffer
+	                [(con->vga_screen_height - 1) * con->vga_screen_width];
+	len = con->vga_screen_width;
+	for (size_t i = 0; i < len; i++) {
+		dest[i] = (uint16_t)con->vga_attrib << 8;
+	}
+
+	con->vga_cursor_x = 0;
+	con->vga_cursor_y = con->vga_screen_height - 1;
+}
+
+static void vga_console_putc(struct vga_console *con, char c)
+{
+	switch (c) {
+	case '\n':
+		con->vga_cursor_x = 0;
+		con->vga_cursor_y++;
+		break;
+	case '\r':
+		con->vga_cursor_x = 0;
+		break;
+	default:
+		con->vga_framebuffer
+			[con->vga_cursor_y * con->vga_screen_width
+		         + con->vga_cursor_x]
+			= ((uint16_t)con->vga_attrib << 8) | c;
+		con->vga_cursor_x++;
+		break;
+	}
+
+	if (con->vga_cursor_x >= con->vga_screen_width) {
+		con->vga_cursor_x = 0;
+		con->vga_cursor_y++;
+	}
+
+	if (con->vga_cursor_y >= con->vga_screen_height) {
+		vga_console_scroll(con);
+	}
+}
+
+static void vgacon_write(struct console *con, const char *s, unsigned int len)
+{
+	for (unsigned int i = 0; i < len; i++) {
+		vga_console_putc(&vga_con, s[i]);
+	}
+
+	vga_console_update_cursor(&vga_con);
+}
+
+static struct console vgacon = {
+	.c_name = "vgacon",
+	.c_flags = CON_BOOT,
+	.c_write = vgacon_write,
+	.c_lock = SPIN_LOCK_INIT,
+};
+
+void vgacon_init(void)
+{
+	vga_console_clear(&vga_con);
+	vga_console_show_cursor(&vga_con);
+	console_register(&vgacon);
+}