kernel: add basic console registration system and printk()

2023-02-04 19:03:45 +00:00
parent d0a431c860
commit 31cb7aab8b
11 changed files with 186 additions and 31 deletions
--- a/arch/x86_64/vgacon.c
+++ b/arch/x86_64/vgacon.c
@@ -0,0 +1,124 @@
+#include <socks/libc/string.h>
+#include <socks/libc/ctype.h>
+#include <socks/machine/ports.h>
+#include <socks/console.h>
+#include <socks/printk.h>
+#include <stdint.h>
+
+#define VGA_PORT_CMD		0x3D4
+#define VGA_PORT_DATA		0x3D5
+
+#define VGA_CHAR(ch, attrib)	((uint16_t)(ch) | ((uint16_t)(attrib) << 8))
+#define DEFAULT_ATTRIB		0x07
+
+static uint16_t *g_console_fb = (uint16_t *)0xb8000;
+static const unsigned int k_console_width = 80;
+static const unsigned int k_console_height = 25;
+static unsigned int g_console_cursor_xpos = 0;
+static unsigned int g_console_cursor_ypos = 0;
+
+static void init_vga_cursor(void)
+{
+	unsigned int start = 0, end = 15;
+	outportb(VGA_PORT_CMD, 0x0A);
+	outportb(VGA_PORT_DATA, (inportb(VGA_PORT_DATA) & 0xC0) | start);
+
+	outportb(VGA_PORT_CMD, 0x0B);
+	outportb(VGA_PORT_DATA, (inportb(VGA_PORT_DATA) & 0xE0) | end);
+}
+
+static void move_vga_cursor(unsigned int x, unsigned int y)
+{
+	unsigned int offset = y * k_console_width + x;
+
+	outportb(VGA_PORT_CMD, 0x0F);
+	outportb(VGA_PORT_DATA, (uint8_t)(offset & 0xFF));
+
+	outportb(VGA_PORT_CMD, 0x0E);
+	outportb(VGA_PORT_DATA, (uint8_t)((offset >> 8) & 0xFF));
+}
+
+static void scroll_display()
+{
+	uint16_t *src = g_console_fb + k_console_width;
+	uint16_t *dst = g_console_fb;
+	size_t n = k_console_width * (k_console_height - 1) * 2;
+
+	memmove(dst, src, n);
+
+	dst = g_console_fb + ((k_console_height - 1) * k_console_width);
+
+	for (int i = 0; i < k_console_width; i++) {
+		dst[i] = VGA_CHAR(0, DEFAULT_ATTRIB);
+	}
+}
+
+static void handle_ctrl(int c)
+{
+	switch (c) {
+	case '\n':
+		g_console_cursor_xpos = 0;
+		g_console_cursor_ypos++;
+
+		if (g_console_cursor_ypos >= k_console_height) {
+			scroll_display();
+			g_console_cursor_ypos = k_console_height - 1;
+		}
+		break;
+	default:
+		break;
+	}
+
+	move_vga_cursor(g_console_cursor_xpos, g_console_cursor_ypos);
+}
+
+static void vgacon_putchar(int c)
+{
+	if (iscntrl(c)) {
+		handle_ctrl(c);
+		return;
+	}
+
+	g_console_fb[(g_console_cursor_ypos * k_console_width) + g_console_cursor_xpos] = VGA_CHAR(c, DEFAULT_ATTRIB);
+
+	g_console_cursor_xpos++;
+
+	if (g_console_cursor_xpos >= k_console_width) {
+		g_console_cursor_xpos = 0;
+		g_console_cursor_ypos++;
+	}
+
+	if (g_console_cursor_ypos >= k_console_height) {
+		scroll_display();
+		g_console_cursor_ypos = k_console_height - 1;
+		g_console_cursor_xpos = 0;
+	}
+
+	move_vga_cursor(g_console_cursor_xpos, g_console_cursor_ypos);
+}
+
+static void vgacon_write(console_t *con, const char *s, unsigned int len)
+{
+	for (unsigned int i = 0; i < len; i++) {
+		vgacon_putchar(s[i]);
+	}
+}
+
+static console_t vgacon = {
+	.c_name = "vgacon",
+	.c_flags = CON_BOOT,
+	.c_write = vgacon_write,
+	.c_lock = SPIN_LOCK_INIT,
+};
+
+void vgacon_init(void)
+{
+	g_console_cursor_xpos = 0;
+	g_console_cursor_ypos = 5;
+
+	init_vga_cursor();
+	move_vga_cursor(g_console_cursor_xpos, g_console_cursor_ypos);
+
+	console_register(&vgacon);
+	early_printk_init(&vgacon);
+}