Refactoring debug terminal

src/kernel/drivers/terminal/vga.c

@@ -0,0 +1,38 @@
+#include <terminal.h>
+#include <memory.h>
+#include <ports.h>
+#include <multiboot.h>
+#include <stddef.h>
+#include <debug.h>
+
+#define VGA_ADDRESS_PORT 0x3D4
+#define VGA_DATA_PORT 0x3D5
+#define VGA_REGISTER_CURSOR_POS_LOW 0xF
+#define VGA_REGISTER_CURSOR_POS_HIGH 0xE
+
+static void *vidmem;
+
+static int setup = 0;
+
+void vga_init(struct fbinfo *fbinfo)
+{
+    (void) fbinfo;
+    vidmem = VGA_MEMORY;
+    memset(vidmem, 0, VGA_SIZE*sizeof(struct vga_cell));
+    setup = 1;
+}
+
+void vga_movecursor(unsigned int cursor)
+{
+    if(!setup) return;
+    outb(VGA_ADDRESS_PORT, VGA_REGISTER_CURSOR_POS_LOW);
+    outb(VGA_DATA_PORT, (uint8_t)(cursor & 0xFF));
+    outb(VGA_ADDRESS_PORT, VGA_REGISTER_CURSOR_POS_HIGH);
+    outb(VGA_DATA_PORT, (uint8_t)((cursor >> 8) & 0xFF));
+}
+
+void vga_flush(struct vga_cell *buffer)
+{
+    if(!setup) return;
+    memcpy(vidmem, buffer, VGA_SIZE*2);
+}