1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/gfx.c b/drivers/gfx.c
new file mode 100644
index 0000000..538dadb
--- /dev/null
+++ b/drivers/gfx.c
@@ -0,0 +1,42 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include "log.h"
+#include "multiboot.h"
+#include "panic.h"
+#include "gfx.h"
+
+static uint8_t *framebuffer = NULL;
+static uint16_t fb_width;
+static uint16_t fb_height;
+/* this is BYTES per pixel */
+static uint8_t  fb_bpp;
+
+const uint16_t *gfx_width = &fb_width;
+const uint16_t *gfx_height = &fb_height;
+
+void gfx_drawpixel(int x, int y, uint32_t col)
+{
+    ((uint32_t*)framebuffer)[y * fb_width + x] = col;
+}
+
+void gfx_clear(uint32_t col)
+{
+    uint8_t *p = framebuffer;
+    uint8_t *stop = framebuffer + fb_width * fb_height * fb_bpp;
+    while(p < stop)
+    {
+        *(uint32_t*)p = col;
+        p += fb_bpp;
+    }
+}
+
+void gfx_init(struct vbe_info_t *vbe_mode_info)
+{
+    framebuffer = (uint8_t*)vbe_mode_info->physbase;
+    fb_width = vbe_mode_info->Xres;
+    fb_height = vbe_mode_info->Yres;
+    fb_bpp = vbe_mode_info->bpp / 8;
+    if(fb_bpp != 4)
+        panic("BPP *MUST* be 32!!!\n");
+    gfx_clear(VGA_RGBPACK(0, 0, 0));
+}