feat: io: serial & console

kernel/include/shitgui.h

@@ -20,11 +20,13 @@ typedef struct {
 } SG_Image;
 
 typedef struct {
-    u32 font_w;
-    u32 font_h;
-} SG_FontMetrics;
+    u32 w;
+    u32 h;
+    const unsigned char* base;
+} SG_Font;
 
 void sg_put_img(SG_Context *ctx, SG_Point *p, SG_Image *img);
 void sg_draw_rect(SG_Context *ctx, SG_Point *p, u32 w, u32 h, u32 color);
+void sg_draw_char_bitmap(SG_Context *ctx, SG_Point *p, char c, u32 color, SG_Font *font);
 
 #endif