add hex printing...ish

1 files changed, 33 insertions, 2 deletions

diff --git a/src/kernel/main.c b/src/kernel/main.c
index ec18738..c1c6ab6 100644
--- a/src/kernel/main.c
+++ b/src/kernel/main.c
@@ -5,20 +5,44 @@ void vga_graphics_write(char);
 void vga_graphics_write_with_attr(char, char);
 void vga_graphics_write_str(char*);
 
+void vga_graphics_byte_hex(char);
+//void vga_graphics_short_hex(short);
+//void vga_graphics_int_hex(int);
+//void vga_graphics_long_hex(long);
+
+void clear();
+
 static short CURSOR_LOC = 0;
+static char* HEX_CHARS = "0123456789abcdef";
+char foo[] = "hello how are you";
 
 void _start() {
+  clear();
   vga_graphics_write_with_attr('a', 1);
   vga_graphics_write_with_attr('/', 2);
   vga_graphics_write_with_attr('b', 3);
-  char foo[] = "hello how are you";
   vga_graphics_write_str(foo);
+  vga_graphics_write(':');
+  vga_graphics_write(' ');
+  vga_graphics_byte_hex(0x40);
   while(1) { }
 }
 
+void clear() {
+  int TERM_WIDTH = 80;
+  int TERM_HEIGHT = 25;
+
+  int i = 0;
+  while(i < TERM_WIDTH * TERM_HEIGHT) {
+    vga_graphics_write_with_attr(' ', 7);
+    i++;
+  }
+  CURSOR_LOC = 0;
+}
+
 void vga_graphics_write_str(char* str) {
   while(*str) {
-    vga_graphics_write(*str++);
+    vga_graphics_write_with_attr(*str++, 7);
   }
 }
 
@@ -32,6 +56,13 @@ void vga_graphics_write(char value) {
   CURSOR_LOC += 2;
 }
 
+void vga_graphics_byte_hex(char value) {
+  char low = value & 0x0f;
+  char high = (value & 0xf0) >> 4;
+  vga_graphics_write(HEX_CHARS[high]);
+  vga_graphics_write(HEX_CHARS[low]);
+}
+
 void vga_graphics_write_at_offset(char value, short offset) {
   __asm__(
     "mov %0, %%al          \n"