1 files changed, 72 insertions, 5 deletions

diff --git a/src/kernel/vga.c b/src/kernel/vga.c
index d0170c0..8e438a8 100644
--- a/src/kernel/vga.c
+++ b/src/kernel/vga.c
@@ -1,14 +1,81 @@
 #include <stdint.h>
+#include <stdbool.h>
 
+#define VGA_COLUMNS 80
+#define VGA_LINES 25
 #define VGA_START (uint16_t *)0x000b8000
-#define VGA_END (VGA_START + 80 * 25)
+#define VGA_END (VGA_START + VGA_COLUMNS * VGA_LINES)
 uint16_t *cursor = VGA_START;
 uint16_t color = 0x1f00;
 
+void vga_scroll() {
+  cursor = VGA_START;
+}
+
+void vga_blank() {
+  uint32_t f = (color << 16) | color | 0x00200020;
+  uint32_t *p = (uint32_t *)VGA_START;
+  while (p < (uint32_t *)VGA_END)
+    *(p++) = f;
+  cursor = VGA_START;
+}
+
+void vga_printch(uint8_t ch) {
+  if (ch == '\n') {
+    if ((cursor = cursor - (cursor - VGA_START) % VGA_COLUMNS + VGA_COLUMNS) == VGA_END)
+      vga_scroll();
+    return;
+  }
+  *(cursor++) = color | ch;
+  if (cursor == VGA_END)
+    vga_scroll();
+}
+
 void vga_printsz(uint8_t *sz) {
-  while (*sz) {
-    *(cursor++) = color | *(sz++);
-    if (cursor == VGA_END)
-      cursor = VGA_START;
+  while (*sz)
+    vga_printch(*(sz++));
+}
+
+void vga_printsn(uint8_t *sn, uint8_t n) {
+  while (n--)
+    vga_printch(*(sn++));
+}
+
+void vga_printu32(uint32_t n) {
+  bool zero = false;
+  for (uint32_t m = 1000000000; m; m /= 10) {
+    uint8_t d = (n / m) % 10;
+    if (zero)
+      vga_printch(d + '0');
+    else if (d) {
+      zero = true;
+      vga_printch(d + '0');
+    }
+  }
+}
+
+void vga_printu16(uint16_t n) {
+  bool zero = false;
+  for (uint16_t m = 10000; m; m /= 10) {
+    uint8_t d = (n / m) % 10;
+    if (zero)
+      vga_printch(d + '0');
+    else if (d) {
+      zero = true;
+      vga_printch(d + '0');
+    }
+  }
+}
+
+void vga_printu8(uint8_t n) {
+  bool zero = false;
+  for (uint8_t m = 100; m; m /= 10) {
+    uint8_t d = (n / m) % 10;
+    if (zero)
+      vga_printch(d + '0');
+    else if (d) {
+      zero = true;
+      vga_printch(d + '0');
+    }
   }
 }
\ No newline at end of file