Meta: Move kernel and userland to their own folders.

This is to allow both the kernel and the userland to share certain
header files and to make the folder structure a bit more clear.

1 files changed, 97 insertions, 0 deletions

diff --git a/kernel/libc/stdio/print.c b/kernel/libc/stdio/print.c
new file mode 100644
index 0000000..8174983
--- /dev/null
+++ b/kernel/libc/stdio/print.c
@@ -0,0 +1,97 @@
+#include "../../drivers/serial.h"
+#include "../include/assert.h"
+#include "../include/stdio.h"
+#include <stdarg.h>
+
+#define TAB_SIZE 8
+
+const char HEX_SET[0x10] = {'0', '1', '2', '3', '4', '5', '6', '7',
+                            '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+
+inline void putc(const char c) { write_serial(c); }
+
+int kprint_hex(uint64_t num) {
+  int c = 2;
+
+  if (num == 0) {
+    putc('0');
+    c++;
+    return c;
+  }
+
+  char str[16] = {0};
+  int i = 0;
+  for (; num != 0 && i < 16; i++, num /= 16)
+    str[i] = HEX_SET[(num % 16)];
+
+  c += i;
+  for (i--; i >= 0; i--)
+    putc(str[i]);
+
+  return c;
+}
+
+int kprint_int(int num) {
+  int c = 0;
+  if (0 == num) {
+    putc('0');
+    c++;
+    return c;
+  }
+  char str[10];
+  int i = 0;
+  for (; num != 0 && i < 10; i++, num /= 10)
+    str[i] = (num % 10) + '0';
+
+  c += i;
+  for (i--; i >= 0; i--)
+    putc(str[i]);
+  return c;
+}
+
+int kprintf(const char *format, ...) {
+  int c = 0;
+  va_list list;
+  va_start(list, format);
+
+  const char *s = format;
+  for (; *s; s++) {
+    if ('%' != *s) {
+      putc(*s);
+      c++;
+      continue;
+    }
+
+    char flag = *(s + 1);
+    if ('\0' == flag)
+      break;
+
+    switch (flag) {
+    case 'c':
+      putc((char)va_arg(list, int));
+      c++;
+      break;
+    case 'd':
+      c += kprint_int(va_arg(list, int));
+      break;
+    case 's':
+      for (char *string = va_arg(list, char *); *string; putc(*string++), c++)
+        ;
+      break;
+    case 'x':
+      c += kprint_hex(va_arg(list, const uint32_t));
+      break;
+    case '%':
+      putc('%');
+      c++;
+      break;
+    default:
+      ASSERT_NOT_REACHED;
+      break;
+    }
+    s++;
+  }
+  return c;
+}
+
+int puts(char *str) { return kprintf("%s\n", str); }