initial razzle

kernel/vga.c

@@ -0,0 +1,157 @@
+#pragma once
+
+#include "./spin_lock.c"
+#include <stdarg.h>
+#include <stdint.h>
+
+#define WIDTH 80
+#define HEIGHT 25
+
+static uint8_t col = 0;
+static uint8_t row = 0;
+static uint8_t color_code = 10;
+static char *vram = (char *)0xb8000;
+
+void clear_screen() {
+  for (int i = 0; i < HEIGHT - 1; i++) {
+    for (int j = 0; j < WIDTH; j++) {
+      vram[(i * WIDTH * 2) + (j * 2)] = 0;
+      // vram[(i * WIDTH * 2) + (j*2 + 1)] = 0;
+    }
+  }
+  row = 0;
+  col = 0;
+}
+
+void putc(char c) {
+  if (col == WIDTH) {
+    row = (row + 1) % HEIGHT;
+    col = 0;
+  }
+
+  if (c == '\n') {
+    for (int i = col; i < WIDTH; i++) {
+      vram[(row * WIDTH * 2) + (i * 2)] = ' ';
+      vram[(row * WIDTH * 2) + (i * 2 + 1)] = color_code;
+    }
+    row = (row + 1) % HEIGHT;
+    col = 0;
+    return;
+  }
+
+  if (c == '\b') {
+    col--;
+    vram[(row * WIDTH * 2) + (col * 2)] = ' ';
+    vram[(row * WIDTH * 2) + (col * 2 + 1)] = color_code;
+    return;
+  }
+
+  vram[(row * WIDTH * 2) + (col * 2)] = c;
+  vram[(row * WIDTH * 2) + (col * 2 + 1)] = color_code;
+  col++;
+}
+
+void print_uint(unsigned int x, uint8_t base) {
+  if (x == 0) {
+    if (base)
+      putc('0');
+    return;
+  }
+
+  print_uint(x / 10, 0);
+  putc('0' + (x % 10));
+}
+
+void print_int(int x, uint8_t base) {
+  if (x == 0) {
+    if (base)
+      putc('0');
+    return;
+  }
+
+  if (x < 0) {
+    putc('-');
+    print_int(-1 * (x / 10), 0);
+    putc('0' + (x % 10));
+  } else {
+    print_int(x / 10, 0);
+    putc('0' + (x % 10));
+  }
+}
+
+void print_hex(int x) {
+  putc('0');
+  putc('x');
+
+  do {
+    unsigned int digit = (x & 0xF0000000) >> 28;
+    putc((digit < 10) ? (digit + '0') : (digit - 10 + 'A'));
+    x <<= 4;
+  } while (x != 0);
+}
+
+void print_string(char *s) {
+  for (uint32_t i = 0; s[i] != '\0'; i++) {
+    putc(s[i]);
+  }
+}
+
+uint32_t lock;
+
+void printf_base(char *str, va_list list) {
+
+  for (uint32_t i = 0; str[i] != '\0'; i++) {
+    if (str[i] == '%') {
+      switch (str[i + 1]) {
+      case '\0':
+        return;
+      case '%': {
+        putc('%');
+        break;
+      }
+
+      case 'c': {
+        putc(va_arg(list, int));
+        break;
+      }
+
+      case 'd': {
+        print_int(va_arg(list, int), 1);
+        break;
+      }
+
+      case 'x': {
+        print_hex(va_arg(list, int));
+        break;
+      }
+
+      case 'u': {
+        print_uint(va_arg(list, unsigned int), 1);
+        break;
+      }
+
+      case 's': {
+        print_string(va_arg(list, char *));
+        break;
+      }
+      }
+      i++;
+    } else {
+      putc(str[i]);
+    }
+  }
+}
+
+void printf_nolock(char *str, ...) {
+  va_list list;
+  va_start(list, str);
+  printf_base(str, list);
+}
+
+void printf(char *str, ...) {
+  va_list list;
+  va_start(list, str);
+  sl_acquire(&lock);
+  printf_base(str, list);
+  sl_release(&lock);
+}