[BOOT] Print functions for debugging

kernel/boot/debug.c

@@ -0,0 +1,132 @@
+#include <debug.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <string.h>
+#include <vga.h>
+#include <serial.h>
+
+void debug_init()
+{
+  vga_init();
+  serial_init(PORT_COM1);
+}
+
+uint64_t num2str(uint64_t num, uint32_t base, char *buf)
+{
+  // Convert a number to string
+  if(num == 0)
+  {
+    buf[0] = '0';
+    buf[1] = '\0';
+    return 0;
+  }
+  uint32_t i=0, j=0;
+  char chars[] = "0123456789ABCDEF";
+  // Build the string starting with the least significant digit
+  while(num > 0)
+  {
+    buf[i++] = chars[num%base];
+    num /= base;
+  }
+
+  // Invert the string to get digits in right order
+  i--;
+  j=0;
+  while(j<i)
+  {
+    char t = buf[i];
+    buf[i--] = buf[j];
+    buf[j++] = t;
+  }
+
+  // Zero terminate
+  buf[i+j+1] = '\0';
+  return i+j+1;
+}
+
+void debug_putch(char c)
+{
+  vga_printch(c);
+  serial_write(PORT_COM1, c);
+}
+void debug_putsn(char *s, size_t n)
+{
+  while(n--)
+    debug_putch(*s++);
+}
+void debug_puts(char *s)
+{
+  debug_putsn(s, strlen(s));
+}
+
+void debug_vprintf(char *str, va_list args)
+{
+  size_t len = 0;
+  if(!(*str))
+    return;
+  if(*str != '%')
+  {
+    while(str[len] && str[len] != '%')
+      len++;
+    debug_putsn(str, len);
+    return debug_vprintf(&str[len], args);
+  }
+  str++;
+  char *prefix;
+  uint32_t base = 0;
+#define DEBUG_VPRINTF_BASE_CHAR 255
+#define DEBUG_VPRINTF_BASE_STR 1024
+  switch(*str)
+  {
+    case 'b':
+      prefix = "0b";
+      base = 2;
+      break;
+    case 'o':
+      prefix = "0";
+      base = 8;
+      break;
+    case 'd':
+      prefix = "";
+      base = 10;
+      break;
+    case 'x':
+      prefix = "0x";
+      base = 16;
+      break;
+    case 'c':
+      prefix = "";
+      base = DEBUG_VPRINTF_BASE_CHAR;
+      break;
+    case 's':
+      prefix = "";
+      base = DEBUG_VPRINTF_BASE_STR;
+      break;
+    case '%':
+    default:
+      debug_putch('%');
+      break;
+  }
+  if(base == DEBUG_VPRINTF_BASE_STR)
+    debug_puts(va_arg(args, char *));
+  else if(base == DEBUG_VPRINTF_BASE_CHAR)
+    debug_putch((char)va_arg(args, uint64_t));
+  else if(base)
+  {
+    uint64_t num = va_arg(args, uint64_t);
+    char buf[128];
+    num2str(num, base, buf);
+    debug_puts(prefix);
+    debug_puts(buf);
+  }
+  str++;
+  return debug_vprintf(str, args);
+}
+
+void debug_printf(char *str, ...)
+{
+  va_list args;
+  va_start(args, str);
+  debug_vprintf(str, args);
+  va_end(args);
+}

kernel/boot/kmain.c

@@ -1,34 +1,22 @@
-#include <mem.h>
-
-#define VGA_MEMORY 0xb8000
-#define VGA_ROWS 24
-#define VGA_COLS 80
-
-void clear_screen()
-{
-  // Clear the video memory
-  unsigned char *m = (void *)P2V(VGA_MEMORY);
-  for(int i = 0; i < VGA_ROWS*VGA_COLS*2; i++)
-  {
-    *m++ = 0;
-  }
-}
-
-void prints(const char *s, unsigned int row, unsigned int col)
-{
-  // Very simple pure ascii string printing
-  unsigned char *m = (void *)P2V(VGA_MEMORY);
-  m += 2*VGA_COLS*row+2*col;
-  while(*s)
-  {
-    *m++ = *s++;
-    *m++ = 0x7;
-  }
-}
+#include <debug.h>
 
 int kmain(void)
 {
-  clear_screen();
-  prints("Hello, world!", 0, 0);
+  debug_init();
+  debug_ok("MITTOS64 kernel booted\n");
+  debug_build_time();
+  debug_git_info();
+
+  // Test the printf functions
+  debug("binary:%b octal:%o dec:%d\n", 0xAA55, 0123, 456);
+  debug("hex:%x string:%s char:%c\n", 0xabcd, "Hello", 'T');
+  debug("pointer:%x\n", kmain);
+
+  debug_info("An information string\n");
+  debug_ok("%s prints ok\n", "This string");
+  debug_warning("A warning message\n");
+  debug_error("%d is less than %x\n", 12, 17);
+
+  debug_info("BOOT COMPLETE\n");
   for(;;)asm("hlt");
 }

kernel/boot/version.c

@@ -0,0 +1,20 @@
+#include <debug.h>
+
+char *_kernel_build_date = __DATE__;
+char *_kernel_build_time = __TIME__;
+
+char *_kernel_git_hash = GITHASH;
+char *_kernel_git_date = GITDATE;
+int _kernel_git_dirty = GITDIRTY;
+char *_kernel_git_message = GITMESSAGE;
+char *_kernel_git_branch = GITBRANCH;
+
+void debug_build_time()
+{
+  debug_info("Kernel built: %s (%s)\n", _kernel_build_date, _kernel_build_time);
+}
+void debug_git_info()
+{
+  debug_info("Kernel git: %s%s%s %s\n", _kernel_git_branch, _kernel_git_hash, (_kernel_git_dirty)?" (dirty)":"", _kernel_git_date);
+  debug_info("Git message: %s\n", _kernel_git_message);
+}