Dump the memory map from limine.

Also adds the ability to print formatted messages.

zion/debug/debug.cpp

@@ -4,17 +4,140 @@
 
 #define COM1 0x3f8
 
-void dbgln(const char* str) {
-  while (*str != 0) {
-    outb(COM1, *str);
-    str++;
-  }
-  outb(COM1, '\n');
+namespace {
+bool is_transmit_empty() { return (inb(COM1 + 5) & 0x20) != 0; }
+
+void dbgputchar(char c) {
+  while (!is_transmit_empty())
+    ;
+
+  outb(COM1, c);
 }
 
-void panic(const char* str) {
+void dbgcstr(const char* str) {
+  for (; *str != '\0'; str++) {
+    dbgputchar(*str);
+  }
+}
+
+void U64ToStr(uint64_t u, char* str) {
+  uint64_t len = 0;
+  uint64_t u2 = u;
+  while (u2 != 0) {
+    len++;
+    u2 /= 10;
+  }
+
+  if (len == 0) {
+    len = 1;
+  }
+
+  str[len] = '\0';
+
+  for (int64_t i = len - 1; i >= 0; i--) {
+    str[i] = (u % 10) + '0';
+    u /= 10;
+  }
+}
+
+void HexToStr(uint64_t u, char* str) {
+  uint64_t len = 0;
+  uint64_t u2 = u;
+  while (u2 != 0) {
+    len++;
+    u2 /= 16;
+  }
+
+  if (len == 0) {
+    len = 1;
+  }
+
+  len += 2;
+  str[0] = '0';
+  str[1] = 'x';
+  str[len] = '\0';
+  const char* hex = "0123456789ABCDEF";
+  for (uint64_t i = len - 1; i > 1; i--) {
+    str[i] = hex[u & 0xF];
+    u >>= 4;
+  }
+}
+
+void MemToStr(uint64_t u, char* str) {
+  str[0] = '0';
+  str[1] = 'x';
+  const char* hex = "0123456789ABCDEF";
+  for (uint64_t i = 0; i < 16; i++) {
+    str[17 - i] = hex[(u >> (i * 4)) & 0xF];
+  }
+  str[18] = '\0';
+}
+
+void dbgln_internal(const char* fmt, va_list args) {
+  for (; *fmt != '\0'; fmt++) {
+    if (*fmt != '%') {
+      dbgputchar(*fmt);
+      continue;
+    }
+    fmt++;
+    switch (*fmt) {
+      case '%':
+        dbgputchar('%');
+        break;
+      case 's': {
+        char* str = va_arg(args, char*);
+        dbgcstr(str);
+        break;
+      }
+      case 'c': {
+        char c = va_arg(args, int);
+        dbgputchar(c);
+        break;
+      }
+      case 'u': {
+        uint64_t u = va_arg(args, uint64_t);
+        char str[21];
+        U64ToStr(u, str);
+        dbgcstr(str);
+        break;
+      }
+      case 'x': {
+        uint64_t u = va_arg(args, uint64_t);
+        char str[19];
+        HexToStr(u, str);
+        dbgcstr(str);
+        break;
+      }
+      case 'm': {
+        uint64_t u = va_arg(args, uint64_t);
+        char str[19];
+        MemToStr(u, str);
+        dbgcstr(str);
+        break;
+      }
+      default: {
+        panic("Bad format char: %c", *fmt);
+      }
+    }
+  }
+  dbgputchar('\n');
+}
+
+}  // namespace
+
+void dbgln(const char* fmt, ...) {
+  va_list arg;
+  va_start(arg, fmt);
+  dbgln_internal(fmt, arg);
+  va_end(arg);
+}
+
+void panic(const char* fmt, ...) {
   asm volatile("cli");
-  dbgln(str);
+  va_list arg;
+  va_start(arg, fmt);
+  dbgln_internal(fmt, arg);
+  va_end(arg);
   dbgln("PANIC");
   while (1)
     ;

zion/debug/debug.h

@@ -1,4 +1,6 @@
 #pragma once
 
-void dbgln(const char* str);
-void panic(const char* str);
+#include <stdarg.h>
+
+void dbgln(const char* str, ...);
+void panic(const char* str, ...);