hexdump.[ch]: utility function for dumping memory regions as hex

Makefile

@@ -67,7 +67,8 @@ KERNEL_OBJ := \
 	kern/libkern/mini-printf.o \
 	kern/libkern/stdio.o \
 	kern/libkern/buddy.o \
-	kern/libkern/badrand.o
+	kern/libkern/badrand.o \
+	kern/libkern/hexdump.o
 
 kern/kernel.elf: $(KERNEL_OBJ)
 	@echo LD $@

kern/libkern/hexdump.c

@@ -0,0 +1,34 @@
+#include <stddef.h>
+#include <ctype.h>
+#include <stdio.h>
+
+void hexdump(const void *data, size_t size) {
+    const unsigned char *p = (const unsigned char *)data;
+    size_t               i, j;
+
+    for (i = 0; i < size; i += 16) {
+        // Print offset
+        kprintf("%08zx  ", i);
+
+        // Print hex bytes
+        for (j = 0; j < 16; j++) {
+            if (i + j < size) {
+                kprintf("%02X ", p[i + j]);
+            } else {
+                kprintf("   "); // padding for incomplete lines
+            }
+            if (j == 7)
+                kprintf(" "); // extra space in middle
+        }
+
+        kprintf(" |");
+
+        // Print ASCII characters
+        for (j = 0; j < 16 && i + j < size; j++) {
+            unsigned char c = p[i + j];
+            kprintf("%c", isprint(c) ? c : '.');
+        }
+
+        kprintf("|\n");
+    }
+}

kern/libkern/hexdump.h

@@ -0,0 +1,8 @@
+#ifndef HEXDUMP_H
+#define HEXDUMP_H
+
+#include <stddef.h>
+
+void hexdump(const void *data, size_t size);
+
+#endif // HEXDUMP_H