Debugging with the heap & changes to it

include/debugging.h

@@ -2,7 +2,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 
-char get_last_key_pressed();
 void print_hex_digit(uint8_t digit);
 void print_hex_byte(uint8_t byte);
 void print_hex_bytes(void* bytes, size_t len);
+void print_heap();

include/kernel/heap.h

@@ -2,6 +2,8 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+extern struct Heap_Metadata global_heap;
+
 struct Heap_Metadata {
     struct Heap_Block* start;
     size_t size;

kernel/debugging.c

@@ -2,6 +2,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <strlib.h>
+#include <kernel/heap.h>
 
 void print_hex_digit(uint8_t digit)
 {
@@ -29,3 +30,29 @@ void print_hex_bytes(void* bytes, size_t len)
         print_hex_byte(value[i - 1]);
     }
 }
+
+void print_heap()
+{
+    struct Heap_Block* current = global_heap.start;
+
+    while (current != 0) {
+        terminal_writestring("Block at: ");
+        print_hex_bytes(&current, 4);
+
+        terminal_writestring("\nSize: ");
+        print_hex_bytes(&current->size, 4);
+
+        terminal_writestring("\nUsed: ");
+        if (current->used) {
+            terminal_writestring("True\n");
+        } else {
+            terminal_writestring("False\n");
+        }
+
+        terminal_writestring("Data: ");
+        print_hex_bytes(&current->data, 4);
+        terminal_putchar('\n');
+
+        current = current->next;
+    }
+}

kernel/heap.c

@@ -5,7 +5,7 @@
 
 #define HEAP_SIZE (256 * 4096)
 
-uint8_t* global_heap_data[HEAP_SIZE];
+uint8_t* global_heap_data[HEAP_SIZE + sizeof(struct Heap_Block)];
 struct Heap_Metadata global_heap;
 
 void heap_init() 
@@ -51,15 +51,22 @@ void* malloc(size_t size)
 void free(void *ptr)
 {
     struct Heap_Block* current = global_heap.start;
-    while (current->data != ptr) { current = current->next; }
-
-    struct Heap_Block* start = current;
+    while (current->data != ptr) { 
+        current = current->next; 
+    }
 
     current->used = false;
 
-    while (current->used == false) {
+    if (current->next == 0) {
+        return;
+    }
+
+    struct Heap_Block* start = current;
+
+    while (current->used == false && current->next != 0) {
         current = current->next;
     }
+
     start->next = current;
     start->size = (uint32_t)start->next - (uint32_t)start->data;
 }