addind more important kernel files and also fixing bugs

kernel/malloc.c

@@ -0,0 +1,97 @@
+#include "malloc.h"
+#include <stdint.h>
+
+static void *heap_start; // Start of the heap
+static void *heap_end;   // End of the heap
+static struct memory_block *free_blocks; // List of free blocks
+
+void init_heap(void *start, void *end)
+{
+    heap_start = start;
+    heap_end = end;
+
+    // Initialize the heap with a single large free block
+    free_blocks = (struct memory_block *)start;
+    free_blocks->size = (uintptr_t)end - (uintptr_t)start - sizeof(struct memory_block);
+    free_blocks->next = NULL;
+    free_blocks->is_free = 1;
+}
+
+void *find_free_block(size_t size) {
+    struct memory_block *current = free_blocks;
+    while (current != NULL) {
+        if (current->is_free && current->size >= size) {
+            return current;
+        }
+        current = current->next;
+    }
+    // No suitable block found
+    return NULL;
+}
+
+void mark_as_used(void *ptr, size_t size) {
+    struct memory_block *block = (struct memory_block *)ptr;
+    block->is_free = 0;
+
+    // If the block is larger than needed, split it
+    if (block->size > size + sizeof(struct memory_block)) {
+        struct memory_block *new_block = (struct memory_block *)((uintptr_t)ptr + size + sizeof(struct memory_block));
+        new_block->size = block->size - size - sizeof(struct memory_block);
+        new_block->next = block->next;
+        new_block->is_free = 1;
+
+        block->size = size;
+        block->next = new_block;
+    }
+}
+
+void mark_as_free(void *ptr) {
+    struct memory_block *block = (struct memory_block *)ptr;
+    block->is_free = 1;
+
+    // Coalesce with next block if it's free
+    if (block->next && block->next->is_free) {
+        block->size += block->next->size + sizeof(struct memory_block);
+        block->next = block->next->next;
+    }
+
+    // TODO: Implement coalescing with previous block
+}
+
+void *malloc(size_t size)
+{
+    if (heap_start == NULL || heap_end == NULL)
+    {
+        // Heap not initialized, cannot allocate
+        return NULL;
+    }
+
+    // Align the size to the word size for efficiency
+    size = (size + sizeof(size_t) - 1) & ~(sizeof(size_t) - 1);
+
+    // Search for a free block of sufficient size
+    void *block = find_free_block(size);
+    if (block != NULL)
+    {
+        // Mark the block as used
+        mark_as_used(block, size);
+        return (void *)((uintptr_t)block + sizeof(struct memory_block));
+    }
+
+    // No suitable block found, out of memory
+    return NULL;
+}
+
+void free(void *ptr)
+{
+    if (ptr == NULL)
+    {
+        return;
+    }
+
+    // Adjust pointer to the start of the memory block
+    struct memory_block *block = (struct memory_block *)((uintptr_t)ptr - sizeof(struct memory_block));
+
+    // Mark the block as free
+    mark_as_free(block);
+}