separating: there will be libk and libc

kernel/kheap.c

@@ -0,0 +1,83 @@
+// Kernel heap management
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "kheap.h"
+#include <stdint.h>
+#include "system.h"
+#include "../libk/stdio.h"
+
+// Free list allocator
+
+static uint8_t heap[HEAP_SIZE];
+static block_t* free_list = NULL;
+
+void init_alloc()
+{
+	free_list = (block_t*)heap;
+	free_list->size = HEAP_SIZE-sizeof(block_t);
+	free_list->next = NULL;
+	printf("[kernel] initialized heap and allocator, start=0x%x\n", heap);
+}
+
+void* malloc(size_t size)
+{
+	block_t* prev = NULL;
+	block_t* curr = free_list;
+
+	while (curr != NULL)
+	{
+		if (curr->size >= size)
+		{
+			if (curr->size > (size_t)(size + sizeof(block_t)))
+			{
+				block_t* new_block = (block_t*)((uint8_t*)curr + sizeof(block_t) + size);
+				new_block->size = curr->size - size - sizeof(block_t);
+				new_block->next = curr->next;
+				curr->size = size;
+				curr->next = new_block;
+			}
+
+			if (prev == NULL)
+			{
+				free_list = curr->next;
+			} else {
+				prev->next = curr->next;
+			}
+
+			return (void*)((uint8_t*)curr + sizeof(block_t));
+		}
+
+		prev = curr;
+		curr = curr->next;
+	}
+
+	return NULL;
+}
+
+void* calloc(size_t num, size_t size)
+{
+	size_t total_size = num*size;
+	void* ptr = malloc(total_size);
+
+	if (ptr != NULL)
+	{
+		uint8_t* byte_ptr = (uint8_t*)ptr;
+		for (size_t i=0; i<total_size; i++)
+		{
+			byte_ptr[i] = 0;
+		}
+	}
+
+	return ptr;
+}
+
+void free(void* ptr)
+{
+	if (ptr == NULL) return;
+
+	block_t* block_to_free = (block_t*)((uint8_t*)ptr - sizeof(block_t));
+	block_to_free->next = free_list;
+	free_list = block_to_free;
+}