User:A22347/Memory Manager

Here is the memory manager for my kernel. Feel free to use.

#define BLOCK_SIZE 64
#define MEMORY_BASE 0x18000000
#define MEMORY_HIGH 0x80000000 
#define MEMORY (MEMORY_HIGH - MEMORY_BASE)
#define BLOCKS (MEMORY / BLOCK_SIZE)

char blocksUsed[BLOCKS] = { 0 };
int tried = 0;
uint8_t* lastFreeAddress = MEMORY_BASE;
uint8_t* lastMallocAddress = MEMORY_BASE;

void* malloc (size_t size)
{
	tried = 0;
	int stage = 0;
	uint8_t* ptr = lastFreeAddress;
	unsigned int blocksAlloced = 0;
	while (blocksAlloced < size) {
		if (blocksUsed[(((unsigned int) ptr + blocksAlloced) - MEMORY_BASE) / BLOCK_SIZE] == 0) {
			blocksAlloced += BLOCK_SIZE ;
		} else {
			ptr += blocksAlloced + BLOCK_SIZE ;

			if (stage == 0) {
				stage = 1;
				ptr = lastMallocAddress;
			}

			blocksAlloced = 0;
		}
	}
	for (int i = 0; i < blocksAlloced / BLOCK_SIZE ; ++i) {
		if (i == blocksAlloced / BLOCK_SIZE - 1) {
			blocksUsed[((((unsigned int) ptr) - MEMORY_BASE) / BLOCK_SIZE) + i] = 2;		//show that this is the last in the block
		} else {
			blocksUsed[((((unsigned int) ptr) - MEMORY_BASE) / BLOCK_SIZE) + i] = 1;
		}

	}
	lastMallocAddress = ptr + blocksAlloced;
	freeBytesApprox -= blocksAlloced;
	return ptr;
}

void free (void *blk)
{
	unsigned int locator = blk;
	while (blocksUsed[((locator - MEMORY_BASE) / BLOCK_SIZE)]) {
		if (blocksUsed[((locator - MEMORY_BASE) / BLOCK_SIZE)] == 2) {
			blocksUsed[((locator - MEMORY_BASE) / BLOCK_SIZE)] = 0;
			break;
		}
		blocksUsed[((locator - MEMORY_BASE) / BLOCK_SIZE)] = 0;
		locator += BLOCK_SIZE;
	}
	lastFreeAddress = blk;
	freeBytesApprox += locator - (int) blk + BLOCK_SIZE;
}