A freestanding buddy heap allocator, preferable for embedded systems / kernel
To use it go to this line and change memmap with however you choose to get your heap memory from. Also make sure to remove the #include sys/mman.h from the top line.
If you don't have your own string library that can do memset and memcpy then there's a simple header file which has these two headers already included in the src/lib folders you don't have to worry about anything.