If you require write access (perhaps for temporary files, logs, etc.), and the storage doesn't have to be persistent in nature (meaning that it doesn't need to survive a reset), then once again the work is done for you.
The QNX Neutrino RTOS allows the RAM in your system to be used as a RAM-disk, without any additional coding or device drivers. The RAM-disk is implemented via the Process Manager — you simply set up a Process Manager link (using the ln command).
For example, to mount the /tmp directory as a RAM-disk, execute the following command:
ln -Ps /dev/shmem /tmp
Or place the following line in your buildfile (we'll talk about buildfiles over the next few chapters):
[type=link] /tmp=/dev/shmem
This instructs the Process Manager to take requests for any files under /tmp and resolve them to the shared memory subsystem. For example, /tmp/AAA4533.tmp becomes a request for /dev/shmem/AAA4533.tmp.
If you need a relatively full-featured, POSIX-style filesystem on a RAM disk, use devf-ram or the builtin RAM disk via io-blk instead.