Porting non-mmu code to MMU -- MMU memcpy SEGV

UPDATE and QUESTION(S)

I got the memory working. The thing that I am unclear upon and would like to understand is the "special node" for the mmap area?

I have the device driver open "/dev/myDDriver0" -- which is MAJOR - 240 and Minor 0

I created a node locally in the directory I'm running the test code: mknod node c 204 0 (same major and minor# )

I HAVE to do an open on that too.

CODE snippet ***********************************************

if ((fdPlayback = open(DevName, O_RDWR | O_NONBLOCK | O_SYNC)) < 0) {

perror("DevNameIO");

printf("error opening device %s\n", DevName);

return -1;

}

if ((fd=open("node", O_RDWR|O_SYNC))<0)

{

perror("open");

exit(-1);

}

So I open that one too and do the "mmap" and all is well.

So - why this special node (why can't I use the file pointer from the device driver open)?

Could someone provide me with some reading to understand this?

I'm going to need to have 2 more memory areas and would like to know what that is going to entail