how to write system calls in Linux

[rkirankumar]

hi all,
I just started working on RH Linux Kernel. Do you have any references for "how to write our own system calls in Linux", which explains step by step so that as a beginner i can grab things easily.





regards,
Kiran.

[lakerdonald]

You mean like open(), read(), fork(), system(), etc.?

[Dolda2000]

I doubt there are any references for that. In fact, it is generally discouraged that you write new syscalls, snce it involves adding an entry for every architecture and lots of cruft here and there.

If you just need an entry point from userspace into a kernel function, I would recommend that you instead write a character device (suggestedly a misc device) and implement it as an ioctl.

[lakerdonald]

I doubt there are any references for that. In fact, it is generally discouraged that you write new syscalls, snce it involves adding an entry for every architecture and lots of cruft here and there.

If you just need an entry point from userspace into a kernel function, I would recommend that you instead write a character device (suggestedly a misc device) and implement it as an ioctl.

This *is* true, but I have seen references on how to do such a thing before, just can't find the URL.
But generally, the only people who write new syscalls are the guys working on the kernel itself.