[Coco] Telnet to your CoCo.. and invite 6 of your friends

Boisy G. Pitre boisy at tee-boy.com
Tue Dec 1 16:36:50 EST 2009


On Dec 1, 2009, at 3:31 PM, Joel Ewy wrote:
> 
> In theory, you can add new system calls by adding os9p[x] modules, and there are versions of os9p3 out there.  So your question is a good one:  what if os9p3 implemented the F$SETID call?  Could that simply override the one in os9p2?  That would be interesting.
> 
> JCE

That's exactly what would happen... when the kernel scans for krnpX modules, it will call the os9 F$SSvc system call to install the system calls in that module; if any of those system calls reuse an existing system call number, then their address will overrwrite the address stored in the system call jump table in RAM.

It's a great way to extend the operating system.
--
Boisy G. Pitre
http://www.tee-boy.com/




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