michael@maui.cs.ucla.edu (08/13/89)
I have some questions on devices drivers. The system is a ATnT 3b1 (sys5 R2, more or less). #1. I am writting a block driver for this, but it is a slow block driver. How do I tell the system that I/O operations should be interruptable, and how should my driver tell that it has been interrupted, what should I do, etc. #2. What systems calls is a device driver allowed to do? In particular, what is the task time allowed to do (in particular, file I/O). #3. How can I track file descriptors? I.e., if some process opens a file, and does things (ioctl calls), and then forks or dups that file descriptor, when my driver is called later I want to be able to track things that were done on a file descriptor basis, not just a device basis. #4. How can I catch write calls made to another device driver? (If it makes a difference, this would be to a loadable device driver (the window driver)) Michael