mipsco questions... and timecounters
Garrett D'Amore <[email protected]> Fri, 08 Sep 2006 19:59:44 -0700
| Newsgroups | gmane.os.netbsd.ports.mipsco |
|---|---|
| Message-ID | <[email protected]> |
I've started looking at mipsco, and it looks like it will be fairly straight-forward to convert it to timecounters and the generic TODR support. However, I have a few questions, which maybe someone can help me out with. First off, the RAMBO timer (TCOUNT/TBREAK). It would be very, very convenient if this timer works like the MIPS3 CP0 timer; that is if TCOUNT is a count up timer, and TBREAK is a compare value. It will be _even better_ if this timer works properly with wrapping. E.g. if I set a TBREAK < TCOUNT, then then the counter will count til it wraps, continue counting from zero, and interrupt when TCOUNT==TBREAK. If those conditions are true, then I can see changing the mipsco code to more closely emulate what we do in mips3 code, so that TCOUNT is allowed to run free, and we use that as the counter for timecounters. If someone can confirm for me that this understanding is correct, and is willing to undertake testing, then I'm willing to make the code modifications, which are simple, to make this work. The next question I have is in regard to the RTC chip. It looks like this is probably an mk48xxx part, and could maybe just use the MI code with an attachment point. Does this sound like a reasonable assessment? Again, I'm willing to make the changes, resulting in more common code and less duplication, if someone can confirm and test for me. -- Garrett D'Amore, Principal Software Engineer Tadpole Computer / Computing Technologies Division, General Dynamics C4 Systems http://www.tadpolecomputer.com/ Phone: 951 325-2134 Fax: 951 325-2191