[ECOS] CYGNUM_HAL_RTC_PERIOD / floating point

Jonathan Larmour jifl@eCosCentric.com
Thu Jan 23 22:14:00 GMT 2003

David N. Welton wrote:
>>You can find the CYGNUM_HAL_RTC_NUMERATOR aloingside the period
>>option in the pcmb package. If you reduce the period by a factor of
>>100, reduce the numerator by a factor of 100.
> Tried that, and things still seem to not work quite right.  I guess
> I'll keep experimenting and see what I can find.

Of course too fast, and you would be swamping the machine with interrupts 
- it may be spending all its time handling them!

Also check the docs for the timer chip. It may not be able to go that 
fast. Should, but may not.

>>Then in the code use a test like:
> That works.  Shall I try and create a patch out of it?

Please do.

> One more thing - I try and set up a floating point variable in my
> cyg_start, and that seems to futz things up but good.
> I had a look in the mailing list archives, and tried a few things like
> turning off the lazy FPU switching, but to no avail.
> This is, as usual on a standard i386 PC booting from floppy.

386DX? 386SX has no FPU. Does FPU work outside of cyg_start in threads?

eCosCentric       http://www.eCosCentric.com/       <info@eCosCentric.com>
--[ "You can complain because roses have thorns, or you ]--
--[  can rejoice because thorns have roses." -Lincoln   ]-- Opinions==mine

Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss

More information about the Ecos-discuss mailing list