Torsten Mohr wrote: > In that file i've also read about an option "ghs", does > that one switch to the Greenhills ABI?
In theory, yes. In practice, I'd be skeptical. It probably hasn't been well tested. > From that file i can't really conclude everything. > For example i don't know if registers 20 and 21 hold the > values 255 and 65535 (an optimisation on V850). The startup > code in newlib assigns them, but does gcc really rely on that > and uses that (this question is just an example)? Try writing a simple example program to check. Since 20 and 21 are not fixed registers, my guess would be no. > Is there a description of the ABI or the ABIs available? Red Hat probably has a manual. If you can find a copy of a Red Hat v850 release, there may be a manual inside it that has ABI info. Otherwise, probably no. Gcc normally does not define the ABI. We just follow ABI standards produced by others. You could try checking in NEC publishes an ABI for the v850. For some embedded targets, gcc defines the ABI because there isn't an external one we can follow. In this case, gcc should document the ABI that it implements. This is done for some targets. If you look, you can see that some targets have a *ABI* or *abi* file that documents the gcc abi. Unfortunately, we don't do this for as many targets as we should. -- Jim Wilson, GNU Tools Support, http://www.specifix.com
