On Wed, Jun 2, 2010 at 3:25 AM, David Given <[email protected]> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 28/05/10 00:00, Andrew Dennison wrote: > [...] >> I can describe it in general terms. > [...snip...] > > That's very interesting; it's nice to hear how this sort of thing works > in the real world. ARM, I presume? If I may ask, what made you decide to > use Prex and not a more established OS like ECOS or FreeRTOS?
BookE PowerPC. First think I did with Prex was port it to a new architecture. We wanted to use the MMU for security reasons as we run "untrusted" generated code. Once we collated our requirements the list of RTOS options got rather narrow. We seriously consider some expensive commercial options too but in the end Prex was the best fit. [...] > I suspect Kohsuke Ohtani simply doesn't have > time/inclination to be a source herder. As you know, it's a thankless > and surprisingly complicated job. In our early discussions he was always keen to get more contributors to Prex. Maybe real life has got in the way over the last few years? I started up my public tree because I wanted to help in this area but all the changes in 0.9 have stalled that effort. > > However, the really nasty bits were (a) figuring out how to drive ld to > link my image together in really non-standard ways and (b) figuring out > the build system. Prex's Make-based build system is a paragon of > excellence compared to most Make build systems, but it's still a Make > build system and therefore inscrutable and horribly inflexible, and I > had to rewrite big chunks of it to support my kernel XIP stuff. We have fixed up a lot of the make file issues in the tree I published. For example we added full dependency checking and support for parallel make. Thinking about it I could not use a Vanilla 0.9 prex as we have improved this area a lot in our tree. I can see why XIP was hard for you. One thing I added long ago was the ability to have static drivers linked into kernel which is why kernel XIP was easy for us. Maybe I should have pushed you towards my 0.8.1 tree after all... Andrew ------------------------------------------------------------------------------ _______________________________________________ Prex-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/prex-devel
