Hello all, so the code in the first post is STILL not updated, even though I posted over a year ago saying "I'll update it when I've cleaned up the code". Someday, I swear....

Anyway, I've made headway on the segfault issue, albeit not actually solved it.

This is all thanks to freemangordon having created opensource libcal (which, BTW, works beautifully for me so far - my development N900 is running with that libcal installed over the stock one with no issues for days now [Edit: well... it worked once I fixed a single missing #include in the cal.h file]. One thing to note - the gcc version built for ARM in the sdk repo, when installed on the N900 (as opposed to scratchbox) is NOT capable of building the library, thanks to some bug in that ARM version of GCC with compiling dynamic things; so it needs to be compiled in scratchbox - I have not tested with the gcc-4.6 that's in the extras-devel repo to see if that does any better).

Long story short, libcal uses semaphores, as provided by semaphore.h. The function sem_open(), specifically, is what is causing the segfault. That's in the semaphore.h library, which means the problem is way deeper than my code, or even libcal code. I guess so early in the boot as my preinit shell, the kernel/OS simply isn't set up enough to even allow semaphores to be used properly.

Two potential workarounds come to mind. 1) figure out how to proceed the boot the minimal amount needed to get working semaphores, and package that with the code - catch segserv (or whatever the segfault error signal is), and run that code in response, or just leave it to the user to run the required stuff (either shell script or built into the rdmod binary invoked by commandline flag). OR 2) rewrite the relevant aspects to NOT use semaphores, build that version of libcal statically into rdmod, and then have it invoke the statically included versions of the functions when it detects semaphores aren't available, under the assumption that so early in the boot nothing else that could access rdmod will be running at the same time.

Further investigation path before I do anything else tho: Figure out why the stock cal-tool, that lets you get r&d mode flags, isn't segfaulting still (if it does with the new libcal, that means the new reverse-engineered libcal isn't 1-to-1 with the old libcal; if it doesn't, then it's worth looking into why cal-tool doesn't fail, or if it's even using libcal at all (or if it just doesn't use it at all)).

Don't expect further progress by me for the next week or two (or more, who knows with my busy schedule and unpredictable direction for my bursts of motivation), because collegiate work and actual work (not that anyone cares, but I got a job as a parttime job as a programmer about two weeks ago: which means I have much less time to donate to community but more more money to donate to members thereof, yay).

But yeah, this is promising. And I felt like updating you guys.