Re: [Ltib] LTIB for Raspberry Pi

[Malloy, Sean C.]

I've been using the custom option to build with my home-grown toolchain, so 
testing the official Pi toolchains shouldn't be a big deal.  RPM-ize-ing the 
officially released toolchains seems like the way to go.  Links to crosstool-ng 
with a sample config file for rpi should satisfy the teach-a-man-to-fish spirit 
of online collaboration.

The shared library situation is puzzling.  Like I said, a hand-built (outside 
of LTIB), dynamically linked HelloWorld executable placed on the Pi produces 
output, and will even run if init=/bin/hi is passed into the kernel.

But any LTIB-produced dynamically linked executables act like the shared libs 
don't exist.   Setting LD_LIBRARY_PATH, LD_RUN_PATH, etc. are of no use.  I've 
attempted to get ltrace (statically linked) to build for ARM, but have quickly 
run into issues (the autoconf that LTIB uses when doing scbuild is too old for 
ltrace's liking), and getting it to cross-compile without LTIB hasn't exactly 
come for free.

So, my thoughts are that I'll rebuild from scratch using an official toolchain 
and see what happens.  I have to test a new toolchain anyway; might as well :)


Someone asked about the Pi's bootloader situation.   My understanding is that 
the GPU runs first when the board is powered up.  It looks for an executable to 
load & run on the first (VFAT) partition on the SD card, and that this 
executable is closed-source, provided by the Pi foundation (and/or Broadcom), 
and does traditional boot-loader-y things, like set up memory (which is shared 
between the GPU and the ARM CPU, I believe), and load a kernel.  I suppose 
there's no reason we couldn't then run uBoot instead of a linux kernel, but 
there seems little point.  There is no ROM part, so the device must boot from 
the SD card.

In any case, I look forward making LTIB generate my very own SD card image file 
:p