Re: chicken-egg problem when building cross toolchain for linux

[Kai Ruottu <kai dot ruottu at wippies dot com>]

11.10.2013 14:27, Warlich, Christof kirjoitti:

> as I need to build a couple of cross toolchains for various target architectures (powerpc, mipsel, i686 and arm, all running Linux with glibc), I'd like to generally understand how proceed. Most notably, I'd like to understand the proper sequence to do the job:
>
> 1) Configuring, building and installing cross binutils works fine.
> 2) But when I try to build a bootstrap gcc in the next step, it complains about missing libc header files.
> 3) Conversely, when I try to install the glibc headers first (make install-headers) , glibc configuration already fails as it does not find the cross compiler:
>
> $ glibc/configure --prefix=3D$PREFIX --host=3D$TARGET --build=3Di686-pc-lin= ux-gnu ...
> checking whether gcc -g -O2 -mlong-double-128 uses IBM extended format... n= o checking whether gcc -g -O2 supports -mabi=3Dibmlongdouble... no
> configure: error: this configuration requires -mlong-double-128 IBM extende= d format support
>
> Can anyone give me a hint on how to resolve this?

You just should understand how the capitalism or the evolutionary 
socialism works...  For instance
if one wants a car with Michelin tyres, instead of buying it without 
tyres at all and then driving with
bare wheels to the Michelin tyre shop, one accepts using the "suitable 
but not right" Goodyears
coming with the car during the trip there.

So, be sure that there are freely downloadable glibcs for powerpc, 
mipsel, i686 and arm to be used
during the "bootstrap trip", when producing the target GCC and its libgcc :

make all-gcc
make all-target-libgcc

If only these will be required from the step-1 GCC.  But of course one 
can build a complete one
aimed for the existing powerpc, mipsel, i686 or arm Linux target system 
from which the glibc was
borrowed.

After GCC is ready, using it to build the "right" glibc from its sources 
is fully possible. Later one
then uses the self-made toolchain components : binutils, glibc, GCC etc. 
when needing to update
one component like update the GCC part...

So the whole "from absolute scratch" idea is based on the Lenin, 
Trotski, Stalin etc. thoughts from
the early 1900's for avoiding to use anything what the bad capitalism 
had created.