Re: egcs-1.1.2 powerpc cross-compiler question.

["Kai Ruottu" <karuottu@freenet.hut.fi>]

Brendan Simon wrote:

> I've tried building egcs-1.1.2 as a powerpc-eabi cross compiler and a
> powerpc-linux cross compiler.

 I think that the general rule would be to use newlib for the embedded target,
and use the available pre-built system libraries and headers for the 'system' 
targets. Normally only the library binaries are available, but for Linux 
also building glibc-2.1 or 2.0.7 or something more new for the
'powerpc-linux-gnu' target later, if the pre-built C-library is 'too old', 
is possible...

> I had instructions from the LinuxPPC web site on building the powerpc-linux
> cross compiler.  The configure command was "configure --target=powerpc-linux
> --with-newlib".

 If this '--with-newlib' means that the Cygnus newlib should be used somehow, 
it sounds like pure bullshit... The GNU glibc-2 is the official Linux 
C-library after the earlier libc5-releases (were these available for 
powerpc-linux at all?)

 One site I found for pre-built RPMs for Linux'es is :

   http://rufus.w3.org/linux/RPM

but don't remember the version of the available C-library binaries for 
powerpc-linux...

> The error message I am getting looks like its related to
> the objective C build which I don't need but I am interested in trying
> it one day.  The errors are: 
> egcs-1.1.2/gcc/objc/runtime.h:31 stdio.h: No such file or directory
> egcs-1.1.2/gcc/objc/runtime.h:31 ctype.h: No such file or directory

 Your cross-compiler didn't find the target headers. If you haven't used any 
own '--prefix=...', the normal place for them is :

    /usr/local/powerpc-linux/include

 I think that it is quite possible to just symlink your current native libc6 
Linux headers (if you have RedHat 5.x etc.) at '/usr/include' there --- some 
minor differences can be between different glibc-2.0.x-releases, but the 'basic 
headers' needed for libobjc.a build should be quite stable and just the same 
between releases...
 
> I did not have these problems building the native linux build of
> egcs-1.1.2.  It obviously knows how/where to find the appropriate
> headers.

 It's 'cpp' which searches for the headers... Perhaps there is an equivalent 
option to the GCC '-print-search-dirs' for 'cpp', but the sure way is to use 
the '-v' and look at a logfile after something like :

   make > MakeLog 2>&1

and see what 'include' directories 'cpp' searches...
 
> How can I get the objc build to find the appropriate header files ?

 Just install them in the proper place... Please look with the

    ./xgcc -print-search-dirs

in the '.../egcs-1.1.2/gcc' build directory and see what the last directories
given for 'programs' and 'libraries' are, and install the headers to the 
'.../include', parallel to these. The default in your configure-command-case 
and target-name could be the '/usr/local/powerpc-linux/include'

 My last hint could be to get the powerpc-linux version of 'ld-linux.so.2' 
also among the powerpc-linux pre-built libs, and set the '-dynamic-linker' in 
'specs' to point to this, equivalent to what I have in my Win32-to-i486-linux
cross-compiler :

*link:
-m elf_i386 %{shared:-shared}
 %{!shared: %{!ibcs: %{!static: %{rdynamic:-export-dynamic}
 %{!dynamic-linker:-dynamic-linker /usr/local/i486-linux-gnu/lib/ld-linux.so.2
 --rpath /usr/local/i486-linux-gnu/lib}} %{static:-static}}} 

(all this stuff just in one line after the '*link:')

 Of course the 'i486-linux-gnu' must be 'powerpc-linux' etc. in your case, but 
the idea is that the 'ld-linux.so.2' is also one of the needed 'libraries'...

 If your 'rpm' utility denies to unpack the PowerPC-Linux RPM in the 
x86-environment, saying that "you don't need it" or "you have wrong system", 
just use the 'rpm2cpio' utility to convert the '.rpm' into a '.cpio' packet:

   rpm2cpio the_packet.rpm > the_packet.cpio

and continue with 'cpio', e.g. using 'cpio -iBdmv < the_packet.cpio' in a 
temporary directory... Sigh, I really hate these 'smart installers'...

 Cheers,  Kai
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