Cross compilation

[Steven W. Orr]

On Tuesday, Nov 28th 2006 at 18:50 +0100, quoth Fernando Apesteguía:

=>Helo list,
=>
=>I'm using FC6 for x86_64. I need to compile a program for linux 32
=>bits. I tried with the -m32 flag to gcc, but I got:
=>
=>core_recv.c:(.text+0x130): undefined reference to `__umoddi3'
=>
=>and tons of ld warnings:
=>
=>/usr/bin/ld: warning: i386 architecture of input file `main.o' is
=>incompatible with i386:x86-64 output
=>
=>I searched in Google, but couldn't find the solution. For the
=>undefinded references I suppose it is because some missing i386
=>libraries right?
=>
=>And what about the other things? How can I compile a 32 bit
=>application under a 64 bit system?

Sorry, but you need to create a seperate cross compiler. You're running on 
a your native system and you're trying to create an executable for another 
machine. So you need a whole different toolchain. The easiest way *might* 
be to use buildroot (just google it please) but the point is that you need 
a whole different setup to target a different machine. gcc, binutils, 
libc, gdb, the whole banana, and the whole thing has to be specific to the 
version of the kernel you're running on the target system. Just don't even 
*try* to figgah out options for your current system. It won't work.