[cfarm-users] gcc230: Unable to use GDB on 64-bit mips executable

[Andy Polyakov]

>> Would it be possible to install a 64-bit version of the debugger if
>> this is available as a package, or otherwise to install 64-bit
>> versions of gmp and mpfr (and possibly several other needed packages)?
> 
> Hello Pierre.
> 
> I do not know whether it would be possible to mix 32-bit and 64-bit
> userspace on MIPS.

It's perfectly possible to mix all three MIPS ABIs, -mabi={32,n32,64}, 
on Linux MIPS. And the machine in question supports all three as it 
stands now.

> Even though the kernel is 64-bit, Debian had all
> userspace packages built for 32-bit,

This doesn't mean that you can't compile and execute 64-bit 
applications, compiler and run-time libraries are there. The fact that 
userspace packages are all 32-bit is likely a matter of minimizing the 
support burden. Idea is that a single MIPS distro can target all MIPS 
platforms by providing a single basic set of 32-bit packages and 
choosing between 32-bit and 64-bit kernels upon installation. This is 
obviously tough if you want to compile a 64-bit application with [a lot 
of] dependencies. I don't have hands-on experience with Linux MIPS, but 
it *might* be possible to 'dpkg --add-architecture mips64' followed by 
'apt-get update' to be able to install 64-bit development packages.

As for gdb, see if gdb-multiarch package works with 64-bit applications.

Cheers.