Gentoo on a AMD Alchemy Au1550?

[nicolab80]

I'm starting a new project and I'd like to use gentoo.
Does anybody get experience with this processor?

[roarinelk]

I use a Stage3 environment for Cobalt with a Au1200 in LE mode.
For my limited uses it works very well (porting Linux over to a
custom made board). The compiler shipping with it unfortunately
segfaults/dies with "wrong-opcode" messages pretty often.
(Probably because the Cobalt uses another MIPS instruction subset?)

The crosscompiler produced by crossdev successfully builds yamon, linux
kernels and other apps (so far I only compiled libusb, usbutils and AMD's
hw accelerated media player).

[roarinelk]

I've created a basic Gentoo environment for MIPS32 Little Endian, consisting of gcc-4.1.1, glibc-2.5, binutils-2.17, latest python, portage, bash, coreutils.
You can emerge stuff with it. If you're interested, I can put it somewhere for you to download (the binpkgs are around 30MB)

[iluxa]

Real question is why would you want to use Gentoo with board like that.
uClibc + buildroot do most adequate job, with cross-compiler setups, base system,
etc. And for those rare cases where you actually need to build something on your target
(i.e. an application just doesn't cross-compile (think FireBird database (enough parenthesis?))
then buildroot can build target toolchain for you as well.)

I'm not trying to discourage use of Gentoo, just you have to assess if it really is what
you need for your project. No experience is better then bad experience
_________________
Ilya A. Volynets-Evenbakh
Total Knowledge. CTO
http://www.total-knowledge.com

CPPSERV: C++ Servlet Container and CSP (C++ Server Pages) parser: Application server for Real Programmers(TM)

[iluxa]

Oh, and as for unsupported command errors, remember that unlike Cobalt,
Au1500 is MIPS32 CPU with no real FPU. You really need to compile from scratch
for it (not an easy thing to do - yet another reason to use buildroot, at the
very least to do a boostrap)
_________________
Ilya A. Volynets-Evenbakh
Total Knowledge. CTO
http://www.total-knowledge.com

CPPSERV: C++ Servlet Container and CSP (C++ Server Pages) parser: Application server for Real Programmers(TM)

[roarinelk]

[nicolab80]

Thank you for your answer!
What I really need is c++ crosscompiler. I'm new with embedded linux hacking. I'm refactoring an old project developed with gxlinux. I'd like to use c++ becouse i'm expert in it and in OOP. I've source code from microcross but there isn't a libstdc++, it is a system based on uclibc.

[iluxa]

Ah.. C++.. Not too good with uClibc, last I heard, however, gentoo is _not_ the distro for
cross-compile targets. It can be used as cross-compile host very well though.

What I'd do is use crossdev to build cross-toolchain for your target, and then
I'd hack buildroot to use that toolchain instead of building its own. This will
get you reasonable setup.
_________________
Ilya A. Volynets-Evenbakh
Total Knowledge. CTO
http://www.total-knowledge.com

CPPSERV: C++ Servlet Container and CSP (C++ Server Pages) parser: Application server for Real Programmers(TM)

[wim-x]

I'm considering buying an Xtreme PC EX6500NG (thin client) with an Alchemy AU1550 (mips32). I already found some recent stage3's in experimental/mips/stages/ but now I was wondering what kind of stage3 and crossdev target I should use to prepare the environment.

• What's the difference between stage3-mips32el and stage3-mipsel1?
  
• Should I use mipsel-unknown-linux-gnu?
  

[roarinelk]

mips32 has a few more opcodes than mips1, but they are compatible.

since the alchemy line has no FPU, I favor mipsel-softfloat-linux-gnu.
in floatmath intensive applications the softfloat toolchain gives a small
performance advantage; hardfloat opcodes are trapped and emulated by
the kernel which takes considerable time. obviously there are ABI differences
which means you must use either soft or hardfloat; mixing them results
in all kinds of weird errors.