[ARMedslack] Building software on ArmedSlack

[Stuart Winter]

Hi Niel

> I noticed most of armedslack is built with the "-march=armv4t" flag.
> Slackware on the other hand uses "-march=armv4 -mtune=xscale" if the
> architecture is set to "arm" and "-march=armv4t" if set to "armel".

This is old stuff for when I was planning on having two ports: arm would
be "old abi" and armel "EABI".
Now there is only one going forward, "arm" for EABI.

-march=armv4 -mtune=xscale is for the Old ABI, ARMedslack 12.2
-march=armv4t is for EABI, -current.

There are only a couple of the build scripts in Slackware which could be
used directly without modification: xap/pidgin, xap/blackbox (in the next
round of updates) and ap/linuxdoc-tools.
It's not too much effort to update the Slackware build scripts to run on
ARMedslack - typically all I do is merge the main content into my template
scripts; it's rare to have to patch or modify.

> I've been using "-march=armv4" for now and the compiled packages are
> working fine.

For 12.2 this is ok but -current should be armv4t.
I actually can't remember why not to use armv4 on -current - I think I
tried it once when I forgot to update a build script, and got weird
results.

> I would like to be able to build packages that work on both the
> SheevaPlug and in Qemu, so that I can use one as a test setup before
> deploying on the other. On the other hand, I would like to get the
> best performance possible. :)

The userland is all the same and both are armv5.  The only different
packages are the kernels which you need for ARM.

QEMU:
Linux slackware 2.6.32.7-versatile #2 PREEMPT Sun Jan 31 21:57:08 GMT 2010
armv5tejl GNU/Linux

Sheevaplug:
Linux zaden 2.6.32.8-kirkwood #2 PREEMPT Sun Feb 14 21:29:38 GMT 2010
armv5tel Feroceon 88FR131 rev 1 (v5l) Marvell SheevaPlug Reference Board
GNU/Linux

If you want the better performance, you could compile it for armv5t but I
doubt you'd notice any difference.  ARMedslack is compiled for armv4t
because it's the lowest ARM CPU still just about sensible to use and there
are many of them in the field.

> As an example, I built Hercules (the mainframe emulator) under
> armedslack and it runs reasonably under Qemu.

You built an emulator inside an emulator?!  what is your x86 hardware?!
QEMU isn't exactly that fast for me even on a reasonable machine!


-- 
Stuart Winter
Slackware ARM: www.armedslack.org