[asterisk-users] Cross compiling Asterisk, Dahdi..

[Tzafrir Cohen]

On Sun, Jan 17, 2010 at 11:37:43AM +0000, Gordon Henderson wrote:
> On Sun, 17 Jan 2010, Tzafrir Cohen wrote:
> 
> > On Sat, Jan 16, 2010 at 03:54:44PM +0000, Gordon Henderson wrote:
> >>
> >> Is there a proper, documented way to cross compile DAHDI and Asterisk for
> >> a processor/system other than the one you're currently typing on?
> >>
> >> Now.. I have been doing this for some time, but it's been really
> >> frustrating every time I change/upgrade, etc.
> >>
> >> I've just tried to compile DAHDI for an AMD Geode system on my development
> >> system which is Intel Atom. Building the kernel is easy - been doing that
> >> for years, but DAHDI is just hard and does the wrong thing.
> >>
> >> So I start by hardwiring HOTPLUG to no because my target device doesn't
> >> support nor need it.
> >
> > HOTPLUG is a slightly misleading name. If it is enabled, it means
> > firmware loading from userspace is enabled in the kernel. If so, drivers
> > for some digium cards will not include the firmware inside them.
> >
> > Most system I know support firmware loading. If you don't use those
> > cards, those drivers will simply be smaller (as they don't include the
> > firmware blobs). In short: leave this one for automatic detection.
> 
> None of the cards I use require firmware loading.
> 
> OK - I build very precise and specific systems. Call me old fashioned if 
> you like, but I compile a kernel with the exact requirements for my 
> systems - no hotplug, no udev, no modules - just a precise kernel and a 
> cut-down installation of my own devising, but it's based on Debian.
> 
> The hotplug check fails on my systems - not sure why, but I've always had 
> to force it to no (as advised by the comments in the makefile!).
> 
> >> Then setting KVERS to be the correct thing,
> >
> > Hmm... I'm not really sure if KVERS is still used (if you explicitly set
> > KSRC, that is).
> 
> Comment in the Makefile under: dahdi-linux-complete-2.2.0.2+2.2.0/linux
> 
> # If you want to build for a kernel other than the current kernel, set KVERS
> 
> So I set KVERS in the environment. That is the only way to get the build 
> process to find the modules directory for my target kernel (cross compiled 
> on my build system). So
> 
>    # echo $KVERS
>    2.6.32.3-dsx-geode
> 
> 
> >> and this
> >> is picked up by the Makefile, but I really want -march=geode and the only
> >> way I've found to get this is to edit Kbuild directly.
> >
> > Kbuild should do that for you. Or rather: if you used that for building
> > the kernel, it should also be used for DAHDI. If this doesn't work, I
> > suspect your kernel tree is misconfigured.
> 
> I doubt it, but am willing to check - it's a vanilla kernel off 
> kernel.org, compiled as per the instructions - the way I've been doing it 
> for ever. I use make menuselect, then select the options I want. Module 
> loading is enabled. Make the kernel (make bzImage)

FWIW, 'make modules_prepare' should be good enough for building (or at
least: test-building) modules. And takes less time.

> , then make modules and 
> make modules_install. Not that there are any modules, but it populates 
> /lib/modules/2.6.32.3-dsx-geode with the right stuff.
> 
> > Reminder: to make Kbuild print the full build lines, use:
> >
> >  make V=1
> 
> Actually, that's handy. I was grepping the output of 'ps' to find the gcc 
> command lines to see what it was doing and make sure it was picking up 
> -march=geode
> 
> >> (And comment out
> >> all the modules I really don't want to build like torisa, xpp, etc. Even
> >> then it still barfed on the VPMADT032 loader, so I just commented that
> >> whole section out.
> >
> > What error did you get?
> 
> WARNING: "voicebus_get_pci_dev" [/var/space/local/src/dsx/dahdi-linux-complete-2.2.0.2+2.2.0/linux/drivers/dahdi/dahdi_vpmadt032_loader.ko] undefined!
> 
> And there are a few more like that.
> 
> Maybe the warnings can be ignored, but my guess is that it's looking for a 
> loader in a kernel that's not configured for hotplug.

If you build a custom kernel anyway, maybe the simplest approach would
be to copy the dahdi files onto the kernel tree and build it there.

drivers/dahdi/Kconfig has:

  config DAHDI_VOICEBUS
        tristate "VoiceBus(tm) Interface Library"
        depends on PCI
        default DAHDI

An example entry for a card that uses it:

  config DAHDI_WCTDM24XXP
        tristate "Digium Wildcard VoiceBus analog card Support"
        depends on DAHDI && DAHDI_VOICEBUS
        default DAHDI

Thus if the instructions from Kconfig are applied, you'll default not to
build any PCI driver without any further effort. Sadly it is not applied
when you build DAHDI as modules.

You'll still have to create the static device files. See
http://svn.debian.org/viewsvn/pkg-voip/dahdi-linux/trunk/debian/make_static_nodes

> 
> >> Now, at install time, it's fiddling with system files on my build box that
> >> it really should not be touching at all - output from make:
> >>
> >> [ `id -u` = 0 ] && /sbin/depmod -a 2.6.32.3-dsx-geode || :
> >> install -d /etc/udev/rules.d
> >> build_tools/genudevrules > /etc/udev/rules.d/dahdi.rules
> >> build_tools/genudevrules: line 3: udevinfo: command not found
> >> build_tools/genudevrules: line 7: udevadm: command not found
> >> install -m 644 drivers/dahdi/xpp/xpp.rules /etc/udev/rules.d/
> >> for hdr in kernel.h user.h fasthdlc.h wctdm_user.h dahdi_config.h; do \
> >>                  install -D -m 644 include/dahdi/$hdr
> >> /usr/include/dahdi/$hdr; \
> >>          done
> >> rmdir: failed to remove `/usr/include/zaptel': No such file or directory
> >> make: [install-include] Error 1 (ignored)
> >>
> >> I don't use udev on my build system, nor my target systems so why is it
> >> bothering... But I feel there really ought to be a means to tell it that
> >> it's not building for the local system, so don't fiddle with local
> >> files...

That one probably needs addressing as well, I guess.

-- 
               Tzafrir Cohen
icq#16849755              jabber:tzafrir.cohen at xorcom.com
+972-50-7952406           mailto:tzafrir.cohen at xorcom.com
http://www.xorcom.com  iax:guest at local.xorcom.com/tzafrir