[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Cross build an arm Debian Live system

On Tue, Jun 14, 2011, Daniel Baumann wrote:
> unfortunately, we're not quite there yet. the missing pieces are:
>   * we'll need armhf port (for efima mx, doesn't bother other arm
>     platforms though), that should mostly be ready on debian-ports.org
>     these days.

 (technically you can use the armel port; it's just not as fast as it
 could be)

>   * live-build should, on arm, seperate rootfs and kernel somehow, so
>     that we can offer one (or two) userspace images, and a multitude of
>     different kernel and initrd images per hardware platform.

 In Linaro, we came to the same conclusion; we're generating on one side
 rootfs tarballs with live-helper and on the other side we're generating
 a special container called a "hwpack" which contains kernel,
 bootloader when applicable, and optimized graphics drivers or such when
 available.  These are combined with linaro-image-tools into a bootable
 SD card image.  I'm not sure which wiki page covers this best, but this
 might be a start:

>   * currently, live-build always builds images natively. for arm, we
>     should use binfmt_misc, so that one can alternatively build it
>     basically everywhere (and specifically on i386 and amd64). zumbi
>     and i talked about that about a year ago on irc (check the logs at
>     live.d.n/archive/irc for more), it contains all necessary
>     information to make it happen (it wasn't implemented yet as there
>     was no way of confirming and testing the resulting images yet, now
>     that i've got and arm device since last summer, this should be much
>     easier in future).

 linaro-image-tools combines the hwpack and the rootfs on a x86 system
 via binfmt_misc; linaro-media-create eventually copies qemu-arm-static
 into the chroot and runs "dpkg -i" on the kernel and other packages.
 We still build the rootfses natively though.

 In the case of live-helper, it would typically be a matter of replacing
 debootstrap with qemu-debootstrap --arch=foo; this wrapper around
 debootstrap is provided in the qemu-user-static package and supports
 armel and armhf.

> apparently, the ubuntu arm/linaro guys are using jasper on arm. i've not
> used that, however, i would prefere having live-boot being improved for
> arm on anything that might be needed for arm (again, not having done
> anything with it on arm yet), but bugs and/or patches are most welcome.

 NB: Linaro doesn't use jasper, but AFAIK Ubuntu still does albeit there
 might be plans to move away from it.

> arm is a regular debian architecture, so yes; and armhf is available on
> debian-ports.org.

 NB: armel is the Debian name -- Debian also had an "arm" architecture
 but that one is definitely not recommended for modern hardware (and
 removed from modern Debian as well).

Loïc Minier

Reply to: