Re: building qt4 for arm

On 12 February 2013 16:28, Rieker Flaik <[email protected]> wrote:
> I'm running debian arm and need to rebuild libqt4 with an additional
> patch. What is the best and fastest way to rebuild that package?

Build it on an ARM box, as Debian packages (in general) need to build
on native hardware.

>
> I also want to mention that I already tried several ways (cross-compile
> and qemu):
>
> 1. cross-compile:
> I have installed the emdebian toolchain by doing:
>
>    aptitude install emdebian-archive-keyring
>    echo "deb http://www.emdebian.org/debian/ squeeze main" >> /etc/apt/sources.list
>    aptitude update
>    aptitude install gcc-4.4-arm-linux-gnueabi cpp-4.4-arm-linux-gnueabi
>
> Then I did:
>    apt-get source libqt4-dev
>    dpkg-buildpackage -aarmel -j4
>
> The build-process started but died after 3 minutes with messages like
> this:
>
>    animation/qsequentialanimationgroup.cpp:467: warning: unused variable ‘q’
>    ../../include/QtCore/../../src/corelib/arch/qatomic_arm.h: Assembler messages:
>    ../../include/QtCore/../../src/corelib/arch/qatomic_arm.h:131: Error: no such instruction: `swpb %al,%bpl,[%rbx]'
>    ../../include/QtCore/../../src/corelib/arch/qatomic_arm.h:131: Error: no such instruction: `swpb %al,%bpl,[%rbx]'
>
> 2. qemu: takes forever and only one Host-CPU is used.

QEMU runs at an equivalent of about 1/12th of the host CPU frequency,
so a 2400MHz 386 emulates at about the speed of a 200MHz ARM CPU.

> I'm still searching for a practicable way of rebuilding bigger debian
> packages.

There's a 500MHz 512MB Debian armel box here that you can use over SSH
- write privately if that would be useful.  Not that it won't still
take forever... (where forever is defined as any time period longer
than an hour :)

For greater speed, you can buy/borrow/use something like a sheevaplug
or whatever the cheap top-end ARM gadget is these days.

   M