How do I emerge a package for a foreign architecture?

dinominant · Tux's lil' helper Joined: 27 Oct 2006 Posts: 102

I have dynamic binary translation setup and working on my aarch64 host (Orange Pi PC2). I want to install a binary package that only has i386 and x86_64 binaries. Is there a way to unmask the i386 version of the package and force portage to install that one -- even though my architecture is different? If I just copy the files over it works, but I would rather have emerge manage the package then inject some binaries into my root filesystem.

The dynamic binary translation may be slow, but it actually works. Sometimes it's the only way.

NeddySeagoon · Posted: Sat Sep 16, 2017 5:24 pm Post subject:

dinominant,

I don't fully understand what you want to do.

You want to run an existing i386/x86_64 binary on an aarch64 system using the binfmt service, or something like it.
If the program in statically linked (unlikely) then qemu should run it.

If its dynamically linked, you need to put it into a chroot, with all its libraries and a static-user QEMU built for the host and run it there.
If you want to, you can do an x32 or amd64 install in this chroot, with the aid of a static-user QEMU.

Like an arm64 chroot on an amd64 system but in reverse.

What's the program?
Its a whole lot less pain to build it for arm64.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

dinominant · Tux's lil' helper Joined: 27 Oct 2006 Posts: 102

I have a working aarch64 host, with qemu statically built. As a proof of concept I have previously setup an entire Gentoo i686 chroot with wine and SkiFree.exe on a raspberry pi 2, which actually worked.

However, in this particular situation I am building a high resolution network flatbed scanner with SANE (using the Epson Perfection V550 which is USB only). It has linux support, but only for x86 and amd64. So I want to use dynamic binary translation so I can use it on my aarch64 Orange Pi PC2. My project is to make the scanner fully autonomous so I can place an item, press the scan button on the Orange Pi, and let it run for hours while it performs a ultra high resolution scan to a network share. Later I plan to add some LED lights so I can try some multi spectral scanning.

The scanner works on my amd64 host perfecly. I want to get it working on arm and arm64. There are no open source drivers that I can build, only x86 and amd64 binaries: https://bugs.gentoo.org/580450

NeddySeagoon · Posted: Sat Sep 16, 2017 7:09 pm Post subject:

dinominant,

That will be iscan then. You will need to run it in a chroot with all the libs that

Tony0945 · Posted: Sat Sep 16, 2017 9:47 pm Post subject:

szatox · Advocate Joined: 27 Aug 2013 Posts: 3445

This "intelligent guess" of yours inflates the data file even though it does not contain any new information.
Being useless, can safely be left out until the end user actually attempts to scale the whole image beyond its limits.
Well, "made up" feels way more honest to me.

NeddySeagoon · Posted: Sat Sep 16, 2017 10:15 pm Post subject:

Tony0945,

There are any number of interpolation algorithms.
They all give different answers and they are all equally valid.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Tony0945 · Posted: Sat Sep 16, 2017 11:10 pm Post subject: ant m

dinominant · Tux's lil' helper Joined: 27 Oct 2006 Posts: 102

I went ahead and tried two approaches with the media-gfx/iscan-plugin-perfection-v550 package (this package works fine on my amd64 host without any chroot or binary translation).

Plan A: installing the i386 package directly on the arm host with qemu dynamic binary translation
With this configuration I modified the media-gfx/iscan-plugin-perfection-v550 ebuild to just install the i386 files.
I am able to run scanimage, but actually scanning does not work.

NeddySeagoon · Posted: Sun Sep 17, 2017 8:56 am Post subject:

dinominant,

The scanner needs a firmware upload that is provided by the binary plugin.
The iscan ebuild hints that iscan itself is arch agnostic but the plugins are not.

As the scanner has its own PSU, it may be enough to run iscan with the plugin on a real 32 or 64 bit system, then move the USB over to the arm64, without powering down.
The firmware will still be loaded. Its a long shot but worth a try. It all depends what the plugin does.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

dinominant · Tux's lil' helper Joined: 27 Oct 2006 Posts: 102

Plan C, which is to run a full i386 vm on the orange pi and pass the scanner usb device to the guest vm... also failed.

Something is very broken with either Qemu, the armbian kernel for the orange pi pc2 I'm using, or both. When I boot the qemu virtual machine without a network adapter I can start the gentoo installation, but if I try to boot it with a network adapter connected to br0 I get a kernel panic as soon as I power on the virtual machine and then the orange pi restarts.

I'm going to start off with an old junk x86_64 laptop first. Then I'm going to try running an armv7hf virtual machine on that with an updated vanilla-sources kernel to see if that works. This way I can eliminate the non-standard orange/raspberry pi kernels and their "stable" drivers from the equation. It's going to be fantastically slow (x86_64-> Qemu -> armv7hf guest -> qemu dynamic translation for the x86_32 scanner parts), but I'm curious if that will work.