Re: Cross compiling user applications for armv7

It is more about how hard it is to setup an environment for cross compiling your own kernel modules or applications for armv7.
I don't really care whether I use Buildroot way of doing things or FreeBSD way.
The difference is that with Buildroot it takes 10 minutes to setup such environment.
With FreeBSD I am struggling for two days.
And the only advice I get is to use arm64 machine.
Well, I don't have any.
And even if I had, I wouldn't use it, because I find this concept deeply "misengineered".

I know that you want to help, and I appreciate it.
I just feel frustrated with the complexity of this conceptually trivial task.

Regards,
Michał Kruszewski


Sent with Proton Mail secure email.

On Saturday, September 13th, 2025 at 4:29 PM, Mark Millard <marklmi@yahoo.com> wrote:

> 
> On Sep 13, 2025, at 00:20, Michał Kruszewski mkru@protonmail.com wrote:
> 
> > Basically you are saying that I should have a separate physical arm64 machine for doing embedded armv7 development on FreeBSD.
> > If I understand this correctly, I just can't understand how can people say that FreeBSD is embedded friendly.
> > This is so much complex and convoluted compared to just using, for example, Buildroot on Linux.
> > This also doesn't feel like a *nix way of solving things.
> > I thought that after cross compiling world and kernel, there is some shell script that I can simply source to start cross-development for target platform.
> 
> 
> I found this AI based note about Buildroot's way of
> putting cross-build toolchains to use:
> 
> QUOTE
> Buildroot pre-configures and compiles all necessarily
> packages during the build process to create a custom
> root filesystem.
> . . .
> Buildroot focuses on static builds, meaing all selected
> packages are compiled and integrated into the final root
> filesystem image during the build process. There is no
> concept of installing or updating packages on the target
> after the initial build.
> END QUOTE
> 
> This is certainly not what the FreeBSD ports tree is
> set up for. Buildroot or analogous does not exist for
> FreeBSD --or most *BSD or Unix-- to my knowledge.
> 
> May be NetBSD's pkgsrc cross build support:
> 
> https://cdn.netbsd.org/pub/pkgsrc/current/pkgsrc/doc/HOWTO-use-crosscompile
> 
> would be closer to how you like to work? (I've never
> used such.)
> 
> > Regards,
> > Michał Kruszewski
> > 
> > Sent with Proton Mail secure email.
> > 
> > On Saturday, September 13th, 2025 at 12:23 AM, Mark Millard marklmi@yahoo.com wrote:
> > 
> > > On Sep 12, 2025, at 14:10, Michał Kruszewski mkru@protonmail.com wrote:
> > > 
> > > > A simple way is to set up an armv7 chroot / jail on an arm64 host such as a Raspberry Pi (Apple devices don't work!).
> > > > Then it's just like a native environment, but usually much faster.
> > > 
> > > > I don't have physical arm64 host.
> > > > I also don't want to create a VM.
> > > > The whole idea seems weird and unnatural.
> > > 
> > > Ignoring the RPi4B detail:
> > > 
> > > FreeBSD official armv7 port-packages are built this way
> > > on arm64 hardware that natively supports user-space
> > > armv7 code. (ampere* systems are used.)
> > > 
> > > FreeBSD official i386 port-packages are built this way
> > > on amd64 hardware that natively supports user-space
> > > i386 code.
> > > 
> > > No use of qemu variants of any kind: no attempt at
> > > non-native-capable host environments.
> > > 
> > > (Back when amd64 and qemu was used for the likes
> > > of armv7, lots of stuff failed to build mcuh of
> > > the time over the years --stuff that builds
> > > just fine now. This was abandoned after native
> > > became available. armv6 was always qemu based
> > > on amd64 and could not build much as of the last
> > > time a build was run.)
> > > 
> > > > It sounds more like an exotic workaround.
> > > 
> > > It is the official technique used for what FreeBSD
> > > distributes for armv7 port-packages.
> > > 
> > > > Regards,
> > > > Michał Kruszewski
> > > > 
> > > > Sent with Proton Mail secure email.
> > > > 
> > > > On Friday, September 12th, 2025 at 10:46 PM, Robert Clausecker fuz@fuz.su wrote:
> > > > 
> > > > > Hi Michał,
> > > > > 
> > > > > A simple way is to set up an armv7 chroot / jail on an arm64 host such as
> > > > > a Raspberry Pi (Apple devices don't work!). Then it's just like a native
> > > > > environment, but usually much faster.
> > > > > 
> > > > > Yours,
> > > > > Robert Clausecker
> > > > > 
> > > > > Am Fri, Sep 12, 2025 at 04:19:42PM +0000 schrieb Michał Kruszewski:
> > > > > 
> > > > > > Is there any tutorial on how to cross compile custom user application for armv7?
> > > > > > I struggle t find any.
> > > > > > Cross compiling the system is pretty easy.
> > > > > > However, how can one cross compile custom user application or kernel drivers.
> > > > > > 
> > > > > > Regards,
> > > > > > Michał Kruszewski
> > > > > > 
> > > > > > Sent with Proton Mail secure email.
> > > > > 
> > > > > --
> > > > > () ascii ribbon campaign - for an encoding-agnostic world
> > > > > /\ - against html email - against proprietary attachments
> > > 
> > > ===
> > > Mark Millard
> > > marklmi at yahoo.com
> 
> 
> ===
> Mark Millard
> marklmi at yahoo.com