arm64 as Tier 1 for FreeBSD 13

[Paul Mather]

On Dec 4, 2019, at 6:30 AM, Ed Maste <emaste at freebsd.org> wrote:

> On Wed, 4 Dec 2019 at 09:49, Paul Mather <paul at gromit.dlib.vt.edu> wrote:
>> 
>> I'm running FreeBSD/arm64 12-STABLE on a Raspberry Pi 3 using a root-on-ZFS setup.  I've been using packaged base for quite some time, cross-building on FreeBSD/amd64.  Every time I upgrade FreeBSD via "pkg upgrade" it seems to me that it does not take an inordinately long time.  It takes longer than packaged base on a regular FreeBSD/amd64 server with spinning disk, but not an excessive amount of time.  It's certainly on the order of minutes, not hours.
> 
> Indeed, migrating to pkg base is the presumed solution for the
> "freebsd-update would be too slow on SD card root" issue.
> 
> Perhaps you wouldn't mind writing up the steps you're using to
> cross-build and install updates?


I am using already existing documentation from the FreeBSD project.  (Many thanks to the original authors!)


1. Building and serving pkg packages

For a long time I have built packages for my FreeBSD systems using Poudriere and serve them over the network via the Poudriere build machine.  See:

	- https://www.freebsd.org/doc/handbook/ports-poudriere.html

I use Nginx (via www/nginx) to serve the pkg repos (based on the /usr/local/share/examples/poudriere/nginx.conf.sample file in the ports-mgmt/poudriere installed port).

Note, you don't really need Poudriere in all this, but I find it useful for also cross-building my FreeBSD/arm64 ports.  Because I was using Poudriere long before PkgBase, I included it here as something folks might also want to use.


2. Cross-building for FreeBSD/arm64

To cross-build, I use the "mk" script provided at the arm/crossbuild section of the FreeBSD Wiki.  See:

	- https://wiki.freebsd.org/arm/crossbuild

In the case of my FreeBSD/arm64 systems, my "config/mk.conf" and "config/make.conf" consist solely of the following:

===== config/mk.conf =====
mk_arch="aarch64"
mk_kernel="GENERIC"
===== config/mk.conf =====

===== config/make.conf =====
REPODIR=/build/repo
===== config/make.conf =====

I have a simple script, "rebuild_os_pkgs" that cross-builds everything and makes the base packages that end up under /build/repo:

===== rebuild_os_pkgs =====
#!/bin/sh
mk buildworld
mk buildkernel
mk packages
===== rebuild_os_pkgs =====

(My "mk" script is in /usr/local/bin.)

To build an updated OS I run that script after first having updated the OS source in the "src" subdirectory (e.g., via "make update").  (You can symlink "src" to "/usr/src" if you want to save space.)  The "mk packages" step results in a pkg-compliant repository with all the PkgBase packages in it.


3. FreeBSD/arm64 PkgBase

I followed the PkgBase documentation at the FreeBSD Wiki to set up my Raspberry Pi 3 to use the OS packages build on the FreeBSD/amd64 build machine using the "rebuild_os_pkgs" script.  See:

	- https://wiki.freebsd.org/PkgBase

I have this snippet on the OS package build machine to serve out the pkg repository created as part of the rebuild_os_pkgs run:

=====
        location /FreeBSD-base {
            alias /build/repo;
            autoindex on;
            allow all;
        }
=====


If you are used to building and serving pkg packages (e.g., ports packages) then the real workhorse in all this is the "mk" cross-building script + FreeBSD build system that is cross-building capable.

I encourage folks to check out the FreeBSD documentation on cross-building for ARM and PkgBase that I mention above.  They have a lot of useful information.

Cheers,

Paul.