Cross-compilation in pkgsrc (user's guide) -*- outline -*-
Taylor R. Campbell <riastradh@NetBSD.org>
$NetBSD: HOWTO-use-crosscompile,v 1.18 2024/06/06 02:38:02 riastradh Exp $
The following steps enable you to build binary packages for a machine
architecture other than the one you are building on. For example, you
might use them on your beefy umpteen-core amd64-based build machine
(the `native' machine) to build packages for your feeble powerpc-based
network appliance (the `target' machine).
These instructions assume you use the conventional privileged paths:
/usr/src for the NetBSD source tree, /usr/obj for the NetBSD object
tree, and /usr/pkgsrc for the pkgsrc tree. If you want to do it
unprivileged, see `* Unprivileged notes' below.
XXX This currently works only for NetBSD.
* Build NetBSD tools and distribution for the target system
Use build.sh to build NetBSD tools and a distribution, and remember
what the destdir and tooldir are -- you'll need them for pkgsrc's
mk.conf.
$ cd /usr/src
$ ./build.sh -m evbppc tools
$ ./build.sh -m evbppc distribution
By default, the destdir will be /usr/obj/destdir.evbppc, and the
tooldir will be (say) /usr/obj/tooldir.NetBSD-6.1-amd64 if you're
running NetBSD 6.1 on amd64.
* Set up mk.conf
In addition to whatever else you want in your mk.conf for pkgsrc, add:
# Cross-compile by default. (Alternatively, instead of having this
# setting in mk.conf, you can cross-build packages by just running
# `make package USE_CROSS_COMPILE=yes'.)
#
# Note: This must use `?=' so it doesn't override pkgsrc's internal
# USE_CROSS_COMPILE=no when recursively building toolchain packages
# that have to run on the host.
USE_CROSS_COMPILE?= yes
# Point pkgsrc at the NetBSD tooldir and destdir for cross builds.
TOOLDIR= /usr/obj/tooldir.NetBSD-6.1-amd64
CROSS_DESTDIR= /usr/obj/destdir.evbppc
# Specify the machine architecture of target packages.
CROSS_MACHINE_ARCH= powerpc
# Specify the OS of target packages.
CROSS_OPSYS= NetBSD
CROSS_OS_VERSION= 10.0
CROSS_OPSYS_VERSION= 100000
CROSS_LOWER_OPSYS= netbsd
CROSS_LOWER_OPSYS_VERSUFFIX= # empty
CROSS_LOWER_OS_VARIANT= # empty
CROSS_LOWER_VARIANT_VERSION= # empty
CROSS_LOWER_VENDOR= # empty
CROSS_OBJECT_FMT= ELF
Optionally, you can set CROSS_LOCALBASE, CROSS_SYSCONFBASE, and
CROSS_VARBASE for cross-compiled packages separately from LOCALBASE,
SYSCONFBASE, and VARBASE for natively compiled packages. For example,
you can use an unprivileged pkgsrc build into /home/user/cross/pkg that
will create packages which install to /opt/pkg:
LOCALBASE= /home/user/cross/pkg
CROSS_LOCALBASE= /opt/pkg
By default, pkgsrc will assume:
CROSS_LOCALBASE= /usr/pkg
CROSS_SYSCONFBASE= /etc
CROSS_VARBASE= /var
That is, no matter what you set LOCALBASE, SYSCONFBASE, and VARBASE to
in mk.conf for native packages, like directores under /home/user, by
default cross-compiled packages will see LOCALBASE=/usr/pkg,
SYSCONFBASE=/etc, and VARBASE=/var.
** Bootstrapped pkgsrc
You can bootstrap pkgsrc or not; it shouldn't make a difference for
cross-compilation. If you do, replace `make' by `bmake' below:
* Make some packages
Now packages you build normally will be cross-compiled for the target:
$ cd /usr/pkgsrc/net/isc-dhcpd4 && make package
You can find the shiny new powerpc package at
/usr/pkgsrc/packages.powerpc/
Any packages needed on natively to build the target packages will be
built and installed automatically, but if for some reason you want to
build a native package, you can run
$ cd /usr/pkgsrc/net/isc-dhcpd4 && make package USE_CROSS_COMPILE=no
* Unprivileged notes
I do all this stuff unprivileged in directories under my home
directory so that it's easy for me to nuke build products without
messing with the package installations I use for development.
NetBSD srcdir: ~/netbsd/current/src
NetBSD objdir: ~/netbsd/current/obj.evbppc
NetBSD tooldir: ~/netbsd/current/obj.evbppc/tooldir.NetBSD-6.1-amd64
NetBSD destdir: ~/netbsd/current/obj.evbppc/destdir.evbppc
pkgsrc: ~/pkgsrc/current/pkgsrc
pkgsrc LOCALBASE: ~/pkgsrc/current/pkg
(~/netbsd/current/src and ~/pkgsrc/current/pkgsrc are actually
read-only null mounts of ~/netbsd/current/src-cvs and
~/pkgsrc/current/pkgsrc-cvs, respectively.)
To build NetBSD, I run:
$ cd ~/netbsd/current/src
$ ./build.sh -O ../obj.evbppc -U -u -m evbppc -j12 tools
$ ./build.sh -O ../obj.evbppc -U -u -m evbppc -j12 distribution
My mk.conf additionally has UNPRIVILEGED=yes, and I bootstrap pkgsrc
with
$ cd ~/pkgsrc/current/pkgsrc/bootstrap
$ ./bootstrap \
--gzip-binary-kit ~/pkgsrc/current/bootstrap/20130422.tgz \
--mk-fragment ~/pkgsrc/current/bootstrap/20130422.mk \
--prefix ~/pkgsrc/current/pkg \
--unprivileged \
--workdir /tmp/bootwork
and various other crud to customize the build and package options.
This requires putting ~/pkgsrc/current/pkg/{bin,sbin} before
/usr/{bin,sbin} in your PATH so that you see bmake and use the right
pkg_* tools. Send me a note if you have questions about my setup.
* Terminology
This document and the relevant pkgsrc variables call the machine on
which the packages are built the `native' machine, and the machine on
which the packages are to be run the `target' machine.
This is different from the GNU build system, which considers three
different machines for so-called Canadian cross-builds, which pkgsrc
does not support:
The `build' machine is the machine on which the software is built.
The `host' machine is the machine on which the software will run.
The `target' machine is the machine that the software is being
configured to operate on, such as a cross-compiler or cross-linker.
These correspond to the pkgsrc nomenclature as follows:
- Native packages configured for native compilation:
GNU pkgsrc
--- ------
build native
host native
target native
- Native packages configured for cross-compilation:
GNU pkgsrc
--- ------
build native
host native
target target
- Target packages:
GNU pkgsrc
--- ------
build native
host target
target target
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