summaryrefslogtreecommitdiff
path: root/doc/HOWTO-use-crosscompile
blob: 1801a10bf992e023ccbd4980cb05d2a4bfd19f14 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
Cross-compilation in pkgsrc (user's guide)              -*- outline -*-
Taylor R. Campbell <riastradh@NetBSD.org>

$NetBSD: HOWTO-use-crosscompile,v 1.4 2016/05/04 02:05:22 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.
   #
   # XXX This currently can't be set to `yes' on the command line,
   # which is a bug.
   USE_CROSS_COMPILE?=  yes

   # This is a kludge for cross-libtool.
   #
   # XXX Should not need this.
   CROSSBASE=           ${LOCALBASE}/cross-${TARGET_ARCH:U${MACHINE_ARCH}}

   .if !empty(USE_CROSS_COMPILE:M[yY][eE][sS])
   # Specify the machine architecture of target packages.
   #
   # XXX This currently can't be set on the command line, which is a
   # bug.
   MACHINE_ARCH=        powerpc

   # Point pkgsrc at the NetBSD tooldir and destdir.
   #
   # XXX There is no obvious variable that is set to amd64 so that we
   # could use
   #
   #    TOOLDIR=        /usr/obj/tooldir.${OPSYS}-${OS_VERSION}-${NATIVE_xyz}
   #
   # MACHINE is amd64 but, since it's not NATIVE_xyz, it's wrong.
   # NATIVE_MACHINE_ARCH is x86_64, not amd64.
   TOOLDIR=             /usr/obj/tooldir.NetBSD-6.1-amd64
   CROSS_DESTDIR=       /usr/obj/destdir.evbppc

   # Put target work and packages in separate directories.  (You might
   # use OBJMACHINE=yes or WRKOBJDIR=/tmp/work.${MACHINE_ARCH} instead
   # for the work directories.)
   #
   # XXX Should not need this.
   PACKAGES=            ${PKGSRCDIR}/packages.${MACHINE_ARCH}
   WRKDIR_BASENAME=     work.${MACHINE_ARCH}
   .endif

You can bootstrap pkgsrc or not; it shouldn't make a difference for
cross-compilation.  If you do, replace `make' by `bmake' below, of
course.

XXX Some variables, notably LOCALBASE and other paths that get baked
into packages, cannot currently be set differently for native and
target packages.

* Work around libtool

Libtool's build system is broken -- it misuses the GNU build system
build/host/target settings.  For now we need to kludge around it
manually:

   $ cd /usr/pkgsrc/cross/libtool-base
   $ make package
   $ pkg_add -m powerpc /usr/pkgsrc/packages.powerpc/All/cross-libtool-base-powerpc-2.4.2.tgz

(This builds a libtool package for the target, and then installs the
target package natively.  This *shouldn't* work, and pkg_add normally
refuses this, but it does work because libtool is a shell script, and
`pkg_add -m powerpc' makes pkg_add pretend we are powerpc to suppress
its refusal.)

* 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

XXX Note that currently you cannot omit USE_CROSS_COMPILE?=yes from
your mk.conf and pass USE_CROSS_COMPILE=yes on the make command line.
This is a bug.

* 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