NAME¶
dpkg-architecture - set and determine the architecture for package building
SYNOPSIS¶
dpkg-architecture [
option...] [
command]
DESCRIPTION¶
dpkg-architecture does provide a facility to determine and set the build and
host architecture for package building.
The build architecture is always determined by an external call to
dpkg(1), and can not be set at the command line.
You can specify the host architecture by providing one or both of the options
-a and
-t. The default is determined by an external call to
gcc(1), or the same as the build architecture if CC or gcc are both not
available. One out of
-a and
-t is sufficient, the value of the
other will be set to a usable default. Indeed, it is often better to only
specify one, because
dpkg-architecture will warn you if your choice
does not match the default.
COMMANDS¶
- -l
- Print the environment variables, one each line, in the
format VARIABLE=value. This is the default action.
- -edebian-architecture
- Check for equality of architecture. By default
debian-architecture is compared against the current Debian
architecture, being the host. This action will not expand the architecture
wildcards. Command finishes with an exit status of 0 if matched, 1 if not
matched.
- -iarchitecture-wildcard
- Check for identity of architecture by expanding
architecture-wildcard as an architecture wildcard and comparing
against the current Debian architecture. Command finishes with an exit
status of 0 if matched, 1 if not matched.
- -qvariable-name
- Print the value of a single variable.
- -s
- Print an export command. This can be used to set the
environment variables using eval.
- -u
- Print a similar command to -s but to unset all
variables.
- -c command
- Execute a command in an environment which has all
variables set to the determined value.
- -L
- Print a list of valid architecture names.
- -?, --help
- Show the usage message and exit.
- --version
- Show the version and exit.
OPTIONS¶
- -adebian-architecture
- Set the Debian architecture.
- -tgnu-system-type
- Set the GNU system type.
- -f
- Values set by existing environment variables with the same
name as used by the scripts are honored (i.e. used by
dpkg-architecture), except if this force flag is present. This
allows the user to override a value even when the call to
dpkg-architecture is buried in some other script (for example
dpkg-buildpackage(1)).
TERMS¶
- build machine
- The machine the package is built on.
- host machine
- The machine the package is built for.
- Debian architecture
- The Debian architecture string, which specifies the binary
tree in the FTP archive. Examples: i386, sparc, hurd-i386.
- architecture wildcard
- An architecture wildcard is a special architecture string
that will match any real architecture being part of it. The general form
is <kernel>-<cpu>. Examples: linux-any, any-i386,
hurd-any.
- GNU system type
- An architecture specification string consisting of two
parts separated by a dash: cpu and system. Examples: i386-linux-gnu,
sparc-linux-gnu, i386-gnu, x86_64-netbsd.
VARIABLES¶
The following variables are set by
dpkg-architecture:
- DEB_BUILD_ARCH
- The Debian architecture of the build machine.
- DEB_BUILD_ARCH_OS
- The Debian system name of the build machine.
- DEB_BUILD_ARCH_CPU
- The Debian cpu name of the build machine.
- DEB_BUILD_ARCH_BITS
- The pointer size of the build machine (in bits).
- DEB_BUILD_ARCH_ENDIAN
- The endianness of the build machine (little / big).
- DEB_BUILD_GNU_CPU
- The CPU part of DEB_BUILD_GNU_TYPE.
- DEB_BUILD_GNU_SYSTEM
- The System part of DEB_BUILD_GNU_TYPE.
- DEB_BUILD_GNU_TYPE
- The GNU system type of the build machine.
- DEB_BUILD_MULTIARCH
- The clarified GNU system type of the build machine, used
for filesystem paths.
- DEB_HOST_ARCH
- The Debian architecture of the host machine.
- DEB_HOST_ARCH_OS
- The Debian system name of the host machine.
- DEB_HOST_ARCH_CPU
- The Debian cpu name of the host machine.
- DEB_HOST_ARCH_BITS
- The pointer size of the host machine (in bits).
- DEB_HOST_ARCH_ENDIAN
- The endianness of the host machine (little / big).
- DEB_HOST_GNU_CPU
- The CPU part of DEB_HOST_GNU_TYPE.
- DEB_HOST_GNU_SYSTEM
- The System part of DEB_HOST_GNU_TYPE.
- DEB_HOST_GNU_TYPE
- The GNU system type of the host machine.
- DEB_HOST_MULTIARCH
- The clarified GNU system type of the host machine, used for
filesystem paths.
DEBIAN/RULES¶
The environment variables set by
dpkg-architecture are passed to
debian/rules as make variables (see make documentation). However, you
should not rely on them, as this breaks manual invocation of the script.
Instead, you should always initialize them using
dpkg-architecture with
the -q option. Here are some examples, which also show how you can improve the
cross compilation support in your package:
Retrieving the GNU system type and forwarding it to ./configure:
-
DEB_BUILD_GNU_TYPE := $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
DEB_HOST_GNU_TYPE := $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
[...]
configure --build=$(DEB_BUILD_GNU_TYPE) --host=$(DEB_HOST_GNU_TYPE)
Doing something only for a specific architecture:
-
DEB_HOST_ARCH := $(shell dpkg-architecture -qDEB_HOST_ARCH)
ifeq ($(DEB_HOST_ARCH),alpha)
[...]
endif
or if you only need to check the CPU or OS type, use the DEB_HOST_ARCH_CPU or
DEB_HOST_ARCH_OS variables.
Note that you can also rely on an external Makefile snippet to properly set all
the variables that
dpkg-architecture can provide:
-
include /usr/share/dpkg/architecture.mk
ifeq ($(DEB_HOST_ARCH),alpha)
[...]
endif
In any case, you should never use
dpkg --print-architecture to get
architecture information during a package build.
BACKWARD COMPATIBILITY¶
The /usr/share/dpkg/architecture.mk Makefile snippet is provided by dpkg-dev
since version 1.16.1.
The DEB_*_ARCH_BITS and DEB_*_ARCH_ENDIAN variables were introduced in dpkg-dev
1.15.4. Using them in
debian/rules thus requires a build-dependency on
dpkg-dev (>= 1.15.4).
The DEB_HOST_ARCH_CPU and DEB_HOST_ARCH_OS variables were introduced in dpkg-dev
1.13.2.
The
-e and
-i options were only introduced in relatively recent
versions of
dpkg-architecture (since dpkg 1.13.13).
EXAMPLES¶
dpkg-buildpackage accepts the
-a option and passes it to
dpkg-architecture. Other examples:
- CC=i386-gnu-gcc dpkg-architecture -c debian/rules
build
- eval `dpkg-architecture -u`
Check if an architecture is equal to the current architecture or a given one:
- dpkg-architecture -elinux-alpha
- dpkg-architecture -amips -elinux-mips
Check if the current architecture or an architecture provided with -a are Linux
systems:
- dpkg-architecture -ilinux-any
- dpkg-architecture -ai386 -ilinux-any
FILES¶
All these files have to be present for
dpkg-architecture to work. Their
location can be overridden at runtime with the environment variable
DPKG_DATADIR.
- /usr/share/dpkg/cputable
- Table of known CPU names and mapping to their GNU
name.
- /usr/share/dpkg/ostable
- Table of known operating system names and mapping to their
GNU name.
- /usr/share/dpkg/triplettable
- Mapping between Debian architecture triplets and Debian
architecture names.
SEE ALSO¶
dpkg-buildpackage(1),
dpkg-cross(1).