NAME
dpkg-architecture - set and determine the architecture for package
building
SYNOPSIS
dpkg-architecture [options] [commands]
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_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.
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:
Instead of:
ARCH=`dpkg --print-architecture`
configure $(ARCH)-linux
please use the following:
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=$(DEB_HOST_GNU_TYPE)
Instead of:
ARCH=`dpkg --print-architecture`
ifeq ($(ARCH),alpha)
...
endif
please use:
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.
In general, calling dpkg in the rules file to get architecture
information is deprecated (unless you want to provide backward
compatibility, see below). Especially the --print-architecture option
is unreliable since we have Debian architectures which don't equal a
processor name.
BACKWARD COMPATIBILITY
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. Before this debian/rules files tended to check the
values of the DEB_HOST_GNU_CPU or DEB_HOST_GNU_TYPE variables which
have been subject to change.
Where debian/rules files check these variables to decide how or what to
compile, this should be updated to use the new variables and values.
You may wish to retain backwards compatibility with older version of
dpkg-dev by using the following code:
DEB_HOST_ARCH_CPU := $(shell dpkg-architecture -qDEB_HOST_ARCH_CPU 2>/dev/null)
DEB_HOST_ARCH_OS := $(shell dpkg-architecture -qDEB_HOST_ARCH_OS 2>/dev/null)
# Take account of old dpkg-architecture output.
ifeq ($(DEB_HOST_ARCH_CPU),)
DEB_HOST_ARCH_CPU := $(shell dpkg-architecture -qDEB_HOST_GNU_CPU)
ifeq ($(DEB_HOST_ARCH_CPU),x86_64)
DEB_HOST_ARCH_CPU := amd64
endif
endif
ifeq ($(DEB_HOST_ARCH_OS),)
DEB_HOST_ARCH_OS := $(subst -gnu,,$(shell dpkg-architecture -qDEB_HOST_GNU_SYSTEM))
ifeq ($(DEB_HOST_ARCH_OS),gnu)
DEB_HOST_ARCH_OS := hurd
endif
endif
And similarly for DEB_BUILD_ARCH_CPU and DEB_BUILD_ARCH_OS.
If you still wish to support versions of dpkg-dev that did not include
dpkg-architecture, the following does the job:
DEB_BUILD_ARCH := $(shell dpkg --print-architecture)
DEB_BUILD_GNU_CPU := $(patsubst hurd-%,%,$(DEB_BUILD_ARCH))
ifeq ($(filter-out hurd-%,$(DEB_BUILD_ARCH)),)
DEB_BUILD_GNU_SYSTEM := gnu
else
DEB_BUILD_GNU_SYSTEM := linux-gnu
endif
DEB_BUILD_GNU_TYPE=$(DEB_BUILD_GNU_CPU)-$(DEB_BUILD_GNU_SYSTEM)
DEB_HOST_ARCH := $(DEB_BUILD_ARCH)
DEB_HOST_GNU_CPU := $(DEB_BUILD_GNU_CPU)
DEB_HOST_GNU_SYSTEM := $(DEB_BUILD_GNU_SYSTEM)
DEB_HOST_GNU_TYPE := $(DEB_BUILD_GNU_TYPE)
Put a subset of these lines at the top of your debian/rules file; these
default values will be overwritten if dpkg-architecture is used.
You don't need the full set. Choose a consistent set which contains the
values you use in the rules file. For example, if you only need the
host Debian architecture, `DEB_HOST_ARCH=`dpkg --print-architecture`'
is sufficient (this is indeed the Debian architecture of the build
machine, but remember that we are only trying to be backward compatible
with native compilation).
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).
AUTHOR
dpkg-architecture and this man page were initially written by Marcus
Brinkmann <brinkmd@debian.org>.