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
--host-arch and
--host-type. 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
--host-arch and
--host-type 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, --list
- Print the environment variables, one each line, in the format
VARIABLE=value. This is the default action.
- -e, --equal architecture
- Check for equality of architecture (since dpkg 1.13.13). It compares the
current or specified Debian host architecture against architecture,
to check if they are equal. This action will not expand the architecture
wildcards. Command finishes with an exit status of 0 if matched, 1 if not
matched.
- -i, --is architecture-wildcard
- Check for identity of architecture (since dpkg 1.13.13). It compares the
current or specified Debian host architecture against
architecture-wildcard after having expanded it as an architecture
wildcard, to check if they match. Command finishes with an exit status of
0 if matched, 1 if not matched.
- -q, --query variable-name
- Print the value of a single variable.
- -s, --print-set
- Print an export command. This can be used to set the environment variables
using eval.
- -u, --print-unset
- Print a similar command to --print-unset but to unset all
variables.
- -c, --command command
- Execute a command in an environment which has all variables set to
the determined value.
- -L, --list-known
- Print a list of valid architecture names. Possibly restricted by one or
more of the matching options --match-wildcard, --match-bits
or --match-endian (since dpkg 1.17.14).
- -?, --help
- Show the usage message and exit.
- --version
- Show the version and exit.
OPTIONS¶
- -a, --host-arch architecture
- Set the host Debian architecture.
- -t, --host-type gnu-system-type
- Set the host GNU system type.
- -A, --target-arch architecture
- Set the target Debian architecture. This is only needed when building a
cross-toolchain, one that will be built on the build architecture, to be
run on the host architecture, and to build code for the target
architecture.
- -T, --target-type gnu-system-type
- Set the target GNU system type.
- -W, --match-wildcard architecture-wildcard
- Restrict the architectures listed by --list-known to ones matching
the specified architecture wildcard (since dpkg 1.17.14).
- -B, --match-bits architecture-bits
- Restrict the architectures listed by --list-known to ones with the
specified CPU bits (since dpkg 1.17.14). Either 32 or
64.
- -E, --match-endian architecture-endianness
- Restrict the architectures listed by --list-known to ones with the
specified endianness (since dpkg 1.17.14). Either little or
big.
- -f, --force
- 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.
- target machine
- The machine the compiler is building 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 hyphen: 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 (since dpkg 1.13.2).
- DEB_BUILD_ARCH_CPU
- The Debian cpu name of the build machine (since dpkg 1.13.2).
- DEB_BUILD_ARCH_BITS
- The pointer size of the build machine (in bits; since dpkg 1.15.4).
- DEB_BUILD_ARCH_ENDIAN
- The endianness of the build machine (little / big; since dpkg
1.15.4).
- 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 (since dpkg 1.16.0).
- DEB_HOST_ARCH
- The Debian architecture of the host machine.
- DEB_HOST_ARCH_OS
- The Debian system name of the host machine (since dpkg 1.13.2).
- DEB_HOST_ARCH_CPU
- The Debian cpu name of the host machine (since dpkg 1.13.2).
- DEB_HOST_ARCH_BITS
- The pointer size of the host machine (in bits; since dpkg 1.15.4).
- DEB_HOST_ARCH_ENDIAN
- The endianness of the host machine (little / big; since dpkg 1.15.4).
- 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 (since dpkg 1.16.0).
- DEB_TARGET_ARCH
- The Debian architecture of the target machine (since dpkg 1.17.14).
- DEB_TARGET_ARCH_OS
- The Debian system name of the target machine (since dpkg 1.17.14).
- DEB_TARGET_ARCH_CPU
- The Debian cpu name of the target machine (since dpkg 1.17.14).
- DEB_TARGET_ARCH_BITS
- The pointer size of the target machine (in bits; since dpkg 1.17.14).
- DEB_TARGET_ARCH_ENDIAN
- The endianness of the target machine (little / big; since dpkg
1.17.14).
- DEB_TARGET_GNU_CPU
- The CPU part of DEB_TARGET_GNU_TYPE (since dpkg 1.17.14).
- DEB_TARGET_GNU_SYSTEM
- The System part of DEB_TARGET_GNU_TYPE (since dpkg 1.17.14).
- DEB_TARGET_GNU_TYPE
- The GNU system type of the target machine (since dpkg 1.17.14).
- DEB_TARGET_MULTIARCH
- The clarified GNU system type of the target machine, used for filesystem
paths (since dpkg 1.17.14).
FILES¶
Architecture tables¶
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.
Packaging support¶
- /usr/share/dpkg/architecture.mk
- Makefile snippet that properly sets and exports all the variables that
dpkg-architecture outputs (since dpkg 1.16.1).
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 the current or specified host architecture is equal to an architecture:
- dpkg-architecture -elinux-alpha
- dpkg-architecture -amips -elinux-mips
Check if the current or specified host architecture is a Linux system:
- dpkg-architecture -ilinux-any
- dpkg-architecture -ai386 -ilinux-any
Usage in 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 ?= $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
[...]
ifeq ($(DEB_BUILD_GNU_TYPE), $(DEB_HOST_GNU_TYPE))
confflags += --build=$(DEB_HOST_GNU_TYPE)
else
confflags += --build=$(DEB_BUILD_GNU_TYPE) \
--host=$(DEB_HOST_GNU_TYPE)
endif
[...]
./configure $(confflags)
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.
NOTES¶
All long command and option names available only since dpkg 1.17.17.
SEE ALSO¶
dpkg-buildpackage(1),
dpkg-cross(1).