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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_TYPE
The GNU system type of the build machine.
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_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_BUILD_ARCH_BITS
The pointer size of the host machine (in bits).
DEB_BUILD_ARCH_ENDIAN
The endianness of the host machine (little / big).
DEB_HOST_GNU_TYPE
The GNU system type of the host machine.
DEB_HOST_GNU_CPU
The CPU part of DEB_HOST_GNU_TYPE.
DEB_HOST_GNU_SYSTEM
The System part of DEB_HOST_GNU_TYPE.
 

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 overriden 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>.


 

Index

NAME
SYNOPSIS
DESCRIPTION
COMMANDS
OPTIONS
TERMS
VARIABLES
DEBIAN/RULES
BACKWARD COMPATIBILITY
EXAMPLES
FILES
SEE ALSO
AUTHOR

This document was created by man2html, using the manual pages.
Time: 15:26:07 GMT, June 11, 2010

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