How to determine host value for configure when using cross compiler
Solution 1
If I use a cross compiler, how can I tell the value of the
--host
option I should give when I run./configure
?
Three machines must be distinguished when discussing toolchain creation
- The build machine, where the toolchain is built.
- The host machine, where the toolchain will be executed.
- The target machine, where the binaries created by the toolchain are executed.
Four common build types are possible for toolchains are:
Native build i.e.
BUILD==HOST==TARGET
Used to build normal gcc for workstation. e.g.BUILD==HOST==TARGET==x86
Cross-build i.e.
BUILD==HOST!=TARGET
Used to build toolchain that works on your workstation but generates binary for target. e.g.BUILD==HOST==x86 TARGET==arm
Cross-native build i.e.
BUILD!=HOST==TARGET
Used to toolchain that works on your target and generates binary for target. e.gBUILD==x86 HOST==TARGET==ARM
Canadian toolchain i.e.
BUILD!=HOST!=TARGET
Used to build ARCHITECTURE A a toolchain runs on B and generates binary for architecture C. e.g.BUILD==x86 HOST==mac TARGET==arm
With armed this basics coming to your question.
For any software, first run ./configure --help
Host type:
--build=BUILD configure for building on BUILD [BUILD=HOST]
--host=HOST configure for HOST [guessed]
--target=TARGET configure for TARGET [TARGET=HOST]
You will find above so depending on what you want to do, you need to set it for cross compiling. If all options are available, then you want to execute on arm target then set --host={your toolchain triplet} --target={your toolchain triplet}
.
For example, if you are using arm-none-linux-gnueabi-gcc
, set --host=arm-none-linux-gnueabi --target=arm-none-linux-gnueabi
. This will write to your makefile.
Finally, generated executable will run on target. For --build
this will be automatically set, no need to worry.
For some software package only two option available i.e host and build
. here if set host
is enough to cross-compile
Specific: I'm using cross compiler for
arm64
arch. What is the correct--host
value to use?
For x86_64, --host={triplet}
is generally given, so I think the same should work for arm64 by setting --host={triplet}
for your toolchain, but I'm not sure.
Solution 2
The easiest way to find out what to input in --host
, is by running config.guess
on the host machine. On my machine it was located in /usr/share/automake-1.15/
, but I recommend running locate config.guess
to find it.
The script is open source (GPL) and available at this address in case it is not available on your machine:
https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess
On my target machine, a tegra X1 (also an aarch64) the answer it gave was aarch64-unknown-linux-gnu, which seems to work fine for cross-compiling.
Solution 3
--host is the "triplet" for the machine on which your resultant build will ultimately run. In your case "arm64" is the architecture, but it is only one piece of the triplet. In any event it maps to the string "aarch64" in the triplet. One possible value is
--host=aarch64-linux-android
this page from gnu.org gives the definitive answer about --host/--target/--build usage
Related videos on Youtube
Omer Dagan
An advocate of Linux, currently using mostly Debian. Big fan of open source. Also consider myself a Pythonist. Cheers
Updated on November 06, 2020Comments
-
Omer Dagan over 3 years
General question: If I use a cross compiler, how can I tell the value of the "--host" option I should give when I run configure?
Specific: I'm using cross compiler for arm64 arch. What is the correct "--host" value to use?
-
jww over 5 yearsThough you asked for the
host
value, I think you really wanted thebuild
value.host
is the machine configure is running on, and you get that withconfig.guess
. You want the triplet forbuild
, and that is the machine the package will eventually run on. (Don't use--target
; that is used for cross-compiling toolchains). The triplets are shared for both, but there is no easy way to get a list of the triplets. Also see How To Configure for Android? on the Autoconf mailing list.
-
-
hesham_EE about 9 yearsThis is a buried gem. Thanks for a well-written answer!
-
PixelPerfect3 over 8 yearsDid anyone figure out what the "--host" value should be for arm64?
-
Zain Ali over 6 years@PixelPerfect3 it should be aarch64-linux
-
OpalApps over 6 yearsSorry to bring that again, but @PixelPerfect3 is right - the question was how to figure out the right values for --host and --target options of the configure. Are there any tools to call, to get the right value? Or any config files to check for these values? Independently of the platform and configurations - generic approach on how to collect these values. Taking parts of "triplets" from tool chain name/prefix is not a generic option. It is more guessing and hoping.
-
OpalApps over 6 yearsThis has to be a correct/accepted answer! Thanks @Drugbird! config.guess delivers at least the host name correctly. Would also be nice to have a correct way to get the target name too. A list of some kind, or reference the hardware vendor refers to. It is difficult to believe that there is nothing like that available.
-
kakyo over 4 yearsWhere to find the list of standard architectures for auto tools? I tried to build for arm64 and X86_64 but they end up having the same architecture when I set host to arm64 and x86_64-apple-darwin.
-
ceztko about 4 yearsIt's very common that autoconf projects will cross compile correctly just with
--host
switch set and correct cross toolchains are used, without the--target
switch. Is it correct to assume that target will be same as--host
when only the latter is present?