a4239f7fd1
This commit introduces the BR2_EXTERNAL environment variable, which will allow to keep Buildroot customization (board-specific configuration files or root filesystem overlays, package Config.in and makefiles, as well as defconfigs) outside of the Buildroot tree. This commit only introduces the variable itself, and ensures that it is available within Config.in options. This allows us to use $BR2_EXTERNAL in a 'source' statement in Config.in. Following patches extend the usage of BR2_EXTERNAL to other areas (packages and defconfigs). In details, this commit: * Introduces the BR2_EXTERNAL Kconfig option. This option has no prompt, and is therefore not visible to the user and also not stored in the .config file. It is automatically set to the value of the BR2_EXTERNAL environment variable. The only purpose of this BR2_EXTERNAL Kconfig option is to allow $BR2_EXTERNAL to be properly expanded when used inside Kconfig source statements. * Calculates the BR2_EXTERNAL value to use. If passed on the command line, then this value is taken in priority, and saved to a .br-external hidden file in the output directory. If not passed on the command line, then we read the .br-external file from the output directory. This allows the user to not pass the BR2_EXTERNAL value at each make invocation. If no BR2_EXTERNAL value is passed, we define it to support/dummy-external, so that the kconfig code finds an existing $(BR2_EXTERNAL)/package/Config.in file to include. * Passes the BR2_EXTERNAL into the *config environment, so that its value is found when parsing/evaluating Config.in files and .config values. Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr> Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr> Acked-by: Ryan Barnett <rjbarnet@rockwellcollins.com> Tested-by: "Samuel Martin" <s.martin49@gmail.com> Acked-by: "Samuel Martin" <s.martin49@gmail.com> Signed-off-by: Peter Korsgaard <peter@korsgaard.com> |
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| docs.html | ||
| download.html | ||
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| footer.html | ||
| git.html | ||
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To build and use the buildroot stuff, do the following:
1) run 'make menuconfig'
2) select the packages you wish to compile
3) run 'make'
4) wait while it compiles
5) Use your shiny new root filesystem. Depending on which sort of
root filesystem you selected, you may want to loop mount it,
chroot into it, nfs mount it on your target device, burn it
to flash, or whatever is appropriate for your target system.
You do not need to be root to build or run buildroot. Have fun!
Offline build:
==============
In order to do an offline-build (not connected to the net), fetch all
selected source by issuing a
$ make source
before you disconnect.
If your build-host is never connected, then you have to copy buildroot
and your toplevel .config to a machine that has an internet-connection
and issue "make source" there, then copy the content of your dl/ dir to
the build-host.
Building out-of-tree:
=====================
Buildroot supports building out of tree with a syntax similar
to the Linux kernel. To use it, add O=<directory> to the
make command line, E.G.:
$ make O=/tmp/build
And all the output files (including .config) will be located under /tmp/build.
More finegrained configuration:
===============================
You can specify a config-file for uClibc:
$ make UCLIBC_CONFIG_FILE=/my/uClibc.config
And you can specify a config-file for busybox:
$ make BUSYBOX_CONFIG_FILE=/my/busybox.config
To use a non-standard host-compiler (if you do not have 'gcc'),
make sure that the compiler is in your PATH and that the library paths are
setup properly, if your compiler is built dynamically:
$ make HOSTCC=gcc-4.3.orig HOSTCXX=gcc-4.3-mine
Depending on your configuration, there are some targets you can use to
use menuconfig of certain packages. This includes:
$ make HOSTCC=gcc-4.3 linux-menuconfig
$ make HOSTCC=gcc-4.3 uclibc-menuconfig
$ make HOSTCC=gcc-4.3 busybox-menuconfig
Please feed suggestions, bug reports, insults, and bribes back to the
buildroot mailing list: buildroot@uclibc.org