c8f2d248f6
This patch updates the generated toolchainfile.cmake to use ccache. When toolchainfile.cmake is used inside Buildroot, using ccache during the build is driven by a CMake knob: USE_CCACHE, automatically set by the cmake-package infrastructure and reflecting the BR2_CCACHE value. Since this toolchainefile.cmake file can be used outside Buildroot, and this file also set a couple of things (among these: the sysroot cflag, some pkg-config environment variables), it is important to set the compiler variables as well to keep the consistency of the cross-compilation configuration. So, when it is used outside Buildroot, using ccache for the build is driven by the ccache program availability. Note that using ccache for the build is achieved by setting the *_ARG1 CMake variables to let CMake use ccache without failing in detecting the compiler. Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> Signed-off-by: Samuel Martin <s.martin49@gmail.com> Cc: Luca Ceresoli <luca@lucaceresoli.net> Cc: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
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@buildroot.org