01c34b38a4
-pipe is causing some build failures in Linux kernel >= 3.17.
Also, nowadays, using -pipe does not gain as much as it used to back in
the days:
Measurements made with a 3.16.7 Linux kernel:
make linux-depends
time sh -c 'make linux-build >/dev/null 2>&1'
Without -pipe:
716.32user 54.44system 3:42.12elapsed 346%CPU
721.22user 54.47system 3:41.81elapsed 349%CPU
722.44user 54.00system 3:42.13elapsed 349%CPU
721.03user 53.81system 3:41.92elapsed 349%CPU
713.21user 53.63system 3:40.51elapsed 347%CPU
706.67user 52.42system 3:38.40elapsed 347%CPU
714.40user 53.18system 3:40.16elapsed 348%CPU
706.01user 53.09system 3:37.87elapsed 348%CPU
705.98user 53.01system 3:38.03elapsed 348%CPU
714.17user 53.55system 3:39.98elapsed 348%CPU
Average: 3:40.29elapsed
With -pipe:
720.13user 53.90system 3:41.98elapsed 348%CPU
713.38user 53.69system 3:40.44elapsed 347%CPU
711.60user 52.81system 3:39.06elapsed 348%CPU
708.66user 53.09system 3:38.59elapsed 348%CPU
711.76user 53.00system 3:38.48elapsed 350%CPU
717.85user 53.97system 3:41.77elapsed 348%CPU
716.77user 53.77system 3:40.91elapsed 348%CPU
717.48user 53.65system 3:41.24elapsed 348%CPU
721.44user 55.67system 3:43.45elapsed 347%CPU
724.61user 55.63system 3:43.35elapsed 349%CPU
Average: 3:40.93elapsed
The delta is well in the measurement noise.
Just get rid of it.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Romain Naour <romain.naour@openwide.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.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