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Thomas Petazzoni 2babed4a50 toolchain-internal: skip gcc-intermediate when possible
When NPTL support was introduced, gcc required a three stages build
process. Since gcc 4.7, this is no longer necessary, and it is
possible to get back to a two stages build process. This patch takes
advantage of this, by doing a two stages build process when possible.

We introduce a few hidden kconfig options:

 * BR2_GCC_VERSION_NEEDS_THREE_STAGE_BUILD, which is set by the gcc
   Config.in logic to indicate that the compiler might need a three
   stages build. Currently, all versions prior to 4.7.x are selecting
   this kconfig option.

 * BR2_TOOLCHAIN_LIBC_NEEDS_THREE_STAGE_BUILD, which indicates whether
   the C library might need a three stages build. This is the case for
   eglibc, and uClibc when NPTL is enabled.

 * BR2_TOOLCHAIN_NEEDS_THREE_STAGE_BUILD finally is enabled when both
   of the previous options are enabled. It indicates that a three
   stages build is actually needed.

In addition to those options, the uClibc/gcc build logic is changed to
use only a two stages build process when possible.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
2013-09-15 22:50:20 +02:00
arch targets: move target options to their own sub-menu 2013-09-05 15:45:24 +02:00
board Merge branch 'next' 2013-08-31 23:32:29 +02:00
boot syslinux: bump to version 4.07 2013-09-11 12:53:53 +02:00
configs configs: bump kernel use for RPi, use simpler defconfig 2013-09-05 15:45:24 +02:00
docs docs/manual: add CVS support documentation 2013-09-13 00:07:07 +02:00
fs package: remove the empty trailing lines 2013-09-13 11:10:23 +02:00
linux linux: bump 3.11.x stable version 2013-09-15 17:30:57 +02:00
package toolchain-internal: skip gcc-intermediate when possible 2013-09-15 22:50:20 +02:00
support apply-patches.sh: detect missing patches 2013-09-15 22:08:46 +02:00
system system: default to devtmpfs for /dev 2013-09-15 22:43:39 +02:00
toolchain toolchain-internal: skip gcc-intermediate when possible 2013-09-15 22:50:20 +02:00
.defconfig buildroot: get rid of s390 support 2009-01-12 14:36:14 +00:00
.gitignore update gitignore 2013-05-04 12:41:55 +02:00
CHANGES Update for 2013.08 2013-08-31 00:33:13 +02:00
Config.in downloads: add basic CVS support 2013-09-13 00:05:43 +02:00
Config.in.legacy module-init-tools: remove package 2013-09-02 22:59:27 +02:00
COPYING clarify license and fix website license link 2009-05-08 09:29:41 +02:00
Makefile Makefile: make $(BUILD_DIR)/.root rule idempotent 2013-09-15 21:46:53 +02:00
Makefile.legacy legacy: add error target for host-pkg-config 2012-11-30 12:07:09 -08:00

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