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Peter Korsgaard 51f5f62754 External toolchain support improvements
Improve external toolchain support

 * Do not put kernel-headers in the dependencies of BASE_TARGETS in
   the case where BR2_TOOLCHAIN_SOURCE is not y. The kernel headers
   are already supposed to be part of the external toolchain, so
   there's no need to download, extract and install them.

 * In the configuration system, don't display the kernel headers
   version selection list when an external toolchain is selected. This
   is implemented by moving the source
   "toolchain/kernel-headers/Config.in" inside the if
   BR2_TOOLCHAIN_SOURCE in toolchain/Config.in.2.

 * Change the description and help message of the BR2_LARGEFILE,
   BR2_INET_IPV6, BR2_INET_RPC, and BR2_SOFT_FLOAT option in
   toolchain/external-toolchain/Config.in. In the case of an external
   toolchain, the semantic of these options is not to enable large
   file support, IPV6 or RPC (since the toolchain is already compiled,
   it has been decided previously). Their semantic is to let Buildroot
   know about the characteristics of the external toolchain being
   used.

   As an improvement, we could guess these values automatically:

    - for BR2_LARGEFILE, look at the value of __UCLIBC_HAS_LFS__ in
      bits/uClibc_config.h in the libc headers directory.

    - for BR2_INET_RPC, look at the value of __UCLIBC_HAS_RPC__ in the
      same file

    - for BR2_INET_IPV6, look at the value of __UCLIBC_HAS_IPV6__ in
      the same file

    - for BR2_SOFT_FLOAT, look at the output of $(CC) -v 2>&1 | grep
      -- "--with-float=soft"

   But I'm not sure how this would be possible, since these values are
   used at configuration-time by other configuration options, not only
   at build time.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2008-11-03 10:18:39 +00:00
docs - extend documentation to mention adding package/foo/Config.in to package/Config.in 2008-10-14 16:20:55 +00:00
package mkdosfs: cleanup target install handling 2008-11-03 06:16:36 +00:00
project buildroot: add QUIET variable and use it for wget/git/svn/configure 2008-10-21 08:56:26 +00:00
scripts new package wizard: change bash-specific construct 2008-10-22 05:19:04 +00:00
target syslinux: fix download url 2008-11-02 19:21:12 +00:00
toolchain External toolchain support improvements 2008-11-03 10:18:39 +00:00
.defconfig defconfig: remove settings with default values 2008-04-04 07:12:42 +00:00
Config.in BR2_HAVE_DOCUMENTATION: add option to remove documentation from target 2008-10-20 11:32:25 +00:00
Makefile External toolchain support improvements 2008-11-03 10:18:39 +00:00
TODO - mark the autotools.in part as taken 2007-09-28 20:52:09 +00:00

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 sortof
    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!

 -Erik

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 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 linux26-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:
	Erik Andersen <andersen@codepoet.org>
or the buildroot mailing list.