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Thomas De Schampheleire 54456cc698 infra: consistently use double dollar signs inside inner-xxx-targets
The inner-xxx-targets in the buildroot package infrastructures are
evaluated using $(eval) which causes variable references to be a bit
different than in regular make code. As we want most references to be
expanded only at the time of the $(eval) we should not use standard
references $(VAR) but rather use double dollar signs $$(VAR). This includes
function references like $(call), $(subst), etc. The only exception is the
reference to pkgdir/pkgname and numbered variables, which are parameters to
the inner block: $(1), $(2), etc.

This patch introduces consistent usage of double-dollar signs throughout the
different inner-xxx-targets blocks.

In some cases, this would potentially cause circular references, in
particular when the value of HOST_FOO_VAR would be obtained from the
corresponding FOO_VAR if HOST_FOO_VAR is not defined. In these cases, a test
is added to check for a host package (the only case where such constructions
are relevant; these are not circular).

Benefits of these changes are:
- behavior of variables is now again as expected. For example, setting
  $(2)_VERSION = virtual in pkg-virtual.mk will effectively work, while
  originally it would cause very odd results.

- The output of 'make printvars' is now much more useful. This target shows
  the value of all variables, and the expression that led to that value.
  However, if the expression was coming from an inner-xxx-targets block, and
  was using single dollar signs, it would show in printvars as
    VAR = value (value)
  while if double dollar signs are used, it would effectively look like
    VAR = value (actual expression)
  as is intended.
  This improvement is for example effective for FOO_DL_VERSION, FOO_RAWNAME,
  FOO_SITE_METHOD and FOO_MAKE.

The correctness of this patch has been verified using 'make printvars',
'make manual' and 'make legal-info' before and after applying this patch,
and comparing the output.

Insight-provided-by: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2014-06-14 19:09:54 +02:00
arch powerpc: add powerpc64 and powerpc64le support 2014-05-26 21:48:33 +02:00
board configs: bump zedboard to 2014.1 2014-06-09 12:09:20 +02:00
boot barebox: bump to version 2014.06.0 2014-06-07 09:24:06 +02:00
configs configs: bump zedboard to 2014.1 2014-06-09 12:09:20 +02:00
docs infra: consistently use double dollar signs inside inner-xxx-targets 2014-06-14 19:09:54 +02:00
fs infra: consistently use double dollar signs inside inner-xxx-targets 2014-06-14 19:09:54 +02:00
linux linux: bump default to version 3.15 2014-06-09 14:50:16 +02:00
package infra: consistently use double dollar signs inside inner-xxx-targets 2014-06-14 19:09:54 +02:00
support graphs/depends: do not draw transitive dependencies by default 2014-06-13 14:39:48 +02:00
system systemd: needs kernel headers >= 3.10 2014-06-13 22:32:37 +02:00
toolchain toolchain-external: add CodeSourcery PowerPC 2012.03 2014-06-14 19:04:50 +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 2014.05 2014-05-31 09:52:49 +02:00
COPYING clarify license and fix website license link 2009-05-08 09:29:41 +02:00
Config.in kernel headers: remove deprecated version 3.8 2014-06-13 22:27:39 +02:00
Config.in.legacy kernel headers: remove deprecated version 3.8 2014-06-13 22:27:39 +02:00
Makefile Makefile: test if dot exists before using it in graph-depends 2014-06-13 14:59:52 +02:00
Makefile.legacy Makefile.legacy: fix recursive invocation with BUILDROOT_DL_DIR and _CONFIG 2014-02-11 08:14:57 +01:00
README docs: Move README file to root 2014-03-03 21:28:39 +01:00

README

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

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