00daf37c4f
When Buildroot is configured to append the root filesystem to the Linux
kernel as initramfs, Buildroot sets the path to the initramfs source
dynamically in the Linux configuration file.
As this path is specified as an absolute path, typically being different
for different users of the same project (e.g. containing a username),
saving the configuration to a version control system (for example using
'make linux-update-defconfig') would result in a difference for this
path at every invocation by a different user.
Although this is technically not an issue, it is confusing that this
generates a difference.
Address this issue by using a not-yet-expanded make variable to specify
the path to the initramfs source. That variable will be expanded by the
Linux build system, which uses it both as a Makefile variable and a
shell variable; thus, it needs to be specified in LINUX_MAKE_ENV (so
it is exported and available in sub-processes of make). Any saved
configuration file would simply contain the reference to the
not-yet-expanded variable.
As in the Linux build system, the config variables are both read from
make as from a shell script, we cannot use $() syntax as this would be
interpreted as a command invocation by the shell. Instead, use ${}
syntax which is interpreted as variable reference both by the shell as
by make.
[Thomas:
- Really make the patch work by using $(LINUX_MAKE_ENV) instead of
$(TARGET_MAKE_ENV). Otherwise, the new BR2_BINARIES_DIR variable is
not passed at all stages of the build process, which makes the
build fail when an initramfs is used.]
Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: "Yann E. Morin" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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|---|---|---|
| arch | ||
| board | ||
| boot | ||
| configs | ||
| docs | ||
| fs | ||
| linux | ||
| package | ||
| support | ||
| system | ||
| toolchain | ||
| .defconfig | ||
| .gitignore | ||
| CHANGES | ||
| Config.in | ||
| Config.in.legacy | ||
| COPYING | ||
| Makefile | ||
| Makefile.legacy | ||
| 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
Please feed suggestions, bug reports, insults, and bribes back to the
buildroot mailing list: buildroot@buildroot.org