mirror of
https://gitlab.com/buildroot.org/buildroot.git
synced 2026-09-10 08:14:09 -09:00
60474dcec6
Turned out that setting a nil-UUID is no better than clearing it. What currently happens is as follows: - first, genext2fs does not generate a UUID - then we tune2fs to upgrade the filesystem - then we run fsck, which generates a random UUID - then we re-run tune2fs to set a nil-UUID So, on the target, if the file system is improperly unmounted (eg. with a power failure), on next boot, fsck may be run, and a new random UUID will be generated. *However*, fsck improperly updates the filesystem when it adds the UUID, and there are a few group descriptor checksum errors. Those errors will go undetected until the next fsck, which will then block for user input (bad on embedded systems, bad). Fix that by systematically generating a random UUID _before_ we call to fsck. A random UUID is not so bad, after all, since there are already so many sources of unpredictability in the filesystem: files date and ordering, files content (date, paths...) which renders a fixed UUID unneeded. And it is still possible to set the UUID in a post-image script if needed, anyway. Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr> Cc: Peter Korsgaard <jacmet@uclibc.org> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
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