[Buildroot] Collection of howtos/FAQ

[Buildroot] Collection of howtos/FAQ

[Chris Packham]

Hi All,

Has anyone collected any howtos/faq for buildroot related things. I
needed to setup a NFS mounted file system and I managed to blunder my
way through following a few hints from searching this mailing list and
reading some of the Linux kernel documentation.

I've distilled my what I've learned into my own short howto which
could be included in the buildroot docs directory (or onto a wiki). Is
there any interest in incorporating something like this into buildroot
or putting a wiki on buildroot.org? I'll post my initial attempt as a
reply to this.

Regards,
Chris

[Buildroot] [PATCH] docs/howto: add howto for nfsroot

[Chris Packham]

Document how to use buildroot to generate a kernel/filesystem cabable of
using/being used for a root filesystem over NFS.
---
 docs/howto/Makefile    |   22 ++++++++++++++++++
 docs/howto/nfsroot.txt |   58 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+), 0 deletions(-)
 create mode 100644 docs/howto/Makefile
 create mode 100644 docs/howto/nfsroot.txt

diff --git a/docs/howto/Makefile b/docs/howto/Makefile
new file mode 100644
index 0000000..d81bbcb
--- /dev/null
+++ b/docs/howto/Makefile
@@ -0,0 +1,22 @@
+OBJS=$(subst .txt,.html,$(wildcard *.txt))
+
+ASCIIDOC=$(shell which asciidoc)
+ASCIIDOC_VER=$(shell $(ASCIIDOC) --version | cut -d' ' -f2)
+ASCIIDOC_ICONDIR=/etc/asciidoc/images/icons
+
+ifeq ($V,)
+	Q=@
+	VERBOSE=
+else
+	Q=
+	VERBOSE=--verbose
+endif
+
+%.html: %.txt
+	$(Q)$(ASCIIDOC) $(VERBOSE) -a toc -a icons \
+		-a iconsdir=$(ASCIIDOC_ICONDIR) -a numbered $<
+
+all: $(OBJS)
+
+clean:
+	$(Q)rm -f $(OBJ)
diff --git a/docs/howto/nfsroot.txt b/docs/howto/nfsroot.txt
new file mode 100644
index 0000000..8a58503
--- /dev/null
+++ b/docs/howto/nfsroot.txt
@@ -0,0 +1,58 @@
+== Buildroot: NFS Root Howto ==
+
+This howto attempts to explain what is needed to mount a file system generated
+by Buildroot and hosted on a development system (referred to as the host) from
+an embedded target device (referred to as the target).
+
+For the purposes of clarity the kernel that was used for this howto was Linux
+Kernel v2.6.32.9 and the Buildroot version was 2010.02-216-gc9d195e.
+
+=== Linux Config ===
+
+The Linux kernel needs to be configured to include a NFS client _and_ support a
+root file system on NFS. The config options +CONFIG_NFS_FS+ and +CONFIG_ROOT_NFS+
+need to be set to Y.
+----
+  buildroot$ make linux26-menuconfig
+----
+The NFS options can be found under the "File Systems" -> "Network File Systems"
+menu. The options are called "NFS client support" and "Root file system on NFS".
+
+=== Linux Command Line (bootargs) ===
+
+The Linux Kernel needs to be told to mount its root file system via NFS, the
+address of the NFS server and the IP address it should use. This is done
+by supplying the kernel a command line with the appropriate arguments. There
+are many ways to do this, the following is the U-Boot setup for a target
+(192.168.1.254) that will mount its filesystem from the directory
++/tftboot/rootfs+ on the host (192.168.1.1).
+----
+  uboot> setenv ipaddr 192.168.1.254
+  uboot> setenv serverip 192.168.1.1
+  uboot> setenv bootargs root=/dev/nfs nfsroot=/tftpboot/rootfs ip=192.168.1.254:192.168.1.1::::eth0:off
+----
+
+=== Buildroot Config ===
+
+The +output/target+ directory is not directly suitable for exporting as a rootfs
+as the permissions are not set correctly and the device nodes are not created.
+To generate a filesystem suitable for exporting the +BR2_TARGET_ROOTFS_TAR+
+config option needs to be set to Y.
+----
+  buildroot$ make menuconfig
+----
+The option can be found under the "Target filesystem options" menu. The option
+is called "tar the root filesystem"
+
+=== Exporting rootfs ===
+
+To export the root file system create a tarball then extract it into the
+directory to be served by the host.
+----
+  buildroot$ make
+  buildroot$ make tarroot
+  buildroot$ sudo tar -xf output/images/rootfs.powerpc.tar -C /tftpboot/rootfs/
+----
+
+=== References ===
+* http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.32.y.git;a=blob;f=Documentation/filesystems/nfsroot.txt;hb=HEAD[Documentation/filesystems/nfsroot.txt]
-- 
1.7.0.1

[Buildroot] Collection of howtos/FAQ

[Paul Jones]

I've also thought it would be good to have a wiki. I've been working on
getting buildroot to work on a friendly arm board and thought it would
be good to share.

Paul.

-----Original Message-----
From: buildroot-bounces@busybox.net
[mailto:buildroot-bounces at busybox.net] On Behalf Of Chris Packham
Sent: Tuesday, 9 March 2010 9:07 AM
To: buildroot at uclibc.org
Subject: [Buildroot] Collection of howtos/FAQ

Hi All,

Has anyone collected any howtos/faq for buildroot related things. I
needed to setup a NFS mounted file system and I managed to blunder my
way through following a few hints from searching this mailing list and
reading some of the Linux kernel documentation.

I've distilled my what I've learned into my own short howto which could
be included in the buildroot docs directory (or onto a wiki). Is there
any interest in incorporating something like this into buildroot or
putting a wiki on buildroot.org? I'll post my initial attempt as a reply
to this.

Regards,
Chris
_______________________________________________
buildroot mailing list
buildroot at busybox.net
http://lists.busybox.net/mailman/listinfo/buildroot