[Buildroot] [PATCH 1/1] Add a filesystem option so a device can be booted over NFS.

[Baruch Siach]

Hi Sagaert,

On Tue, Jul 15, 2014 at 03:21:16PM +0200, Sagaert Johan wrote:
> This options allows specifying a directory where the target rootfs is
> copied to so it can be used to boot a device over NFS.
> 
> Signed-off-by: Sagaert Johan <sagaert.johan at skynet.be>
> ---
>  Makefile         |  5 +++++
>  fs/Config.in     |  1 +
>  fs/nfs/Config.in | 13 +++++++++++++
>  fs/nfs/nfs.mk    | 16 ++++++++++++++++
>  4 files changed, 35 insertions(+)
>  create mode 100644 fs/nfs/Config.in
>  create mode 100644 fs/nfs/nfs.mk
> 
> diff --git a/Makefile b/Makefile
> index dcbf2b3..4c7a707 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -833,6 +833,11 @@ clean:
>  	rm -rf $(TARGET_DIR) $(BINARIES_DIR) $(HOST_DIR) \
>  		$(BUILD_DIR) $(BASE_DIR)/staging \
>  		$(LEGAL_INFO_DIR)
> +ifeq ($(BR2_TARGET_ROOTFS_NFS),y)
> +		if [ -d $(TARGET_ROOTFS_NFS_PATH) ]; then \
> +			rm -rf $(TARGET_ROOTFS_NFS_PATH) ;\
> +		fi

Too many indentation tabs here.

> +endif
>  
>  distclean: clean
>  ifeq ($(DL_DIR),$(TOPDIR)/dl)
> diff --git a/fs/Config.in b/fs/Config.in
> index 5853113..aa1460b 100644
> --- a/fs/Config.in
> +++ b/fs/Config.in
> @@ -7,6 +7,7 @@ source "fs/ext2/Config.in"
>  source "fs/initramfs/Config.in"
>  source "fs/iso9660/Config.in"
>  source "fs/jffs2/Config.in"
> +source "fs/nfs/Config.in"
>  source "fs/romfs/Config.in"
>  source "fs/squashfs/Config.in"
>  source "fs/tar/Config.in"
> diff --git a/fs/nfs/Config.in b/fs/nfs/Config.in
> new file mode 100644
> index 0000000..cf32619
> --- /dev/null
> +++ b/fs/nfs/Config.in
> @@ -0,0 +1,13 @@
> +config BR2_TARGET_ROOTFS_NFS
> +	bool "create NFS boot directory"
> +	help
> +	  Creates a directory that contains the rootfs for booting over NFS.
> +
> +if BR2_TARGET_ROOTFS_NFS
> +config BR2_TARGET_ROOTFS_NFS_PATH
> +	string "path to the directory used for booting over NFS"
> +	default "~/nfsrootfs"
> +	help
> +	  Path to the directory used for booting over NFS.
> +	  (This should also be added to your /etc/exports file.)
> +endif
> diff --git a/fs/nfs/nfs.mk b/fs/nfs/nfs.mk
> new file mode 100644
> index 0000000..003ce71
> --- /dev/null
> +++ b/fs/nfs/nfs.mk
> @@ -0,0 +1,15 @@
> +################################################################################
> +#
> +# create a directory for booting the device from an NFS.
> +#
> +################################################################################
> +
> +TARGET_ROOTFS_NFS_PATH := $(call qstrip,$(BR2_TARGET_ROOTFS_NFS_PATH))
> +
> +define ROOTFS_NFS_CMD
> +	rm -rf $(TARGET_ROOTFS_NFS_PATH) ;\
> +	mkdir -p  $(TARGET_ROOTFS_NFS_PATH) ;\
> +	cp -r $(TARGET_DIR)/* $(TARGET_ROOTFS_NFS_PATH)

This doesn't look right. What about creating device nodes and SUID binaries? 
You must be root for that, $(TARGET_DIR) doesn't carry this information 
(fakeroot does that), and even if it did cp doesn't preserve these attributes. 
A better approach would be to extract a generated tar image, but you still 
must be root for that.

baruch

> +endef
> +
> +$(eval $(call ROOTFS_TARGET,nfs))

-- 
     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
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