[Buildroot] Why is extfs filesystem mandatory?

[Thomas Petazzoni]

Hello,

On Tue, 07 Sep 2010 13:42:47 -0400
"James J. Dines" <jdines at jdines.net> wrote:

> Yes, that was the issue.  I have to admit I feel a bit foolish having
> not looked more closely at the dependencies by choosong the help
> option, but on the other hand I cannot imagine why this dependency
> exists. Obviously one can have an iso image without having an ext2
> filesystem, or there would be no such thing as an iso image for
> Windows.

Well, the ISO image is in fact a little bit more than just an ISO image
of the filesystem: it's a bootable ISO image, and the build process for
this image considers that the root filesystem is an ext2 initrd for the
ISO image.

From fs/iso9660/iso9660.mk :

        cp $(GRUB_DIR)/stage2/stage2_eltorito
        $(ISO9660_TARGET_DIR)/boot/grub/ cp $(ISO9660_BOOT_MENU)
        $(ISO9660_TARGET_DIR)/boot/grub/menu.lst cp
        $(LINUX26_IMAGE_PATH) $(ISO9660_TARGET_DIR)/kernel cp
        $(BINARIES_DIR)/rootfs.ext2 $(ISO9660_TARGET_DIR)/initrd

I must admit that I'm not an user of this feature, so when I did the
cleanup/rewrite of filesystem support, I left it as it was. Maybe it
needs to work differently.

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com