[Buildroot] [PATCH 1/1] new package - generate iso with isolinux bootloader

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Arnout Vandecappelle,

On Tue, 28 Jan 2014 18:33:24 +0100, Arnout Vandecappelle wrote:

>   To be honest it has been a couple of years since I tried it, and I 
> don't remember exactly. Here are a few issues that I can think of now.
> 
> * It doesn't actually build a rootfs, but rather a bootable image.

Well, yes, that's true, but it was since the beginning the idea of this
iso9660 support, and the additional 'isolinux' filesystem being
proposed is exactly the same: a bootable image, except that it uses a
different bootloader.

> * grub has issues cross-compiling between x86_64 and i386 - but your 
> recent patches may have fixed that.

Yes, they fixed that.

> * Bug#6092 (closed now, but not at the time I posted it).

Yes, I've closed it, because it works for me.

> * The issue that grub was built without iso support (fixed now, but not 
> at the time I posted it).

Yes, it is fixed.

>   Possibly iso9660 is working reliably by now.

It works for me, at least, and was also reported to work by Thierry
Bultel, IIRC.

> >>    A second generic comment is about the choice of booting with an
> >> initramfs. Why not boot with a (rockridge) iso9660 rootfs? Clearly it
> >> puts a bit more strain on the kernel config since iso9660 as well as the
> >> bus drivers (sata, usb) have to be linked in, but I think that would be a
> >> much nicer solution. This type of image containing the actual rootfs in a
> >> different format should really be generated by a post-image script
> >> instead of a filesystem target. Can the rest of the list give their opinion?
> >
> > I don't think that ISO9660 supports symbolic links, ownership,
> > permissions, device files and all these Unix filesystem features that
> > are typically needed to use a given filesystem type as a Linux root
> > filesystem.
> 
>   That's what RockRidge is for.

Aaah, interesting, I didn't know that. So it would probably make a lot
of sense to improve the ISO9660 support to:

 * Generate just an ISO9660 root filesystem image by default

 * Optionally, make it bootable using either Grub or isolinux

 * Optionally, replace the ISO9660 root filesystem by an initramfs

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com