Re: CTF: UEFI HTTP boot support

> On Tue, Jun 16, 2020, 17:53 Miguel C <miguelmclara_at_gmail.com> wrote:
> 
> > On Tue, Jun 16, 2020 at 4:35 PM Rodney W. Grimes <
> > freebsd-rwg_at_gndrsh.dnsmgr.net> wrote:
> >
> > > > I've been trying out FreeBSD with raspberry Pi4 (4GB) and wanted to see
> > > > what the state of HTTP BOOT is in FreeBSD, so I bumped into this!
> > > >
> > > > I'm curious if it should be possible to point to a img/iso directly (I
> > > > tried to use the img.xz unpacked it and make it available on a local
> > web
> > > > server and that didn't seem to work for me)  but maybe thats cause
> > those
> > > > images miss something, so arm64 aside does that work for amd64? I.E.
> > > using
> > > > the bootonly.iso?
> > >
> > > One problem you run into in attemtping this is even if you get an
> > > image downloaded and started that image is being provided by some
> > > memory device driver that emulates some type of iso device.
> > > FreeBSD does not have a driver for that device so once the kernel
> > > gets to the point of mounting its root file system it falls on
> > > its face with a mountroot failure.
> > >
> > > >
> > > > And on the other hand is there any doc on how to set up dhcp/http
> > > specific
> > > > to FreeBSD similar to
> > https://en.opensuse.org/UEFI_HTTPBoot_Server_Setup
> > > ?
> > >
> > > Since Linux uses this idea of a kernel payload and an initrd payload
> > > to boot with it is much easier to get these 2 things over the network
> > > and then have a workable system.  FreeBSD does not have the initrd
> > > payload and that complicates things, you need a functionaly filesystem
> > > avaliable at the end of kernel initilization.
> > > >
> > > > I looked into
> > https://www.freebsd.org/doc/handbook/network-diskless.html
> > > > but that doesn't seem to be up to date (or at least it focuses only on
> > > PXE
> > > > and TFTP).
> > >
> > > Yes, old but workable.  I have a more advanced system that supports NFS
> > > booting using NFS support in PXE.  The only thing done via tftp is to
> > > upgrade the PXE running on the client to one that speaks NFS, then the
> > > kernel is loaded via NFS and the root file system is later provided
> > > via NFS.  The use of NFS provides very fast boots, and I do not need
> > > a web server to do it :-).
> > >
> > > > For clarification my ultimate goal is to use a few pi4's as "thin
> > > clients",
> > > > so eventually I will have to setup an image of the system with the
> > needed
> > > > software (freerdp) but for starters I just wanted to check if pointing
> > > > directly to a img/iso would work and that does not seem to be the case.
> > >
> > > I would strongly suggest use of NFS instead of trying to provide an
> > > ISO image, as you no longer need to store the ISO in memory on the
> > > client box, and with a pi4 your already memory contrained.
> > >
> >
> > Thanks for the tips, but I was really looking for HTTP BOOT info no NFS,
> > that's why I replied to this thread.
> >
> > I might look into that at some point if HTTP BOOT is not an option of
> > course, but this thread is about a Call for Testers for UEFI HTTP BOOT, not
> > NFS and I would like to help test, the pi4 project just conveniently
> > touches on the same use case (an it also does have support for http boot
> > using https://rpi4-uefi.dev/) so I'm curious if I can test that way.
> >
> > Other than the iso I can ofc attempt the dhcp+dns+webserver setup but for
> > that I would need a bit more guidance as the linked URL here is linux
> > centric, hence why some docs would help.
> >
> 
> >
> >
> Am I just misremembering or can't you get freebsd to load an mfsroot-image,
> which can act as rw fs ?

Yes, but that is *not* an .iso as was asked above.

> I seem to remember pc-bsd DVDs using this say 7 years ago.

Yes.

> 
> You would of course have to modify/build your own iso image with the
> mfsroot-image on it.

Perhaps, if you can get the mfsroot image into memory by the loader
while you still have access to the bios code.

> Best regards
> Andreas

-- 
Rod Grimes                                                 rgrimes_at_freebsd.org