[PATCH v4 00/33] Initial implementation of standard boot

Thu Mar 24 03:18:04 CET 2022

Hi Mark,

On Wed, 23 Mar 2022 at 17:15, Mark Kettenis <mark.kettenis at xs4all.nl> wrote:
>
> > From: Michael Nazzareno Trimarchi <michael at amarulasolutions.com>
> > Date: Wed, 23 Mar 2022 20:21:22 +0100
> >
> > Hi Tom
> >
> > On Wed, Mar 23, 2022 at 7:46 PM Simon Glass <sjg at chromium.org> wrote:
> > >
> > > Hi Tom,
> > >
> > > On Wed, 23 Mar 2022 at 08:05, Tom Rini <trini at konsulko.com> wrote:
> > > >
> > > > On Sun, Mar 06, 2022 at 05:49:43AM -0700, Simon Glass wrote:
> > > > >
> > > > > The bootflow feature provide a built-in way for U-Boot to automatically
> > > > > boot an Operating System without custom scripting and other customisation.
> > > > > This is called 'standard boot' since it provides a standard way for
> > > > > U-Boot to boot a distro, without scripting.
> > > > >
> > > > > It introduces the following concepts:
> > > > >
> > > > >    - bootdev - a device which can hold a distro
> > > > >    - bootmeth - a method to scan a bootdev to find bootflows (owned by
> > > > >                 U-Boot)
> > > > >    - bootflow - a description of how to boot (owned by the distro)
> > > > >
> > > > > This series provides an implementation of these, enabled to scan for
> > > > > bootflows from MMC, USB and Ethernet. It supports the existing distro
> > > > > boot as well as the EFI loader flow (bootefi/bootmgr). It works
> > > > > similiarly to the existing script-based approach, but is native to
> > > > > U-Boot.
> > > > >
> > > > > With this we can boot on a Raspberry Pi 3 with just one command:
> > > > >
> > > > >    bootflow scan -lb
> > > > >
> > > > > which means to scan, listing (-l) each bootflow and trying to boot each
> > > > > one (-b). The final patch shows this.
> > > > >
> > > > > With a standard way to identify boot devices, booting become easier. It
> > > > > also should be possible to support U-Boot scripts, for backwards
> > > > > compatibility only.
> > > > >
> > > > > This series relies on the PXE clean-up series, posted here:
> > > > >
> > > > >    https://patchwork.ozlabs.org/project/uboot/list/?series=267078
> > > > >
> > > > > For documentation, see the 'doc' patch.
> > > > >
> > > > > For version 2, a new naming scheme is used as above:
> > > > >
> > > > >    - bootdev is used instead of bootdevice, because 'device' is overused,
> > > > >        is everywhere in U-Boot, can be confused with udevice
> > > > >    - bootmeth - because 'method' is too vanilla, appears 1300 times in
> > > > >        U-Boot
> > > > >
> > > > > Also in version 2, drivers are introduced for the boot methods, to make
> > > > > it more extensible. Booting a custom OS is simply a matter of creating a
> > > > > bootmeth for it and implementing the read_file() and boot() methods.
> > > > >
> > > > > Version 4 makes some minor improvements and leaves out the RFC patch for
> > > > > rpi conversion, in the hope of getting the base support applied sooner
> > > > > rather than later.
> > > > >
> > > > > The design is described in these two documents:
> > > > >
> > > > > https://drive.google.com/file/d/1ggW0KJpUOR__vBkj3l61L2dav4ZkNC12/view?usp=sharing
> > > > >
> > > > > https://drive.google.com/file/d/1kTrflO9vvGlKp-ZH_jlgb9TY3WYG6FF9/view?usp=sharing
> > > >
> > > > I keep putting off commenting more here, but, I still feel this is the
> > > > wrong direction.  What problems do we have today with distro boot?
> > > > Well, we haven't figured out how to move configuring it out of the board
> > > > config.h file.  But that's just one of a half dozen or so examples of
> > > > how we haven't figured out a good solution to configuring the default
> > > > environment.  And only some of those other examples are boot related
> > > > (the NXP chain of trust booting stuff is another boot example, ETHPRIME,
> > > > HOSTNAME, etc, are non-boot examples).
> > > >
> > > > We also aren't improving testing of "can we boot" here, because what
> > > > THAT needs is setting up LAVA and booting some installers on some
> > > > hardware (and some QEMU).  That's testing that Linux boot works.  Today
> > > > we have tests for hush parsing, and if distro boot makes use of
> > > > something we don't have a test for, we need a test for it.  This adds
> > > > tests for itself, which is good.
> > > >
> > > > And I still don't see an example of where this demonstrates that
> > > > existing non-UEFI boot cases are now easier to handle or cleaner to
> > > > handle or otherwise better.
> > > >
> > > > In that this is an attempt to tackle one of the long standing needed
> > > > migrations (be able to drop board config.h files), something here needs
> > > > doing.  But I don't see this as the right direction, sorry.
> > >
> > > Does anyone have a better idea for all of this? This is a solid base
> > > we can build on but we can't make any progress while this is just
> > > patches. What not apply it and we can move forward?
> > >
> >
> > I agree with Simon. Having a well documented flow, help to integrate
> > products and have a standard
> > way to handle the booting flow
> >
> > > - solves the env problem for distro boot in that we don't need the scripts
> > > - gets rid of the scripts which are a confusing mess
> > > - provides proper high-level concepts of boot device and boot method
> > > - allows testing of the U-Boot part of 'can we boot' because we have
> > > tests for all the cases - we can expand this over time
> > > - allows non-UEFI boot cases like Chrome OS, which is currently just a
> > > hack for one board[1]
> > > - provides a programmatic base for A/B boot, etc.
> > >
> > > I feel the same way with Takahiro's series, which has been out-of-tree
> > > for too long.
> >
> > I don't see the problem in having it merged. I'm dealing every day
> > with crazy script to handle situation like [1] and I think that
> > company that integrates their product can benefits on those
> > changes. They can be improved with other people wants to use it in
> > their products.
>
> Well, I've tried to convert Apple M1 over to standard boot but failed.
> That may be because the current implementation lacks NVMe support.
> But to me that indicates that the coee is incomplete and not ready to
> be merged.

If that would change your mind I would be happy to do that work. I
added USB for this series since someone asked about that. NVMe is an
interesting case since there are multiple LUNs, as I understand it.

But there is a lot more to this series than just doing things a different way...

Regards,
Simon

>
> > > Please reconsider this. What do we have to lose?
> > >
> > > Regards,
> > > Simon
> > >
> > > [1] CONFIG_BOOTCOMMAND="tpm init; tpm startup TPM2_SU_CLEAR; read mmc
> > > 0:2 100000 0 80; setexpr loader *001004f0; setexpr size *00100518;
> > > setexpr blocks $size / 200; read mmc 0:2 100000 80 $blocks; setexpr
> > > setup $loader - 1000; setexpr cmdline_ptr $loader - 2000; setexpr.s
> > > cmdline *$cmdline_ptr; setexpr cmdline gsub %U \\\\${uuid}; if part
> > > uuid mmc 0:2 uuid; then zboot start 100000 0 0 0 $setup cmdline; zboot
> > > load; zboot setup; zboot dump; zboot go;fi"
> >
> >
> >
> > --
> > Michael Nazzareno Trimarchi
> > Co-Founder & Chief Executive Officer
> > M. +39 347 913 2170
> > michael at amarulasolutions.com
> > __________________________________
> >
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> >