Re: [edk2][PATCH 1/1] MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on platform recovery


Samer El-Haj-Mahmoud
 

All,

Please take a moment to add any comments to this UEFI ECR BZ. This is needed to UEFI Forum can make a decision and close the ECR.
https://bugzilla.tianocore.org/show_bug.cgi?id=3336


Thanks,
--Samer

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Samer
El-Haj-Mahmoud via groups.io
Sent: Tuesday, April 13, 2021 3:48 PM
To: devel@edk2.groups.io; pete@akeo.ie; Laszlo Ersek
<lersek@redhat.com>; Leif Lindholm <leif@nuviainc.com>; Ni, Ray
<ray.ni@intel.com>; zhichao.gao@intel.com
Cc: Andrei Warkentin (awarkentin@vmware.com)
<awarkentin@vmware.com>; Ard Biesheuvel <ardb+tianocore@kernel.org>;
Andrew Fish <afish@apple.com>; Michael D Kinney
<michael.d.kinney@intel.com>; Jian J Wang <jian.j.wang@intel.com>; Hao A
Wu <hao.a.wu@intel.com>; Sunny.Hsuanwen.Wang@gmail.com; Samer El-
Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>; Sunny Wang
<Sunny.Wang@arm.com>
Subject: Re: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on platform
recovery

In order to make progress on this, I opened a code-first ECR against the UEFI
spec to clarify the language around the Boot#### options processing.

Code First ECR: https://bugzilla.tianocore.org/show_bug.cgi?id=3336

Feedback on the proposed language is appreciated. Please provide the
feedback directly in the BZ above.

I will update the thread/BZ with results from USWG.

Thanks,
--Samer

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Pete
Batard via groups.io
Sent: Thursday, February 25, 2021 5:55 AM
To: Wang, Sunny (HPS SW) <sunnywang@hpe.com>; Laszlo Ersek
<lersek@redhat.com>; Leif Lindholm <leif@nuviainc.com>;
devel@edk2.groups.io; Ni, Ray <ray.ni@intel.com>;
zhichao.gao@intel.com
Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>; Andrei
Warkentin (awarkentin@vmware.com) <awarkentin@vmware.com>; Ard
Biesheuvel <ardb+tianocore@kernel.org>; Andrew Fish
<afish@apple.com>;
Michael D Kinney <michael.d.kinney@intel.com>; Jian J Wang
<jian.j.wang@intel.com>; Hao A Wu <hao.a.wu@intel.com>;
Sunny.Hsuanwen.Wang@gmail.com
Subject: Re: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on platform
recovery

Hi Sunny,

I appreciate the input, but seeing that it is clear that no consensus
has been reached with regards to how the specs should be interpreted,
and that at least 4 separate people have now indicated that their
interpretation is different from the one you are putting forward (i.e.
you assert that the current code implementation is specs compliant
whereas we assert that the current code implementation is not specs
compliant), I believe that any further work on this will have to be
conditioned, first, by a specs update, that removes any ambiguity as
to the scope in which ReadyToBoot should apply.

Until that has happened, it seems very pointless to me to start
talking possible code workarounds, because we still can't appear to be
in agreement as to whether the current code implementation of
ReadyToBoot is specs compliant or not.

Now, even as I am the one proposing it, I'm afraid that I am not
planning to be the one opening a formal specs update request, since
there really is only so much more time I am willing to devote to this
matter. But I am hoping somebody else will.

Regards,

/Pete

On 2021.02.22 09:28, Wang, Sunny (HPS SW) wrote:
Hi all,

How about we signal ReadyToBoot ONLY for the default platform
recovery
option? The default platform recovery option here means the one
created by the code below in BdsEntry().
Status = EfiBootManagerInitializeLoadOption (
&PlatformDefaultBootOption,
LoadOptionNumberUnassigned,
LoadOptionTypePlatformRecovery,
LOAD_OPTION_ACTIVE,
L"Default PlatformRecovery",
FilePath,
NULL,
0
);

In other words, we just need to slightly update Pete's patch as the
following (adding the code below to EfiBootManagerProcessLoadOption()):

+ if ((LoadOption->OptionType == LoadOptionTypePlatformRecovery)
+ &&
StrCmp (LoadOption ->Description, L"Default
PlatformRecovery")) {
+ //
+ // Signal the EVT_SIGNAL_READY_TO_BOOT event when we are
about
to load and execute the boot option.
+ //
+ EfiSignalEventReadyToBoot ();

+ //
+ // Report Status Code to indicate ReadyToBoot was signalled
+ //
+ REPORT_STATUS_CODE (EFI_PROGRESS_CODE,
+ (EFI_SOFTWARE_DXE_BS_DRIVER |
+ EFI_SW_DXE_BS_PC_READY_TO_BOOT_EVENT));
+ }

I think the existing platforms that have their platform-specific
PlatformRecovery option may also do either of the following things to
make the system have no chance to load the default platform recovery
option because they do have a better way to recover the boot options:
1. Make their PlatformRecovery option have higher priority than
the
default platform recovery option (has a lower number (####) than the
default platform recovery option)
2. Remove the default platform recovery option.
Therefore, if we only signal ReadyToBoot for the default platform
recovery
option, this may not affect the existing platforms because the code
may never be run on these platforms.





If the solution above doesn't work, I think the suggestion (Solution 2:
adding a new application as a PlatformRecovery####) I mentioned, in
the beginning, can be re-considered. The suggestion (solution 2) is
based on the thoughts below:
1. I think that processing/evaluating the Boot#### can be
interpreted as
the code after the comment " 6. Load EFI boot option to ImageHandle"
in
EfiBootManagerBoot() because these code are similar to the code in
EfiBootManagerProcessLoadOption(). Based on this, I think our current
implementation is compliant with the description below in the UEFI
spec. Of course, we can improve our implementation by moving the code
for processing/evaluating the Boot#### from EfiBootManagerBoot() to
EfiBootManagerProcessLoadOption() and make EfiBootManagerBoot() call
EfiBootManagerProcessLoadOption().
“After all SysPrep#### variables have been launched
and exited,
the platform shall notify EFI_EVENT_GROUP_READY_TO_BOOT event
group
and begin to evaluate Boot#### variables with Attributes set to
LOAD_OPTION_CATEGORY_BOOT according to the order defined by
BootOrder.
The FilePathList of variables marked LOAD_OPTION_CATEGORY_BOOT shall
not be evaluated prior to the completion of
EFI_EVENT_GROUP_READY_TO_BOOT event group processing."
2. Moreover, it looks like we want to process
PlatformRecovery####
option in the same way as Boot#### (do more things like setting
BootCurrent for PlatformRecovery####). If so, I would still prefer to
do what I suggest in the beginning to create a new application as a
new PlatformRecovery#### option for generating and launching a boot
option for the bootable image that is found by using a short-form File
Path Media Device Path so that we won't run into other difficulties.
At least, I already saw the difficulty of no connection between
BootCurrent variable and PlatformRecovery#### variable. Of course,
this application can be implemented without platform specific stuff,
so it can be commonly used by all platforms that need to load a boot image
discovered by using short-form File Path Media Device Path.




Regards,
Sunny Wang

-----Original Message-----
From: Laszlo Ersek <lersek@redhat.com>
Sent: Wednesday, February 17, 2021 10:26 PM
To: Pete Batard <pete@akeo.ie>; Leif Lindholm <leif@nuviainc.com>;
devel@edk2.groups.io
Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>; Andrei
Warkentin (awarkentin@vmware.com) <awarkentin@vmware.com>;
Wang, Sunny
(HPS SW) <sunnywang@hpe.com>; zhichao.gao@intel.com;
ray.ni@intel.com;
Ard Biesheuvel <ardb+tianocore@kernel.org>; Andrew Fish
<afish@apple.com>; Michael D Kinney <michael.d.kinney@intel.com>;
Jian J Wang <jian.j.wang@intel.com>; Hao A Wu <hao.a.wu@intel.com>
Subject: Re: [EXTERNAL] Re: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on platform
recovery

On 02/17/21 13:18, Pete Batard wrote:
Hi Leif,

Thanks for trying to resurrect this issue.

At this stage, and despite some initial pushback in the bugzilla
ticket, I believe we can all agree with the consensus that
UefiBootManagerLib is not in fact specs-compliant and therefore
needs to be fixed, one way or another, to make it specs-compliant.

My take on this is that, rather than propose a new patch, I'd much
rather have the current maintainers agree on the course of action
to fix the library (which, as Leif suggests, might very well be to
split the library into a specs-compliant and non-specs-compliant
version), as it would of course be better if the fix came from
people who have better understanding of the ramifications we might
face with trying to correct the current behaviour, and especially,
who have knowledge of the platforms that might be impacted from
making the lib specs-
compliant.

Especially, I don't think that the patch that I originally
submitted for this, or the additional proposals we made, are still
receivable, as they seem to fall short of fixing the issue in a
manner that all platforms can be happy with. And that is why I'd
like to hear from the maintainers on what their preferred approach
would be.

A new Feature PCD could satisfy both sets of platforms, could it not?

(Sorry if the original patch already had such a PCD; I don't
remember.)

Of course then we'd have a debate around the DEC default for the new
PCD
-- I'd say the default value of the PCD should match the
spec-mandated
behavior.

I don't recall any specifics, but a bug-compat pattern that's
sometimes used
is this:

if (BugCompatEnabled) {
//
// do the right thing in the wrong place, for legacy platforms' sake
//
Foo ();
}

//
// Do some stuff.
//
Bar ();

if (!BugCompatEnabled) {
//
// do the right thing in the right place, for conformant platforms
//
Foo ();
}

Not sure if it applies here.

Thanks
Laszlo


On 2021.02.17 11:42, Leif Lindholm wrote:
Hi Pete, +various

Resurrecting this old thread since Ard pointed out an issue I ran
into myself had already been encountered by Pete.
And the bugzilla ticket (directly below this reply) has had no
relevant progress since August.

Executive summary:
The current UefiBootManagerLib implementation of the
PlatformRecovery path does not notify the
EFI_EVENT_GROUP_READY_TO_BOOT event.

The argument has been made that since changing this would affect
an unnamed number of non-public platforms, the behaviour cannot be
changed even though it violates the UEFI specification.

I disagree with that statement. If we want to fork
UefiBootManagerLib into a BrokenLegacyUefiBootManagerLib and an
actually correct one, and have those platforms move to the
BrokenLegacy variant, I'm OK with that.

But using the default version should give specification-compliant
behaviour.

/
Leif

On Tue, Jun 30, 2020 at 18:17:10 +0100, Pete Batard wrote:
Please note that I have created a bug report
(https://bugzilla.tianocore.org/show_bug.cgi?id=2831) to address
the non-compliance issue was raised during the course of the
discussion below.

Regards,

/Pete


On 2020.06.17 18:06, Samer El-Haj-Mahmoud wrote:
I worked with Pete offline on this..

This code seems to be violating the UEFI Spec:

https://github.com/tianocore/edk2/blob/a56af23f066e2816c67b7c6e64d
e
7ddefcd70780/MdeModulePkg/Library/UefiBootManagerLib/BmBoot.c#L176
3


//
// 3. Signal the EVT_SIGNAL_READY_TO_BOOT event when we
are
about to load and execute
// the boot option.
//
if (BmIsBootManagerMenuFilePath (BootOption->FilePath)) {
DEBUG ((EFI_D_INFO, "[Bds] Booting Boot Manager Menu.\n"));
BmStopHotkeyService (NULL, NULL);
} else {
EfiSignalEventReadyToBoot();
//
// Report Status Code to indicate ReadyToBoot was signalled
//
REPORT_STATUS_CODE (EFI_PROGRESS_CODE,
(EFI_SOFTWARE_DXE_BS_DRIVER |
EFI_SW_DXE_BS_PC_READY_TO_BOOT_EVENT));
//
// 4. Repair system through DriverHealth protocol
//
BmRepairAllControllers (0);
}

The UEFI Spec section 3.1.7 clearly states that Boot Options
(and their FilePathList) *shall not* be evaluated prior to the
completion of EFI_EVENT_GROUP_READY_TO_BOOT event group
processing:

"After all SysPrep#### variables have been launched and exited,
the platform shall notify EFI_EVENT_GROUP_READY_TO_BOOT
event
group and begin to evaluate Boot#### variables with Attributes
set to LOAD_OPTION_CATEGORY_BOOT according to the order
defined
by
BootOrder. The FilePathList of variables marked
LOAD_OPTION_CATEGORY_BOOT shall not be evaluated prior to
the
completion of EFI_EVENT_GROUP_READY_TO_BOOT event group
processing."

This is a prescriptive language that is stronger than the
language in section 7.1 which defines the ReadyToBoot event
group in a general way:

"EFI_EVENT_GROUP_RESET_SYSTEM
This event group is notified by the system when ResetSystem() is
invoked and the system is about to be reset. The event group is
only notified prior to ExitBootServices() invocation."

The EDK2 code in the else block above (to call
EfiSignalEventReadyToBoot() ) need to move before the code that
is processing BootOption->FilePath. In fact, why is this
signaling even a BootManager task? It should be a higher level
BDS task (after processing SysPrp and before processing Boot
options, per the
spec).
This would be somewhere around
https://github.com/tianocore/edk2/blob/b15646484eaffcf7cc464fdea02
1
4498f26addc2/MdeModulePkg/Universal/BdsDxe/BdsEntry.c#L1007
where SysPrep is processed.

This should also take care of the issue Pete reported in this
thread, without the need for explicitly signaling ReadyToBoot
from PlatformRecovery (or changing the UEFI spec).

Thanks,
--Samer



From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
Samer El-Haj-Mahmoud via groups.io
Sent: Wednesday, June 17, 2020 12:42 PM
To: devel@edk2.groups.io; Andrei Warkentin
(awarkentin@vmware.com)
<awarkentin@vmware.com>; Wang, Sunny (HPS SW)
<sunnywang@hpe.com>;
pete@akeo.ie
Cc: zhichao.gao@intel.com; ray.ni@intel.com; Ard Biesheuvel
<Ard.Biesheuvel@arm.com>; leif@nuviainc.com; Samer El-Haj-
Mahmoud
<Samer.El-Haj-Mahmoud@arm.com>
Subject: Re: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on
platform
recovery

The UEFI spec (3.1.7) says:

"After all SysPrep#### variables have been launched and exited,
the platform shall notify EFI_EVENT_GROUP_READY_TO_BOOT
event
group and begin to evaluate Boot#### variables with Attributes
set to LOAD_OPTION_CATEGORY_BOOT according to the order
defined
by
BootOrder. The FilePathList of variables marked
LOAD_OPTION_CATEGORY_BOOT shall not be evaluated prior to
the
completion of EFI_EVENT_GROUP_READY_TO_BOOT event group
processing."

The way I read this, I expect ReadyToBoot to be signaled after
SysPrep#### (if any) are processed, but before Boot#### are
processed. Is my understanding correct that this language
implies ReadyToBoot need to be signaled even if BootOrder does
not contain any Boot#### options marked as
LOAD_OPTION_CATEGORY_BOOT?
And if
so, is EDK2 not doing this, which leads us to this patch
(signaling it in PlatformRecovery?)



From: mailto:devel@edk2.groups.io
<mailto:devel@edk2.groups.io>
On
Behalf Of Andrei Warkentin via groups.io
Sent: Wednesday, June 17, 2020 12:37 PM
To: Wang, Sunny (HPS SW) <mailto:sunnywang@hpe.com>;
mailto:devel@edk2.groups.io; mailto:pete@akeo.ie
Cc: mailto:zhichao.gao@intel.com; mailto:ray.ni@intel.com; Ard
Biesheuvel <mailto:Ard.Biesheuvel@arm.com>;
mailto:leif@nuviainc.com
Subject: Re: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on
platform
recovery

Thanks Pete.

I think the question I have, that I hope Tiano veterans can
chime in, is whether we are doing the right thing, or if we
should be overriding the boot mode? I.e. is it normal that we
boot up in recovery until options are saved?


A


________________________________________
From: mailto:devel@edk2.groups.io
<mailto:devel@edk2.groups.io>
on
behalf of Pete Batard via groups.io
<mailto:pete=akeo.ie@groups.io>
Sent: Wednesday, June 17, 2020 11:34 AM
To: Wang, Sunny (HPS SW) <mailto:sunnywang@hpe.com>;
mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
Cc: mailto:zhichao.gao@intel.com <mailto:zhichao.gao@intel.com>;
mailto:ray.ni@intel.com <mailto:ray.ni@intel.com>;
mailto:ard.biesheuvel@arm.com
<mailto:ard.biesheuvel@arm.com>;
mailto:leif@nuviainc.com <mailto:leif@nuviainc.com>
Subject: Re: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on
platform
recovery

On 2020.06.17 14:04, Wang, Sunny (HPS SW) wrote:
Thanks for checking my comments, Pete.

Or is the "one more" the issue, meaning that it would get
signaled more than once?
[Sunny] Yeah, it would get signaled more than once if the
PlatformRecovery option (a UEFI application) calls
EfiBootManagerBoot() to launch the recovered boot option inside
of the application.
Okay.

One element that I'm going to point out is that, with the
current
EDK2 code (i.e. without this proposal applied), and after a user
goes into the setup to save their boot options in order for
regular boot options to get executed instead of PlaformRecovery,
the OnReadyToBoot event is actually called twice.

So my understanding is that, while we of course want to avoid
this and any patch proposal should actively try to prevent it,
it seems we already have behaviour in EDK2 that can lead to
OnReadyToBoot being signalled more than once.

At least the current Pi 4 platform does demonstrate this behaviour.
For instance, if you run DEBUG, you will see two instances of:

RemoveDtStdoutPath: could not retrieve DT blob - Not Found

which is a one-instance message generated from the
ConsolePrefDxe's
OnReadyToBoot() call. I've also confirmed more specifically that
OnReadyToBoot() is indeed called twice.

I don't recall us doing much of any special with regards to boot
options for the Pi platform, so my guess is that it's probably
not the only platform where OnReadyToBoot might be signalled
more
than
once, and that this might be tied to a default EDK2 behaviour.
Therefore I don't see having a repeated event as a major deal
breaker (though, again, if we can avoid that, we of course will
want to).

I don't mind trying an alternative approach, but I don't
understand how what you describe would help. Can you please
be
more specific about what you have in mind?
[Sunny] Sure. I added more information below. If it is still
not clear enough, feel free to let me know.
1. Create a UEFI application with the code to signal
ReadyToBoot and pick /efi/boot/bootaa64.efi from either SD or
USB and run it.
So that would basically be adding code that duplicates, in part,
what Platform Recovery already does.

I have to be honest: Even outside of the extra work this would
require, I don't really like the idea of having to write our own
application, as it will introduce new possible points of
failures and require extra maintenance (especially as we will
want to be able to handle network boot and other options, and
before long, I fear that we're going to have to write our own Pi
specific boot manager). Doing so simply because the current
Platform Recovery, which does suit our needs otherwise, is not
designed to call ReadyToBoot does not seem like the best course
of action in my book.

Instead, I still logically believe that any option that calls a
boot loader should signal ReadyToBoot, regardless of whether it
was launched from Boot Manager or Platform Recovery, and that it
shouldn't be left to each platform to work around that.

Of course, I understand that this would require a specs change,
and that it also may have ramifications for existing platforms
that interpret the current specs pedantically. But to me,
regardless of what the specs appear to be limiting it to right
now, the logic of a "ReadyToBoot"
event is that it should be signalled whenever a bootloader is
about to be executed, rather than only when a bootloader
happened to be launched through a formal Boot Manager option.

I would therefore appreciate if other people could weigh in on
this matter, to see if I'm the only one who believes that we
could ultimately have more to gain from signalling ReadyToBoot
with PlatformRecovery options than leaving things as they stand
right now...

2. Then, call EfiBootManagerInitializeLoadOption like
the following in a DXE driver or other places before "Default
PlatformRecovery" registration:
Status = EfiBootManagerInitializeLoadOption (
&LoadOption,

0,
-> 0 is the OptionNumber to let application be load before "
Default PlatformRecovery" option
LoadOptionTypePlatformRecovery,
LOAD_OPTION_ACTIVE,
L"Application for recovering boot options",

FilePath,
-> FilePath is the Application's device path,
NULL,
0
);


My reasoning is that, if PlatformRecovery#### can execute a
regular bootloader like /efi/boot/boot####.efi from
installation media, then it should go through the same kind of
initialization that happens for a regular boot option, and
that should include signaling the ReadyToBoot event.
[Sunny] Thanks for clarifying this, and Sorry about that I
missed your cover letter for this patch. I was just thinking
that we may not really need to make this behavior change in
both EDK II code and UEFI specification for solving the problem
specific to the case that OS is loaded by "Default
PlatformRecovery" option,
The way I see it is that the Pi platform is unlikely to be the
only one where PlatformRecovery is seen as a means to install an
OS.
Granted, this may seem like abusing the option, but since UEFI
doesn't provide an "Initial OS Install" mode, I would assert
that it as good a use of this option as any.

In other words, I don't think this improvement would only
benefit the Pi platform.

and I'm also not sure if it is worth making this change to
affect some of the system or BIOS vendors who have
implemented
their PlatformRecovery option.
That's a legitimate concern, and I would agree the one major
potential pitfall of this proposal, if there happens to exist a
system where an OnReadyToBoot even before running the
recovery
option can have adverse effects.

I don't really believe that such a system exists, because I
expect most recovery boot loaders to also work (or at least have
been designed to
work) as regular boot options. But I don't have enough
experience with platform recovery to know if that's a correct
assertion to make...

If the alternative approach I mentioned works for you, I think
that would be an easier solution.
Right now, even as the patch proposal has multiple issues that
require it to be amended (Don't signal ReadyToBoot except for
PlatformRecovery
+ Prevent situations where ReadyToBoot could be signalled
+ multiple
times) I still see it as both an easier solution than the
alternative, as well as one that *should* benefit people who
design Platform Recovery UEFI applications in the long run. So
that is why I am still trying to advocate for it.

But I very much hear your concerns, and I agree that specs
changes are better avoided when possible.

Thus, at this stage, even as I don't want to drag this
discussion much further, I don't feel like I want to commit to
one solution or the other before we have had a chance to hear
other people, who may have their own opinion on the matter,
express their views.

Regards,

/Pete



Regards,
Sunny Wang

-----Original Message-----
From: Pete Batard [mailto:pete@akeo.ie]
Sent: Wednesday, June 17, 2020 6:59 PM
To: Wang, Sunny (HPS SW) <mailto:sunnywang@hpe.com>;
mailto:devel@edk2.groups.io
Cc: mailto:zhichao.gao@intel.com; mailto:ray.ni@intel.com;
mailto:ard.biesheuvel@arm.com; mailto:leif@nuviainc.com
Subject: Re: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on
platform
recovery

Hi Sunny, thanks for looking into this.

On 2020.06.17 09:16, Wang, Sunny (HPS SW) wrote:
Hi Pete.

Since the EfiBootManagerProcessLoadOption is called by
ProcessLoadOptions as well, your change would also cause some
unexpected behavior like:
1. Signal one more ReadyToBoot for the PlatformRecovery option
which is an application that calls EfiBootManagerBoot() to
launch its recovered boot option.
I'm not sure I understand how this part is unwanted.

The point of this patch is to ensure that ReadyToBoot is
signalled for the PlatformRecovery option, so isn't what you
describe above exactly what we want?

Or is the "one more" the issue, meaning that it would get
signalled more than once?


2. Signal ReadyToBoot for SysPrep#### or Driver#### that is
not really a "boot" option.
Yes, I've been wondering about that, because BdsEntry.c's
ProcessLoadOptions(), which calls
EfiBootManagerProcessLoadOption(),
mentions that it will load will load and start every
Driver####, SysPrep#### or PlatformRecovery####. But the
comment about the
while() loop in EfiBootManagerProcessLoadOption() only mentions
PlatformRecovery####.

If needed, I guess we could amend the patch to detect the type
of option and only signal ReadyToBoot for PlatformRecovery####.

To solve your problem, creating a PlatformRecovery option with
the smallest option number and using it instead of default one
(with short-form File Path Media Device Path) looks like a
simpler solution.
I don't mind trying an alternative approach, but I don't
understand how what you describe would help. Can you please be
more specific about what you have in mind?

Our main issue here is that we must have ReadyToBoot signalled
so that the ReadyToBoot() function callback from
EmbeddedPkg/Drivers/ConsolePrefDxe gets executed in order for
the
boot loader invoked from PlatformRecovery#### to use a
properly initialized graphical console. So I'm not sure I quite
get how switching from one PlatformRecovery#### option to
another would improve things.

If it helps, here is what we currently default to, in terms of
boot options, on a Raspberry Pi 4 platform with a newly build
firmware:

[Bds]=============Begin Load Options Dumping
...=============
Driver Options:
SysPrep Options:
Boot Options:
Boot0000: UiApp 0x0109
Boot0001: UEFI Shell 0x0000
PlatformRecovery Options:
PlatformRecovery0000: Default PlatformRecovery
0x0001 [Bds]=============End Load Options
Dumping=============

With this, PlatformRecovery0000 gets executed by default, which
is what we want, since it will pick /efi/boot/bootaa64.efi from
either SD or USB and run it, the only issue being that, because
ReadyToBoot has not been executed, the graphical console is not
operative so users can't interact with the OS installer.

So I'm really not sure how adding an extra PlatformRecovery####
would help. And I'm also not too familiar with how one would go
around to add such an entry...

By the way, I also checked the UEFI specification. It looks
making sense to only signal ReadyToBoot for boot option
(Boot####).

That's something I considered too, but I disagree with this
conclusion.

My reasoning is that, if PlatformRecovery#### can execute a
regular bootloader like /efi/boot/boot####.efi from
installation media, then it should go through the same kind of
initialization that happens for a regular boot option, and that
should include signalling the ReadyToBoot event.

If there was a special bootloader for PlatformRecovery#### (e.g.
/efi/boot/recovery####.efi) then I would agree with only
signalling ReadyToBoot for a formal Boot#### option. But that
isn't the case, so I think it is reasonable to want to have
ReadyToBoot also occur when a /efi/boot/boot####.efi
bootloader
is executed from PlatformRecovery####., especially when we
know
it can be crucial to ensuring that the end user can actually
use the
graphical console.

Therefore, your change may also require specification change.
Yes, I mentioned that in the cover letter for this patch
(https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%
2
Fedk2.groups.io%2Fg%2Fdevel%2Fmessage%2F61327&amp;data=02%7C01%
7C
a
warkentin%40vmware.com%7C5f90d077bc7949c1122f08d812dc48d3%7Cb391
3
8
ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637280084611749324&amp;sdat
a
=
2%2B%2FcvMkrmZGTRRLDGSuMsKbiyDOGtwYwZ7qSqMyMicc%3D&amp;res
erved=0
), which also describes the issue we are trying to solve in
greater details. This is what I wrote:

---------------------------------------------------------------
--
-
------

Note however that this may require a specs update, as the
current UEFI specs for EFI_BOOT_SERVICES.CreateEventEx() have:

> EFI_EVENT_GROUP_READY_TO_BOOT
> This event group is notified by the system when the
Boot Manager
> is about to load and execute a boot option.

and, once this patch has been applied, we may want to update
this section to mention that it applies to both Boot Manager
and Platform Recovery.
---------------------------------------------------------------
--
-
------



Again, I don't have an issue with trying to use an alternate
approach to solve our problem (though I ultimately believe
that, if PlatformRecovery#### can launch a
/efi/boot/boot####.efi bootloader then we must update the
specs
and the code to have ReadyToBoot also signalled then, because
that's the logical thing to do). But right now, I'm not seeing
how to achieve that when PlatformRecovery#### is the option
that is used to launch the OS installation the bootloader. So
if you can provide mode details on how exactly you think
creating an alternate PlatformRecovery option would help, I would
appreciate it.

Regards,

/Pete


Regards,
Sunny Wang

-----Original Message-----
From: mailto:devel@edk2.groups.io
[mailto:devel@edk2.groups.io]
On Behalf Of Pete Batard
Sent: Tuesday, June 16, 2020 5:56 PM
To: mailto:devel@edk2.groups.io
Cc: mailto:zhichao.gao@intel.com; mailto:ray.ni@intel.com;
mailto:ard.biesheuvel@arm.com; mailto:leif@nuviainc.com
Subject: [edk2-devel] [edk2][PATCH 1/1]
MdeModulePkg/UefiBootManagerLib: Signal ReadyToBoot on
platform
recovery

Currently, the ReadyToBoot event is only signaled when a
formal Boot Manager option is executed (in BmBoot.c ->
EfiBootManagerBoot ()).

However, with the introduction of Platform Recovery in UEFI
2.5, which may lead to the execution of a boot loader that has
similar requirements to a regular one, yet is not launched as
a Boot Manager option, it also becomes necessary to signal
ReadyToBoot when a Platform Recovery boot loader runs.

Especially, this can be critical to ensuring that the
graphical console is actually usable during platform recovery,
as some platforms do rely on the ConsolePrefDxe driver, which
only performs console initialization after ReadyToBoot is
triggered.

This patch fixes that behaviour by calling
EfiSignalEventReadyToBoot () in
EfiBootManagerProcessLoadOption
(), which is the function that sets up the platform recovery
boot process.

Signed-off-by: Pete Batard <mailto:pete@akeo.ie>
---
MdeModulePkg/Library/UefiBootManagerLib/BmLoadOption.c
| 9
+++++++++
1 file changed, 9 insertions(+)

diff --git
a/MdeModulePkg/Library/UefiBootManagerLib/BmLoadOption.c
b/MdeModulePkg/Library/UefiBootManagerLib/BmLoadOption.c
index 89372b3b97b8..117f1f5b124c 100644
---
a/MdeModulePkg/Library/UefiBootManagerLib/BmLoadOption.c
+++
b/MdeModulePkg/Library/UefiBootManagerLib/BmLoadOption.c
@@ -1376,6 +1376,15 @@ EfiBootManagerProcessLoadOption (
return EFI_SUCCESS;
}

+ //
+ // Signal the EVT_SIGNAL_READY_TO_BOOT event when we
are
+about
to load and execute the boot option.
+ //
+ EfiSignalEventReadyToBoot ();
+ //
+ // Report Status Code to indicate ReadyToBoot was signalled
+// REPORT_STATUS_CODE (EFI_PROGRESS_CODE,
(EFI_SOFTWARE_DXE_BS_DRIVER |
+ EFI_SW_DXE_BS_PC_READY_TO_BOOT_EVENT));
+
//
// Load and start the load option.
//
--
2.21.0.windows.1




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not disclose the contents to any other person, use it for any
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you.





IMPORTANT NOTICE: The contents of this email and any attachments are
confidential and may also be privileged. If you are not the intended recipient,
please notify the sender immediately and do not disclose the contents to any
other person, use it for any purpose, or store or copy the information in any
medium. Thank you.



IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

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