Re: [PATCH 0/5] ArmPkg/PlatformBootManagerLib: play nice without ConnectAll()

["Leif Lindholm" <leif@nuviainc.com>]

On Tue, May 26, 2020 at 18:13:54 +0200, Ard Biesheuvel wrote:
> Currently, Armpkg's PlatformBootManagerLib connects all controller to
> their drivers recursively, even if the active boot option does not
> require it. There are some historical reasons for this, some of which are
> being addressed in separate patches.
> 
> This series addresses the way ArmPkg's PlatformBootManagerLib implementation
> deals with the UEFI Shell and the UiApp: currently, the shell is always
> added as an ordinary boot option, which will be started if no other boot
> options can be started, or if it is the first one in the boot order.
> 
> Once we remove the ConnectAll() call from PlatformBootManagerLib, those shells
> will be launched without any block or other devices connected, which may
> confuse novice users. So before doing so, let's make the handling a bit more
> sane:
> - add a 's' hotkey that enters the UEFI shell regardless of its priority
>   in the BootOrder - this shell will be entered with no devices connected
>   after patch #4
> - enter the UiApp as a last resort if no boot options can be started
> - make the UEFI Shell boot option hidden, so it is not started by default
>   (only by hotkey or BootNext)
> - remove the ConnectAll() call from PlatformBootManagerLib
> - finally, add a plugin library for UiApp to expose the UEFI Shell via an
>   ordinary main menu option (this works around the fact that patch #3 will
>   result in the UEFI Shell disappearing from the Boot Manager list).
>   Entering the shell this way will resemble the old situation, given that
>   UiApp connects all devices and refreshes all boot options etc at launch.

I get why this set was sent in isolation, but could we also discuss
somewhat what we would plan to do with the edk2-platforms that make
use of the ArmPkg PlatformBootManagerLib?

Not attempting a fallback boot onto network is probably an acceptable
change to pick up, but having an undocumented hotkey as the only way
into a shell that now doesn't map devices could be a bit aggravating.

/
    Leif

> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Leif Lindholm <leif@nuviainc.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Zhichao Gao <zhichao.gao@intel.com>
> 
> Ard Biesheuvel (5):
>   ArmPkg/PlatformBootManagerLib: register 's' as UEFI Shell hotkey
>   ArmPkg/PlatformBootManagerLib: fall back to the UiApp on boot failure
>   ArmPkg/PlatformBootManagerLib: hide UEFI Shell as a regular boot
>     option
>   ArmPkg/PlatformBootManagerLib: don't connect all devices on each boot
>   ShellPkg: add BootManager library to add UEFI Shell menu option
> 
>  .../ShellBootManagerLib.inf                   |  45 +++
>  .../ShellBootManagerLib/ShellBootManagerLib.h |  44 +++
>  .../PlatformBootManagerLib/PlatformBm.c       |  37 ++-
>  .../ShellBootManagerLib/ShellBootManagerLib.c | 258 ++++++++++++++++++
>  .../ShellBootManagerLib/ShellBmStrings.uni    |  17 ++
>  .../ShellBootManagerLib/ShellBmVfr.Vfr        |  37 +++
>  6 files changed, 425 insertions(+), 13 deletions(-)
>  create mode 100644 ShellPkg/Library/ShellBootManagerLib/ShellBootManagerLib.inf
>  create mode 100644 ShellPkg/Library/ShellBootManagerLib/ShellBootManagerLib.h
>  create mode 100644 ShellPkg/Library/ShellBootManagerLib/ShellBootManagerLib.c
>  create mode 100644 ShellPkg/Library/ShellBootManagerLib/ShellBmStrings.uni
>  create mode 100644 ShellPkg/Library/ShellBootManagerLib/ShellBmVfr.Vfr
> 
> -- 
> 2.17.1
>