In theory we should be properly cleaning up all the device drivers before
hitting the big reset. The partition manager will issue flush commands to
attached disks as it goes down. This assures that devices running in WB mode,
which correctly handle flush/sync/etc commands, are persisted to physical
media before reset.
Without this, there are definitely cases where the relevant specifications
don't guarantee persistence of data in their buffers in the face of reset
conditions. We can't really do anything about the many devices that don't
honor persistence requests, but we can start here.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Commit 94e9fba43d introduced an unconditional
call to PcdGet32 after we exit boot services, that produces a kernel panic
on Linux reset.
This addendum to the previous commit ensures that we only read the PCD and
apply the delay while we are still in UEFI, which is what we want anyway as
the goal was to fix the storage of NV variables set by the user from within
the UEFI firmware interface.
Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Due to the method in which NV variables are stored on removable media
for the Raspberry Pi platform, and the manner in which we dump updated
variables right before reset, it is possible, and has been repeatedly
demonstrated with SSD-based USB 3.0 devices, that the updated file does
not actually end up being written to permanent storage, due to the
device write-cache not having enough time to be flushed before reset.
To compensate for this, since we don't know of a generic method that
would allow turning off USB mass storage devices write cache (and also
because we are seeing an issue that seems related for SD-based media),
we add a new reset delay PCD, which can be set by the user, and which
we also set as required when NV variables are being dumped.
Our testing show that, with more than 3 seconds of extra delay, the
storage media has enough time to finalize its internal write, thus
solving the issue of configuration changes not being persisted.
Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Andrei Warkentin <awarkentin@vmware.com>
Tested-by: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>
In preparation for adding Raspberry Pi 4 support, the Pi 3 platform
is restructured by factorizing all the drivers and libraries that are
going to be commonly used by the two platforms.
Because much of the Pi 4 SoC is an extension of the Pi 3 one this
means that almost everything, except the ACPI tables, is moved up
into a new common RaspberryPi/ subdirectory that will serve both
platforms. The .dec is also moved to this directory, under a new
RaspberryPi.dec name, and existing references to it are updated.
This commit requires the edk2-non-osi in use to contain commit 243e55f622ea
in order to build.
Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
