[PATCH 0/2] Fix CMDLINE_EXTEND handling for FDT "bootargs"

From: Will Deacon
Date: Thu Feb 25 2021 - 08:00:35 EST


Hi folks,

We recently [1] enabled support for CMDLINE_EXTEND on arm64, however
when I started looking at replacing Android's out-of-tree implementation [2]
with the upstream version, I noticed that the two behave significantly
differently: Android follows the Kconfig help text of appending the
bootloader arguments to the kernel command line, whereas upstream appends
the kernel command line to the bootloader arguments. That is, except for
the EFI stub, which follows the documented behaviour.

I think the documented behaviour is more useful, so this patch series
reworks the FDT code to follow that and updates the very recently merged
arm64 idreg early command-line parsing as well.

I'd like to take the first patch as a fix via the arm64 tree.

Cheers,

Will

[1] https://lore.kernel.org/r/160650434702.20875.12520970127987518808.b4-ty@xxxxxxx
[2] https://android-review.googlesource.com/c/kernel/common/+/841045

--->8

Cc: Max Uvarov <muvarov@xxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Doug Anderson <dianders@xxxxxxxxxxxx>
Cc: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
Cc: Frank Rowand <frowand.list@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: <kernel-team@xxxxxxxxxxx>
Cc: <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: <devicetree@xxxxxxxxxxxxxxx>

Will Deacon (2):
arm64: cpufeatures: Fix handling of CONFIG_CMDLINE for idreg overrides
of/fdt: Append bootloader arguments when CMDLINE_EXTEND=y

arch/arm64/kernel/idreg-override.c | 44 +++++++++++---------
drivers/of/fdt.c | 64 ++++++++++++++++++------------
2 files changed, 64 insertions(+), 44 deletions(-)

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2.30.1.766.gb4fecdf3b7-goog