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    efi: Add 'capsule' update support · f0133f3c
    Matt Fleming 提交于
    The EFI capsule mechanism allows data blobs to be passed to the EFI
    firmware. A common use case is performing firmware updates. This patch
    just introduces the main infrastructure for interacting with the
    firmware, and a driver that allows users to upload capsules will come
    in a later patch.
    
    Once a capsule has been passed to the firmware, the next reboot must
    be performed using the ResetSystem() EFI runtime service, which may
    involve overriding the reboot type specified by reboot=. This ensures
    the reset value returned by QueryCapsuleCapabilities() is used to
    reset the system, which is required for the capsule to be processed.
    efi_capsule_pending() is provided for this purpose.
    
    At the moment we only allow a single capsule blob to be sent to the
    firmware despite the fact that UpdateCapsule() takes a 'CapsuleCount'
    parameter. This simplifies the API and shouldn't result in any
    downside since it is still possible to send multiple capsules by
    repeatedly calling UpdateCapsule().
    Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
    Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
    Cc: Kweh Hock Leong <hock.leong.kweh@intel.com>
    Cc: Mark Salter <msalter@redhat.com>
    Cc: Peter Jones <pjones@redhat.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: joeyli <jlee@suse.com>
    Cc: linux-efi@vger.kernel.org
    Link: http://lkml.kernel.org/r/1461614832-17633-28-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
    f0133f3c
reboot.c 1.4 KB