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efi: Add 'capsule' update support

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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: Matt 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.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Matt Fleming
2016-04-25 21:06:59 +01:00
committed by Ingo Molnar
parent 806b0351c9
commit f0133f3c5b
4 changed files with 326 additions and 1 deletions
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14
include/linux/efi.h
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@@ -124,6 +124,13 @@ typedef struct {
u32 imagesize;
} efi_capsule_header_t;
/*
* EFI capsule flags
*/
#define EFI_CAPSULE_PERSIST_ACROSS_RESET 0x00010000
#define EFI_CAPSULE_POPULATE_SYSTEM_TABLE 0x00020000
#define EFI_CAPSULE_INITIATE_RESET 0x00040000
/*
* Allocation types for calls to boottime->allocate_pages.
*/
@@ -1370,6 +1377,13 @@ int efivars_sysfs_init(void);
#define EFIVARS_DATA_SIZE_MAX 1024
#endif /* CONFIG_EFI_VARS */
extern bool efi_capsule_pending(int *reset_type);
extern int efi_capsule_supported(efi_guid_t guid, u32 flags,
size_t size, int *reset);
extern int efi_capsule_update(efi_capsule_header_t *capsule,
struct page **pages);
#ifdef CONFIG_EFI_RUNTIME_MAP
int efi_runtime_map_init(struct kobject *);