[PATCH] efi_loader: Allow capsule update on-disk without checking OsIndications

[AKASHI Takahiro]

On Tue, Jun 29, 2021 at 09:43:40AM +0200, Heinrich Schuchardt wrote:
> On 6/29/21 6:55 AM, Ilias Apalodimas wrote:
> > From: apalos <ilias.apalodimas at linaro.org>
> > 
> > Although U-Boot supports capsule update on-disk, it's lack of support for
> > SetVariable at runtime prevents applications like fwupd from using it.
> > 
> > In order to perform the capsule update on-disk the spec says that the OS
> > must copy the capsule to the \EFI\UpdateCapsule directory and set a bit in
> > the OsIndications variable.  The firmware then checks for the
> > EFI_OS_INDICATIONS_FILE_CAPSULE_DELIVERY_SUPPORTED bit in OsIndications
> > variable, which is set by submitter to trigger processing of the capsule
> > on next reboot.
> > 
> > Let's add a config option which ignores the bit checking in OsIndications
> > and just rely on the capsule being present.  Since U-Boot deletes the
> > capsule while processing it, we won't end up running it multiple times.
> > 
> > Note that this is allowed for all capsules.  In the future once,
> > authenticated capsules is fully supported, we can limit the functionality
> > to those only.
> > 
> > Signed-off-by: apalos <ilias.apalodimas at linaro.org>
> > ---
> >   lib/efi_loader/Kconfig       |  9 +++++++++
> >   lib/efi_loader/efi_capsule.c | 36 ++++++++++++++++++++++++++++--------
> >   2 files changed, 37 insertions(+), 8 deletions(-)
> > 
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index 684adfb62379..5a3820e76122 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -137,6 +137,15 @@ config EFI_CAPSULE_ON_DISK
> >   	  under a specific directory on UEFI system partition instead of
> >   	  via UpdateCapsule API.
> > 
> > +config EFI_IGNORE_OSINDICATIONS
> > +	bool "Ignore OsIndications for CapsuleUpdate on-disk"
> > +	depends on EFI_CAPSULE_ON_DISK
> > +	default n
> > +	help
> > +	  There are boards were we can't support SetVariable at runtime.
> > +	  Select this option if you want to use capsule-on-disk feature,
> > +	  without setting the OsIndications bit.

Obviously, this option breaks the conformance to UEFI specification
and must be turned on carefully in the limited use cases.
You should describe that here explicitly.

Additionally, you may add
   depends on !EFI_MM_COMM_TEE (or better config?)

-Takahiro Akashi


> >   config EFI_CAPSULE_ON_DISK_EARLY
> >   	bool "Initiate capsule-on-disk at U-Boot boottime"
> >   	depends on EFI_CAPSULE_ON_DISK
> > diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
> > index d7136035d8f9..50bed32bfb3b 100644
> > --- a/lib/efi_loader/efi_capsule.c
> > +++ b/lib/efi_loader/efi_capsule.c
> > @@ -948,6 +948,33 @@ efi_status_t __weak efi_load_capsule_drivers(void)
> >   	return ret;
> >   }
> > 
> > +/**
> > + * check_run_capsules - Check whether capsule update should run
> > + *
> > + * The spec says OsIndications must be set in order to run the capsule update
> > + * on-disk.  Since U-Boot doesn't support runtime SetVariable, allow capsules to
> > + * run explicitly if CONFIG_EFI_IGNORE_OSINDICATIONS is selected
> > + */
> > +static bool check_run_capsules(void)
> > +{
> > +	u64 os_indications;
> > +	efi_uintn_t size;
> > +	efi_status_t ret;
> > +
> > +	if (IS_ENABLED(CONFIG_EFI_IGNORE_OSINDICATIONS))
> > +		return true;
> > +
> > +	size = sizeof(os_indications);
> > +	ret = efi_get_variable_int(L"OsIndications", &efi_global_variable_guid,
> > +				   NULL, &size, &os_indications, NULL);
> > +	if (ret == EFI_SUCCESS &&
> > +	    (os_indications
> > +	      & EFI_OS_INDICATIONS_FILE_CAPSULE_DELIVERY_SUPPORTED))
> 
> The bit EFI_OS_INDICATIONS_FILE_CAPSULE_DELIVERY_SUPPORTED must be
> cleared in OsIndications after successfully applying the capsule. See
> related patch
> 
> [PATCH 1/1] efi_loader: fix set_capsule_result()
> https://lists.denx.de/pipermail/u-boot/2021-June/453111.html
> 
> Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> 
> > +		return true;
> > +
> > +	return false;
> > +}
> > +
> >   /**
> >    * efi_launch_capsule - launch capsules
> >    *
> > @@ -958,20 +985,13 @@ efi_status_t __weak efi_load_capsule_drivers(void)
> >    */
> >   efi_status_t efi_launch_capsules(void)
> >   {
> > -	u64 os_indications;
> > -	efi_uintn_t size;
> >   	struct efi_capsule_header *capsule = NULL;
> >   	u16 **files;
> >   	unsigned int nfiles, index, i;
> >   	u16 variable_name16[12];
> >   	efi_status_t ret;
> > 
> > -	size = sizeof(os_indications);
> > -	ret = efi_get_variable_int(L"OsIndications", &efi_global_variable_guid,
> > -				   NULL, &size, &os_indications, NULL);
> > -	if (ret != EFI_SUCCESS ||
> > -	    !(os_indications
> > -	      & EFI_OS_INDICATIONS_FILE_CAPSULE_DELIVERY_SUPPORTED))
> > +	if (!check_run_capsules())
> >   		return EFI_SUCCESS;
> > 
> >   	index = get_last_capsule();
> > 
>