[U-Boot] [RFC 2/6] efi: add RuntimeServicesSupported variable

[AKASHI Takahiro]

On Thu, Jun 13, 2019 at 07:56:19AM +0200, Heinrich Schuchardt wrote:
> 
> 
> On 6/5/19 6:21 AM, AKASHI Takahiro wrote:
> > This variable is defined in UEFI specification 2.8, section 8.1.
> > Its value should be updated whenever we add any usable runtime services
> > function.
> 
> It is also required by the EBBR specification.
> 
> >
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> > ---
> >  include/efi_api.h            | 15 +++++++++++++++
> >  include/efi_loader.h         |  3 +++
> >  lib/efi_loader/efi_runtime.c | 28 ++++++++++++++++++++++++++++
> >  lib/efi_loader/efi_setup.c   |  5 +++++
> >  4 files changed, 51 insertions(+)
> >
> > diff --git a/include/efi_api.h b/include/efi_api.h
> > index 65584dd2d82a..d7d95edd4dfc 100644
> > --- a/include/efi_api.h
> > +++ b/include/efi_api.h
> > @@ -213,6 +213,21 @@ struct efi_capsule_header {
> >  	u32 capsule_image_size;
> >  };
> >
> > +#define EFI_RT_SUPPORTED_GET_TIME			0x0001
> > +#define EFI_RT_SUPPORTED_SET_TIME			0x0002
> > +#define EFI_RT_SUPPORTED_GET_WAKEUP_TIME		0x0004
> > +#define EFI_RT_SUPPORTED_SET_WAKEUP_TIME		0x0008
> > +#define EFI_RT_SUPPORTED_GET_VARIABLE			0x0010
> > +#define EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME		0x0020
> > +#define EFI_RT_SUPPORTED_SET_VARIABLE			0x0040
> > +#define EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP	0x0080
> > +#define EFI_RT_SUPPORTED_CONVERT_POINTER		0x0100
> > +#define EFI_RT_SUPPORTED_GET_NEXT_HIGH_MONOTONIC_COUNT	0x0200
> > +#define EFI_RT_SUPPORTED_RESET_SYSTEM			0x0400
> > +#define EFI_RT_SUPPORTED_UPDATE_CAPSULE			0x0800
> > +#define EFI_RT_SUPPORTED_QUERY_CAPSULE_CAPABILITIES	0x1000
> > +#define EFI_RT_SUPPORTED_QUERY_VARIABLE_INFO		0x2000
> > +
> >  struct efi_runtime_services {
> >  	struct efi_table_hdr hdr;
> >  	efi_status_t (EFIAPI *get_time)(struct efi_time *time,
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index 23ce73226762..7bd8002e303e 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -573,6 +573,9 @@ static inline int guidcmp(const efi_guid_t *g1, const efi_guid_t *g2)
> >  #define __efi_runtime_data __attribute__ ((section (".data.efi_runtime")))
> >  #define __efi_runtime __attribute__ ((section (".text.efi_runtime")))
> >
> > +/* Indicate supported runtime services */
> > +efi_status_t efi_init_runtime_supported(void);
> > +
> >  /* Update CRC32 in table header */
> >  void __efi_runtime efi_update_table_header_crc32(struct efi_table_hdr *table);
> >
> > diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> > index 60442cb21d37..cf202bb9ec07 100644
> > --- a/lib/efi_loader/efi_runtime.c
> > +++ b/lib/efi_loader/efi_runtime.c
> > @@ -89,6 +89,34 @@ struct elf_rela {
> >   * handle a good number of runtime callbacks
> >   */
> >
> > +efi_status_t efi_init_runtime_supported(void)
> > +{
> > +	u16 efi_runtime_services_supported;
> > +
> > +	/*
> > +	 * This value must be synced with efi_runtime_detach_list
> > +	 * as well as efi_runtime_services.
> > +	 */
> > +	efi_runtime_services_supported = EFI_RT_SUPPORTED_RESET_SYSTEM;
> 
> This support is system dependent, e.g. on RK3288 systems it does not exist.

efi_reset_system() is defined as a weak function and so
there is no easy way to determine whether this API is supported or not.

> > +#ifdef CONFIG_EFI_GET_TIME
> > +	efi_runtime_services_supported |= EFI_RT_SUPPORTED_GET_TIME;
> 
> We do not support this at runtime.

Okay, I will drop it.

> > +#endif
> > +#ifdef CONFIG_EFI_SET_TIME
> > +	efi_runtime_services_supported |= EFI_RT_SUPPORTED_SET_TIME;
> 
> We do not support this at runtime.

ditto

> > +#endif
> > +#ifdef CONFIG_EFI_RUNTIME_SET_VIRTUAL_ADDRESS_MAP
> > +	efi_runtime_services_supported |=
> > +				EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP;
> 
> Our support is incomplete as we have not implemented ConvertPointer().

Incomplete?
My patch#3 adds ConvertPointer().

-Takahiro Akashi

> For unsupported services we will have to change the return value to
> EFI_UNSUPPORTED. But that will be a separate patch.
> 
> Best regards
> 
> Heinrich
> 
> > +#endif
> > +
> > +	return EFI_CALL(efi_set_variable(L"RuntimeServicesSupported",
> > +					 &efi_global_variable_guid,
> > +					 EFI_VARIABLE_BOOTSERVICE_ACCESS |
> > +					 EFI_VARIABLE_RUNTIME_ACCESS,
> > +					 sizeof(efi_runtime_services_supported),
> > +					 &efi_runtime_services_supported));
> > +}
> > +
> >  /**
> >   * efi_update_table_header_crc32() - Update crc32 in table header
> >   *
> > diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
> > index 45d6aca051f3..75fa344060d5 100644
> > --- a/lib/efi_loader/efi_setup.c
> > +++ b/lib/efi_loader/efi_setup.c
> > @@ -123,6 +123,11 @@ efi_status_t efi_init_obj_list(void)
> >  	if (ret != EFI_SUCCESS)
> >  		goto out;
> >
> > +	/* Indicate supported runtime services */
> > +	ret = efi_init_runtime_supported();
> > +	if (ret != EFI_SUCCESS)
> > +		goto out;
> > +
> >  	/* Initialize system table */
> >  	ret = efi_initialize_system_table();
> >  	if (ret != EFI_SUCCESS)
> >