Return EFI_INVALID_PARAMETER if attribute only has EFI_VARIABLE_NON_VOLATILE set
Hi Liming, Hao, and all
Now we’re checking the SCT runtime variable service test case. https://github.com/tianocore/edk2-test/blob/92a0343c1553342c53fae9d9d646b763add232c0/uefi-sct/SctPkg/TestCase/UEFI/EFI/RuntimeServices/VariableServices/BlackBoxTest/VariableServicesBBTestConformance.c#L3401 and have a question below.
Is there any use case to call the runtime variable service functions with the Attributes that only has EFI_VARIABLE_NON_VOLATILE set?
We checked UEFI spec, documents, and current EDK2 implementation. There is no specific description or any implementation for this. However, there seems an implication that EFI_VARIABLE_NON_VOLATILE must be set with at least EFI_VARIABLE_BOOTSERVICE_ACCESS. Actually, it looks like making NO sense to have a variable attribute combination that doesn’t have any XXXXX_ACCESS attribute (BS, RT, or AT) set.
Therefore, we think only having EFI_VARIABLE_NON_VOLATILE set may be an invalid case and would like to add a check into the EDK2 variable driver to return EFI_INVALID_PARAMETER. What do you guys think?
On 10/21/21 12:18, Sunny Wang wrote:
Hi Liming, Hao, and allThe Self Certification Test (SCT) II Case Specification, June 2017
explicitly forbids this value for QueryVariableInfo():
Call QueryVariableInfo service with the Attributes:
The returned code must be EFI_INVALID_PARAMETER.
This corresponds to the UEFI specification saying:
Status Codes returned
An invalid combination of attribute bits was supplied.
A variable being not accessible at BootTime seems not to be foreseen by
If software uses a nonvolatile variable, it should use a variable that
is only accessible at boot services time if possible.
Attributes that have EFI_VARIABLE_RUNTIME_ACCESS set must also have
This sounds like a nonvolatile variable should always be accessible at
boot services time. But an explicit rule forbidding the creation of
inaccessible variables, i.e. without EFI_VARIABLE_BOOTSERVICE_ACCESS, is
It would be good to have a paragraph in the specification that
unambiguously defines which combination of attribute bits are valid.
"All variables must be created with attribute bit