If the platform has an RTC, then EFI_GET_TIME and EFI_SET_TIME are required before ExitBootServices(). Clarify this in the spec.

Also specify that EFI_{GET,SET}_WAKEUP_TIME are required before ExitBootService() if the RTC can wakeup the platform.

Signed-off-by: Grant Likely grant.likely@arm.com ---

Reading through the RTC text it didn't seem clear to me. How's this for a clarification?

g.

source/chapter2-uefi.rst | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/source/chapter2-uefi.rst b/source/chapter2-uefi.rst index 9906fd9..ab22932 100644 --- a/source/chapter2-uefi.rst +++ b/source/chapter2-uefi.rst @@ -159,16 +159,16 @@ are required to be implemented during boot services and runtime services. - Before ExitBootServices() - After ExitBootServices() * - `EFI_GET_TIME` - - Optional + - Required if RTC present - Optional * - `EFI_SET_TIME` - - Optional + - Required if RTC present - Optional * - `EFI_GET_WAKEUP_TIME` - - Optional + - Required if wakeup supported - Optional * - `EFI_SET_WAKEUP_TIME` - - Optional + - Required if wakeup supported - Optional * - `EFI_SET_VIRTUAL_ADDRESS_MAP` - N/A @@ -227,8 +227,11 @@ it may not be possible to access the RTC from runtime services. e.g., The RTC may be on a shared I2C bus which runtime services cannot access because it will conflict with the OS.

-If firmware does not support access to the RTC, then GetTime() and -SetTime() shall return EFI_UNSUPPORTED, +If an RTC is present, then GetTime() and SetTime() must be supported +before ExitBootServices() is called. + +However, if firmware does not support access to the RTC after +ExitBootServices(), then GetTime() and SetTime() shall return EFI_UNSUPPORTED and the OS must use a device driver to control the RTC.

UEFI Reset and Shutdown