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 <[email protected]>
---
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
--
2.20.1
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