audk/ArmPlatformPkg/Library
Laszlo Ersek d85bf54b7f ArmPlatformPkg/PL031RealTimeClockLib: remove needless instance init steps
RealTimeClockLib instances are consumed by edk2's
EmbeddedPkg/RealTimeClockRuntimeDxe driver. In its entry point function
InitializeRealTimeClock(), the driver:

(1) calls LibRtcInitialize(),

(2) sets the GetTime(), SetTime(), GetWakeupTime() and SetWakeupTime()
    runtime services to its own similarly-named functions -- where those
    functions wrap the corresponding RealTimeClockLib APIs,

(3) installs EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL with a NULL protocol
    interface.

Steps (2) and (3) conform to PI v1.8 sections II-9.7.2.4 through
II-9.7.2.7.

However, this means that LibRtcInitialize() (of any RealTimeClockLib
instance) should not itself (a) set the GetTime(), SetTime(),
GetWakeupTime() and SetWakeupTime() runtime services, nor (b) install
EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL. The runtime service pointers will be
overwritten in step (2) anyway, and step (3) will uselessly install a
second (NULL-interface) EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL instance in the
protocol database. (The protocol only serves to notify the DXE Foundation
about said runtime services being available.)

Clean up ArmPlatformPkg/PL031RealTimeClockLib accordingly (it only has
code that's redundant for step (3); it does not try to set "gRT" fields).

(Note that the lib instance INF file already does not list
gEfiRealTimeClockArchProtocolGuid.)

Tested with ArmVirtQemu.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4565
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231020121748.44862-1-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
[lersek@redhat.com: shorten patch subject line]
2023-10-24 16:05:00 +00:00
..
ArmMaliDp ArmPlatformPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00
ArmPlatformLibNull ArmPlatformPkg: Remove RVCT support 2022-05-13 14:58:54 +00:00
ArmPlatformStackLib ArmPlatformPkg: Remove RVCT support 2022-05-13 14:58:54 +00:00
HdLcd ArmPlatformPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00
LcdHwNullLib ArmPlatformPkg: Replace BSD License with BSD+Patent License 2019-04-09 09:10:21 -07:00
LcdPlatformNullLib ArmPlatformPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00
PL011SerialPortLib ArmPlatformPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00
PL011UartClockLib ArmPlatformPkg: Fix Ecc error 8001 2021-04-15 19:24:14 +00:00
PL011UartLib ArmPlatformPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00
PL031RealTimeClockLib ArmPlatformPkg/PL031RealTimeClockLib: remove needless instance init steps 2023-10-24 16:05:00 +00:00
PL111Lcd ArmPlatformPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00
PrePiHobListPointerLib ArmPlatformPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00