* [PATCH 1/2] EmbeddedPkg/RealTimeClockRuntimeDxe: move common functionality into core
@ 2017-11-05 16:52 Ard Biesheuvel
2017-11-05 16:52 ` [PATCH 2/2] ArmPlatformPkg/PL031RealTimeClockLib: remove validation and DST handling Ard Biesheuvel
0 siblings, 1 reply; 3+ messages in thread
From: Ard Biesheuvel @ 2017-11-05 16:52 UTC (permalink / raw)
To: edk2-devel, leif.lindholm; +Cc: Ard Biesheuvel
RealTimeClockRuntimeDxe defers the hardware/platform specific handling
of reading/setting the hardware clock to RealTimeClockLib, but for
unknown reasons, it also defers common functionality such as input
validation and recording the timezone and DST settings (which are
informational only and not managed by hardware)
This has led to a lot of duplication in implementations of RealTimeClockLib
as well as TimeBaseLib, to the point where each library implementation
has its own set of UEFI variables to record the timezone and DST settings.
This makes little sense, and so let's update RealTimeClockRuntimeDxe now
to allow future implementations to rely on the core driver to take care of
these things.
Note that reading the timezone and DST settings occurs before calling into
the library, so we can phase out this behavior gradually from library
implementations in EDK2, edk2-platforms or out of tree.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClock.c | 165 +++++++++++++++++++-
EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClockRuntimeDxe.inf | 11 +-
2 files changed, 166 insertions(+), 10 deletions(-)
diff --git a/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClock.c b/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClock.c
index f1e067c0b59e..944bdac1a3f9 100644
--- a/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClock.c
+++ b/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClock.c
@@ -1,10 +1,8 @@
/** @file
Implement EFI RealTimeClock runtime services via RTC Lib.
- Currently this driver does not support runtime virtual calling.
-
-
Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+ Copyright (c) 2017, Linaro, Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
@@ -17,14 +15,116 @@
**/
#include <PiDxe.h>
+#include <Library/DebugLib.h>
+#include <Library/RealTimeClockLib.h>
#include <Library/UefiLib.h>
#include <Library/UefiBootServicesTableLib.h>
-#include <Library/RealTimeClockLib.h>
+#include <Library/UefiRuntimeLib.h>
#include <Protocol/RealTimeClock.h>
EFI_HANDLE mHandle = NULL;
+//
+// These values can be set by SetTime () and need to be returned by GetTime ()
+// but cannot usually be kept by the RTC hardware, so we store them in a UEFI
+// variable instead.
+//
+typedef struct {
+ INT16 TimeZone;
+ UINT8 Daylight;
+} NON_VOLATILE_TIME_SETTINGS;
+
+STATIC CONST CHAR16 mTimeSettingsVariableName[] = L"RtcTimeSettings";
+STATIC NON_VOLATILE_TIME_SETTINGS mTimeSettings;
+
+STATIC
+BOOLEAN
+IsValidTimeZone (
+ IN INT16 TimeZone
+ )
+{
+ return TimeZone == EFI_UNSPECIFIED_TIMEZONE ||
+ (TimeZone >= -1440 && TimeZone <= 1440);
+}
+
+STATIC
+BOOLEAN
+IsValidDaylight (
+ IN INT8 Daylight
+ )
+{
+ return Daylight == 0 ||
+ Daylight == EFI_TIME_ADJUST_DAYLIGHT ||
+ Daylight == (EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT);
+}
+
+STATIC
+BOOLEAN
+EFIAPI
+IsLeapYear (
+ IN EFI_TIME *Time
+ )
+{
+ if (Time->Year % 4 == 0) {
+ if (Time->Year % 100 == 0) {
+ if (Time->Year % 400 == 0) {
+ return TRUE;
+ } else {
+ return FALSE;
+ }
+ } else {
+ return TRUE;
+ }
+ } else {
+ return FALSE;
+ }
+}
+STATIC CONST INTN mDayOfMonth[12] = {
+ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+STATIC
+BOOLEAN
+EFIAPI
+IsDayValid (
+ IN EFI_TIME *Time
+ )
+{
+ ASSERT (Time->Day >= 1);
+ ASSERT (Time->Day <= mDayOfMonth[Time->Month - 1]);
+ ASSERT (Time->Month != 2 || (IsLeapYear (Time) && Time->Day <= 29));
+
+ if (Time->Day < 1 ||
+ Time->Day > mDayOfMonth[Time->Month - 1] ||
+ (Time->Month == 2 && (!IsLeapYear (Time) && Time->Day > 28))) {
+ return FALSE;
+ }
+ return TRUE;
+}
+
+STATIC
+BOOLEAN
+EFIAPI
+IsTimeValid(
+ IN EFI_TIME *Time
+ )
+{
+ // Check the input parameters are within the range specified by UEFI
+ if (Time->Year < 1900 ||
+ Time->Year > 9999 ||
+ Time->Month < 1 ||
+ Time->Month > 12 ||
+ !IsDayValid (Time) ||
+ Time->Hour > 23 ||
+ Time->Minute > 59 ||
+ Time->Second > 59 ||
+ !IsValidTimeZone (Time->TimeZone) ||
+ !IsValidDaylight (Time->Daylight)) {
+ return FALSE;
+ }
+ return TRUE;
+}
/**
Returns the current time and date information, and the time-keeping capabilities
@@ -46,6 +146,13 @@ GetTime (
OUT EFI_TIME_CAPABILITIES *Capabilities
)
{
+ //
+ // Set these first so the RealTimeClockLib implementation
+ // can override them based on its own settings.
+ //
+ Time->TimeZone = mTimeSettings.TimeZone;
+ Time->Daylight = mTimeSettings.Daylight;
+
return LibGetTime (Time, Capabilities);
}
@@ -67,7 +174,41 @@ SetTime (
IN EFI_TIME *Time
)
{
- return LibSetTime (Time);
+ EFI_STATUS Status;
+ BOOLEAN TimeSettingsChanged;
+
+ if (!IsTimeValid (Time)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ TimeSettingsChanged = FALSE;
+ if (mTimeSettings.TimeZone != Time->TimeZone ||
+ mTimeSettings.Daylight != Time->Daylight) {
+
+ mTimeSettings.TimeZone = Time->TimeZone;
+ mTimeSettings.Daylight = Time->Daylight;
+ TimeSettingsChanged = TRUE;
+ }
+
+ Status = LibSetTime (Time);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ if (TimeSettingsChanged) {
+ Status = EfiSetVariable (
+ (CHAR16 *)mTimeSettingsVariableName,
+ &gEfiCallerIdGuid,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ sizeof (mTimeSettings),
+ (VOID *)&mTimeSettings);
+ if (EFI_ERROR (Status)) {
+ return EFI_DEVICE_ERROR;
+ }
+ }
+ return EFI_SUCCESS;
}
@@ -138,12 +279,26 @@ InitializeRealTimeClock (
)
{
EFI_STATUS Status;
+ UINTN Size;
Status = LibRtcInitialize (ImageHandle, SystemTable);
if (EFI_ERROR (Status)) {
return Status;
}
+ Size = sizeof (mTimeSettings);
+ Status = EfiGetVariable ((CHAR16 *)mTimeSettingsVariableName,
+ &gEfiCallerIdGuid, NULL, &Size, (VOID *)&mTimeSettings);
+ if (EFI_ERROR (Status) ||
+ !IsValidTimeZone (mTimeSettings.TimeZone) ||
+ !IsValidDaylight (mTimeSettings.Daylight)) {
+ DEBUG ((DEBUG_WARN, "%a: using default timezone/daylight settings\n",
+ __FUNCTION__));
+
+ mTimeSettings.TimeZone = EFI_UNSPECIFIED_TIMEZONE;
+ mTimeSettings.Daylight = 0;
+ }
+
SystemTable->RuntimeServices->GetTime = GetTime;
SystemTable->RuntimeServices->SetTime = SetTime;
SystemTable->RuntimeServices->GetWakeupTime = GetWakeupTime;
diff --git a/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClockRuntimeDxe.inf b/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClockRuntimeDxe.inf
index 186d4610bd42..d0520392f145 100644
--- a/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClockRuntimeDxe.inf
+++ b/EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClockRuntimeDxe.inf
@@ -1,8 +1,8 @@
#/** @file
-# Reset Architectural Protocol Driver as defined in PI
+# Real Time Clock Architectural Protocol Driver as defined in PI
#
-# This Reset module simulates system reset by process exit on NT.
-# Copyright (c) 2006 - 2007, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2006 - 2007, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2017, Linaro, Ltd. All rights reserved.<BR>
#
# This program and the accompanying materials
# are licensed and made available under the terms and conditions of the BSD License
@@ -31,10 +31,11 @@ [Packages]
EmbeddedPkg/EmbeddedPkg.dec
[LibraryClasses]
- UefiBootServicesTableLib
- UefiDriverEntryPoint
DebugLib
RealTimeClockLib
+ UefiBootServicesTableLib
+ UefiDriverEntryPoint
+ UefiRuntimeLib
[Protocols]
gEfiRealTimeClockArchProtocolGuid
--
2.11.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/2] ArmPlatformPkg/PL031RealTimeClockLib: remove validation and DST handling
2017-11-05 16:52 [PATCH 1/2] EmbeddedPkg/RealTimeClockRuntimeDxe: move common functionality into core Ard Biesheuvel
@ 2017-11-05 16:52 ` Ard Biesheuvel
2017-11-05 17:32 ` Ard Biesheuvel
0 siblings, 1 reply; 3+ messages in thread
From: Ard Biesheuvel @ 2017-11-05 16:52 UTC (permalink / raw)
To: edk2-devel, leif.lindholm; +Cc: Ard Biesheuvel
This library, which is intended to encapsulate the hardware specifics
of the ARM PL031 RTC, also implements its own input validation routines,
and even makes a feeble attempt at timezone and DST handling.
The input validation belongs in the core driver, and has been introduced
there, so we can remove it. As for the DST handling, this code is simply
wrong, and the UEFI spec's definition of EFI_TIME simply does not carry
enough information to convert a UNIX timestamp (seconds since 1/1/1970)
into a local time value. The EFI_TIME_ADJUST_DAYLIGHT/EFI_TIME_IN_DAYLIGHT
flags we do have only tell us whether our clock is adjusted back and
forth for DST, and whether it is currently set to DST or not.
What the PL031 driver attempts to do is convert the UNIX timestamp to
a local time, by adding the timezone offset (which is fair), but it
also adds an hour if the EFI_TIME_IN_DAYLIGHT is set. However, that flag
does not imply that DST is currently in effect, it only implies that the
clock is running an hour ahead of its standard time, and the UEFI spec
leaves it up to the OS to update the clock when necessary.
To really perform this conversion correctly, we lack sufficient information
about the timezone: our timezone setting is defined as minutes ahead or
behind UTC, but many different DST regimes may be in effect in the same
geographical (i.e., longitude based) timezone, including ones where the
clock moves back and forth twice a year.
So let's remove all of it, and rely on the core driver to record the
timezone and DST flags, and treat them as informational only (as the
spec intends)
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c | 194 +-------------------
1 file changed, 8 insertions(+), 186 deletions(-)
diff --git a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
index 41ebcb95ab85..e0d90f853fca 100644
--- a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
+++ b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
@@ -40,8 +40,6 @@
#include <ArmPlatform.h>
-STATIC CONST CHAR16 mTimeZoneVariableName[] = L"PL031RtcTimeZone";
-STATIC CONST CHAR16 mDaylightVariableName[] = L"PL031RtcDaylight";
STATIC BOOLEAN mPL031Initialized = FALSE;
STATIC EFI_EVENT mRtcVirtualAddrChangeEvent;
STATIC UINTN mPL031RtcBase;
@@ -134,15 +132,12 @@ LibGetTime (
{
EFI_STATUS Status = EFI_SUCCESS;
UINT32 EpochSeconds;
- INT16 TimeZone;
- UINT8 Daylight;
- UINTN Size;
// Initialize the hardware if not already done
if (!mPL031Initialized) {
Status = InitializePL031 ();
if (EFI_ERROR (Status)) {
- goto EXIT;
+ return Status;
}
}
@@ -156,7 +151,7 @@ LibGetTime (
Status = EFI_SUCCESS;
} else if (EFI_ERROR (Status)) {
// Battery backed up hardware RTC exists but could not be read due to error. Abort.
- goto EXIT;
+ return Status;
} else {
// Battery backed up hardware RTC exists and we read the time correctly from it.
// Now sync the PL031 to the new time.
@@ -165,107 +160,7 @@ LibGetTime (
// Ensure Time is a valid pointer
if (Time == NULL) {
- Status = EFI_INVALID_PARAMETER;
- goto EXIT;
- }
-
- // Get the current time zone information from non-volatile storage
- Size = sizeof (TimeZone);
- Status = EfiGetVariable (
- (CHAR16 *)mTimeZoneVariableName,
- &gEfiCallerIdGuid,
- NULL,
- &Size,
- (VOID *)&TimeZone
- );
-
- if (EFI_ERROR (Status)) {
- ASSERT(Status != EFI_INVALID_PARAMETER);
- ASSERT(Status != EFI_BUFFER_TOO_SMALL);
-
- if (Status != EFI_NOT_FOUND)
- goto EXIT;
-
- // The time zone variable does not exist in non-volatile storage, so create it.
- Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
- // Store it
- Status = EfiSetVariable (
- (CHAR16 *)mTimeZoneVariableName,
- &gEfiCallerIdGuid,
- EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
- Size,
- (VOID *)&(Time->TimeZone)
- );
- if (EFI_ERROR (Status)) {
- DEBUG ((
- EFI_D_ERROR,
- "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
- mTimeZoneVariableName,
- Status
- ));
- goto EXIT;
- }
- } else {
- // Got the time zone
- Time->TimeZone = TimeZone;
-
- // Check TimeZone bounds: -1440 to 1440 or 2047
- if (((Time->TimeZone < -1440) || (Time->TimeZone > 1440))
- && (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE)) {
- Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
- }
-
- // Adjust for the correct time zone
- if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
- EpochSeconds += Time->TimeZone * SEC_PER_MIN;
- }
- }
-
- // Get the current daylight information from non-volatile storage
- Size = sizeof (Daylight);
- Status = EfiGetVariable (
- (CHAR16 *)mDaylightVariableName,
- &gEfiCallerIdGuid,
- NULL,
- &Size,
- (VOID *)&Daylight
- );
-
- if (EFI_ERROR (Status)) {
- ASSERT(Status != EFI_INVALID_PARAMETER);
- ASSERT(Status != EFI_BUFFER_TOO_SMALL);
-
- if (Status != EFI_NOT_FOUND)
- goto EXIT;
-
- // The daylight variable does not exist in non-volatile storage, so create it.
- Time->Daylight = 0;
- // Store it
- Status = EfiSetVariable (
- (CHAR16 *)mDaylightVariableName,
- &gEfiCallerIdGuid,
- EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
- Size,
- (VOID *)&(Time->Daylight)
- );
- if (EFI_ERROR (Status)) {
- DEBUG ((
- EFI_D_ERROR,
- "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
- mDaylightVariableName,
- Status
- ));
- goto EXIT;
- }
- } else {
- // Got the daylight information
- Time->Daylight = Daylight;
-
- // Adjust for the correct period
- if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
- // Convert to adjusted time, i.e. spring forwards one hour
- EpochSeconds += SEC_PER_HOUR;
- }
+ return EFI_INVALID_PARAMETER;
}
// Convert from internal 32-bit time to UEFI time
@@ -281,8 +176,7 @@ LibGetTime (
Capabilities->SetsToZero = FALSE;
}
- EXIT:
- return Status;
+ return EFI_SUCCESS;
}
@@ -305,55 +199,24 @@ LibSetTime (
EFI_STATUS Status;
UINTN EpochSeconds;
- // Check the input parameters are within the range specified by UEFI
- if ((Time->Year < 1900) ||
- (Time->Year > 9999) ||
- (Time->Month < 1 ) ||
- (Time->Month > 12 ) ||
- (!IsDayValid (Time) ) ||
- (Time->Hour > 23 ) ||
- (Time->Minute > 59 ) ||
- (Time->Second > 59 ) ||
- (Time->Nanosecond > 999999999) ||
- (!((Time->TimeZone == EFI_UNSPECIFIED_TIMEZONE) || ((Time->TimeZone >= -1440) && (Time->TimeZone <= 1440)))) ||
- (Time->Daylight & (~(EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT)))
- ) {
- Status = EFI_INVALID_PARAMETER;
- goto EXIT;
- }
-
// Because the PL031 is a 32-bit counter counting seconds,
// the maximum time span is just over 136 years.
// Time is stored in Unix Epoch format, so it starts in 1970,
// Therefore it can not exceed the year 2106.
if ((Time->Year < 1970) || (Time->Year >= 2106)) {
- Status = EFI_UNSUPPORTED;
- goto EXIT;
+ return EFI_UNSUPPORTED;
}
// Initialize the hardware if not already done
if (!mPL031Initialized) {
Status = InitializePL031 ();
if (EFI_ERROR (Status)) {
- goto EXIT;
+ return Status;
}
}
EpochSeconds = EfiTimeToEpoch (Time);
- // Adjust for the correct time zone, i.e. convert to UTC time zone
- if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
- EpochSeconds -= Time->TimeZone * SEC_PER_MIN;
- }
-
- // TODO: Automatic Daylight activation
-
- // Adjust for the correct period
- if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
- // Convert to un-adjusted time, i.e. fall back one hour
- EpochSeconds -= SEC_PER_HOUR;
- }
-
// On some platforms we may have access to a battery backed up hardware clock.
//
// If such RTC exists then it must be updated first, before the PL031,
@@ -364,54 +227,13 @@ LibSetTime (
Status = ArmPlatformSysConfigSet (SYS_CFG_RTC, EpochSeconds);
if ((EFI_ERROR (Status)) && (Status != EFI_UNSUPPORTED)){
// Any status message except SUCCESS and UNSUPPORTED indicates a hardware failure.
- goto EXIT;
+ return Status;
}
-
// Set the PL031
MmioWrite32 (mPL031RtcBase + PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
- // The accesses to Variable Services can be very slow, because we may be writing to Flash.
- // Do this after having set the RTC.
-
- // Save the current time zone information into non-volatile storage
- Status = EfiSetVariable (
- (CHAR16 *)mTimeZoneVariableName,
- &gEfiCallerIdGuid,
- EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
- sizeof (Time->TimeZone),
- (VOID *)&(Time->TimeZone)
- );
- if (EFI_ERROR (Status)) {
- DEBUG ((
- EFI_D_ERROR,
- "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
- mTimeZoneVariableName,
- Status
- ));
- goto EXIT;
- }
-
- // Save the current daylight information into non-volatile storage
- Status = EfiSetVariable (
- (CHAR16 *)mDaylightVariableName,
- &gEfiCallerIdGuid,
- EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
- sizeof(Time->Daylight),
- (VOID *)&(Time->Daylight)
- );
- if (EFI_ERROR (Status)) {
- DEBUG ((
- EFI_D_ERROR,
- "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
- mDaylightVariableName,
- Status
- ));
- goto EXIT;
- }
-
- EXIT:
- return Status;
+ return EFI_SUCCESS;
}
--
2.11.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2] ArmPlatformPkg/PL031RealTimeClockLib: remove validation and DST handling
2017-11-05 16:52 ` [PATCH 2/2] ArmPlatformPkg/PL031RealTimeClockLib: remove validation and DST handling Ard Biesheuvel
@ 2017-11-05 17:32 ` Ard Biesheuvel
0 siblings, 0 replies; 3+ messages in thread
From: Ard Biesheuvel @ 2017-11-05 17:32 UTC (permalink / raw)
To: edk2-devel, leif.lindholm
> On 5 Nov 2017, at 16:52, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>
> This library, which is intended to encapsulate the hardware specifics
> of the ARM PL031 RTC, also implements its own input validation routines,
> and even makes a feeble attempt at timezone and DST handling.
>
> The input validation belongs in the core driver, and has been introduced
> there, so we can remove it. As for the DST handling, this code is simply
> wrong, and the UEFI spec's definition of EFI_TIME simply does not carry
> enough information to convert a UNIX timestamp (seconds since 1/1/1970)
> into a local time value. The EFI_TIME_ADJUST_DAYLIGHT/EFI_TIME_IN_DAYLIGHT
> flags we do have only tell us whether our clock is adjusted back and
> forth for DST, and whether it is currently set to DST or not.
>
> What the PL031 driver attempts to do is convert the UNIX timestamp to
> a local time, by adding the timezone offset (which is fair), but it
> also adds an hour if the EFI_TIME_IN_DAYLIGHT is set. However, that flag
> does not imply that DST is currently in effect, it only implies that the
> clock is running an hour ahead of its standard time, and the UEFI spec
> leaves it up to the OS to update the clock when necessary.
>
> To really perform this conversion correctly, we lack sufficient information
> about the timezone: our timezone setting is defined as minutes ahead or
> behind UTC, but many different DST regimes may be in effect in the same
> geographical (i.e., longitude based) timezone, including ones where the
> clock moves back and forth twice a year.
>
> So let's remove all of it, and rely on the core driver to record the
> timezone and DST flags, and treat them as informational only (as the
> spec intends)
>
After reading the code more carefully, it seems I was wrong about this: the code does not make inferences about whether dst is currently in effect or not, it just subtracts an additional hour if the attribute tells us the clock has been adjusted.
So the question remains whethr there is point to doing so. I think there is, given that UEFI may not own the pl031 exclusively, but shares access with qemu/kvm under virtualization.
So please disregard that part of the patch, I will resubmit with those bits reinstated.
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
> ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c | 194 +-------------------
> 1 file changed, 8 insertions(+), 186 deletions(-)
>
> diff --git a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
> index 41ebcb95ab85..e0d90f853fca 100644
> --- a/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
> +++ b/ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
> @@ -40,8 +40,6 @@
>
> #include <ArmPlatform.h>
>
> -STATIC CONST CHAR16 mTimeZoneVariableName[] = L"PL031RtcTimeZone";
> -STATIC CONST CHAR16 mDaylightVariableName[] = L"PL031RtcDaylight";
> STATIC BOOLEAN mPL031Initialized = FALSE;
> STATIC EFI_EVENT mRtcVirtualAddrChangeEvent;
> STATIC UINTN mPL031RtcBase;
> @@ -134,15 +132,12 @@ LibGetTime (
> {
> EFI_STATUS Status = EFI_SUCCESS;
> UINT32 EpochSeconds;
> - INT16 TimeZone;
> - UINT8 Daylight;
> - UINTN Size;
>
> // Initialize the hardware if not already done
> if (!mPL031Initialized) {
> Status = InitializePL031 ();
> if (EFI_ERROR (Status)) {
> - goto EXIT;
> + return Status;
> }
> }
>
> @@ -156,7 +151,7 @@ LibGetTime (
> Status = EFI_SUCCESS;
> } else if (EFI_ERROR (Status)) {
> // Battery backed up hardware RTC exists but could not be read due to error. Abort.
> - goto EXIT;
> + return Status;
> } else {
> // Battery backed up hardware RTC exists and we read the time correctly from it.
> // Now sync the PL031 to the new time.
> @@ -165,107 +160,7 @@ LibGetTime (
>
> // Ensure Time is a valid pointer
> if (Time == NULL) {
> - Status = EFI_INVALID_PARAMETER;
> - goto EXIT;
> - }
> -
> - // Get the current time zone information from non-volatile storage
> - Size = sizeof (TimeZone);
> - Status = EfiGetVariable (
> - (CHAR16 *)mTimeZoneVariableName,
> - &gEfiCallerIdGuid,
> - NULL,
> - &Size,
> - (VOID *)&TimeZone
> - );
> -
> - if (EFI_ERROR (Status)) {
> - ASSERT(Status != EFI_INVALID_PARAMETER);
> - ASSERT(Status != EFI_BUFFER_TOO_SMALL);
> -
> - if (Status != EFI_NOT_FOUND)
> - goto EXIT;
> -
> - // The time zone variable does not exist in non-volatile storage, so create it.
> - Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
> - // Store it
> - Status = EfiSetVariable (
> - (CHAR16 *)mTimeZoneVariableName,
> - &gEfiCallerIdGuid,
> - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
> - Size,
> - (VOID *)&(Time->TimeZone)
> - );
> - if (EFI_ERROR (Status)) {
> - DEBUG ((
> - EFI_D_ERROR,
> - "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
> - mTimeZoneVariableName,
> - Status
> - ));
> - goto EXIT;
> - }
> - } else {
> - // Got the time zone
> - Time->TimeZone = TimeZone;
> -
> - // Check TimeZone bounds: -1440 to 1440 or 2047
> - if (((Time->TimeZone < -1440) || (Time->TimeZone > 1440))
> - && (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE)) {
> - Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
> - }
> -
> - // Adjust for the correct time zone
> - if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
> - EpochSeconds += Time->TimeZone * SEC_PER_MIN;
> - }
> - }
> -
> - // Get the current daylight information from non-volatile storage
> - Size = sizeof (Daylight);
> - Status = EfiGetVariable (
> - (CHAR16 *)mDaylightVariableName,
> - &gEfiCallerIdGuid,
> - NULL,
> - &Size,
> - (VOID *)&Daylight
> - );
> -
> - if (EFI_ERROR (Status)) {
> - ASSERT(Status != EFI_INVALID_PARAMETER);
> - ASSERT(Status != EFI_BUFFER_TOO_SMALL);
> -
> - if (Status != EFI_NOT_FOUND)
> - goto EXIT;
> -
> - // The daylight variable does not exist in non-volatile storage, so create it.
> - Time->Daylight = 0;
> - // Store it
> - Status = EfiSetVariable (
> - (CHAR16 *)mDaylightVariableName,
> - &gEfiCallerIdGuid,
> - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
> - Size,
> - (VOID *)&(Time->Daylight)
> - );
> - if (EFI_ERROR (Status)) {
> - DEBUG ((
> - EFI_D_ERROR,
> - "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
> - mDaylightVariableName,
> - Status
> - ));
> - goto EXIT;
> - }
> - } else {
> - // Got the daylight information
> - Time->Daylight = Daylight;
> -
> - // Adjust for the correct period
> - if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
> - // Convert to adjusted time, i.e. spring forwards one hour
> - EpochSeconds += SEC_PER_HOUR;
> - }
> + return EFI_INVALID_PARAMETER;
> }
>
> // Convert from internal 32-bit time to UEFI time
> @@ -281,8 +176,7 @@ LibGetTime (
> Capabilities->SetsToZero = FALSE;
> }
>
> - EXIT:
> - return Status;
> + return EFI_SUCCESS;
> }
>
>
> @@ -305,55 +199,24 @@ LibSetTime (
> EFI_STATUS Status;
> UINTN EpochSeconds;
>
> - // Check the input parameters are within the range specified by UEFI
> - if ((Time->Year < 1900) ||
> - (Time->Year > 9999) ||
> - (Time->Month < 1 ) ||
> - (Time->Month > 12 ) ||
> - (!IsDayValid (Time) ) ||
> - (Time->Hour > 23 ) ||
> - (Time->Minute > 59 ) ||
> - (Time->Second > 59 ) ||
> - (Time->Nanosecond > 999999999) ||
> - (!((Time->TimeZone == EFI_UNSPECIFIED_TIMEZONE) || ((Time->TimeZone >= -1440) && (Time->TimeZone <= 1440)))) ||
> - (Time->Daylight & (~(EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT)))
> - ) {
> - Status = EFI_INVALID_PARAMETER;
> - goto EXIT;
> - }
> -
> // Because the PL031 is a 32-bit counter counting seconds,
> // the maximum time span is just over 136 years.
> // Time is stored in Unix Epoch format, so it starts in 1970,
> // Therefore it can not exceed the year 2106.
> if ((Time->Year < 1970) || (Time->Year >= 2106)) {
> - Status = EFI_UNSUPPORTED;
> - goto EXIT;
> + return EFI_UNSUPPORTED;
> }
>
> // Initialize the hardware if not already done
> if (!mPL031Initialized) {
> Status = InitializePL031 ();
> if (EFI_ERROR (Status)) {
> - goto EXIT;
> + return Status;
> }
> }
>
> EpochSeconds = EfiTimeToEpoch (Time);
>
> - // Adjust for the correct time zone, i.e. convert to UTC time zone
> - if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
> - EpochSeconds -= Time->TimeZone * SEC_PER_MIN;
> - }
> -
> - // TODO: Automatic Daylight activation
> -
> - // Adjust for the correct period
> - if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
> - // Convert to un-adjusted time, i.e. fall back one hour
> - EpochSeconds -= SEC_PER_HOUR;
> - }
> -
> // On some platforms we may have access to a battery backed up hardware clock.
> //
> // If such RTC exists then it must be updated first, before the PL031,
> @@ -364,54 +227,13 @@ LibSetTime (
> Status = ArmPlatformSysConfigSet (SYS_CFG_RTC, EpochSeconds);
> if ((EFI_ERROR (Status)) && (Status != EFI_UNSUPPORTED)){
> // Any status message except SUCCESS and UNSUPPORTED indicates a hardware failure.
> - goto EXIT;
> + return Status;
> }
>
> -
> // Set the PL031
> MmioWrite32 (mPL031RtcBase + PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
>
> - // The accesses to Variable Services can be very slow, because we may be writing to Flash.
> - // Do this after having set the RTC.
> -
> - // Save the current time zone information into non-volatile storage
> - Status = EfiSetVariable (
> - (CHAR16 *)mTimeZoneVariableName,
> - &gEfiCallerIdGuid,
> - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
> - sizeof (Time->TimeZone),
> - (VOID *)&(Time->TimeZone)
> - );
> - if (EFI_ERROR (Status)) {
> - DEBUG ((
> - EFI_D_ERROR,
> - "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
> - mTimeZoneVariableName,
> - Status
> - ));
> - goto EXIT;
> - }
> -
> - // Save the current daylight information into non-volatile storage
> - Status = EfiSetVariable (
> - (CHAR16 *)mDaylightVariableName,
> - &gEfiCallerIdGuid,
> - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
> - sizeof(Time->Daylight),
> - (VOID *)&(Time->Daylight)
> - );
> - if (EFI_ERROR (Status)) {
> - DEBUG ((
> - EFI_D_ERROR,
> - "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
> - mDaylightVariableName,
> - Status
> - ));
> - goto EXIT;
> - }
> -
> - EXIT:
> - return Status;
> + return EFI_SUCCESS;
> }
>
>
> --
> 2.11.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-11-05 17:29 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-11-05 16:52 [PATCH 1/2] EmbeddedPkg/RealTimeClockRuntimeDxe: move common functionality into core Ard Biesheuvel
2017-11-05 16:52 ` [PATCH 2/2] ArmPlatformPkg/PL031RealTimeClockLib: remove validation and DST handling Ard Biesheuvel
2017-11-05 17:32 ` Ard Biesheuvel
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