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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:17:27 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:17:27 +0000
commitf215e02bf85f68d3a6106c2a1f4f7f063f819064 (patch)
tree6bb5b92c046312c4e95ac2620b10ddf482d3fa8b /src/VBox/Devices/EFI/Firmware/EmbeddedPkg/MetronomeDxe/Metronome.c
parentInitial commit. (diff)
downloadvirtualbox-f215e02bf85f68d3a6106c2a1f4f7f063f819064.tar.xz
virtualbox-f215e02bf85f68d3a6106c2a1f4f7f063f819064.zip
Adding upstream version 7.0.14-dfsg.upstream/7.0.14-dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/EmbeddedPkg/MetronomeDxe/Metronome.c')
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diff --git a/src/VBox/Devices/EFI/Firmware/EmbeddedPkg/MetronomeDxe/Metronome.c b/src/VBox/Devices/EFI/Firmware/EmbeddedPkg/MetronomeDxe/Metronome.c
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+/** @file
+
+ Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+ Copyright (c) 2013, ARM Ltd. All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiDxe.h>
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+#include <Library/PcdLib.h>
+#include <Library/TimerLib.h>
+
+#include <Protocol/Metronome.h>
+
+EFI_STATUS
+EFIAPI
+WaitForTick (
+ IN EFI_METRONOME_ARCH_PROTOCOL *This,
+ IN UINT32 TickNumber
+ );
+
+/**
+ Interface structure for the Metronome Architectural Protocol.
+
+ @par Protocol Description:
+ This protocol provides access to a known time source in the platform to the
+ core. The core uses this known time source to produce core services that
+ require calibrated delays.
+
+ @param WaitForTick
+ Waits for a specified number of ticks from a known time source
+ in the platform. The actual time passed between entry of this
+ function and the first tick is between 0 and TickPeriod 100 nS
+ units. If you want to guarantee that at least TickPeriod time
+ has elapsed, wait for two ticks.
+
+ @param TickPeriod
+ The period of platform's known time source in 100 nS units.
+ This value on any platform must be at least 10 uS, and must not
+ exceed 200 uS. The value in this field is a constant that must
+ not be modified after the Metronome architectural protocol is
+ installed. All consumers must treat this as a read-only field.
+
+**/
+EFI_METRONOME_ARCH_PROTOCOL gMetronome = {
+ WaitForTick,
+ FixedPcdGet32 (PcdMetronomeTickPeriod)
+};
+
+
+/**
+ The WaitForTick() function waits for the number of ticks specified by
+ TickNumber from a known time source in the platform. If TickNumber of
+ ticks are detected, then EFI_SUCCESS is returned. The actual time passed
+ between entry of this function and the first tick is between 0 and
+ TickPeriod 100 nS units. If you want to guarantee that at least TickPeriod
+ time has elapsed, wait for two ticks. This function waits for a hardware
+ event to determine when a tick occurs. It is possible for interrupt
+ processing, or exception processing to interrupt the execution of the
+ WaitForTick() function. Depending on the hardware source for the ticks, it
+ is possible for a tick to be missed. This function cannot guarantee that
+ ticks will not be missed. If a timeout occurs waiting for the specified
+ number of ticks, then EFI_TIMEOUT is returned.
+
+ @param This The EFI_METRONOME_ARCH_PROTOCOL instance.
+ @param TickNumber Number of ticks to wait.
+
+ @retval EFI_SUCCESS The wait for the number of ticks specified by TickNumber
+ succeeded.
+ @retval EFI_TIMEOUT A timeout occurred waiting for the specified number of ticks.
+
+**/
+EFI_STATUS
+EFIAPI
+WaitForTick (
+ IN EFI_METRONOME_ARCH_PROTOCOL *This,
+ IN UINT32 TickNumber
+ )
+{
+ //
+ // Compute how long to stall the CPU.
+ // gMetronome.TickPeriod is in 100 ns units so it needs to be divided by 10
+ // to get it in microseconds units.
+ //
+ MicroSecondDelay (TickNumber * gMetronome.TickPeriod / 10);
+ return EFI_SUCCESS;
+}
+
+
+EFI_HANDLE gMetronomeHandle = NULL;
+
+
+
+/**
+ Initialize the state information for the CPU Architectural Protocol
+
+ @param ImageHandle of the loaded driver
+ @param SystemTable Pointer to the System Table
+
+ @retval EFI_SUCCESS Protocol registered
+ @retval EFI_OUT_OF_RESOURCES Cannot allocate protocol data structure
+ @retval EFI_DEVICE_ERROR Hardware problems
+
+**/
+EFI_STATUS
+EFIAPI
+MetronomeInitialize (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+
+ //
+ // Do any hardware init required to make WaitForTick () to work here.
+ //
+
+ Status = gBS->InstallMultipleProtocolInterfaces (
+ &gMetronomeHandle,
+ &gEfiMetronomeArchProtocolGuid, &gMetronome,
+ NULL
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ return Status;
+}
+