1 /**@file
2
3 Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
4 This program and the accompanying materials
5 are licensed and made available under the terms and conditions of the BSD License
6 which accompanies this distribution. The full text of the license may be found at
7 http://opensource.org/licenses/bsd-license.php
8
9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11
12 Module Name:
13
14 Metronome.c
15
16 Abstract:
17
18 NT Emulation Metronome Architectural Protocol Driver as defined in DXE CIS
19
20 **/
21
22 #include "Metronome.h"
23
24 //
25 // Global Variables
26 //
27 EFI_METRONOME_ARCH_PROTOCOL mMetronome = {
28 WinNtMetronomeDriverWaitForTick,
29 TICK_PERIOD
30 };
31
32 //
33 // Worker Functions
34 //
35
36 EFI_STATUS
37 EFIAPI
WinNtMetronomeDriverWaitForTick(IN EFI_METRONOME_ARCH_PROTOCOL * This,IN UINT32 TickNumber)38 WinNtMetronomeDriverWaitForTick (
39 IN EFI_METRONOME_ARCH_PROTOCOL *This,
40 IN UINT32 TickNumber
41 )
42 /*++
43
44 Routine Description:
45
46 The WaitForTick() function waits for the number of ticks specified by
47 TickNumber from a known time source in the platform. If TickNumber of
48 ticks are detected, then EFI_SUCCESS is returned. The actual time passed
49 between entry of this function and the first tick is between 0 and
50 TickPeriod 100 nS units. If you want to guarantee that at least TickPeriod
51 time has elapsed, wait for two ticks. This function waits for a hardware
52 event to determine when a tick occurs. It is possible for interrupt
53 processing, or exception processing to interrupt the execution of the
54 WaitForTick() function. Depending on the hardware source for the ticks, it
55 is possible for a tick to be missed. This function cannot guarantee that
56 ticks will not be missed. If a timeout occurs waiting for the specified
57 number of ticks, then EFI_TIMEOUT is returned.
58
59 Arguments:
60
61 This - The EFI_METRONOME_ARCH_PROTOCOL instance.
62 TickNumber - Number of ticks to wait.
63
64 Returns:
65
66 EFI_SUCCESS - The wait for the number of ticks specified by TickNumber
67 succeeded.
68
69 --*/
70 {
71 UINT64 SleepTime;
72
73 //
74 // Calculate the time to sleep. Win API smallest unit to sleep is 1 millisec
75 // Tick Period is in 100ns units, divide by 10000 to convert to ms
76 //
77 SleepTime = DivU64x32 (MultU64x32 ((UINT64) TickNumber, TICK_PERIOD) + 9999, 10000);
78 gWinNt->Sleep ((UINT32) SleepTime);
79
80 return EFI_SUCCESS;
81 }
82
83
84 EFI_STATUS
85 EFIAPI
WinNtMetronomeDriverInitialize(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)86 WinNtMetronomeDriverInitialize (
87 IN EFI_HANDLE ImageHandle,
88 IN EFI_SYSTEM_TABLE *SystemTable
89 )
90 /*++
91
92 Routine Description:
93
94 Initialize the Metronome Architectural Protocol driver
95
96 Arguments:
97
98 ImageHandle - ImageHandle of the loaded driver
99
100
101 SystemTable - Pointer to the System Table
102
103 Returns:
104
105 EFI_SUCCESS - Metronome Architectural Protocol created
106
107 EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.
108
109 EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.
110
111 --*/
112 {
113 EFI_STATUS Status;
114 EFI_HANDLE Handle;
115
116
117 //
118 // Install the Metronome Architectural Protocol onto a new handle
119 //
120 Handle = NULL;
121 Status = gBS->InstallProtocolInterface (
122 &Handle,
123 &gEfiMetronomeArchProtocolGuid,
124 EFI_NATIVE_INTERFACE,
125 &mMetronome
126 );
127
128 return Status;
129 }
130