clock.c File Reference

#include <hal.h>

Include dependency graph for clock.c:

Go to the source code of this file.

Macros
#define	LPT_STATUS   0x42
#define	SYSTEM_CLOCK_8_MHZ   0x20

Functions
VOID NTAPI	HalpInitializeClockPc98 (VOID)

Variables
ULONG	PIT_FREQUENCY
HALP_ROLLOVER	HalpRolloverTable [15]
static const HALP_ROLLOVER	RolloverTable1 [15]
static const HALP_ROLLOVER	RolloverTable2 [15]

Macro Definition Documentation

LPT_STATUS

#define LPT_STATUS   0x42

Definition at line 14 of file clock.c.

SYSTEM_CLOCK_8_MHZ

#define SYSTEM_CLOCK_8_MHZ   0x20

Definition at line 15 of file clock.c.

Function Documentation

HalpInitializeClockPc98()

VOID NTAPI HalpInitializeClockPc98

(

VOID

)

Definition at line 62 of file clock.c.

{
    /* Obtain system clock value from the parallel port */
    if (__inbyte(LPT_STATUS) & SYSTEM_CLOCK_8_MHZ)
    {
        PIT_FREQUENCY = TIMER_FREQUENCY_1;
        RtlCopyMemory(HalpRolloverTable, RolloverTable1, sizeof(HALP_ROLLOVER) * 15);
    }
    else
    {
        PIT_FREQUENCY = TIMER_FREQUENCY_2;
        RtlCopyMemory(HalpRolloverTable, RolloverTable2, sizeof(HALP_ROLLOVER) * 15);
    }
}

Referenced by HalpInitializeClock().

Variable Documentation

HalpRolloverTable

HALP_ROLLOVER HalpRolloverTable[15]

Definition at line 18 of file clock.c.

PIT_FREQUENCY

ULONG PIT_FREQUENCY

Definition at line 17 of file clock.c.

Referenced by HalpInitializeClockPc98().

RolloverTable1

const HALP_ROLLOVER RolloverTable1[15]

static

Initial value:

=
{
    {1996, 9996}, 
    {3993, 19997},
    {5990, 29998},
    {7987, 39999},
    {9984, 50000},
    {11980, 59996},
    {13977, 69997},
    {15974, 79998},
    {17971, 89999},
    {19968, 100000},
    {21964, 109996},
    {23961, 119997},
    {25958, 129998},
    {27955, 139999},
    {29951, 149995} 
}

Definition at line 21 of file clock.c.

Referenced by HalpInitializeClockPc98().

RolloverTable2

const HALP_ROLLOVER RolloverTable2[15]

static

Initial value:

=
{
    {2463, 10022}, 
    {4912, 19987},
    {7376, 30013},
    {9825, 39978},
    {12288, 50000},
    {14751, 60022},
    {17200, 69987},
    {19664, 80013},
    {22113, 89978},
    {24576, 100000},
    {27039, 110022},
    {29488, 119987},
    {31952, 130013},
    {34401, 139978},
    {36864, 150000} 
}

Definition at line 39 of file clock.c.

Referenced by HalpInitializeClockPc98().