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/*
*********************************************************************************************************
* PC SUPPORT FUNCTIONS
*
* (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
* All Rights Reserved
*
* File : PC.C
* By : Jean J. Labrosse
*********************************************************************************************************
*/
#include "includes.h"
#include "lcd12864.h"
/*
*********************************************************************************************************
* CONSTANTS
*********************************************************************************************************
*/
#define DISP_BASE 0xB800 /* Base segment of display (0xB800=VGA, 0xB000=Mono) */
#define DISP_MAX_X 16 /* Maximum number of columns */
#define DISP_MAX_Y 8 /* Maximum number of rows */
#define TICK_T0_8254_CWR 0x43 /* 8254 PIT Control Word Register address. */
#define TICK_T0_8254_CTR0 0x40 /* 8254 PIT Timer 0 Register address. */
#define TICK_T0_8254_CTR1 0x41 /* 8254 PIT Timer 1 Register address. */
#define TICK_T0_8254_CTR2 0x42 /* 8254 PIT Timer 2 Register address. */
#define TICK_T0_8254_CTR0_MODE3 0x36 /* 8254 PIT Binary Mode 3 for Counter 0 control word. */
#define TICK_T0_8254_CTR2_MODE0 0xB0 /* 8254 PIT Binary Mode 0 for Counter 2 control word. */
#define TICK_T0_8254_CTR2_LATCH 0x80 /* 8254 PIT Latch command control word */
#define VECT_TICK 0x08 /* Vector number for 82C54 timer tick */
#define VECT_DOS_CHAIN 0x81 /* Vector number used to chain DOS */
/*
*********************************************************************************************************
* LOCAL GLOBAL VARIABLES
*********************************************************************************************************
*/
static INT16U PC_ElapsedOverhead;
static jmp_buf PC_JumpBuf;
static BOOLEAN PC_ExitFlag;
void (*PC_TickISR)(void);
/*$PAGE*/
/*
*********************************************************************************************************
* DISPLAY A SINGLE CHARACTER AT 'X' & 'Y' COORDINATE
*
* Description : This function writes a single character anywhere on the PC's screen. This function
* writes directly to video RAM instead of using the BIOS for speed reasons. It assumed
* that the video adapter is VGA compatible. Video RAM starts at absolute address
* 0x000B8000. Each character on the screen is composed of two bytes: the ASCII character
* to appear on the screen followed by a video attribute. An attribute of 0x07 displays
* the character in WHITE with a black background.
*
* Arguments : x corresponds to the desired column on the screen. Valid columns numbers are from
* 0 to 79. Column 0 corresponds to the leftmost column.
* y corresponds to the desired row on the screen. Valid row numbers are from 0 to 24.
* Line 0 corresponds to the topmost row.
* c Is the ASCII character to display. You can also specify a character with a
* numeric value higher than 128. In this case, special character based graphics
* will be displayed.
* color specifies the foreground/background color to use (see PC.H for available choices)
* and whether the character will blink or not.
*
* Returns : None
*********************************************************************************************************
*/
void PC_DispChar (INT8U x, INT8U y, INT8U c, INT8U color)
{
WriteChar( x*8, y, c, 1 );
}
/*$PAGE*/
/*
*********************************************************************************************************
* CLEAR A COLUMN
*
* Description : This function clears one of the 80 columns on the PC's screen by directly accessing video
* RAM instead of using the BIOS. It assumed that the video adapter is VGA compatible.
* Video RAM starts at absolute address 0x000B8000. Each character on the screen is
* composed of two bytes: the ASCII character to appear on the screen followed by a video
* attribute. An attribute of 0x07 displays the character in WHITE with a black background.
*
* Arguments : x corresponds to the desired column to clear. Valid column numbers are from
* 0 to 79. Column 0 corresponds to the leftmost column.
*
* color specifies the foreground/background color combination to use
* (see PC.H for available choices)
*
* Returns : None
*********************************************************************************************************
*/
void PC_DispClrCol (INT8U x, INT8U color)
{
INT8U far *pscr;
INT8U i;
pscr = (INT8U far *)MK_FP(DISP_BASE, (INT16U)x * 2);
for (i = 0; i < DISP_MAX_Y; i++) {
*pscr++ = ' '; /* Put ' ' character in video RAM */
*pscr-- = color; /* Put video attribute in video RAM */
pscr = pscr + DISP_MAX_X * 2; /* Position on next row */
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* CLEAR A ROW
*
* Description : This function clears one of the 25 lines on the PC's screen by directly accessing video
* RAM instead of using the BIOS. It assumed that the video adapter is VGA compatible.
* Video RAM starts at absolute address 0x000B8000. Each character on the screen is
* composed of two bytes: the ASCII character to appear on the screen followed by a video
* attribute. An attribute of 0x07 displays the character in WHITE with a black background.
*
* Arguments : y corresponds to the desired row to clear. Valid row numbers are from
* 0 to 24. Row 0 corresponds to the topmost line.
*
* color specifies the foreground/background color combination to use
* (see PC.H for available choices)
*
* Returns : None
*********************************************************************************************************
*/
void PC_DispClrRow (INT8U y, INT8U color)
{
INT8U far *pscr;
INT8U i;
pscr = (INT8U far *)MK_FP(DISP_BASE, (INT16U)y * DISP_MAX_X * 2);
for (i = 0; i < DISP_MAX_X; i++) {
*pscr++ = ' '; /* Put ' ' character in video RAM */
*pscr++ = color; /* Put video attribute in video RAM */
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* CLEAR SCREEN
*
* Description : This function clears the PC's screen by directly accessing video RAM instead of using
* the BIOS. It assumed that the video adapter is VGA compatible. Video RAM starts at
* absolute address 0x000B8000. Each character on the screen is composed of two bytes:
* the ASCII character to appear on the screen followed by a video attribute. An attribute
* of 0x07 displays the character in WHITE with a black background.
*
* Arguments : color specifies the foreground/background color combination to use
* (see PC.H for available choices)
*
* Returns : None
*********************************************************************************************************
*/
void PC_DispClrScr (INT8U color)
{
InitLCD( );
}
/*$PAGE*/
/*
*********************************************************************************************************
* DISPLAY A STRING AT 'X' & 'Y' COORDINATE
*
* Description : This function writes an ASCII string anywhere on the PC's screen. This function writes
* directly to video RAM instead of using the BIOS for speed reasons. It assumed that the
* video adapter is VGA compatible. Video RAM starts at absolute address 0x000B8000. Each
* character on the screen is composed of two bytes: the ASCII character to appear on the
* screen followed by a video attribute. An attribute of 0x07 displays the character in
* WHITE with a black background.
*
* Arguments : x corresponds to the desired column on the screen. Valid columns numbers are from
* 0 to 79. Column 0 corresponds to the leftmost column.
* y corresponds to the desired row on the screen. Valid row numbers are from 0 to 24.
* Line 0 corresponds to the topmost row.
* s Is the ASCII string to display. You can also specify a string containing
* characters with numeric values higher than 128. In this case, special character
* based graphics will be displayed.
* color specifies the foreground/background color to use (see PC.H for available choices)
* and whether the characters will blink or not.
*
* Returns : None
*********************************************************************************************************
*/
void PC_DispStr (INT8U x, INT8U y, INT8U *s, INT8U color)
{
WriteString( x*8, y, s, 1 );
}
/*$PAGE*/
/*
*********************************************************************************************************
* RETURN TO DOS
*
* Description : This functions returns control back to DOS by doing a 'long jump' back to the saved
* location stored in 'PC_JumpBuf'. The saved location was established by the function
* 'PC_DOSSaveReturn()'. After execution of the long jump, execution will resume at the
* line following the 'set jump' back in 'PC_DOSSaveReturn()'. Setting the flag
* 'PC_ExitFlag' to TRUE ensures that the 'if' statement in 'PC_DOSSaveReturn()' executes.
*
* Arguments : None
*
* Returns : None
*********************************************************************************************************
*/
void PC_DOSReturn (void)
{
PC_ExitFlag = TRUE; /* Indicate we are returning to DOS */
longjmp(PC_JumpBuf, 1); /* Jump back to saved environment */
}
/*$PAGE*/
/*
*********************************************************************************************************
* SAVE DOS RETURN LOCATION
*
* Description : This function saves the location of where we are in DOS so that it can be recovered.
* This allows us to abort multitasking under uC/OS-II and return back to DOS as if we had
* never left. When this function is called by 'main()', it sets 'PC_ExitFlag' to FALSE
* so that we don't take the 'if' branch. Instead, the CPU registers are saved in the
* long jump buffer 'PC_JumpBuf' and we simply return to the caller. If a 'long jump' is
* performed using the jump buffer then, execution would resume at the 'if' statement and
* this time, if 'PC_ExitFlag' is set to TRUE then we would execute the 'if' statements and
* restore the DOS environment.
*
* Arguments : None
*
* Returns : None
*********************************************************************************************************
*/
void PC_DOSSaveReturn (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
PC_ExitFlag = FALSE; /* Indicate that we are not exiting yet! */
OSTickDOSCtr = 1; /* Initialize the DOS tick counter */
PC_TickISR =(void (*)())PC_VectGet(VECT_TICK); /* Get MS-DOS's tick vector */
PC_VectSet(VECT_DOS_CHAIN, PC_TickISR); /* Store MS-DOS's tick to chain */
setjmp(PC_JumpBuf); /* Capture where we are in DOS */
if (PC_ExitFlag == TRUE) { /* See if we are exiting back to DOS */
OS_ENTER_CRITICAL();
PC_SetTickRate(18); /* Restore tick rate to 18.2 Hz */
OS_EXIT_CRITICAL();
PC_VectSet(VECT_TICK, PC_TickISR); /* Restore DOS's tick vector */
PC_DispClrScr(DISP_FGND_WHITE + DISP_BGND_BLACK); /* Clear the display */
exit(0); /* Return to DOS */
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* ELAPSED TIME INITIALIZATION
*
* Description : This function initialize the elapsed time module by determining how long the START and
* STOP functions take to execute. In other words, this function calibrates this module
* to account for the processing time of the START and STOP functions.
*
* Arguments : None.
*
* Returns : None.
*********************************************************************************************************
*/
void PC_ElapsedInit(void)
{
PC_ElapsedOverhead = 0;
PC_ElapsedStart();
PC_ElapsedOverhead = PC_ElapsedStop();
}
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZE PC'S TIMER #2
*
* Description : This function initialize the PC's Timer #2 to be used to measure the time between events.
* Timer #2 will be running when the function returns.
*
* Arguments : None.
*
* Returns : None.
*********************************************************************************************************
*/
void PC_ElapsedStart(void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
INT8U data;
OS_ENTER_CRITICAL();
data = (INT8U)inp(0x61); /* Disable timer #2 */
data &= 0xFE;
outp(0x61, data);
outp(TICK_T0_8254_CWR, TICK_T0_8254_CTR2_MODE0); /* Program timer #2 for Mode 0 */
outp(TICK_T0_8254_CTR2, 0xFF);
outp(TICK_T0_8254_CTR2, 0xFF);
data |= 0x01; /* Start the timer */
outp(0x61, data);
OS_EXIT_CRITICAL();
}
/*$PAGE*/
/*
*********************************************************************************************************
* STOP THE PC'S TIMER #2 AND GET ELAPSED TIME
*
* Description : This function stops the PC's Timer #2, obtains the elapsed counts from when it was
* started and converts the elapsed counts to micro-seconds.
*
* Arguments : None.
*
* Returns : The number of micro-seconds since the timer was last started.
*
* Notes : - The returned time accounts for the processing time of the START and STOP functions.
* - 54926 represents 54926S-16 or, 0.838097 which is used to convert timer counts to
* micro-seconds. The clock source for the PC's timer #2 is 1.19318 MHz (or 0.838097 uS)
*********************************************************************************************************
*/
INT16U PC_ElapsedStop(void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
INT8U data;
INT8U low;
INT8U high;
INT16U cnts;
OS_ENTER_CRITICAL();
data = (INT8U)inp(0x61); /* Disable the timer */
data &= 0xFE;
outp(0x61, data);
outp(TICK_T0_8254_CWR, TICK_T0_8254_CTR2_LATCH); /* Latch the timer value */
low = inp(TICK_T0_8254_CTR2);
high = inp(TICK_T0_8254_CTR2);
cnts = (INT16U)0xFFFF - (((INT16U)high << 8) + (INT16U)low); /* Compute time it took for operation */
OS_EXIT_CRITICAL();
return ((INT16U)((INT32U)cnts * 54926L >> 16) - PC_ElapsedOverhead);
}
/*$PAGE*/
/*
*********************************************************************************************************
* GET THE CURRENT DATE AND TIME
*
* Description: This function obtains the current date and time from the PC.
*
* Arguments : s is a pointer to where the ASCII string of the current date and time will be stored.
* You must allocate at least 21 bytes (includes the NUL) of storage in the return
* string. The date and time will be formatted as follows:
*
* "YYYY-MM-DD HH:MM:SS"
*
* Returns : none
*********************************************************************************************************
*/
void PC_GetDateTime (char *s)
{
struct time now;
struct date today;
gettime(&now);
getdate(&today);
sprintf(s, "%04d-%02d-%02d %02d:%02d:%02d",
today.da_year,
today.da_mon,
today.da_day,
now.ti_hour,
now.ti_min,
now.ti_sec);
}
/*$PAGE*/
/*
*********************************************************************************************************
* CHECK AND GET KEYBOARD KEY
*
* Description: This function checks to see if a key has been pressed at the keyboard and returns TRUE if
* so. Also, if a key is pressed, the key is read and copied where the argument is pointing
* to.
*
* Arguments : c is a pointer to where the read key will be stored.
*
* Returns : TRUE if a key was pressed
* FALSE otherwise
*********************************************************************************************************
*/
BOOLEAN PC_GetKey (INT16S *c)
{
if (kbhit()) { /* See if a key has been pressed */
*c = (INT16S)getch(); /* Get key pressed */
return (TRUE);
} else {
*c = 0x00; /* No key pressed */
return (FALSE);
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* SET THE PC'S TICK FREQUENCY
*
* Description: This function is called to change the tick rate of a PC.
*
* Arguments : freq is the desired frequency of the ticker (in Hz)
*
* Returns : none
*
* Notes : 1) The magic number 2386360 is actually twice the input frequency of the 8254 chip which
* is always 1.193180 MHz.
* 2) The equation computes the counts needed to load into the 8254. The strange equation
* is actually used to round the number using integer arithmetic. This is equivalent to
* the floating point equation:
*
* 1193180.0 Hz
* count = ------------ + 0.5
* freq
*********************************************************************************************************
*/
void PC_SetTickRate (INT16U freq)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
INT16U count;
if (freq == 18) /* See if we need to restore the DOS frequency */
count = 54925;
else if (freq > 0)
{
/* Compute 8254 counts for desired frequency and ... */
/* ... round to nearest count */
count = (INT16U)(((INT32U)2000000L / freq + 1) >> 1);
}
else
count = 54925;
OS_ENTER_CRITICAL();
outp(TICK_T0_8254_CWR, TICK_T0_8254_CTR0_MODE3); /* Load the 8254 with desired frequency */
outp(TICK_T0_8254_CTR0, count & 0xFF); /* Low byte */
outp(TICK_T0_8254_CTR0, (count >> 8) & 0xFF); /* High byte */
OS_EXIT_CRITICAL();
}
/*$PAGE*/
/*
*********************************************************************************************************
* OBTAIN INTERRUPT VECTOR
*
* Description: This function reads the pointer stored at the specified vector.
*
* Arguments : vect is the desired interrupt vector number, a number between 0 and 255.
*
* Returns : The address of the Interrupt handler stored at the desired vector location.
*********************************************************************************************************
*/
void *PC_VectGet (INT8U vect)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
INT16U *pvect;
INT16U off;
INT16U seg;
pvect = (INT16U *)MK_FP(0x0000, vect * 4); /* Point into IVT at desired vector location */
OS_ENTER_CRITICAL();
off = *pvect++; /* Obtain the vector's OFFSET */
seg = *pvect; /* Obtain the vector's SEGMENT */
OS_EXIT_CRITICAL();
return (MK_FP(seg, off));
}
/*
*********************************************************************************************************
* INSTALL INTERRUPT VECTOR
*
* Description: This function sets an interrupt vector in the interrupt vector table.
*
* Arguments : vect is the desired interrupt vector number, a number between 0 and 255.
* isr is a pointer to a function to execute when the interrupt or exception occurs.
*
* Returns : none
*********************************************************************************************************
*/
void PC_VectSet (INT8U vect, void (*isr)(void))
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
INT16U *pvect;
pvect = (INT16U *)MK_FP(0x0000, vect * 4); /* Point into IVT at desired vector location */
OS_ENTER_CRITICAL();
*pvect++ = (INT16U)FP_OFF(isr); /* Store ISR offset */
*pvect = (INT16U)FP_SEG(isr); /* Store ISR segment */
OS_EXIT_CRITICAL();
}