PC.C
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上传日期:2013-04-13
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文件大小:24k
- /*
- *********************************************************************************************************
- * PC SUPPORT FUNCTIONS
- *
- * (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
- * All Rights Reserved
- *
- * File : PC.C
- * By : Jean J. Labrosse
- *********************************************************************************************************
- */
- #include "ucos_ii.h"
- #include "pc.h"
- #include <stdio.h>
- #include <stdlib.h>
- #include <setjmp.h>
- /*
- PC display by KC51 emulation
- */
- #define interrupt
- #define far xdata
- #define MK_FP(s, o) ((INT8U xdata *)(INT16U)(o))
- #define getvect(vect) ((vect=vect),((void*)NULL))
- #define setvect(vect, isr) (vect=vect, isr=isr)
- int OSTickDOSCtr;
- const char code * const code ExitNotice[]=
- {
- "Exit program",
- "Program has terminated",
- "Reset the processor to restart the program"
- };
- bit kbhit() KCREENTRANT;
- INT8U getch() KCREENTRANT;
- void exit(INT8U ec) KCREENTRANT
- {
- static char str[64];
- #if OS_CRITICAL_METHOD == 3
- OS_CPU_SR cpu_sr;
- #endif
- OS_ENTER_CRITICAL();
- for(;;)
- {
- INT8U i;
- for(i=0; i<sizeof(ExitNotice)/sizeof(ExitNotice[0]); i++)
- {
- PC_DispStr (0, 8+i, ExitNotice[i], DISP_FGND_WHITE + DISP_BGND_BLACK);
- }
- sprintf(str, "Exit code = %bd", ec);
- PC_DispStr (0, 24, str, DISP_FGND_WHITE + DISP_BGND_BLACK);
- while(! kbhit());
- getch();
- TR0=0;
- ET0=0;
- ((void(*)(void))0)();
- }
- OS_EXIT_CRITICAL();
- }
- /*
- INT8U inp(INT8U p)
- {
- INT8U far *pscr;
- pscr = MK_FP(DISP_BASE, 0x1000+p);
- return * pscr;
- }
- */
- void outp(INT8U p, INT8U d)
- {
- INT8U far *pscr;
- pscr = MK_FP(DISP_BASE, 0x1000+p);
- *pscr = d;
- }
- struct time
- {
- INT8U ti_hour, ti_min, ti_sec;
- };
- struct date
- {
- INT8U da_year, da_mon, da_day;
- };
- void gettime(struct time * pti) KCREENTRANT
- {
- INT8U far *pscr;
- pscr = MK_FP(DISP_BASE, 0x2010);
- pti->ti_hour =* pscr ++;
- pti->ti_min =* pscr ++;
- pti->ti_sec =* pscr;
- }
- void getdate(struct date * pdt) KCREENTRANT
- {
- INT8U far *pscr;
- pscr = MK_FP(DISP_BASE, 0x2020);
- pdt->da_year = * pscr ++;
- pdt->da_mon = * pscr ++;
- pdt->da_day = * pscr;
- }
- /*
- INT8U random(INT8U seed) KCREENTRANT
- {
- INT8U xdata * p;
- p=MK_FP(0, 0x2032);
- return ((*p)^((INT16U) rand())) % (INT16U)seed;
- }
- */
- INT8U random(INT8U seed) KCREENTRANT
- {
- INT8U i;
- i=(((INT16U) rand())^((INT16U) rand())+TL0) % (INT16U)seed;
- return i;
- }
- bit kbhit() KCREENTRANT
- {
- INT8U far *pscr;
- pscr = MK_FP(DISP_BASE, 0x2030);
- return *pscr;
- }
- INT8U getch() KCREENTRANT
- {
- INT8U far *pscr;
- pscr = MK_FP(DISP_BASE, 0x2031);
- return *pscr;
- }
- /*
- *********************************************************************************************************
- * CONSTANTS
- *********************************************************************************************************
- */
- #define DISP_BASE 0xB800 /* Base segment of display (0xB800=VGA, 0xB000=Mono) */
- #define DISP_MAX_X 80 /* Maximum number of columns */
- #define DISP_MAX_Y 25 /* 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);
- /*$PAGE*/
- /*
- *********************************************************************************************************
- * CLEAR SCREEN
- *
- * Description : This function clears the PC's screen by directly accessing video RAM instead of using
- * the BIOS. It assumed that the video adapter is VGA compatible. Video RAM starts at
- * absolute address 0x000B8000. Each character on the screen is composed of two bytes:
- * the ASCII character to appear on the screen followed by a video attribute. An attribute
- * of 0x07 displays the character in WHITE with a black background.
- *
- * Arguments : color specifies the foreground/background color combination to use
- * (see PC.H for available choices)
- *
- * Returns : None
- *********************************************************************************************************
- */
- void PC_DispClrScr (INT8U color) KCREENTRANT
- {
- INT8U far *pscr;
- INT16U i;
- pscr = MK_FP(DISP_BASE, 0x0000);
- for (i = 0; i < (DISP_MAX_X * DISP_MAX_Y); i++) { /* PC display has 80 columns and 25 lines */
- *pscr++ = ' '; /* Put ' ' character in video RAM */
- *pscr++ = color; /* Put video attribute in video RAM */
- }
- }
- /*$PAGE*/
- /*
- *********************************************************************************************************
- * CLEAR A LINE
- *
- * 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 line to clear. Valid line numbers are from
- * 0 to 24. Line 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_DispClrLine (INT8U y, INT8U color) KCREENTRANT
- {
- INT8U far *pscr;
- INT8U i;
- pscr = 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 */
- }
- }
- /*$PAGE*/
- /*
- *********************************************************************************************************
- * DISPLAY A SINGLE CHARACTER AT 'X' & 'Y' COORDINATE
- *
- * Description : This function writes a single character anywhere on the PC's screen. This function
- * writes directly to video RAM instead of using the BIOS for speed reasons. It assumed
- * that the video adapter is VGA compatible. Video RAM starts at absolute address
- * 0x000B8000. Each character on the screen is composed of two bytes: the ASCII character
- * to appear on the screen followed by a video attribute. An attribute of 0x07 displays
- * the character in WHITE with a black background.
- *
- * Arguments : x corresponds to the desired column on the screen. Valid columns numbers are from
- * 0 to 79. Column 0 corresponds to the leftmost column.
- * y corresponds to the desired row on the screen. Valid row numbers are from 0 to 24.
- * Line 0 corresponds to the topmost row.
- * c Is the ASCII character to display. You can also specify a character with a
- * numeric value higher than 128. In this case, special character based graphics
- * will be displayed.
- * color specifies the foreground/background color to use (see PC.H for available choices)
- * and whether the character will blink or not.
- *
- * Returns : None
- *********************************************************************************************************
- */
- void PC_DispChar (INT8U x, INT8U y, INT8U cc, INT8U color) KCREENTRANT
- {
- INT8U far *pscr;
- INT16U offset;
- offset = (INT16U)y * DISP_MAX_X * 2 + (INT16U)x * 2; /* Calculate position on the screen */
- pscr = MK_FP(DISP_BASE, offset);
- *pscr++ = cc; /* Put character in video RAM */
- *pscr = color; /* Put video attribute in video RAM */
- }
- /*$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) KCREENTRANT
- {
- INT8U far *pscr;
- INT16U offset;
- offset = (INT16U)y * DISP_MAX_X * 2 + (INT16U)x * 2; /* Calculate position of 1st character */
- pscr = MK_FP(DISP_BASE, offset);
- while (*s) {
- *pscr++ = *s++; /* Put character in video RAM */
- *pscr++ = color; /* Put video attribute in video RAM */
- }
- }
- /*$PAGE*/
- /*
- *********************************************************************************************************
- * RETURN TO DOS
- *
- * Description : This functions returns control back to DOS by doing a 'long jump' back to the saved
- * location stored in 'PC_JumpBuf'. The saved location was established by the function
- * 'PC_DOSSaveReturn()'. After execution of the long jump, execution will resume at the
- * line following the 'set jump' back in 'PC_DOSSaveReturn()'. Setting the flag
- * 'PC_ExitFlag' to TRUE ensures that the 'if' statement in 'PC_DOSSaveReturn()' executes.
- *
- * Arguments : None
- *
- * Returns : None
- *********************************************************************************************************
- */
- void PC_DOSReturn (void) KCREENTRANT
- {
- PC_ExitFlag = TRUE; /* Indicate we are returning to DOS */
- longjmp(PC_JumpBuf, 1); /* Jump back to saved environment */
- }
- /*$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) KCREENTRANT
- {
- #if OS_CRITICAL_METHOD == 3
- 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 = PC_VectGet(VECT_TICK); /* Get MS-DOS's tick vector */
-
- OS_ENTER_CRITICAL();
- PC_VectSet(VECT_DOS_CHAIN, PC_TickISR); /* Store MS-DOS's tick to chain */
- OS_EXIT_CRITICAL();
-
- 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 */
- PC_VectSet(VECT_TICK, PC_TickISR); /* Restore DOS's tick vector */
- OS_EXIT_CRITICAL();
- PC_DispClrScr(DISP_FGND_WHITE + DISP_BGND_BLACK); /* Clear the display */
- exit(0); /* Return to DOS */
- }
- }
- /*$PAGE*/
- /*
- *********************************************************************************************************
- * ELAPSED TIME INITIALIZATION
- *
- * Description : This function initialize the elapsed time module by determining how long the START and
- * STOP functions take to execute. In other words, this function calibrates this module
- * to account for the processing time of the START and STOP functions.
- *
- * Arguments : None.
- *
- * Returns : None.
- *********************************************************************************************************
- */
- void PC_ElapsedInit(void) KCREENTRANT
- {
- PC_ElapsedOverhead = 0;
- PC_ElapsedStart();
- PC_ElapsedOverhead = PC_ElapsedStop();
- }
- /*$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.
- *********************************************************************************************************
- */
- data INT16U TickCount;
- void UserTickTimer(void) KCREENTRANT
- {
- TickCount++;
- }
- void PC_ElapsedStart(void) KCREENTRANT
- {
- //
- // INT8U vdata;
- //
- //
- // vdata = (INT8U)inp(0x61); /* Disable timer #2 */
- // vdata &= 0xFE;
- // outp(0x61, vdata);
- // 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);
- // vdata |= 0x01; /* Start the timer */
- // outp(0x61, vdata);
- TickCount=0;
- }
- /*$PAGE*/
- /*
- *********************************************************************************************************
- * STOP THE PC'S TIMER #2 AND GET ELAPSED TIME
- *
- * Description : This function stops the PC's Timer #2, obtains the elapsed counts from when it was
- * started and converts the elapsed counts to micro-seconds.
- *
- * Arguments : None.
- *
- * Returns : The number of micro-seconds since the timer was last started.
- *
- * Notes : - The returned time accounts for the processing time of the START and STOP functions.
- * - 54926 represents 54926S-16 or, 0.838097 which is used to convert timer counts to
- * micro-seconds. The clock source for the PC's timer #2 is 1.19318 MHz (or 0.838097 uS)
- *********************************************************************************************************
- */
- INT16U PC_ElapsedStop(void) KCREENTRANT
- {
- return TickCount;
- // INT8U vdata;
- // INT8U low;
- // INT8U high;
- // INT16U cnts;
- //
- //
- // vdata = inp(0x61); /* Disable the timer */
- // vdata &= 0xFE;
- // outp(0x61, vdata);
- // outp(TICK_T0_8254_CWR, TICK_T0_8254_CTR2_LATCH); /* Latch the timer value */
- // low = inp(TICK_T0_8254_CTR2);
- // high = inp(TICK_T0_8254_CTR2);
- // cnts = (INT16U)0xFFFF - (((INT16U)high << 8) + (INT16U)low); /* Compute time it took for operation */
- // return ((INT16U)((ULONG)cnts * 54926L >> 16) - PC_ElapsedOverhead);
- }
- /*$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 19 bytes (includes the NUL) of storage in the return
- * string.
- *
- * Returns : none
- *********************************************************************************************************
- */
- void PC_GetDateTime (char *s) KCREENTRANT
- {
- struct time now;
- struct date today;
- gettime(&now);
- getdate(&today);
- sprintf(s, "%02bd-%02bd-%02bd %02bd:%02bd:%02bd",
- today.da_mon,
- today.da_day,
- today.da_year,
- now.ti_hour,
- now.ti_min,
- now.ti_sec);
- }
- /*$PAGE*/
- /*
- *********************************************************************************************************
- * CHECK AND GET KEYBOARD KEY
- *
- * Description: This function checks to see if a key has been pressed at the keyboard and returns TRUE if
- * so. Also, if a key is pressed, the key is read and copied where the argument is pointing
- * to.
- *
- * Arguments : c is a pointer to where the read key will be stored.
- *
- * Returns : TRUE if a key was pressed
- * FALSE otherwise
- *********************************************************************************************************
- */
- BOOLEAN PC_GetKey (INT16S *c) KCREENTRANT
- {
- if (kbhit()) { /* See if a key has been pressed */
- *c = getch(); /* Get key pressed */
- return (TRUE);
- } else {
- *c = 0x00; /* No key pressed */
- return (FALSE);
- }
- }
- /*$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) KCREENTRANT
- {
- INT16U count;
- if (freq == 18) { /* See if we need to restore the DOS frequency */
- count = 0;
- } else if (freq > 0) {
- /* Compute 8254 counts for desired frequency and ... */
- /* ... round to nearest count */
- count = (INT16U)(((INT32U)2386360L / freq + 1) >> 1);
- } else {
- count = 0;
- }
- 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 */
- }
- /*$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 : none
- *********************************************************************************************************
- */
- void *PC_VectGet (INT8U vect) KCREENTRANT
- {
- return (getvect(vect));
- }
- /*
- *********************************************************************************************************
- * 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)) KCREENTRANT
- {
- setvect(vect, (void interrupt (*)(void))isr);
- }