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Diffstat (limited to 'board/MAI/bios_emulator/scitech/src/pm/dos/_lztimer.asm')
| -rw-r--r-- | board/MAI/bios_emulator/scitech/src/pm/dos/_lztimer.asm | 438 |
1 files changed, 0 insertions, 438 deletions
diff --git a/board/MAI/bios_emulator/scitech/src/pm/dos/_lztimer.asm b/board/MAI/bios_emulator/scitech/src/pm/dos/_lztimer.asm deleted file mode 100644 index a4a9c7916e..0000000000 --- a/board/MAI/bios_emulator/scitech/src/pm/dos/_lztimer.asm +++ /dev/null @@ -1,438 +0,0 @@ -;**************************************************************************** -;* -;* SciTech OS Portability Manager Library -;* -;* ======================================================================== -;* -;* The contents of this file are subject to the SciTech MGL Public -;* License Version 1.0 (the "License"); you may not use this file -;* except in compliance with the License. You may obtain a copy of -;* the License at http://www.scitechsoft.com/mgl-license.txt -;* -;* Software distributed under the License is distributed on an -;* "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or -;* implied. See the License for the specific language governing -;* rights and limitations under the License. -;* -;* The Original Code is Copyright (C) 1991-1998 SciTech Software, Inc. -;* -;* The Initial Developer of the Original Code is SciTech Software, Inc. -;* All Rights Reserved. -;* -;* ======================================================================== -;* -;* Language: NASM or TASM Assembler -;* Environment: IBM PC (MS DOS) -;* -;* Description: Uses the 8253 timer and the BIOS time-of-day count to time -;* the performance of code that takes less than an hour to -;* execute. -;* -;* The routines in this package only works with interrupts -;* enabled, and in fact will explicitly turn interrupts on -;* in order to ensure we get accurate results from the timer. -;* -;* Externally 'C' callable routines: -;* -;* LZ_timerOn: Saves the BIOS time of day count and starts the -;* long period Zen Timer. -;* -;* LZ_timerLap: Latches the current count, and keeps the timer running -;* -;* LZ_timerOff: Stops the long-period Zen Timer and saves the timer -;* count and the BIOS time of day count. -;* -;* LZ_timerCount: Returns an unsigned long representing the timed count -;* in microseconds. If more than an hour passed during -;* the timing interval, LZ_timerCount will return the -;* value 0xFFFFFFFF (an invalid count). -;* -;* Note: If either more than an hour passes between calls to LZ_timerOn -;* and LZ_timerOff, an error is reported. For timing code that takes -;* more than a few minutes to execute, use the low resolution -;* Ultra Long Period Zen Timer code, which should be accurate -;* enough for most purposes. -;* -;* Note: Each block of code being timed should ideally be run several -;* times, with at least two similar readings required to -;* establish a true measurement, in order to eliminate any -;* variability caused by interrupts. -;* -;* Note: Interrupts must not be disabled for more than 54 ms at a -;* stretch during the timing interval. Because interrupts are -;* enabled, key, mice, and other devices that generate interrupts -;* should not be used during the timing interval. -;* -;* Note: Any extra code running off the timer interrupt (such as -;* some memory resident utilities) will increase the time -;* measured by the Zen Timer. -;* -;* Note: These routines can introduce inaccuracies of up to a few -;* tenths of a second into the system clock count for each -;* code section being timed. Consequently, it's a good idea to -;* reboot at the conclusion of timing sessions. (The -;* battery-backed clock, if any, is not affected by the Zen -;* timer.) -;* -;* All registers and all flags are preserved by all routines, except -;* interrupts which are always turned on -;* -;**************************************************************************** - - IDEAL - -include "scitech.mac" - -;**************************************************************************** -; -; Equates used by long period Zen Timer -; -;**************************************************************************** - -; Base address of 8253 timer chip - -BASE_8253 equ 40h - -; The address of the timer 0 count registers in the 8253 - -TIMER_0_8253 equ BASE_8253 + 0 - -; The address of the mode register in the 8253 - -MODE_8253 equ BASE_8253 + 3 - -; The address of the BIOS timer count variable in the BIOS data area. - -TIMER_COUNT equ 6Ch - -; Macro to delay briefly to ensure that enough time has elapsed between -; successive I/O accesses so that the device being accessed can respond -; to both accesses even on a very fast PC. - -ifdef USE_NASM -%macro DELAY 0 - jmp short $+2 - jmp short $+2 - jmp short $+2 -%endmacro -else -macro DELAY - jmp short $+2 - jmp short $+2 - jmp short $+2 -endm -endif - -header _lztimer - -begdataseg _lztimer - - cextern _ZTimerBIOSPtr,DPTR - -StartBIOSCount dd 0 ; Starting BIOS count dword -EndBIOSCount dd 0 ; Ending BIOS count dword -EndTimedCount dw 0 ; Timer 0 count at the end of timing period - -enddataseg _lztimer - -begcodeseg _lztimer ; Start of code segment - -;---------------------------------------------------------------------------- -; void LZ_timerOn(void); -;---------------------------------------------------------------------------- -; Starts the Long period Zen timer counting. -;---------------------------------------------------------------------------- -cprocstart LZ_timerOn - -; Set the timer 0 of the 8253 to mode 2 (divide-by-N), to cause -; linear counting rather than count-by-two counting. Also stops -; timer 0 until the timer count is loaded, except on PS/2 computers. - - mov al,00110100b ; mode 2 - out MODE_8253,al - -; Set the timer count to 0, so we know we won't get another timer -; interrupt right away. Note: this introduces an inaccuracy of up to 54 ms -; in the system clock count each time it is executed. - - DELAY - sub al,al - out TIMER_0_8253,al ; lsb - DELAY - out TIMER_0_8253,al ; msb - -; Store the timing start BIOS count - - use_es -ifdef flatmodel - mov ebx,[_ZTimerBIOSPtr] -else - les bx,[_ZTimerBIOSPtr] -endif - cli ; No interrupts while we grab the count - mov eax,[_ES _bx+TIMER_COUNT] - sti - mov [StartBIOSCount],eax - unuse_es - -; Set the timer count to 0 again to start the timing interval. - - mov al,00110100b ; set up to load initial - out MODE_8253,al ; timer count - DELAY - sub al,al - out TIMER_0_8253,al ; load count lsb - DELAY - out TIMER_0_8253,al ; load count msb - - ret - -cprocend - -;---------------------------------------------------------------------------- -; void LZ_timerOff(void); -;---------------------------------------------------------------------------- -; Stops the long period Zen timer and saves count. -;---------------------------------------------------------------------------- -cprocstart LZ_timerOff - -; Latch the timer count. - - mov al,00000000b ; latch timer 0 - out MODE_8253,al - cli ; Stop the BIOS count - -; Read the BIOS count. (Since interrupts are disabled, the BIOS -; count won't change). - - use_es -ifdef flatmodel - mov ebx,[_ZTimerBIOSPtr] -else - les bx,[_ZTimerBIOSPtr] -endif - mov eax,[_ES _bx+TIMER_COUNT] - mov [EndBIOSCount],eax - unuse_es - -; Read out the count we latched earlier. - - in al,TIMER_0_8253 ; least significant byte - DELAY - mov ah,al - in al,TIMER_0_8253 ; most significant byte - xchg ah,al - neg ax ; Convert from countdown remaining - ; to elapsed count - mov [EndTimedCount],ax - sti ; Let the BIOS count continue - - ret - -cprocend - -;---------------------------------------------------------------------------- -; unsigned long LZ_timerLap(void) -;---------------------------------------------------------------------------- -; Latches the current count and converts it to a microsecond timing value, -; but leaves the timer still running. We dont check for and overflow, -; where the time has gone over an hour in this routine, since we want it -; to execute as fast as possible. -;---------------------------------------------------------------------------- -cprocstart LZ_timerLap - - push ebx ; Save EBX for 32 bit code - -; Latch the timer count. - - mov al,00000000b ; latch timer 0 - out MODE_8253,al - cli ; Stop the BIOS count - -; Read the BIOS count. (Since interrupts are disabled, the BIOS -; count wont change). - - use_es -ifdef flatmodel - mov ebx,[_ZTimerBIOSPtr] -else - les bx,[_ZTimerBIOSPtr] -endif - mov eax,[_ES _bx+TIMER_COUNT] - mov [EndBIOSCount],eax - unuse_es - -; Read out the count we latched earlier. - - in al,TIMER_0_8253 ; least significant byte - DELAY - mov ah,al - in al,TIMER_0_8253 ; most significant byte - xchg ah,al - neg ax ; Convert from countdown remaining - ; to elapsed count - mov [EndTimedCount],ax - sti ; Let the BIOS count continue - -; See if a midnight boundary has passed and adjust the finishing BIOS -; count by the number of ticks in 24 hours. We wont be able to detect -; more than 24 hours, but at least we can time across a midnight -; boundary - - mov eax,[EndBIOSCount] ; Is end < start? - cmp eax,[StartBIOSCount] - jae @@CalcBIOSTime ; No, calculate the time taken - -; Adjust the finishing time by adding the number of ticks in 24 hours -; (1573040). - - add [DWORD EndBIOSCount],1800B0h - -; Convert the BIOS time to microseconds - -@@CalcBIOSTime: - mov ax,[WORD EndBIOSCount] - sub ax,[WORD StartBIOSCount] - mov dx,54925 ; Number of microseconds each - ; BIOS count represents. - mul dx - mov bx,ax ; set aside BIOS count in - mov cx,dx ; microseconds - -; Convert timer count to microseconds - - push _si - mov ax,[EndTimedCount] - mov si,8381 - mul si - mov si,10000 - div si ; * 0.8381 = * 8381 / 10000 - pop _si - -; Add the timer and BIOS counts together to get an overall time in -; microseconds. - - add ax,bx - adc cx,0 -ifdef flatmodel - shl ecx,16 - mov cx,ax - mov eax,ecx ; EAX := timer count -else - mov dx,cx -endif - pop ebx ; Restore EBX for 32 bit code - ret - -cprocend - -;---------------------------------------------------------------------------- -; unsigned long LZ_timerCount(void); -;---------------------------------------------------------------------------- -; Returns an unsigned long representing the net time in microseconds. -; -; If an hour has passed while timing, we return 0xFFFFFFFF as the count -; (which is not a possible count in itself). -;---------------------------------------------------------------------------- -cprocstart LZ_timerCount - - push ebx ; Save EBX for 32 bit code - -; See if a midnight boundary has passed and adjust the finishing BIOS -; count by the number of ticks in 24 hours. We wont be able to detect -; more than 24 hours, but at least we can time across a midnight -; boundary - - mov eax,[EndBIOSCount] ; Is end < start? - cmp eax,[StartBIOSCount] - jae @@CheckForHour ; No, check for hour passing - -; Adjust the finishing time by adding the number of ticks in 24 hours -; (1573040). - - add [DWORD EndBIOSCount],1800B0h - -; See if more than an hour passed during timing. If so, notify the user. - -@@CheckForHour: - mov ax,[WORD StartBIOSCount+2] - cmp ax,[WORD EndBIOSCount+2] - jz @@CalcBIOSTime ; Hour count didn't change, so - ; everything is fine - - inc ax - cmp ax,[WORD EndBIOSCount+2] - jnz @@TestTooLong ; Two hour boundaries passed, so the - ; results are no good - mov ax,[WORD EndBIOSCount] - cmp ax,[WORD StartBIOSCount] - jb @@CalcBIOSTime ; a single hour boundary passed. That's - ; OK, so long as the total time wasn't - ; more than an hour. - -; Over an hour elapsed passed during timing, which renders -; the results invalid. Notify the user. This misses the case where a -; multiple of 24 hours has passed, but we'll rely on the perspicacity of -; the user to detect that case :-). - -@@TestTooLong: -ifdef flatmodel - mov eax,0FFFFFFFFh -else - mov ax,0FFFFh - mov dx,0FFFFh -endif - jmp short @@Done - -; Convert the BIOS time to microseconds - -@@CalcBIOSTime: - mov ax,[WORD EndBIOSCount] - sub ax,[WORD StartBIOSCount] - mov dx,54925 ; Number of microseconds each - ; BIOS count represents. - mul dx - mov bx,ax ; set aside BIOS count in - mov cx,dx ; microseconds - -; Convert timer count to microseconds - - push _si - mov ax,[EndTimedCount] - mov si,8381 - mul si - mov si,10000 - div si ; * 0.8381 = * 8381 / 10000 - pop _si - -; Add the timer and BIOS counts together to get an overall time in -; microseconds. - - add ax,bx - adc cx,0 -ifdef flatmodel - shl ecx,16 - mov cx,ax - mov eax,ecx ; EAX := timer count -else - mov dx,cx -endif - -@@Done: pop ebx ; Restore EBX for 32 bit code - ret - -cprocend - -cprocstart LZ_disable - cli - ret -cprocend - -cprocstart LZ_enable - sti - ret -cprocend - -endcodeseg _lztimer - - END |
