| 1 | ; Project name : XTIDE Universal BIOS
|
|---|
| 2 | ; Description : Timeout and delay functions for INT 13h services.
|
|---|
| 3 |
|
|---|
| 4 | ; Section containing code
|
|---|
| 5 | SECTION .text
|
|---|
| 6 |
|
|---|
| 7 | ;--------------------------------------------------------------------
|
|---|
| 8 | ; HTimer_InitializeTimeoutWithTicksInCL
|
|---|
| 9 | ; Parameters:
|
|---|
| 10 | ; CL: Timeout value in system timer ticks
|
|---|
| 11 | ; DS: Segment to RAMVARS
|
|---|
| 12 | ; Returns:
|
|---|
| 13 | ; Nothing
|
|---|
| 14 | ; Corrupts registers:
|
|---|
| 15 | ; CX
|
|---|
| 16 | ;--------------------------------------------------------------------
|
|---|
| 17 | ALIGN JUMP_ALIGN
|
|---|
| 18 | HTimer_InitializeTimeoutWithTicksInCL:
|
|---|
| 19 | xor ch, ch ; Timeout ticks now in CX
|
|---|
| 20 | mov [RAMVARS.wTimeoutCounter], cx ; Store timeout ticks
|
|---|
| 21 | call ReadTimeFromBdaToCX
|
|---|
| 22 | add [RAMVARS.wTimeoutCounter], cx ; End time for timeout
|
|---|
| 23 | ret
|
|---|
| 24 |
|
|---|
| 25 |
|
|---|
| 26 | ;--------------------------------------------------------------------
|
|---|
| 27 | ; HTimer_SetCFifTimeout
|
|---|
| 28 | ; Parameters:
|
|---|
| 29 | ; DS: Segment to RAMVARS
|
|---|
| 30 | ; Returns:
|
|---|
| 31 | ; CF: Set if timeout
|
|---|
| 32 | ; Cleared if time left
|
|---|
| 33 | ; Corrupts registers:
|
|---|
| 34 | ; CX
|
|---|
| 35 | ;--------------------------------------------------------------------
|
|---|
| 36 | ALIGN JUMP_ALIGN
|
|---|
| 37 | HTimer_SetCFifTimeout:
|
|---|
| 38 | call ReadTimeFromBdaToCX
|
|---|
| 39 | cmp [RAMVARS.wTimeoutCounter], cx
|
|---|
| 40 | ret
|
|---|
| 41 |
|
|---|
| 42 |
|
|---|
| 43 | ;--------------------------------------------------------------------
|
|---|
| 44 | ; Delay is always at least one millisecond since
|
|---|
| 45 | ; RTC resolution is 977 microsecs.
|
|---|
| 46 | ;
|
|---|
| 47 | ; HTimer_DelayMicrosecondsFromAX
|
|---|
| 48 | ; Parameters:
|
|---|
| 49 | ; AX: Number of microsecs to wait
|
|---|
| 50 | ; Returns:
|
|---|
| 51 | ; Nothing
|
|---|
| 52 | ; Corrupts registers:
|
|---|
| 53 | ; AX
|
|---|
| 54 | ;--------------------------------------------------------------------
|
|---|
| 55 | HTimer_DelayMicrosecondsFromAX:
|
|---|
| 56 | %ifndef USE_AT
|
|---|
| 57 | mov ax, 1
|
|---|
| 58 | ; Fall to Delay_TimerTicksFromAX
|
|---|
| 59 | %else
|
|---|
| 60 | push dx
|
|---|
| 61 | push cx
|
|---|
| 62 |
|
|---|
| 63 | xor cx, cx
|
|---|
| 64 | xchg dx, ax ; Microsecs now in CX:DX
|
|---|
| 65 | mov ah, EVENT_WAIT
|
|---|
| 66 | int BIOS_SYSTEM_INTERRUPT_15h
|
|---|
| 67 | sti ; XT BIOSes return with interrupt disabled
|
|---|
| 68 |
|
|---|
| 69 | pop cx
|
|---|
| 70 | pop dx
|
|---|
| 71 | mov ax, 1 ; Prepare to wait 1 timer tick
|
|---|
| 72 | jc SHORT HTimer_DelayTimerTicksFromAX ; Event Wait was unsupported or busy
|
|---|
| 73 | ret
|
|---|
| 74 | %endif
|
|---|
| 75 |
|
|---|
| 76 |
|
|---|
| 77 | ;--------------------------------------------------------------------
|
|---|
| 78 | ; First tick might take 0...54.9 ms and remaining ticks
|
|---|
| 79 | ; will occur at 54.9 ms intervals.
|
|---|
| 80 | ;
|
|---|
| 81 | ; HTimer_DelayTimerTicksFromAX
|
|---|
| 82 | ; Parameters:
|
|---|
| 83 | ; AX: Number of timer ticks to wait
|
|---|
| 84 | ; Returns:
|
|---|
| 85 | ; Nothing
|
|---|
| 86 | ; Corrupts registers:
|
|---|
| 87 | ; AX
|
|---|
| 88 | ;--------------------------------------------------------------------
|
|---|
| 89 | HTimer_DelayTimerTicksFromAX:
|
|---|
| 90 | sti ; Make sure that interrupts are enabled
|
|---|
| 91 | call ReadTimeFromBdaToCX
|
|---|
| 92 | add ax, cx ; AX = end time
|
|---|
| 93 | .WaitLoop:
|
|---|
| 94 | call ReadTimeFromBdaToCX
|
|---|
| 95 | cmp cx, ax
|
|---|
| 96 | jb SHORT .WaitLoop ; Loop until end time is reached
|
|---|
| 97 | ret
|
|---|
| 98 |
|
|---|
| 99 |
|
|---|
| 100 | ;--------------------------------------------------------------------
|
|---|
| 101 | ; ReadTimeFromBdaToCX
|
|---|
| 102 | ; Parameters
|
|---|
| 103 | ; Nothing
|
|---|
| 104 | ; Returns:
|
|---|
| 105 | ; CX: System time in 54.9 ms ticks
|
|---|
| 106 | ; Corrupts registers:
|
|---|
| 107 | ; Nothing
|
|---|
| 108 | ;--------------------------------------------------------------------
|
|---|
| 109 | ALIGN JUMP_ALIGN
|
|---|
| 110 | ReadTimeFromBdaToCX:
|
|---|
| 111 | push ds
|
|---|
| 112 | LOAD_BDA_SEGMENT_TO ds, cx
|
|---|
| 113 | mov cx, [BDA.dwTimerTicks] ; Read low WORD only
|
|---|
| 114 | pop ds
|
|---|
| 115 | ret
|
|---|
