| 1 | ; Project name : XTIDE Universal BIOS
|
|---|
| 2 | ; Description : Timeout and delay functions for INT 13h services.
|
|---|
| 3 |
|
|---|
| 4 | ;
|
|---|
| 5 | ; XTIDE Universal BIOS and Associated Tools
|
|---|
| 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
|
|---|
| 7 | ;
|
|---|
| 8 | ; This program is free software; you can redistribute it and/or modify
|
|---|
| 9 | ; it under the terms of the GNU General Public License as published by
|
|---|
| 10 | ; the Free Software Foundation; either version 2 of the License, or
|
|---|
| 11 | ; (at your option) any later version.
|
|---|
| 12 | ;
|
|---|
| 13 | ; This program is distributed in the hope that it will be useful,
|
|---|
| 14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|---|
| 16 | ; GNU General Public License for more details.
|
|---|
| 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
|
|---|
| 18 | ;
|
|---|
| 19 |
|
|---|
| 20 | ; Section containing code
|
|---|
| 21 | SECTION .text
|
|---|
| 22 |
|
|---|
| 23 | ;--------------------------------------------------------------------
|
|---|
| 24 | ; Timer_InitializeTimeoutWithTicksInCL
|
|---|
| 25 | ; Parameters:
|
|---|
| 26 | ; CL: Timeout value in system timer ticks
|
|---|
| 27 | ; DS: Segment to RAMVARS
|
|---|
| 28 | ; Returns:
|
|---|
| 29 | ; Nothing
|
|---|
| 30 | ; Corrupts registers:
|
|---|
| 31 | ; CX
|
|---|
| 32 | ;--------------------------------------------------------------------
|
|---|
| 33 | ALIGN JUMP_ALIGN
|
|---|
| 34 | Timer_InitializeTimeoutWithTicksInCL:
|
|---|
| 35 | mov [RAMVARS.bTimeoutTicksLeft], cl ; Ticks until timeout
|
|---|
| 36 | call ReadTimeFromBdaToCX
|
|---|
| 37 | mov [RAMVARS.bLastTimeoutUpdate], cl ; Start time
|
|---|
| 38 | ret
|
|---|
| 39 |
|
|---|
| 40 |
|
|---|
| 41 | ;--------------------------------------------------------------------
|
|---|
| 42 | ; Timer_SetCFifTimeout
|
|---|
| 43 | ; Parameters:
|
|---|
| 44 | ; DS: Segment to RAMVARS
|
|---|
| 45 | ; Returns:
|
|---|
| 46 | ; CF: Set if timeout
|
|---|
| 47 | ; Cleared if time left
|
|---|
| 48 | ; Corrupts registers:
|
|---|
| 49 | ; CX
|
|---|
| 50 | ;--------------------------------------------------------------------
|
|---|
| 51 | ALIGN JUMP_ALIGN
|
|---|
| 52 | Timer_SetCFifTimeout:
|
|---|
| 53 | call ReadTimeFromBdaToCX
|
|---|
| 54 | cmp cl, [RAMVARS.bLastTimeoutUpdate]
|
|---|
| 55 | je SHORT .StillPollingTheSameTick
|
|---|
| 56 | mov [RAMVARS.bLastTimeoutUpdate], cl
|
|---|
| 57 | sub BYTE [RAMVARS.bTimeoutTicksLeft], 1 ; DEC does not update CF
|
|---|
| 58 | .StillPollingTheSameTick:
|
|---|
| 59 | ret
|
|---|
| 60 |
|
|---|
| 61 |
|
|---|
| 62 | ;--------------------------------------------------------------------
|
|---|
| 63 | ; Delay is always at least one millisecond since
|
|---|
| 64 | ; RTC resolution is 977 microsecs.
|
|---|
| 65 | ;
|
|---|
| 66 | ; Timer_DelayMicrosecondsFromAX
|
|---|
| 67 | ; Parameters:
|
|---|
| 68 | ; AX: Number of microsecs to wait
|
|---|
| 69 | ; Returns:
|
|---|
| 70 | ; Nothing
|
|---|
| 71 | ; Corrupts registers:
|
|---|
| 72 | ; AX
|
|---|
| 73 | ;--------------------------------------------------------------------
|
|---|
| 74 | Timer_DelayMicrosecondsFromAX:
|
|---|
| 75 | %ifndef USE_AT
|
|---|
| 76 | mov ax, 2
|
|---|
| 77 | ; Fall to Timer_DelayTimerTicksFromAX
|
|---|
| 78 | %else
|
|---|
| 79 | push dx
|
|---|
| 80 | push cx
|
|---|
| 81 |
|
|---|
| 82 | xor cx, cx
|
|---|
| 83 | xchg dx, ax ; Microsecs now in CX:DX
|
|---|
| 84 | mov ah, EVENT_WAIT
|
|---|
| 85 | int BIOS_SYSTEM_INTERRUPT_15h
|
|---|
| 86 | sti ; XT BIOSes return with interrupts disabled. TODO: Maybe we can remove this since it's in an AT-only block?
|
|---|
| 87 |
|
|---|
| 88 | pop cx
|
|---|
| 89 | pop dx
|
|---|
| 90 | mov ax, 1 ; Prepare to wait 1 timer tick
|
|---|
| 91 | jc SHORT Timer_DelayTimerTicksFromAX ; Event Wait was unsupported or busy
|
|---|
| 92 | ret
|
|---|
| 93 | %endif
|
|---|
| 94 |
|
|---|
| 95 |
|
|---|
| 96 | ;--------------------------------------------------------------------
|
|---|
| 97 | ; First tick might take 0...54.9 ms and remaining ticks
|
|---|
| 98 | ; will occur at 54.9 ms intervals.
|
|---|
| 99 | ;
|
|---|
| 100 | ; Timer_DelayTimerTicksFromAX
|
|---|
| 101 | ; Parameters:
|
|---|
| 102 | ; AX: Number of timer ticks to wait
|
|---|
| 103 | ; Returns:
|
|---|
| 104 | ; Nothing
|
|---|
| 105 | ; Corrupts registers:
|
|---|
| 106 | ; AX
|
|---|
| 107 | ;--------------------------------------------------------------------
|
|---|
| 108 | Timer_DelayTimerTicksFromAX:
|
|---|
| 109 | sti ; Make sure that interrupts are enabled
|
|---|
| 110 | call ReadTimeFromBdaToCX
|
|---|
| 111 | add ax, cx ; AX = end time
|
|---|
| 112 | .WaitLoop:
|
|---|
| 113 | call ReadTimeFromBdaToCX
|
|---|
| 114 | cmp cx, ax
|
|---|
| 115 | jne SHORT .WaitLoop ; Loop until end time is reached
|
|---|
| 116 | ret
|
|---|
| 117 |
|
|---|
| 118 |
|
|---|
| 119 | ;--------------------------------------------------------------------
|
|---|
| 120 | ; ReadTimeFromBdaToCX
|
|---|
| 121 | ; Parameters
|
|---|
| 122 | ; Nothing
|
|---|
| 123 | ; Returns:
|
|---|
| 124 | ; CX: System time in 54.9 ms ticks
|
|---|
| 125 | ; Corrupts registers:
|
|---|
| 126 | ; Nothing
|
|---|
| 127 | ;--------------------------------------------------------------------
|
|---|
| 128 | ALIGN JUMP_ALIGN
|
|---|
| 129 | ReadTimeFromBdaToCX:
|
|---|
| 130 | push ds
|
|---|
| 131 | LOAD_BDA_SEGMENT_TO ds, cx
|
|---|
| 132 | mov cx, [BDA.dwTimerTicks] ; Read low WORD only
|
|---|
| 133 | pop ds
|
|---|
| 134 | ret
|
|---|
