[140] | 1 | ; Project name : XTIDE Universal BIOS |
---|
| 2 | ; Description : Timeout and delay functions for INT 13h services. |
---|
| 3 | |
---|
[376] | 4 | ; |
---|
[526] | 5 | ; XTIDE Universal BIOS and Associated Tools |
---|
| 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team. |
---|
[376] | 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. |
---|
[526] | 12 | ; |
---|
[376] | 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. |
---|
[526] | 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
---|
| 18 | ; |
---|
[376] | 19 | |
---|
[140] | 20 | ; Section containing code |
---|
| 21 | SECTION .text |
---|
| 22 | |
---|
| 23 | ;-------------------------------------------------------------------- |
---|
[155] | 24 | ; Timer_InitializeTimeoutWithTicksInCL |
---|
[140] | 25 | ; Parameters: |
---|
[155] | 26 | ; CL: Timeout value in system timer ticks |
---|
[140] | 27 | ; DS: Segment to RAMVARS |
---|
| 28 | ; Returns: |
---|
| 29 | ; Nothing |
---|
| 30 | ; Corrupts registers: |
---|
| 31 | ; CX |
---|
| 32 | ;-------------------------------------------------------------------- |
---|
| 33 | ALIGN JUMP_ALIGN |
---|
[155] | 34 | Timer_InitializeTimeoutWithTicksInCL: |
---|
| 35 | mov [RAMVARS.bTimeoutTicksLeft], cl ; Ticks until timeout |
---|
[140] | 36 | call ReadTimeFromBdaToCX |
---|
[155] | 37 | mov [RAMVARS.bLastTimeoutUpdate], cl ; Start time |
---|
[140] | 38 | ret |
---|
| 39 | |
---|
| 40 | |
---|
| 41 | ;-------------------------------------------------------------------- |
---|
[155] | 42 | ; Timer_SetCFifTimeout |
---|
[140] | 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 |
---|
[155] | 52 | Timer_SetCFifTimeout: |
---|
[140] | 53 | call ReadTimeFromBdaToCX |
---|
[155] | 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: |
---|
[140] | 59 | ret |
---|
| 60 | |
---|
| 61 | |
---|
| 62 | ;-------------------------------------------------------------------- |
---|
| 63 | ; Delay is always at least one millisecond since |
---|
| 64 | ; RTC resolution is 977 microsecs. |
---|
| 65 | ; |
---|
[155] | 66 | ; Timer_DelayMicrosecondsFromAX |
---|
[140] | 67 | ; Parameters: |
---|
| 68 | ; AX: Number of microsecs to wait |
---|
| 69 | ; Returns: |
---|
| 70 | ; Nothing |
---|
| 71 | ; Corrupts registers: |
---|
| 72 | ; AX |
---|
| 73 | ;-------------------------------------------------------------------- |
---|
[155] | 74 | Timer_DelayMicrosecondsFromAX: |
---|
[140] | 75 | %ifndef USE_AT |
---|
[150] | 76 | mov ax, 2 |
---|
[181] | 77 | ; Fall to Timer_DelayTimerTicksFromAX |
---|
[140] | 78 | %else |
---|
| 79 | push dx |
---|
| 80 | push cx |
---|
| 81 | |
---|
| 82 | xor cx, cx |
---|
[148] | 83 | xchg dx, ax ; Microsecs now in CX:DX |
---|
[140] | 84 | mov ah, EVENT_WAIT |
---|
| 85 | int BIOS_SYSTEM_INTERRUPT_15h |
---|
[181] | 86 | sti ; XT BIOSes return with interrupts disabled. TODO: Maybe we can remove this since it's in an AT-only block? |
---|
[140] | 87 | |
---|
| 88 | pop cx |
---|
| 89 | pop dx |
---|
[148] | 90 | mov ax, 1 ; Prepare to wait 1 timer tick |
---|
[155] | 91 | jc SHORT Timer_DelayTimerTicksFromAX ; Event Wait was unsupported or busy |
---|
[140] | 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 | ; |
---|
[155] | 100 | ; Timer_DelayTimerTicksFromAX |
---|
[140] | 101 | ; Parameters: |
---|
| 102 | ; AX: Number of timer ticks to wait |
---|
| 103 | ; Returns: |
---|
| 104 | ; Nothing |
---|
| 105 | ; Corrupts registers: |
---|
| 106 | ; AX |
---|
| 107 | ;-------------------------------------------------------------------- |
---|
[155] | 108 | Timer_DelayTimerTicksFromAX: |
---|
[140] | 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 |
---|
[155] | 115 | jne SHORT .WaitLoop ; Loop until end time is reached |
---|
[140] | 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 |
---|