[41] | 1 | ; Project name : Assembly Library |
---|
| 2 | ; Description : Functions for system timer related operations. |
---|
| 3 | |
---|
[376] | 4 | ; |
---|
[491] | 5 | ; XTIDE Universal BIOS and Associated Tools |
---|
[526] | 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. |
---|
[491] | 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 |
---|
[491] | 16 | ; GNU General Public License for more details. |
---|
[376] | 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
---|
[491] | 18 | ; |
---|
[376] | 19 | |
---|
[491] | 20 | ; With a PIT input clock of 1193181.6666... Hz and a maximum |
---|
| 21 | ; 16 bit divisor of 65536 (if PIT programmed with 0) we get: |
---|
| 22 | ; |
---|
| 23 | ; Clock / Divisor = ~18.2065 ticks per second |
---|
| 24 | ; Clock * SecondsPerMinute / Divisor = ~1092 ticks per minute |
---|
| 25 | ; Clock * SecondsPerHour / Divisor = ~65543 ticks per hour |
---|
| 26 | ; |
---|
| 27 | ; Since 65543 can't fit in a 16 bit register we use the |
---|
| 28 | ; maximum possible instead and disregard the last ~8 ticks. |
---|
| 29 | |
---|
| 30 | TICKS_PER_HOUR EQU 65535 |
---|
[41] | 31 | TICKS_PER_MINUTE EQU 1092 |
---|
| 32 | TICKS_PER_SECOND EQU 18 |
---|
| 33 | |
---|
| 34 | |
---|
| 35 | ; Section containing code |
---|
| 36 | SECTION .text |
---|
| 37 | |
---|
| 38 | ;-------------------------------------------------------------------- |
---|
[491] | 39 | ; TimerTicks_GetHoursToAXandRemainderTicksToDXfromTicksInDXAX |
---|
| 40 | ; TimerTicks_GetMinutesToAXandRemainderTicksToDXfromTicksInDX |
---|
| 41 | ; TimerTicks_GetSecondsToAXandRemainderTicksToDXfromTicksInDX |
---|
[41] | 42 | ; Parameters |
---|
| 43 | ; DX(:AX): Timer ticks to convert |
---|
| 44 | ; Returns: |
---|
| 45 | ; AX: Hours, minutes or seconds |
---|
| 46 | ; DX: Remainder ticks |
---|
| 47 | ; Corrupts registers: |
---|
| 48 | ; CX |
---|
| 49 | ;-------------------------------------------------------------------- |
---|
[592] | 50 | %ifndef EXCLUDE_FROM_XUB |
---|
[370] | 51 | %ifndef EXCLUDE_FROM_XTIDECFG |
---|
[41] | 52 | ALIGN JUMP_ALIGN |
---|
[491] | 53 | TimerTicks_GetHoursToAXandRemainderTicksToDXfromTicksInDXAX: |
---|
[41] | 54 | mov cx, TICKS_PER_HOUR |
---|
| 55 | div cx ; Divide DX:AX by CX, Hours to AX, remainder ticks to DX |
---|
| 56 | ret |
---|
[370] | 57 | %endif ; EXCLUDE_FROM_XTIDECFG |
---|
[41] | 58 | |
---|
| 59 | ALIGN JUMP_ALIGN |
---|
[491] | 60 | TimerTicks_GetMinutesToAXandRemainderTicksToDXfromTicksInDX: |
---|
[41] | 61 | xor ax, ax |
---|
| 62 | xchg ax, dx ; Ticks now in DX:AX |
---|
| 63 | mov cx, TICKS_PER_MINUTE |
---|
| 64 | div cx ; Divide DX:AX by CX, Minutes to AX, remainder ticks to DX |
---|
| 65 | ret |
---|
[592] | 66 | %endif ; EXCLUDE_FROM_XUB |
---|
[106] | 67 | |
---|
[592] | 68 | %ifndef EXCLUDE_FROM_XUB OR EXCLUDE_FROM_XTIDECFG |
---|
[41] | 69 | ALIGN JUMP_ALIGN |
---|
[491] | 70 | TimerTicks_GetSecondsToAXandRemainderTicksToDXfromTicksInDX: |
---|
| 71 | ; This procedure can handle at most 4607 ticks in DX (almost 256 seconds) |
---|
| 72 | ; More than 4607 ticks will generate a divide overflow exception! |
---|
[41] | 73 | xchg ax, dx ; Ticks now in AX |
---|
| 74 | mov cl, TICKS_PER_SECOND |
---|
| 75 | div cl ; Divide AX by CL, Seconds to AL, remainder ticks to AH |
---|
| 76 | xor dx, dx |
---|
| 77 | xchg dl, ah ; Seconds in AX, remainder in DX |
---|
| 78 | ret |
---|
[489] | 79 | %endif |
---|
[41] | 80 | |
---|
[491] | 81 | |
---|
[592] | 82 | %ifdef EXCLUDE_FROM_XUB |
---|
[491] | 83 | %ifndef MODULE_BOOT_MENU |
---|
| 84 | %define EXCLUDE |
---|
| 85 | %endif |
---|
| 86 | %endif |
---|
[41] | 87 | ;-------------------------------------------------------------------- |
---|
[491] | 88 | ; TimerTicks_GetSecondsToAXfromTicksInDX |
---|
| 89 | ; Parameters |
---|
| 90 | ; DX: Timer ticks to convert |
---|
| 91 | ; Returns: |
---|
| 92 | ; AX: Seconds |
---|
| 93 | ; Corrupts registers: |
---|
| 94 | ; DX |
---|
| 95 | ;-------------------------------------------------------------------- |
---|
| 96 | %ifndef EXCLUDE ; 1 of 3 |
---|
| 97 | ALIGN JUMP_ALIGN |
---|
| 98 | TimerTicks_GetSecondsToAXfromTicksInDX: |
---|
| 99 | mov ax, 3600 ; Approximately 65536 / (Clock / Divisor) |
---|
| 100 | mul dx |
---|
| 101 | xchg dx, ax |
---|
| 102 | ret |
---|
| 103 | %endif |
---|
| 104 | |
---|
| 105 | |
---|
| 106 | ;-------------------------------------------------------------------- |
---|
[41] | 107 | ; First tick might take 0...54.9 ms and remaining ticks |
---|
| 108 | ; will occur at 54.9 ms intervals. Use delay of two (or more) ticks to |
---|
| 109 | ; ensure at least 54.9 ms timeout. |
---|
| 110 | ; |
---|
| 111 | ; TimerTicks_InitializeTimeoutFromAX |
---|
| 112 | ; Parameters: |
---|
| 113 | ; AX: Timeout ticks (54.9 ms) before timeout |
---|
| 114 | ; DS:BX: Ptr to timeout variable WORD |
---|
| 115 | ; Returns: |
---|
| 116 | ; [DS:BX]: Initialized for TimerTicks_SetCarryIfTimeoutFromDSBX |
---|
| 117 | ; Corrupts registers: |
---|
| 118 | ; AX |
---|
| 119 | ;-------------------------------------------------------------------- |
---|
[491] | 120 | %ifndef EXCLUDE ; 2 of 3 |
---|
[41] | 121 | ALIGN JUMP_ALIGN |
---|
| 122 | TimerTicks_InitializeTimeoutFromAX: |
---|
| 123 | mov [bx], ax ; Store timeout ticks |
---|
| 124 | call TimerTicks_ReadFromBdaToAX |
---|
[119] | 125 | add [bx], ax ; [bx] now contains end time for timeout |
---|
[41] | 126 | ret |
---|
[489] | 127 | %endif |
---|
[41] | 128 | |
---|
[491] | 129 | |
---|
[41] | 130 | ;-------------------------------------------------------------------- |
---|
[60] | 131 | ; TimerTicks_GetTimeoutTicksLeftToAXfromDSBX |
---|
[41] | 132 | ; Parameters: |
---|
| 133 | ; DS:BX: Ptr to timeout variable WORD |
---|
| 134 | ; Returns: |
---|
[85] | 135 | ; AX: Number of ticks left before timeout |
---|
[41] | 136 | ; CF: Set if timeout |
---|
| 137 | ; Cleared if time left |
---|
| 138 | ; Corrupts registers: |
---|
| 139 | ; Nothing |
---|
| 140 | ;-------------------------------------------------------------------- |
---|
[491] | 141 | %ifndef EXCLUDE ; 3 of 3 |
---|
[41] | 142 | ALIGN JUMP_ALIGN |
---|
[60] | 143 | TimerTicks_GetTimeoutTicksLeftToAXfromDSBX: |
---|
| 144 | push dx |
---|
| 145 | mov dx, [bx] |
---|
[41] | 146 | call TimerTicks_ReadFromBdaToAX |
---|
[60] | 147 | xchg ax, dx |
---|
| 148 | sub ax, dx ; AX = End time - current time |
---|
| 149 | pop dx |
---|
[41] | 150 | ret |
---|
[489] | 151 | %endif |
---|
[41] | 152 | |
---|
[491] | 153 | %undef EXCLUDE |
---|
| 154 | |
---|
| 155 | |
---|
[41] | 156 | ;-------------------------------------------------------------------- |
---|
| 157 | ; TimerTicks_GetElapsedToAXandResetDSBX |
---|
| 158 | ; Parameters |
---|
| 159 | ; DS:BX: Ptr to WORD containing previous reset time |
---|
| 160 | ; Returns: |
---|
| 161 | ; AX: 54.9 ms ticks elapsed since last reset |
---|
| 162 | ; [DS:BX]: Reset to latest time |
---|
| 163 | ; Corrupts registers: |
---|
| 164 | ; Nothing |
---|
| 165 | ;-------------------------------------------------------------------- |
---|
[592] | 166 | %ifndef EXCLUDE_FROM_XUB OR EXCLUDE_FROM_XTIDECFG |
---|
[41] | 167 | ALIGN JUMP_ALIGN |
---|
| 168 | TimerTicks_GetElapsedToAXandResetDSBX: |
---|
| 169 | call TimerTicks_ReadFromBdaToAX |
---|
| 170 | push ax |
---|
| 171 | sub ax, [bx] |
---|
| 172 | pop WORD [bx] ; Latest time to [DS:BX] |
---|
| 173 | ret |
---|
[131] | 174 | %endif |
---|
[41] | 175 | |
---|
[491] | 176 | |
---|
[41] | 177 | ;-------------------------------------------------------------------- |
---|
| 178 | ; TimerTicks_GetElapsedToAXfromDSBX |
---|
| 179 | ; Parameters |
---|
| 180 | ; DS:BX: Ptr to WORD containing previous update time |
---|
| 181 | ; Returns: |
---|
| 182 | ; AX: 54.9 ms ticks elapsed since initializing [DS:BX] |
---|
| 183 | ; Corrupts registers: |
---|
| 184 | ; Nothing |
---|
| 185 | ;-------------------------------------------------------------------- |
---|
[592] | 186 | %ifndef EXCLUDE_FROM_XUB OR EXCLUDE_FROM_XTIDECFG |
---|
[41] | 187 | ALIGN JUMP_ALIGN |
---|
| 188 | TimerTicks_GetElapsedToAXfromDSBX: |
---|
| 189 | call TimerTicks_ReadFromBdaToAX |
---|
| 190 | sub ax, [bx] |
---|
| 191 | ret |
---|
[131] | 192 | %endif |
---|
[41] | 193 | |
---|
| 194 | |
---|
| 195 | ;-------------------------------------------------------------------- |
---|
| 196 | ; TimerTicks_ReadFromBdaToAX |
---|
| 197 | ; Parameters |
---|
| 198 | ; Nothing |
---|
| 199 | ; Returns: |
---|
| 200 | ; AX: System time in 54.9 ms ticks |
---|
| 201 | ; Corrupts registers: |
---|
| 202 | ; Nothing |
---|
| 203 | ;-------------------------------------------------------------------- |
---|
[592] | 204 | %ifdef EXCLUDE_FROM_XUB |
---|
[605] | 205 | %ifndef MODULE_BOOT_MENU |
---|
[491] | 206 | %define EXCLUDE |
---|
| 207 | %endif |
---|
| 208 | %endif |
---|
| 209 | |
---|
| 210 | %ifndef EXCLUDE |
---|
[41] | 211 | ALIGN JUMP_ALIGN |
---|
| 212 | TimerTicks_ReadFromBdaToAX: |
---|
| 213 | push ds |
---|
| 214 | |
---|
| 215 | LOAD_BDA_SEGMENT_TO ds, ax |
---|
| 216 | mov ax, [BDA.dwTimerTicks] ; Read low WORD only |
---|
| 217 | |
---|
| 218 | pop ds |
---|
| 219 | ret |
---|
[491] | 220 | %endif |
---|
| 221 | %undef EXCLUDE |
---|