| [140] | 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 | ;-------------------------------------------------------------------- |
|---|
| [150] | 8 | ; HTimer_InitializeTimeoutWithTicksInCX |
|---|
| [140] | 9 | ; Parameters: |
|---|
| [150] | 10 | ; CX: Timeout value in system timer ticks |
|---|
| [140] | 11 | ; DS: Segment to RAMVARS |
|---|
| 12 | ; Returns: |
|---|
| 13 | ; Nothing |
|---|
| 14 | ; Corrupts registers: |
|---|
| 15 | ; CX |
|---|
| 16 | ;-------------------------------------------------------------------- |
|---|
| 17 | ALIGN JUMP_ALIGN |
|---|
| [150] | 18 | HTimer_InitializeTimeoutWithTicksInCX: |
|---|
| [140] | 19 | mov [RAMVARS.wTimeoutCounter], cx ; Store timeout ticks |
|---|
| 20 | call ReadTimeFromBdaToCX |
|---|
| 21 | add [RAMVARS.wTimeoutCounter], cx ; End time for timeout |
|---|
| 22 | ret |
|---|
| 23 | |
|---|
| 24 | |
|---|
| 25 | ;-------------------------------------------------------------------- |
|---|
| 26 | ; HTimer_SetCFifTimeout |
|---|
| 27 | ; Parameters: |
|---|
| 28 | ; DS: Segment to RAMVARS |
|---|
| 29 | ; Returns: |
|---|
| 30 | ; CF: Set if timeout |
|---|
| 31 | ; Cleared if time left |
|---|
| 32 | ; Corrupts registers: |
|---|
| 33 | ; CX |
|---|
| 34 | ;-------------------------------------------------------------------- |
|---|
| 35 | ALIGN JUMP_ALIGN |
|---|
| 36 | HTimer_SetCFifTimeout: |
|---|
| 37 | call ReadTimeFromBdaToCX |
|---|
| 38 | cmp [RAMVARS.wTimeoutCounter], cx |
|---|
| 39 | ret |
|---|
| 40 | |
|---|
| 41 | |
|---|
| 42 | ;-------------------------------------------------------------------- |
|---|
| 43 | ; Delay is always at least one millisecond since |
|---|
| 44 | ; RTC resolution is 977 microsecs. |
|---|
| 45 | ; |
|---|
| [148] | 46 | ; HTimer_DelayMicrosecondsFromAX |
|---|
| [140] | 47 | ; Parameters: |
|---|
| 48 | ; AX: Number of microsecs to wait |
|---|
| 49 | ; Returns: |
|---|
| 50 | ; Nothing |
|---|
| 51 | ; Corrupts registers: |
|---|
| 52 | ; AX |
|---|
| 53 | ;-------------------------------------------------------------------- |
|---|
| [148] | 54 | HTimer_DelayMicrosecondsFromAX: |
|---|
| [140] | 55 | %ifndef USE_AT |
|---|
| [150] | 56 | mov ax, 2 |
|---|
| [140] | 57 | ; Fall to Delay_TimerTicksFromAX |
|---|
| 58 | %else |
|---|
| 59 | push dx |
|---|
| 60 | push cx |
|---|
| 61 | |
|---|
| 62 | xor cx, cx |
|---|
| [148] | 63 | xchg dx, ax ; Microsecs now in CX:DX |
|---|
| [140] | 64 | mov ah, EVENT_WAIT |
|---|
| 65 | int BIOS_SYSTEM_INTERRUPT_15h |
|---|
| [148] | 66 | sti ; XT BIOSes return with interrupt disabled |
|---|
| [140] | 67 | |
|---|
| 68 | pop cx |
|---|
| 69 | pop dx |
|---|
| [148] | 70 | mov ax, 1 ; Prepare to wait 1 timer tick |
|---|
| 71 | jc SHORT HTimer_DelayTimerTicksFromAX ; Event Wait was unsupported or busy |
|---|
| [140] | 72 | ret |
|---|
| 73 | %endif |
|---|
| 74 | |
|---|
| 75 | |
|---|
| 76 | ;-------------------------------------------------------------------- |
|---|
| 77 | ; First tick might take 0...54.9 ms and remaining ticks |
|---|
| 78 | ; will occur at 54.9 ms intervals. |
|---|
| 79 | ; |
|---|
| [148] | 80 | ; HTimer_DelayTimerTicksFromAX |
|---|
| [140] | 81 | ; Parameters: |
|---|
| 82 | ; AX: Number of timer ticks to wait |
|---|
| 83 | ; Returns: |
|---|
| 84 | ; Nothing |
|---|
| 85 | ; Corrupts registers: |
|---|
| 86 | ; AX |
|---|
| 87 | ;-------------------------------------------------------------------- |
|---|
| [148] | 88 | HTimer_DelayTimerTicksFromAX: |
|---|
| [140] | 89 | sti ; Make sure that interrupts are enabled |
|---|
| 90 | call ReadTimeFromBdaToCX |
|---|
| 91 | add ax, cx ; AX = end time |
|---|
| 92 | .WaitLoop: |
|---|
| 93 | call ReadTimeFromBdaToCX |
|---|
| 94 | cmp cx, ax |
|---|
| 95 | jb SHORT .WaitLoop ; Loop until end time is reached |
|---|
| 96 | ret |
|---|
| 97 | |
|---|
| 98 | |
|---|
| 99 | ;-------------------------------------------------------------------- |
|---|
| 100 | ; ReadTimeFromBdaToCX |
|---|
| 101 | ; Parameters |
|---|
| 102 | ; Nothing |
|---|
| 103 | ; Returns: |
|---|
| 104 | ; CX: System time in 54.9 ms ticks |
|---|
| 105 | ; Corrupts registers: |
|---|
| 106 | ; Nothing |
|---|
| 107 | ;-------------------------------------------------------------------- |
|---|
| 108 | ALIGN JUMP_ALIGN |
|---|
| 109 | ReadTimeFromBdaToCX: |
|---|
| 110 | push ds |
|---|
| 111 | LOAD_BDA_SEGMENT_TO ds, cx |
|---|
| 112 | mov cx, [BDA.dwTimerTicks] ; Read low WORD only |
|---|
| 113 | pop ds |
|---|
| 114 | ret |
|---|
