; Copyright 1996 Acorn Computers Ltd
;
; Licensed under the Apache License, Version 2.0 (the "License");
; you may not use this file except in compliance with the License.
; You may obtain a copy of the License at
;
; http://www.apache.org/licenses/LICENSE-2.0
;
; Unless required by applicable law or agreed to in writing, software
; distributed under the License is distributed on an "AS IS" BASIS,
; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
; See the License for the specific language governing permissions and
; limitations under the License.
;
; > $.Source.PMF.realtime
; *****************************************************************************
;
; SWI OS_ResyncTime
;
; in: r0 = 0 - Real time clock soft copy only
; r0 <> 0 reserved for future expansion
; out: registers preserved
; or VS and R0 -> error
;
ResyncTimeSWI ROUT
Push "R1, R12, LR"
BYTEWS WsPtr
BL RTCToRealTime
MOVVC R1, #Service_RTCSynchronised
BLVC Issue_Service
Pull "R1, R12, LR"
B SLVK_TestV
; *****************************************************************************
;
; SetTime - Write the CMOS clock time and update 5-byte RealTime
;
; in: UTC time:
; R0 = hours
; R1 = minutes
; R2 = day of month (1-based)
; R3 = month (1-based)
; R5 = year (lo)
; R6 = year (hi)
; R7 = seconds
; R8 = centiseconds
; out: registers preserved
; or VS and R0 -> error
;
; If R0,R2,R5 or R6 is -1 then the time,date,year,century (respectively) will not be written.
; However if R2=-1, R5 & R6 will also be -1, so only R0 (for time) and R2 (for D/M/Y) need checking.
;
SetTime ROUT
Push "R4, R9, LR"
; Prepare BCD data on stack
ASSERT (RTCTimeStruct_Size :AND: 3)=0
SUB R13, R13, #RTCTimeStruct_Size
MOV R9, R13
MOV R4, R0
; Ensure struct matches our setting order
ASSERT RTCTimeStruct_Centiseconds = 0
ASSERT RTCTimeStruct_Seconds = 1
ASSERT RTCTimeStruct_Minutes = 2
ASSERT RTCTimeStruct_Hours = 3
ASSERT RTCTimeStruct_DayOfMonth = 4
ASSERT RTCTimeStruct_Month = 5
ASSERT RTCTimeStruct_YearLO = 6
ASSERT RTCTimeStruct_YearHI = 7
; Are we setting the time?
CMP R4, #-1
STREQ R4, [R9], #4 ; Conveniently, 4 bytes of time info
BEQ %FT11
MOV R0, R8
BL HTBS9
MOV R0, R7
BL HTBS9
MOV R0, R1
BL HTBS9
MOV R0, R4
BL HTBS9
11
; Are we setting the date?
CMP R2, #-1
STREQ R2, [R9], #4 ; Conveniently, 4 bytes of date info
BEQ %FT12
MOV R0, R2
BL HTBS9
MOV R0, R3
BL HTBS9
MOV R0, R5
BL HTBS9
MOV R0, R6
BL HTBS9
12
MOV R0, SP
SWI XRTC_Write ; Try update hardware
MOV R0, R4
BL RegToRealTime ; Update soft copy regardless
CLRV
ADD SP, SP, #RTCTimeStruct_Size
Pull "R4, R9, PC"
; *****************************************************************************
;
; ReadTime - Read the CMOS clock time
;
; in: -
; out: R0 = hours
; R1 = minutes
; R2 = day of month (1-based)
; R3 = month (1-based)
; R5 = year (lo)
; R6 = year (hi)
; R7 = seconds
; R8 = centiseconds
; or VS and R0 -> error
ReadTime ROUT
Push "LR"
; Receive BCD data on stack
ASSERT (RTCTimeStruct_Size :AND: 3)=0
SUB R13, R13, #RTCTimeStruct_Size
MOV R0, R13
SWI XRTC_Read
ADDVS R13, R13, #RTCTimeStruct_Size
Pull "PC",VS
; Now convert the BCD ordinals
LDRB R0, [R13, #RTCTimeStruct_Centiseconds]
BL BCDToHex
MOV R8, R0 ; centiseconds
LDRB R0, [R13, #RTCTimeStruct_Seconds]
BL BCDToHex
MOV R7, R0 ; seconds
LDRB R0, [R13, #RTCTimeStruct_Minutes]
BL BCDToHex
MOV R1, R0 ; minutes
LDRB R0, [R13, #RTCTimeStruct_DayOfMonth]
BL BCDToHex
MOV R2, R0 ; days
LDRB R0, [R13, #RTCTimeStruct_Month]
BL BCDToHex
MOV R3, R0 ; months
LDRB R0, [R13, #RTCTimeStruct_YearLO]
BL BCDToHex
MOV R5, R0 ; year lo
LDRB R0, [R13, #RTCTimeStruct_YearHI]
BL BCDToHex
MOV R6, R0 ; year hi
LDRB R0, [R13, #RTCTimeStruct_Hours]
BL BCDToHex
; hours
CLRV
; We're done with our stack data, remove it
ADD R13, R13, #RTCTimeStruct_Size
Pull "PC"
; *****************************************************************************
;
; RTCToRealTime - Set RealTime from actual RTC
;
; in: R12 -> BYTEWS
; out: all registers preserved
; or VS and R0 -> error
;
RTCToRealTime ROUT
Push "R0-R9, LR"
BL ReadTime ; R0 := hours, R1 := minutes
; R2 := days, R3 := months
; R5 := year(lo), R6 := year(hi)
; R7 := seconds, R8 := centiseconds
BVS %FT10
BL ConvertTo5Byte
BL Store5ByteInRealTime
CLRV
10
STRVS R0, [SP, #0]
Pull "R0-R9, PC"
; *****************************************************************************
;
; RegToRealTime - Set RealTime from a bunch of registers
;
; in: R12 -> BYTEWS
; R0-R3, R5-R8 = validated time and date
; out: all registers preserved
;
RegToRealTime ROUT
Push "R0-R9, LR"
BL ConvertTo5Byte
BL Store5ByteInRealTime
Pull "R0-R9, PC"
; *****************************************************************************
;
; Store5ByteInRealTime - put 5 byte centisecond UTC time into soft copy
;
; in: R7 = low word of time
; R8 = high byte of time
; R12 -> BYTEWS
; out: all registers preserved
;
Store5ByteInRealTime
Push "LR"
PHPSEI ; disable IRQs for this bit
STR R7, RealTime +0
STRB R8, RealTime +4
PLP
Pull "PC"
; *****************************************************************************
;
; ConvertTo5Byte - Convert ordinals to 5 byte time
;
; in: R12 -> BYTEWS
; R0-R3, R5-R8 = time and date
; out: R7 = low word
; R8 = high byte
; or R7 = R8 = -1 if conversion failed
;
ConvertTo5Byte ROUT
Push "LR"
MOV R4, R5 ; R4 := year MOD 100
MOV R5, R6 ; R5 := year DIV 100
MOV R6, R7 ; R6 := seconds
MOV R7, R8 ; R7 := centiseconds
MOV R9, #24
SUB R2, R2, #1 ; decrement day (day=1 => nowt to add)
MLA R0, R9, R2, R0 ; R0 = hours + day*24
MOV R9, #60
MLA R1, R0, R9, R1 ; R1 = mins + hours*60
MLA R6, R1, R9, R6 ; R6 = secs + mins*60
MOV R9, #100
MLA R7, R6, R9, R7 ; R7 = centisecs + secs*100
ADR R0, STMonths-4 ; Point to table (month = 1..12)
LDR R1, [R0, R3, LSL #2] ; get word of offset
ADD R7, R7, R1 ; add to total
; if not had leap day in this year yet, then exclude this year from the
; leap day calculations
CMP R3, #3 ; if month >= 3
SBCS R0, R4, #0 ; then R0,R1 = R4,R5
MOVCC R0, #99 ; else R0,R1 = R4,R5 -1
SBC R1, R5, #0
; want (yl+100*yh) DIV 4 - (yl+100*yh) DIV 100 + (yl+100*yh) DIV 400
; = (yl DIV 4)+ (25*yh) - yh + (yh DIV 4)
; = (yl >> 2) + 24*yh + (yh >> 2)
MOV R0, R0, LSR #2 ; yl >> 2
ADD R0, R0, R1, LSR #2 ; + yh >> 2
ADD R0, R0, R1, LSL #4 ; + yh * 16
ADD R0, R0, R1, LSL #3 ; + yh * 8
; now subtract off the number of leap days in first 1900 years = 460
SUBS R0, R0, #460
BCC BadYear ; before 1900, so bad
CMP R0, #86 ; if more than 86 days, then it's
BCS BadYear ; after 2248, so bad
LDR R9, =ticksperday ; multiply by ticksperday and add to
MLA R7, R9, R0, R7 ; total (no overflow possible as this
; can never be more than 85+31 days)
; now add on (year-1900)*ticksperyear
SUBS R5, R5, #19 ; subtract off 1900
BCC BadYear
MOV R9, #100
MLA R4, R9, R5, R4 ; R4 = year-1900
LDR R0, =ticksperyear ; lo word of amount to add on
MOV R1, #0 ; hi word of amount to add on
MOV R8, #0 ; hi word of result
10
MOVS R4, R4, LSR #1
BCC %FT15
ADDS R7, R7, R0 ; if bit set then add on amount
ADCS R8, R8, R1
BCS BadYear ; overflow => bad time value
15
ADDS R0, R0, R0 ; shift up amount
ADCS R1, R1, R1
TEQ R4, #0 ; if still bits to add in
BNE %BT10 ; then loop
CMP R8, #&100 ; R8 must only be a byte
Pull "PC",CC
BadYear
MOV R7, #-1
MOV R8, #-1
Pull "PC"
; *****************************************************************************
tickspersecond * 100
ticksperminute * tickspersecond * 60
ticksperhour * ticksperminute * 60
ticksperday * ticksperhour * 24
ticksperyear * ticksperday * 365 ; &BBF81E00
STMonths
DCD &00000000 ; Jan
DCD &0FF6EA00 ; Feb
DCD &1E625200 ; Mar
DCD &2E593C00 ; Apr
DCD &3DCC5000 ; May
DCD &4DC33A00 ; Jun
DCD &5D364E00 ; Jul
DCD &6D2D3800 ; Aug
DCD &7D242200 ; Sep
DCD &8C973600 ; Oct
DCD &9C8E2000 ; Nov
DCD &AC013400 ; Dec
DCD &F0000000 ; terminator, must be less than this (+1)
LTORG
END