Add HAL RTC support to Cortex branch of kernel, clean up RTCSupport code

Detail:
  HAL kernels (on the Cortex branch at least) now support HALDevice-based RTCs. If the kernels own RTC code is disabled or fails to detect an RTC, then after HAL_InitDevices is called the HALDevice list will be scanned for any HAL-resident RTC devices.
  Additionally, the RTCSupport flag (in Hdr:Machine.Machine), which was previously TRUE for all HAL kernels, can now be set to FALSE in HAL kernels to disable the kernels own IIC RTC code. This allows the unwanted legacy RTC code to be disabled for machines which are known to use HAL RTCs instead.
  hdr/RTCDevice - new header describing data structures used for HAL RTC device
  hdr/HALDevice - added RTCDevice device type, IIC serial bus type
  hdr/KernelWS - upgraded RTCFitted from a 1 byte field to 4 byte. It now stores either a null value (for no RTC), a value <2048 for an IIC RTC address, or a value >= 2048 for a RTCDevice ptr
  Makefile - added header export of hdr/RTCDevice
  s/GetAll - include hdr/RTCDevice
  s/NewReset - initialise HAL RTC after HAL_InitDevices if required
  s/PMF/i2cutils, s/PMF/osinit, s/PMF/osword - modifications to allow use of HAL RTC (and disallow use of builtin IIC RTC)
Admin:
  Tested on rev C2 beagleboard


Version 5.35, 4.79.2.98.2.11. Tagged as 'Kernel-5_35-4_79_2_98_2_11'

Makefile

@@ -64,6 +64,7 @@ EXPORTS   = ${EXP_HDR}.EnvNumbers \
             ${EXP_HDR}.VduExt \
             ${EXP_HDR}.HALEntries \
             ${EXP_HDR}.HALDevice \
+            ${EXP_HDR}.RTCDevice \
             ${EXP_HDR}.OSEntries \
             ${C_EXP_HDR}.RISCOS \
             ${C_EXP_HDR}.HALEntries \
@@ -163,6 +164,9 @@ ${EXP_HDR}.HALEntries: hdr.HALEntries
 ${EXP_HDR}.HALDevice: hdr.HALDevice
 	${CP} hdr.HALDevice $@ ${CPFLAGS}
 	
+${EXP_HDR}.RTCDevice: hdr.RTCDevice
+	${CP} hdr.RTCDevice $@ ${CPFLAGS}
+	
 ${EXP_HDR}.OSEntries: hdr.OSEntries
 	${CP} hdr.OSEntries $@ ${CPFLAGS}
 	

VersionASM

@@ -13,11 +13,11 @@
                         GBLS    Module_ComponentPath
 Module_MajorVersion     SETS    "5.35"
 Module_Version          SETA    535
-Module_MinorVersion     SETS    "4.79.2.98.2.10"
-Module_Date             SETS    "17 Jul 2009"
-Module_ApplicationDate  SETS    "17-Jul-09"
+Module_MinorVersion     SETS    "4.79.2.98.2.11"
+Module_Date             SETS    "23 Jul 2009"
+Module_ApplicationDate  SETS    "23-Jul-09"
 Module_ComponentName    SETS    "Kernel"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/Kernel"
-Module_FullVersion      SETS    "5.35 (4.79.2.98.2.10)"
-Module_HelpVersion      SETS    "5.35 (17 Jul 2009) 4.79.2.98.2.10"
+Module_FullVersion      SETS    "5.35 (4.79.2.98.2.11)"
+Module_HelpVersion      SETS    "5.35 (23 Jul 2009) 4.79.2.98.2.11"
                         END

VersionNum

@@ -5,19 +5,19 @@
  *
  */
 #define Module_MajorVersion_CMHG        5.35
-#define Module_MinorVersion_CMHG        4.79.2.98.2.10
-#define Module_Date_CMHG                17 Jul 2009
+#define Module_MinorVersion_CMHG        4.79.2.98.2.11
+#define Module_Date_CMHG                23 Jul 2009
 
 #define Module_MajorVersion             "5.35"
 #define Module_Version                  535
-#define Module_MinorVersion             "4.79.2.98.2.10"
-#define Module_Date                     "17 Jul 2009"
+#define Module_MinorVersion             "4.79.2.98.2.11"
+#define Module_Date                     "23 Jul 2009"
 
-#define Module_ApplicationDate          "17-Jul-09"
+#define Module_ApplicationDate          "23-Jul-09"
 
 #define Module_ComponentName            "Kernel"
 #define Module_ComponentPath            "castle/RiscOS/Sources/Kernel"
 
-#define Module_FullVersion              "5.35 (4.79.2.98.2.10)"
-#define Module_HelpVersion              "5.35 (17 Jul 2009) 4.79.2.98.2.10"
+#define Module_FullVersion              "5.35 (4.79.2.98.2.11)"
+#define Module_HelpVersion              "5.35 (23 Jul 2009) 4.79.2.98.2.11"
 #define Module_LibraryVersionInfo       "5:35"

hdr/HALDevice

@@ -56,6 +56,7 @@ HALDeviceSysPeri_IntC   #       1       ; Interrupt controller
 HALDeviceSysPeri_DMAC   #       1       ; DMA controller
 HALDeviceSysPeri_DMAB   #       1       ; DMA channel - buffer type
 HALDeviceSysPeri_DMAL   #       1       ; DMA channel - list type
+HALDeviceSysPeri_RTC    #       1       ; RTCDevice
 
 HALDeviceType_Comms     *       4 :SHL: 8
                         ^       1
@@ -86,7 +87,7 @@ HALDeviceExpBus_PCI     *       2 :SHL: 24
 HALDeviceBus_Ser        *       4 :SHL: 28
 
 HALDeviceSerBus_ACLink  *       0 :SHL: 24
-
+HALDeviceSerBus_IIC     *       1 :SHL: 24
 
                                 ^       0
 HALDeviceID_AudC_M5451          #       1
@@ -104,6 +105,9 @@ HALDeviceID_DMAB_M1535          #       1
                                 ^       0
 HALDeviceID_DMAL_M5229          #       1
 
+                                ^       0
+HALDeviceID_RTC_TPS65950        #       1
+
  ]
 
         OPT     OldOpt

hdr/KernelWS

@@ -1267,6 +1267,8 @@ ProcVec_End             #       0
 ProcVecPreVeneersSize   *       4*4     ; Space for preveneers for loading handler addresses from 0 page.
 ProcVecPreVeneers       #       ProcVecPreVeneersSize
 
+RTCFitted          #    4               ; =0 no RTC, <2048 = address of I2C RTC, >=2048 = HALDevice_RTC ptr
+
  [ :DEF: ShowWS
         ! 0, "Free space before DebuggerSpace = ":CC::STR:(&300-@)
  ]
@@ -1278,7 +1280,6 @@ Export_DebuggerSpace    #       16*8    ; Debugger module needs some zero page
 ; NVRAM support
 
 NVRamSize          #    1               ; Size of NVRam (E2ROM & CMOS) fitted in 256byte units
-RTCFitted          #    1               ; flag non zero if RTC is fitted
 NVRamBase          #    1               ; Base of NVRam
 NVRamSpeed         #    1               ; Clock hold time in 0.5s units
 NVRamPageSize      #    1               ; Page size for writing (log2)

hdr/RTCDevice

+; Copyright 2009 Castle Technology 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.
+;
+
+; Public interface (ie interface to the kernel) of RTC HAL devices
+
+        GET     hdr:HALDevice
+
+OldOpt  SETA    {OPT}
+        OPT     OptNoList+OptNoP1List
+
+ [ :LNOT: :DEF: Included_Hdr_RTCDevice
+                       GBLL Included_Hdr_RTCDevice
+Included_Hdr_RTCDevice SETL {TRUE}
+
+; Device for each RTC controller
+
+                                ^       0
+                                #       HALDeviceSize
+HALDevice_RTCTimeFormat         #       1
+HALDevice_RTCFormatFlags        #       1
+                                #       2 ; Padding
+HALDevice_RTCReadTime           #       4
+HALDevice_RTCWriteTime          #       4
+HALDevice_RTC_Size              *       :INDEX: @
+
+; Supported time formats for communication with RISC OS
+RTCTimeFormat_BCD               *       0
+
+; BCD format details
+RTCFormatFlags_BCD_1BasedDay     *      1 :SHL: 0 ; is DayOfMonth 0-based or 1-based?
+RTCFormatFlags_BCD_1BasedMonth   *      1 :SHL: 1 ; is Month 0-based or 1-based?
+RTCFormatFlags_BCD_NeedsYearHelp *      1 :SHL: 2 ; If this is set, RISC OS assumes only the RTC is only able to store the two lowest bits of YearLO. If this is unset, the RTC must be able to store the full two-byte year.
+
+; Struct for storing BCD time
+                                ^       0
+RTCTimeStruct_BCD_Centiseconds  #       1
+RTCTimeStruct_BCD_Seconds       #       1
+RTCTimeStruct_BCD_Minutes       #       1
+RTCTimeStruct_BCD_Hours         #       1
+RTCTimeStruct_BCD_DayOfMonth    #       1
+RTCTimeStruct_BCD_Month         #       1
+RTCTimeStruct_BCD_YearLO        #       1
+RTCTimeStruct_BCD_YearHI        #       1
+RTCTimeStruct_BCD_Size          *       :INDEX: @
+
+; Return codes
+RTCRetCode_OK                   *       0
+RTCRetCode_Error                *       -1 ; Generic nonspecific error
+RTCRetCode_InvalidTime          *       -2 ; For write operations, indicates that the RTC cannot be programmed with the supplied time. For read operations, indicates that the RTC has been detected as containing an invalid time (e.g. following power loss)
+
+ ]
+
+        OPT     OldOpt
+        END

s/GetAll

@@ -42,6 +42,7 @@ ShowWS  SETL    {TRUE}                          ; Make KernelWS be verbose
         GET     Hdr:KernelWS
         GET     Hdr:HALEntries
         GET     Hdr:HALDevice
+        GET     Hdr:RTCDevice
         GET     Hdr:OSEntries
         GET     Hdr:Services
         GET     Hdr:FSNumbers

s/NewReset

@@ -1882,6 +1882,7 @@ ResetPart1Done                          ; R0 is reset type
         STR     R0, [R0, #DeviceCount]
         STR     R0, [R0, #DeviceTable]
         CallHAL HAL_InitDevices         ; get HAL to register any devices it has
+        BL      LookForHALRTC ; Check if an RTC was just added. This is currently the only place where HAL RTCs are checked for; if we wanted to check anywhere else (e.g. after ROM module initialisation) then we'd have to listen for Service_Hardware so we can cope with device removal
  |
         BL      L1L2PTenhancements      ; little tricks on cacheability etc for performance
  ]
@@ -2349,4 +2350,40 @@ HexTable = "0123456789ABCDEF"
 
 ; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
+ [ HAL
+LookForHALRTC
+	Push "R0-R2,R8,R14"
+	MOV	R0, #0
+	LDR	R0, [R0, #RTCFitted]
+	CMP	R0, #0
+	Pull "R0-R2,R8,PC",NE ; We already have an RTC
+	LDR	R0, =(0:SHL:16)+HALDeviceType_SysPeri+HALDeviceSysPeri_RTC
+	MOV	R1, #0
+	MOV	R8, #4
+01
+	SWI	XOS_Hardware
+	Pull "R0-R2,R8,PC",VS
+	CMP	R1, #-1
+	Pull "R0-R2,R8,PC",EQ
+	LDR	R14, [R2, #HALDevice_Location]
+	; Currently, we only support devices located on IIC bus 0
+	CMP	R14, #HALDeviceBus_Ser+HALDeviceSerBus_IIC
+	BNE	%BT01
+	; Try activating
+	Push "R0-R3,R12"
+	MOV	R0, R2
+	MOV	LR, PC
+	LDR	PC, [R2, #HALDevice_Activate]
+	CMP	R0, #1
+	Pull "R0-R3,R12"
+	BNE	%BT01
+	DebugTX "HAL RTC detected!"
+	MOV	R0, #0
+	STR	R2, [R0, #RTCFitted]
+	; Read the time from the RTC into RealTime, and fixup YearCMOS if needed
+	BL	CheckYear
+	DebugTX "Leaving LookForHALRTC"
+	Pull "R0-R2,R8,PC"
+ ]
+
         END

s/PMF/i2cutils

@@ -549,8 +549,9 @@ Read
         CMP     R0, #&10                ; don't cache the clock
   [     E2ROMSupport
         BHS     %FT13
+        ; If there's no RTC, read dummy values from the cache
         MOV     R14, #0
-        LDRB    R14, [R14, #RTCFitted]
+        LDR     R14, [R14, #RTCFitted]
         TEQ     R14, #0
         BNE     %FT15
   |
@@ -1043,7 +1044,7 @@ GetI2CAddress ROUT
 
 ; address is < end address -> is valid
 	MOV	R1, #0
-	;LDRB	R1, [R1, #RTCFitted]    ; This causes a headache if both an RTC and NVRAM are fitted
+	;LDR	R1, [R1, #RTCFitted]    ; This causes a headache if both an RTC and NVRAM are fitted
 	;TEQ	R1, #0
 	;LDREQB  R1, [R1, #NVRamBase]   ; RTC overlaps bottom of NVRAM
 	LDRB    R1, [R1, #NVRamBase]    ; RTC overlaps bottom of NVRAM
@@ -1192,27 +1193,90 @@ MakeChecksum	ROUT
 ; in:	UTC time:
 ;	R0 = hours
 ;	R1 = minutes
-;	R2 = day of month
-;	R3 = month
+;	R2 = day of month (1-based)
+;	R3 = month (1-based)
 ;	R5 = year (lo)
 ;	R6 = year (hi)
 ;	R7 = seconds
 ;	R8 = centiseconds
 ;
-;	If R0,R2,R5 or R6 is -1 then the time,date,year,century (respectively) will not be written
+;	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-R10, R14"	; save registers
 
 	LDR	R10, =ZeroPage
-	LDRB	R10, [R10, #RTCFitted]
+	LDR	R10, [R10, #RTCFitted]
+ [ HAL
+        CMP	R10, #2048 ; Is it an I2C address or HALDevice_RTC ptr?
+        BLO	%FT15
+	Push	"R0-R3,R12"
+	MOV	R4, R0			; copy hours in R4
+        ; Prepare BCD data on stack
+        ASSERT (RTCTimeStruct_BCD_Size :AND: 3)=0
+        SUB	R13, R13, #RTCTimeStruct_BCD_Size
+        MOV	R9, R13
+        ; Ensure struct matches our setting order
+        ASSERT RTCTimeStruct_BCD_Centiseconds = 0
+        ASSERT RTCTimeStruct_BCD_Seconds = 1
+        ASSERT RTCTimeStruct_BCD_Minutes = 2
+        ASSERT RTCTimeStruct_BCD_Hours = 3
+        ASSERT RTCTimeStruct_BCD_DayOfMonth = 4
+        ASSERT RTCTimeStruct_BCD_Month = 5
+        ASSERT RTCTimeStruct_BCD_YearLO = 6
+        ASSERT RTCTimeStruct_BCD_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
+        LDRB	R1, [R10, #HALDevice_RTCFormatFlags]
+        MOV	R0, R2
+        TST	R1, #RTCFormatFlags_BCD_1BasedDay
+        SUBEQ	R0, R0, #1
+        BL	HTBS9
+        TST	R1, #RTCFormatFlags_BCD_1BasedMonth
+        MOV	R0, R3
+        SUBEQ	R0, R0, #1
+        BL	HTBS9
+        MOV	R0, R5
+        BL	HTBS9
+        MOV	R0, R6
+        BL	HTBS9
+12
+        SUB	R1, R9, #8
+        MOV	R0, R10
+        ADRL	R2, HALRTC_IICOp
+        MOV	LR, PC
+        LDR	PC, [R10, #HALDevice_RTCWriteTime]
+	; Unfortunately, we don't do anything with the return code at the moment.
+13
+	ADD	R13, R13, #RTCTimeStruct_BCD_Size ; RTCTimeStruct
+	Pull	"R0-R3,R12"
+	BL	RTCToRealTime
+	Pull	"R4, R9-R10, PC"
+15
+ ] ; HAL
+ [ RTCSupport :LOR: :LNOT: HAL
         TEQ     R10, #0			; no RTC - just set soft copy
         BNE     %FT20
-
+ ]
         BL      RegToRealTime
         Pull    "R4, R9-R10, PC"
-
+ [ RTCSupport  :LOR: :LNOT: HAL
 20
 	Push	"R0-R2"
 	MOV	R4, R0			; copy hours in R4
@@ -1294,6 +1358,7 @@ SetTime ROUT
         Push    "R14"
         BL      IIC_Op                  ; write the prepared block with retries
 	Pull    "PC"
+ ] ; RTCSupport :LOR: :LNOT: HAL
 
 ; *****************************************************************************
 ;
@@ -1303,20 +1368,72 @@ SetTime ROUT
 ;
 ; out:	R0 = hours
 ;	R1 = minutes
-;	R2 = days
-;	R3 = months
+;	R2 = days (1-based)
+;	R3 = months (1-based)
 ;	R5 = year (lo)
 ;	R6 = year (hi)
 ;	R7 = seconds
 ;	R8 = centiseconds
-;
+;	Note: Returns garbage if no RTC, or an error occurs!
 
 ReadTime ROUT
 	Push	"R4, R14"
-        SUB     R13, R13, #(12*2)+6+1+1
 
         LDR	R14, =ZeroPage
-        LDRB	R2, [R14, #RTCFitted]
+        LDR	R2, [R14, #RTCFitted]
+ [ HAL
+	CMP	R2, #2048 ; IIC address or RTCDevice ptr?
+	BLO	%FT49
+	Push	"R12"
+	MOV	R6, R2
+	MOV	R0, R2
+	SUB	R13, R13, #RTCTimeStruct_BCD_Size
+	MOV	R1, R13
+	ADRL	R2, HALRTC_IICOp
+	MOV	LR, PC
+	LDR	PC, [R0, #HALDevice_RTCReadTime]
+	; Not really much point checking the error code since we have no way of returning an error to the caller
+	; So just read the junk data and be done with it
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_Centiseconds]
+	BL	BCDToHex
+	MOV	R8, R0			; centiseconds
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_Seconds]
+	BL	BCDToHex
+	MOV	R7, R0			; seconds
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_Minutes]
+	BL	BCDToHex
+	MOV	R1, R0			; minutes
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_Hours]
+	BL	BCDToHex
+	MOV	R4, R0			; hours
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_DayOfMonth]
+	BL	BCDToHex
+	LDRB	R12, [R6, #HALDevice_RTCFormatFlags]
+	MOV	R2, R0
+	TST	R12, #RTCFormatFlags_BCD_1BasedDay
+	ADDEQ	R2, R2, #1		; days
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_Month]
+	BL	BCDToHex
+	MOV	R3, R0
+	TST	R12, #RTCFormatFlags_BCD_1BasedMonth
+	ADDEQ	R3, R3, #1		; months
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_YearLO]
+	BL	BCDToHex
+	MOV	R5, R0			; year lo
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_YearHI]
+	BL	BCDToHex
+	; We're done with our stack data, remove it
+	ADD	R13, R13, #RTCTimeStruct_BCD_Size
+	MOV	R6, R0			; year hi
+	; If the RTC can reliably store the year, we don't need to use the CMOS copy
+	TST	R12, #RTCFormatFlags_BCD_NeedsYearHelp
+	Pull	"R12"
+	BEQ	DontReadTimeYear
+	B	ReadTimeYear
+49
+ ] ; HAL
+ [ RTCSupport :LOR: :LNOT: HAL
+        SUB     R13, R13, #(12*2)+6+1+1
         ORR     R14, R2, #1:SHL:29      ; retry
         STR     R14, [R13, #8]          ; transfer 1 address
         ADD     R0, R14, #1
@@ -1361,6 +1478,7 @@ ReadTime ROUT
         AND     R0, R0, #&1F            ; month (clear day of week bits)
         BL      BCDToHex
         MOV     R3, R0
+	ADD     R13, R13, #(12*2)+6+1+1
 	B	ReadTimeYear
 
 50
@@ -1381,25 +1499,26 @@ ReadTime ROUT
         LDRB    R0, [R13, #6]
         BL      BCDToHex
         MOV     R3, R0                  ; month
+	ADD     R13, R13, #(12*2)+6+1+1
+ ] ; RTCSupport :LOR: :LNOT: HAL
 
 ReadTimeYear
-	ADD     R13, R13, #(12*2)+6+1+1
 	MOV	R0, #YearCMOS
 	BL	Read
 	MOV	R5, R0			; year (lo)
 	MOV	R0, #YearCMOS+1
 	BL	Read
 	MOV	R6, R0			; year (hi)
-
+DontReadTimeYear
 	MOV	R0, R4			; put hours in R0
 
 	TEQ	R2, #0			; Ensure day/month are non-zero (LRust, fix RP-0370)
 	MOVEQ	R2, #1			; No then force 1st
 	TEQ	R3, #0			; Invalid month?
 	MOVEQ	R3, #1			; Yes then force Jan
-
 	Pull	"R4, PC"
 
+ [ RTCSupport :LOR: :LNOT: HAL
 ; *****************************************************************************
 ;
 ;       InitRTC - Force the clock into a known state (incase of new battery)
@@ -1433,6 +1552,35 @@ InitRTC
 65
 	ADD	R13, R13, #4
 	Pull    "R0-R2, PC"
+ ] ; RTCSupport :LOR: :LNOT: HAL
+
+
+ [ HAL
+; *****************************************************************************
+;
+;       HALRTC_IICOp - Wrapper for IIC_OpV to allow it to be called from HALDevice RTC drivers
+;
+;  in:  R0 = iic_transfer *
+;	R1 = number of transfers
+;	R2 = 'kernel workspace ptr' - currently unused
+; out:  R0 = HAL_IICOp error code
+
+HALRTC_IICOp
+	Push	"R14"
+	BL	IIC_OpV
+	; Translate the RISC OS error code back into an IIC one we can pass to the driver
+	LDRVS	R2, [R0]
+	LDRVS	R1, =ErrorNumber_IIC_Busy
+	MOV	R0, #5 ; EERROR
+	TEQ	R2, R1 ; Won't modify V
+	MOVEQ	R0, #3 ; EBUSY
+	LDRVS	R1, =ErrorNumber_IIC_NoAcknowledge
+	TEQ	R2, R1
+	MOVEQ	R0, #2 ; ENOACK
+	MOVVC	R0, #0 ; ECOMPLETED
+	Pull	"PC"
+ ]
+
 
 ; *****************************************************************************
 ;
@@ -1458,12 +1606,12 @@ InitCMOSCache	Entry "r1-r6, sb,r12"
 	BVC	%FT13
 	MOV	R0, #RTCAddressPHI
 	BL	DummyAccess
-	STRVSB  R4, [R2, #RTCFitted]
+	STRVS   R4, [R2, #RTCFitted]
 13
-	STRVCB  R0, [R2, #RTCFitted]
+	STRVC   R0, [R2, #RTCFitted]
 	BLVC    InitRTC
      |
-        STRB    R4, [R2, #RTCFitted]
+        STR     R4, [R2, #RTCFitted]
      ]
 
  [ HAL

s/PMF/osinit

@@ -176,7 +176,7 @@ BuffPtrInitLoop
 secs0070 *      (86400*(365*70+18))     ; from time() in risc_oslib.c.armsys
 
         MOV     R1, #0
-        LDRB    R0, [R1, #RTCFitted]
+        LDR     R0, [R1, #RTCFitted]
         TEQ     R0, #0                  ; when zero,no RTC
         BNE     %FT28
         LDR     R7, =(secs0070 * 100)   ; centiseconds LSW

s/PMF/osword

@@ -729,7 +729,53 @@ OsWord0F_5byte
 CheckYear ROUT
         Push    "R0,R1,R2,R14"
         MOV     R0, #0
-        LDRB    R0, [R0, #RTCFitted]
+        LDR     R0, [R0, #RTCFitted]
+ [ HAL
+	CMP	R0, #2048
+  [ RTCSupport
+	BLO	%FT8
+  |
+	BLO	%FT15
+  ]
+	; Ask the RTC what it thinks the year is
+	Push	"R3,R10,R12"
+	MOV	R10, R0
+	SUB	R13, R13, #RTCTimeStruct_BCD_Size
+	MOV	R1, R13
+	ADRL	R2, HALRTC_IICOp
+	MOV	LR, PC
+	LDR	PC, [R0, #HALDevice_RTCReadTime]
+	; Did we succeed?
+	CMP	R0, #RTCRetCode_OK
+	LDRB	R0, [R13, #RTCTimeStruct_BCD_YearLO]
+	LDRB	R1, [R13, #RTCTimeStruct_BCD_YearHI]
+	ADD	R13, R13, #RTCTimeStruct_BCD_Size
+	LDRB	R2, [R10, #HALDevice_RTCFormatFlags]
+	Pull	"R3,R10,R12"
+	BNE	%FT15
+	TST	R2, #RTCFormatFlags_BCD_NeedsYearHelp
+	BNE	%FT9
+	; Year is reliable; convert R0 & R1 to ints and update CMOS if necessary.
+	BL	BCDToHex
+	MOV	R2, R1
+	MOV	R1, R0 ; YearLO
+	MOV	R0, #YearCMOS
+	BL	Read
+	CMP	R0, R1
+	MOVNE	R0, #YearCMOS
+	BLNE	Write
+	MOV	R0, R2
+	BL	BCDToHex
+	MOV	R1, R0 ; YearHI
+	MOV	R0, #YearCMOS+1
+	BL	Read
+	CMP	R0, R1
+	MOVNE	R0, #YearCMOS+1
+	BLNE	Write
+	B	%FT15
+8
+ ] ; HAL
+ [ RTCSupport :LOR: :LNOT: HAL
         TEQ     R0, #RTCAddressPHI
         MOVEQ   R1, #5
         MOVNE   R1, #6                  ; year address (dependant on RTC)
@@ -747,7 +793,9 @@ CheckYear ROUT
 
         TEQ     R1, #RTCAddressPHI+1
         MOVEQ   R1, R0, LSR #6
-        ANDNE   R1, R0, #3              ; R1= year MOD 4
+ ] ; RTCSupport :LOR: :LNOT: HAL
+9
+        ANDNE   R1, R0, #3              ; R1= year MOD 4. Note sharing of NE condition with HAL code.
         MOV     R0, #YearCMOS
         BL      Read
         AND     R2, R0, #3
@@ -770,7 +818,7 @@ CheckYear ROUT
         MOV     R1, R2
         MOV     R0, #YearCMOS
         BL      Write
-
+15
         BL      RTCToRealTime
         Pull    "R0,R1,R2,PC"