Fix drive lock status reporting for empty drives

Detail:
  s/DriverCode - Change IsDrawerLocked handler to read the lock status from the drive via mode page &2A, rather than doing a completely unrelated TEST UNIT READY command. On the offchance that &2A isn't implemented, just fall back on our softcopy of the lock state, which is effectively what TEST UNIT READY was doing in the first place.
Admin:
  Tested on Iyonix
  CD_IsDrawerLocked now returns a sensible value for empty drives, instead of a drive empty error
  Fixes issue reported on forums where CDFS iconbar menu doesn't allow empty drives to be ejected (for ATAPI, at least):
  https://www.riscosopen.org/forum/forums/4/topics/3652


Version 1.44. Tagged as 'ATAPI-1_44'

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "1.43"
-Module_Version          SETA    143
+Module_MajorVersion     SETS    "1.44"
+Module_Version          SETA    144
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "22 Apr 2017"
-Module_ApplicationDate  SETS    "22-Apr-17"
+Module_Date             SETS    "10 Feb 2018"
+Module_ApplicationDate  SETS    "10-Feb-18"
 Module_ComponentName    SETS    "ATAPI"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/HWSupport/CD/ATAPI"
-Module_FullVersion      SETS    "1.43"
-Module_HelpVersion      SETS    "1.43 (22 Apr 2017)"
+Module_FullVersion      SETS    "1.44"
+Module_HelpVersion      SETS    "1.44 (10 Feb 2018)"
                         END

VersionNum

-/* (1.43)
+/* (1.44)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        1.43
+#define Module_MajorVersion_CMHG        1.44
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                22 Apr 2017
+#define Module_Date_CMHG                10 Feb 2018
 
-#define Module_MajorVersion             "1.43"
-#define Module_Version                  143
+#define Module_MajorVersion             "1.44"
+#define Module_Version                  144
 #define Module_MinorVersion             ""
-#define Module_Date                     "22 Apr 2017"
+#define Module_Date                     "10 Feb 2018"
 
-#define Module_ApplicationDate          "22-Apr-17"
+#define Module_ApplicationDate          "10-Feb-18"
 
 #define Module_ComponentName            "ATAPI"
 #define Module_ComponentPath            "castle/RiscOS/Sources/HWSupport/CD/ATAPI"
 
-#define Module_FullVersion              "1.43"
-#define Module_HelpVersion              "1.43 (22 Apr 2017)"
-#define Module_LibraryVersionInfo       "1:43"
+#define Module_FullVersion              "1.44"
+#define Module_HelpVersion              "1.44 (10 Feb 2018)"
+#define Module_LibraryVersionInfo       "1:44"

s/DriverCode

@@ -2647,23 +2647,40 @@ IsDrawerLocked ROUT
 ;
 ;-----------------------------------------------------------------------------------------------
 
-;-----------------------------
-; Test Unit Ready Command
-;-----------------------------
-
-     MOV           r0, # nodata + ATAPIOP__COMMAND_PACKET
+;----------------------------------
+; Get all of the Mode pages
+;----------------------------------
+     MOV           r0, # readdata + ATAPIOP__COMMAND_PACKET
      MOV           r1, # 12
-     ADR           r2, DS_CDBTestUnitReady
-     MOV           r3, # 0
-     MOV           r4, # 0
-
+     ADRL          r2, GP_CurrentModeSense
+     ADR           r3, buffer
+     LDR           r4, = BUFFER_SIZE
      MOV           r8, # ATAPICONTROL__SEND_COMMAND
 
      BL            ATAPI_Control
-
      BLVC          Extras_ConvertControlBlockToDrive
      BVS           error_handler
 
+;-----------------------------------------------------
+; Find page &2a containing lock status
+;-----------------------------------------------------
+     MOV           r1, # &2a
+     ADR           r2, buffer
+     BL            GP_FindModePage
+
+     TEQ           r2, # 0
+     BEQ           %FT90
+
+; Check lock status
+     LDRB          r1, [ r2, # 1 ]
+     CMP           r1, #28
+     BLO           %FT90
+     LDRB          r1, [ r2, # 6 ]
+     MOV           r1, r1, LSR #1
+     AND           r1, r1, #1
+     BL            Extras_SetDrawerStatus
+90
+; Fall back to the cached status if we couldn't get real value from drive
      BL            Extras_GetDrawerStatus
 
 ;-----------------------------
@@ -2671,11 +2688,6 @@ IsDrawerLocked ROUT
      CLRV
      MACRO__EXIT_DRIVER_WITH_R0
 
-DS_CDBTestUnitReady
-     DCD           0
-     DCD           0
-     DCD           0
-
 ;-----------------------------------------------------------------------------------------------
 ;AudioControl ROUT
 ;