Make the Wimp automatically switch VFP contexts

Detail:
  s/Wimp, s/Wimp01, s/Wimp02, s/Wimp03, s/Wimp07 - The Wimp now uses the VFPSupport module to switch VFP contexts when performing task switches.
  Each task begins with the null context active (i.e. no VFP/NEON access). When paging out a task the ID of the active context is saved in the Wimp's per-task workspace. This context is then restored when the task is about to be resumed.
  Context save/restore is performed while the right task's memory is paged in, so it's safe to use with contexts located in application space.
Admin:
  Tested with Iyonix & Beagle ROM builds.


Version 5.09. Tagged as 'Wimp-5_09'

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "5.08"
-Module_Version          SETA    508
+Module_MajorVersion     SETS    "5.09"
+Module_Version          SETA    509
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "14 Mar 2010"
-Module_ApplicationDate  SETS    "14-Mar-10"
+Module_Date             SETS    "26 Nov 2010"
+Module_ApplicationDate  SETS    "26-Nov-10"
 Module_ComponentName    SETS    "Wimp"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/Desktop/Wimp"
-Module_FullVersion      SETS    "5.08"
-Module_HelpVersion      SETS    "5.08 (14 Mar 2010)"
+Module_FullVersion      SETS    "5.09"
+Module_HelpVersion      SETS    "5.09 (26 Nov 2010)"
                         END

VersionNum

-/* (5.08)
+/* (5.09)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        5.08
+#define Module_MajorVersion_CMHG        5.09
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                14 Mar 2010
+#define Module_Date_CMHG                26 Nov 2010
 
-#define Module_MajorVersion             "5.08"
-#define Module_Version                  508
+#define Module_MajorVersion             "5.09"
+#define Module_Version                  509
 #define Module_MinorVersion             ""
-#define Module_Date                     "14 Mar 2010"
+#define Module_Date                     "26 Nov 2010"
 
-#define Module_ApplicationDate          "14-Mar-10"
+#define Module_ApplicationDate          "26-Nov-10"
 
 #define Module_ComponentName            "Wimp"
 #define Module_ComponentPath            "castle/RiscOS/Sources/Desktop/Wimp"
 
-#define Module_FullVersion              "5.08"
-#define Module_HelpVersion              "5.08 (14 Mar 2010)"
-#define Module_LibraryVersionInfo       "5:8"
+#define Module_FullVersion              "5.09"
+#define Module_HelpVersion              "5.09 (26 Nov 2010)"
+#define Module_LibraryVersionInfo       "5:9"

s/Wimp

@@ -58,6 +58,7 @@ Module_BaseAddr
         GET     hdr:ScrBlank
         GET     hdr:OsWords
         GET     hdr:Countries
+        GET     hdr:VFPSupport
 
         GET     VersionASM
 

s/Wimp01

@@ -613,6 +613,7 @@ priority_top      *     1:SHL:20
 
 task_environment  #     4*3*MaxEnvNumber        ; environment pointers
 task_registers    #     4*17                    ; USR register set
+task_vfpcontext   #     4                       ; VFPSupport context ID
 task_datasize     #     0
 
 ; extra bits for Wimp_Poll - not stored in task_flagword

s/Wimp02

@@ -51,6 +51,7 @@ markinitialised
         STR     R14,[R2,#task_fpblock]
         STR     R14,[R2,#task_windows]
         STR     R14,[R2,#task_messagessize]
+        STR     R14,[R2,#task_vfpcontext]
 
         MOV     R14,#-1
         STR     R14,[R2,#task_messages] ; flag as accepting all messages

s/Wimp03

@@ -437,6 +437,15 @@ SWIWimp_Poll
         STR     userblk,[R4,#task_registers+4*1]        ; and user R1
         STR     R2,[R4,#task_registers+4*2]             ; and target time
 ;
+; save VFP context. Can't save lazily since it might be in application space.
+;
+        MOV     R0,#0
+        MOV     R1,#0
+        SWI     XVFPSupport_ChangeContext
+        MOVVS   R0,#0 ; Ignore error (probably means VFPSupport isn't loaded)
+        STR     R0,[R4,#task_vfpcontext]
+        CLRV
+;
 ; check to see if there are any more outstanding parents
 ;
 taskisused

s/Wimp07

@@ -747,6 +747,16 @@ SWIWimp_StartTask
         BLVC    saveFPregs                      ; R4 -> task block
         BVS     ExitWimp
 ;
+; save VFP context. Can't save lazily since it might be in application space.
+;
+        Push    "R0-R1"
+        MOV     R0,#0
+        MOV     R1,#0
+        SWI     XVFPSupport_ChangeContext
+        MOVVS   R0,#0 ; Ignore error (probably means VFPSupport isn't loaded)
+        STR     R0,[R4,#task_vfpcontext]
+        Pull    "R0-R1"
+;
 ; find a spare task handle for the new task
 ;
         ADRL    R5,taskpointers
@@ -1074,56 +1084,62 @@ returnerror
 01
       ]
 
+        Push    "R0-R1"
         LDR     R4,[wsptr,handle]
         TEQ     R4,#task_unused
 
       [ debugtask4
 ; Stamp with event time for task priority and swapping
 
-        Push    "R0",NE
         SWINE   XOS_ReadMonotonicTime
         BEQ     %FT00
         Debug   task4,"Time",R0
 00
         STRNE   R0,[R4,#task_eventtime]
-        Pull    "R0",NE
       ]
 
 ; restore FP registers if they were saved (ie. save block present)
 
-        LDRNE   R4,[R4,#task_fpblock]
-        TEQNE   R4,#0                   ; NE => restore registers
+        LDRNE   R0,[R4,#task_fpblock]
+        TEQNE   R0,#0                   ; NE => restore registers
         MOVEQ   R5,#C_runtime_status    ; ensure caller gets &70000 if he didn't save regs
         WFSEQ   R5
         BEQ     %FT01
 
-        Debug   fp,"Restoring FP state from block at",R4
+        Debug   fp,"Restoring FP state from block at",R0
 
         MOV     R5,#0                   ; avoid FP exceptions
         WFS     R5                      ; will still occur if FPEmulator RMKilled
       [ FPE4
        [ false
-        LFM     F0,4,[R4,#fp_reg0]      ; (only gets here if active previously)
-        LFM     F4,4,[R4,#fp_reg4]
+        LFM     F0,4,[R0,#fp_reg0]      ; (only gets here if active previously)
+        LFM     F4,4,[R0,#fp_reg4]
        |
         ; AAsm assembles the above as post-indexed not pre-indexed.
         ; Do it manually (bluch).
-        DCD     &ED940200 :OR: (fp_reg0:SHR:2)
-        DCD     &ED944200 :OR: (fp_reg4:SHR:2)
+        DCD     &ED900200 :OR: (fp_reg0:SHR:2)
+        DCD     &ED904200 :OR: (fp_reg4:SHR:2)
        ]
       |
-        LDFE    F0,[R4,#fp_reg0]        ; (only gets here if active previously)
-        LDFE    F1,[R4,#fp_reg1]
-        LDFE    F2,[R4,#fp_reg2]
-        LDFE    F3,[R4,#fp_reg3]
-        LDFE    F4,[R4,#fp_reg4]
-        LDFE    F5,[R4,#fp_reg5]
-        LDFE    F6,[R4,#fp_reg6]
-        LDFE    F7,[R4,#fp_reg7]
+        LDFE    F0,[R0,#fp_reg0]        ; (only gets here if active previously)
+        LDFE    F1,[R0,#fp_reg1]
+        LDFE    F2,[R0,#fp_reg2]
+        LDFE    F3,[R0,#fp_reg3]
+        LDFE    F4,[R0,#fp_reg4]
+        LDFE    F5,[R0,#fp_reg5]
+        LDFE    F6,[R0,#fp_reg6]
+        LDFE    F7,[R0,#fp_reg7]
       ]
-        LDR     R5,[R4,#fp_status]
+        LDR     R5,[R0,#fp_status]
         WFS     R5
 01
+; restore VFP context
+        TEQ     R4,#task_unused
+        LDRNE   R0,[R4,#task_vfpcontext]
+        MOVNE   R1,#VFPSupport_ChangeContext_Lazy
+        TEQNE   R0,#0 ; We should already be on the null context, so only call if user does have a context to restore
+        SWINE   XVFPSupport_ChangeContext
+        Pull    "R0-R1"
 ;
       [ StartTaskPostFilter
         LDR     R14,sender