Automatically adjust wimpslot when running AIFs via FSControl 4

Detail:
  s/FSCommon - Adjust ValidateR2R5_WriteToCoreCodeLoad to try and increase the wimpslot if it isn't already big enough to contain the region being validated (i.e. the program being loaded)
  s/FSControl - FSControl 4 now checks AIF memory limts and tries to extend wimpslot as necessary both before and after decompression. An extra 8K is added to the calculated memory requirements to take into account memory which isn't declared in the header (root stack chunk?) which is required by SCL initialisation.
Admin:
  Tested in Iyonix ROM softload
  This should eliminate most/all of the "No writeable memory at this address", abort on data transfer, and "Not enough memory for C library" errors users receive due to the wimpslot being too small when all they want to do is run a program


Version 2.81. Tagged as 'FileSwitch-2_81'

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "2.80"
-Module_Version          SETA    280
+Module_MajorVersion     SETS    "2.81"
+Module_Version          SETA    281
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "05 Jan 2013"
-Module_ApplicationDate  SETS    "05-Jan-13"
+Module_Date             SETS    "13 Jan 2013"
+Module_ApplicationDate  SETS    "13-Jan-13"
 Module_ComponentName    SETS    "FileSwitch"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/FileSys/FileSwitch"
-Module_FullVersion      SETS    "2.80"
-Module_HelpVersion      SETS    "2.80 (05 Jan 2013)"
+Module_FullVersion      SETS    "2.81"
+Module_HelpVersion      SETS    "2.81 (13 Jan 2013)"
                         END

VersionNum

-/* (2.80)
+/* (2.81)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        2.80
+#define Module_MajorVersion_CMHG        2.81
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                05 Jan 2013
+#define Module_Date_CMHG                13 Jan 2013
 
-#define Module_MajorVersion             "2.80"
-#define Module_Version                  280
+#define Module_MajorVersion             "2.81"
+#define Module_Version                  281
 #define Module_MinorVersion             ""
-#define Module_Date                     "05 Jan 2013"
+#define Module_Date                     "13 Jan 2013"
 
-#define Module_ApplicationDate          "05-Jan-13"
+#define Module_ApplicationDate          "13-Jan-13"
 
 #define Module_ComponentName            "FileSwitch"
 #define Module_ComponentPath            "castle/RiscOS/Sources/FileSys/FileSwitch"
 
-#define Module_FullVersion              "2.80"
-#define Module_HelpVersion              "2.80 (05 Jan 2013)"
-#define Module_LibraryVersionInfo       "2:80"
+#define Module_FullVersion              "2.81"
+#define Module_HelpVersion              "2.81 (13 Jan 2013)"
+#define Module_LibraryVersionInfo       "2:81"

s/FSCommon

@@ -1624,6 +1624,40 @@ ValidateR2R5_WriteToCore ALTENTRY
 
 ValidateR2R5_WriteToCoreCodeLoad ALTENTRY
 
+        ; Be nice and try and allocate however much memory is needed
+        ; First check if R2..R5 fits in application limit
+        MOV     r0, #11
+        SWI     XWimp_ReadSysInfo
+        BVS     %FT96
+
+        ; Start in &8000...ApplicationLimit ?
+        CMP     r2, #&8000
+        CMPHS   r0, r2
+        BLO     %FT96           ; No
+
+        ; Yes, start's in range, is end?
+        CMP     r5, r0
+        BHI     %BA90           ; No - give error
+
+        ; Good, now check if wimp slot is already big enough
+        Push    "r2,r4"
+        MVN     r0, #0
+        MVN     r1, #0
+        SWI     XWimp_SlotSize
+        BVS     %FT95
+        SUB     r1, r5, #&8000
+        CMP     r1, r0
+        BLE     %FT95
+
+        ; Attempt resize
+        MOV     r0, r1
+        MVN     r1, #0
+        SWI     XWimp_SlotSize
+95
+        Pull    "r2,r4"
+96
+        CLRV
+
         ; Do standard check
         BL      ValidateR2R5_WriteToCore
 

s/FSControl

@@ -378,9 +378,12 @@ Run_UndatedFile
         Push    "r1"                    ; Remember the old cache setting
   ]
 
+        ; Check memory before decompression, since decompression code is dumb
+        MOV     r2, #&8000
+        BL      CheckAIFMemoryLimit     ; Ignore any returned error since nonstandard compression may confuse our memory usage calculations
+
         MOV     r0, #0                  ; Pre-decompression service call
         MOV     r1, #Service_UKCompression
-        MOV     r2, #&8000
         MOV     r3, r7
         MOV     r4, #&8000
         SWI     XOS_ServiceCall         ; A claimant of this does the decompression
@@ -406,24 +409,7 @@ Run_UndatedFile
         SWI     XOS_SynchroniseCodeAreas
  ]
 
- [ {TRUE}
-        ;Check absolute AIF image memory limits
-        LDR     lr, [r2, #&0C]
-        AND     lr, lr, #&FF000000
-        TEQ     lr, #&EB000000          ; is this instruction a branch
-        BNE     %FT71                   ; nope - not executable AIF then
-        LDR     lr, [r2, #&10]!         ; should be SWI OS_Exit (&EF000011 for AIF), R2 := R2 + 16
-        SUB     lr, lr, #&EF000000
-        TEQ     lr, #&00000011          ; OS_Exit check worked?
-        LDMEQIB r2, {r0,r1,r5,lr}       ; load RO size, RW size, Debug size, ZI size
-        MOV     r2, #&8000              ; R2 := &8000 like it was before
-        BNE     %FT71                   ; not AIF then
-
-        ADD     lr, lr, r5              ; lr := debug + zero init
-        ADD     r0, r0, r1              ; R0 := read only + read write
-        ADD     r0, r0, lr              ; R0 := read only + read write + debug + zero init
-        ADD     r5, r2, r0              ; R5 := base address + size required
-        BL      ValidateR2R5_WriteToCoreCodeLoad
+        BL      CheckAIFMemoryLimit
         BVC     %FT71
         ; /* dead here - need to generate an error */
         addr    r0, ErrorBlock_CoreNotWriteable
@@ -431,7 +417,7 @@ Run_UndatedFile
         SWI     XMessageTrans_ErrorLookup
         SWI     OS_GenerateError
 71
- ]
+
  [ StrongARM
         ;Finally, prepare to run the thing!
         MOV     r2, r4                  ; We're gonna jump in where we're told!.
@@ -540,6 +526,34 @@ Run_TransientFile
 
         LTORG
 
+CheckAIFMemoryLimit ROUT
+        Entry   "r5"
+        ; Check absolute AIF memory limits
+        ; R2 = &8000
+        ; R0-R1 corruptible
+        ; V set/clear on exit for bad/good
+        LDR     lr, [r2, #&0C]
+        AND     lr, lr, #&FF000000
+        TEQ     lr, #&EB000000          ; is this instruction a branch
+        BNE     %FT90                   ; nope - not executable AIF then
+        LDR     lr, [r2, #&10]!         ; should be SWI OS_Exit (&EF000011 for AIF), R2 := R2 + 16
+        SUB     lr, lr, #&EF000000
+        TEQ     lr, #&00000011          ; OS_Exit check worked?
+        LDMEQIB r2, {r0,r1,r5,lr}       ; load RO size, RW size, Debug size, ZI size
+        MOV     r2, #&8000              ; R2 := &8000 like it was before
+        BNE     %FT90                   ; not AIF then
+
+        ADD     lr, lr, r5              ; lr := debug + zero init
+        ADD     r0, r0, r1              ; R0 := read only + read write
+        ADD     r0, r0, lr              ; R0 := read only + read write + debug + zero init
+        ADD     r0, r0, #&2000          ; 8K extra to avoid "Not enough memoy for C library" from silly C stubs
+        ADD     r5, r2, r0              ; R5 := base address + size required
+        BL      ValidateR2R5_WriteToCoreCodeLoad
+        EXIT
+90
+        CLRV
+        EXIT
+
 ; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 ; This is where position independent code will return to if it does MOV pc, lr