Changes to Lazy task swapping to support abort handler in abort mode (now that we can count to 32).

LazyFixup now ensures all app pages are mapped in before handing
on a real (no-lazy) abort. This allows an abort handler in app
space itself, without scrambling the details of the original
abort (via a lazy abort in abort mode).
Many a happy minute spent coding and testing for recursive
aborts and fixups, but lets just pretend it doesn't happen
shall we.
Tested with simple popbang code on ARM9 desktop build.

Version 5.35, 4.79.2.36. Tagged as 'Kernel-5_35-4_79_2_36'

VersionASM

@@ -13,12 +13,12 @@
                         GBLS    Module_ComponentPath
 Module_MajorVersion     SETS    "5.35"
 Module_Version          SETA    535
-Module_MinorVersion     SETS    "4.79.2.35"
+Module_MinorVersion     SETS    "4.79.2.36"
 Module_Date             SETS    "13 Jun 2001"
 Module_ApplicationDate2 SETS    "13-Jun-01"
 Module_ApplicationDate4 SETS    "13-Jun-2001"
 Module_ComponentName    SETS    "Kernel"
 Module_ComponentPath    SETS    "RiscOS/Sources/Kernel"
-Module_FullVersion      SETS    "5.35 (4.79.2.35)"
-Module_HelpVersion      SETS    "5.35 (13 Jun 2001) 4.79.2.35"
+Module_FullVersion      SETS    "5.35 (4.79.2.36)"
+Module_HelpVersion      SETS    "5.35 (13 Jun 2001) 4.79.2.36"
                         END

VersionNum

@@ -4,12 +4,12 @@
  *
  */
 #define Module_MajorVersion_CMHG        5.35
-#define Module_MinorVersion_CMHG        4.79.2.35
+#define Module_MinorVersion_CMHG        4.79.2.36
 #define Module_Date_CMHG                13 Jun 2001
 
 #define Module_MajorVersion             "5.35"
 #define Module_Version                  535
-#define Module_MinorVersion             "4.79.2.35"
+#define Module_MinorVersion             "4.79.2.36"
 #define Module_Date                     "13 Jun 2001"
 
 #define Module_ApplicationDate2         "13-Jun-01"
@@ -18,5 +18,5 @@
 #define Module_ComponentName            "Kernel"
 #define Module_ComponentPath            "RiscOS/Sources/Kernel"
 
-#define Module_FullVersion              "5.35 (4.79.2.35)"
-#define Module_HelpVersion              "5.35 (13 Jun 2001) (4.79.2.35)"
+#define Module_FullVersion              "5.35 (4.79.2.36)"
+#define Module_HelpVersion              "5.35 (13 Jun 2001) (4.79.2.36)"

s/AMBControl/memmap

@@ -63,19 +63,19 @@ AMB_LazyFixUp ROUT
         MOV     r12,#AMBControl_ws
         LDR     r12,[r12]
         CMP     r12,#0
-        BEQ     %FT20
+        BEQ     %FT90                                    ;not initialised!
         LDR     r1,AMBFlags
         TST     r1,#AMBFlag_LazyMapIn_disable :OR: AMBFlag_LazyMapIn_suspend
-        BNE     %FT20
-        SUBS    r0,r0,#ApplicationStart
-        BMI     %FT20
-        MOV     r0,r0,LSR #Log2PageSize                  ;address now in terms of pages from ApplicationStart
+        BNE     %FT90                                    ;not active
         LDR     r1,AMBMappedInNode
         CMP     r1,#0
-        BEQ     %FT20
+        BEQ     %FT90                                    ;no current node
         LDR     r2,[r1,#AMBNode_Npages]
+        SUBS    r0,r0,#ApplicationStart
+        BMI     %FT20                                    ;abort not in current app space
+        MOV     r0,r0,LSR #Log2PageSize                  ;address now in terms of pages from ApplicationStart
         CMP     r2,r0
-        BLS     %FT20
+        BLS     %FT20                                    ;abort not in current app space
 ;
 ; check/update the MappedIn bitmap
 ;
@@ -119,7 +119,28 @@ AMB_LazyFixUp ROUT
         STMIA   r5,{r0,r1}                               ;update CAM entry
         MOV     r12,r7
         MOV     pc,lr                                    ;r0 is non-zero, NE status
+;
+; not our abort, but is possible that client abort handler is in app space, so force all
+; app space pages in now (so that client abort handler does not cause lazy abort, scribbling over original abort details)
+;
+        ASSERT  No26bitCode                              ;assumes we have an abort stack! (recursive lazy fixup aborts may occur)
 20
+        MOV     r1,#ApplicationStart                     ;good old page walk to provoke lazy fixups
+        LDR     r2,AMBMappedInNode
+        LDR     r2,[r2,#AMBNode_Npages]
+        CMP     r2,#0
+        BEQ     %FT90
+        MRS     r0,SPSR                                  ;preserve SPSR_abort for original abort details
+        MOV     r4,lr                                    ;preserve lr_abort so we can return properly (!)
+30
+        LDR     r3,[r1]                                  ;bring that page in by the magic of aborts
+        SUBS    r2,r2,#1
+        ADD     r1,r1,#PageSize
+        BNE     %BT30
+        MSR     SPSR_all,r0                              ;SPSR for original abort
+        MOV     lr,r4                                    ;restore return address
+;
+90
         MOVS    r0,#0
         MOV     r12,r7
         MOV     pc,lr                                    ;r0 is zero, EQ status