More code uses logical_to_physical & physical_to_ppn

GetPageFlagsForR0IntoR6 & MoveCAMatR0toR3 changed to use
logical_to_physical & physical_to_ppn, to reduce the number of routines
which are performing direct page table access.

s/MemMap2

@@ -15,64 +15,37 @@
 
 ; in:   r0 = logical address where page is now
 
-GetPageFlagsForR0IntoR6 Entry "R0-R2, R4-R5, R7"
-;
-; code from MoveCAMatR0toR3
-;
-        LDR     r5, =L2PT
-        ADD     r4, r5, r0, LSR #10             ; r4 -> L2PT for log addr r0
-        MOV     r2, r4, LSR #12
-        LDR     r2, [r5, r2, LSL #2]            ; r2 = L2PT entry for r4
-        TST     r2, #3                          ; if no page there
-        BEQ     %FT90                           ; then cam corrupt
-
-        LDR     r4, [r4]                        ; r4 = L2PT entry for r0
-        TST     r4, #3                          ; check entry is valid too
-        BEQ     %FT91
-        MOV     r4, r4, LSR #12                 ; r4 = phys addr >> 12
-
-        LDR     r2, =ZeroPage
-        LDR     r6, [r2, #MaxCamEntry]
-        ADD     r5, r2, #PhysRamTable
-      [ ZeroPage <> 0
-        MOV     r2, #0
-      ]
-10
-        CMP     r2, r6                          ; if page we've got to is > max
-        BHI     %FT92                           ; then corrupt
-        LDMIA   r5!, {r7, lr}                   ; get phys.addr, size
-        SUB     r7, r4, r7, LSR #12             ; number of pages into this bank
-        CMP     r7, lr, LSR #12                 ; if too many
-        ADDCS   r2, r2, lr, LSR #12             ; then advance physical page no.
-        BCS     %BT10                           ; and loop
-
-        ADD     r2, r2, r7                      ; add on number of pages within bank
-;
-; code from BangCamUpdate
-;
-        LDR     r1, =ZeroPage
-        LDR     r1, [r1, #CamEntriesPointer]
-        ADD     r1, r1, r2, LSL #CAM_EntrySizeLog2 ; point at cam entry (logaddr, PPL)
-        ASSERT  CAM_LogAddr=0
-        ASSERT  CAM_PageFlags=4
-        LDMIA   r1, {r0, r6}                    ; r0 = current logaddress, r6 = current PPL
+GetPageFlagsForR0IntoR6 Entry "r3-r5,r8-r11"
+        MOV     r4, r0
+        BL      logical_to_physical
+        BCS     %FT91
+        LDR     r4, =ZeroPage
+        LDR     r7, [r4, #MaxCamEntry]
+        BL      physical_to_ppn
+        BCS     %FT92
+        ; r3 = page number
+        LDR     r4, [r4, #CamEntriesPointer]
+        ADD     r4, r4, r3, LSL #CAM_EntrySizeLog2
+        LDR     r6, [r4, #CAM_PageFlags]
         EXIT
 
 90
-        ADR     lr, NoL2ForPageBeingRemovedError ; NB don't corrupt r0 yet - we need that in block as evidence
+        ADR     r11, NoL2ForPageBeingRemovedError ; NB don't corrupt r0 yet - we need that in block as evidence
 95
-        STR     lr, [sp]                        ; update returned r0
+        Push    "r1"
         BL      StoreDebugRegs
+        Pull    "r1"
+        MOV     r0, r11
         PullEnv                                 ; seriously broken memory
         SETV
         MOV     pc, lr
 
 91
-        ADR     lr, PageBeingRemovedNotPresentError
+        ADR     r11, PageBeingRemovedNotPresentError
         B       %BT95
 
 92
-        ADR     lr, PhysicalAddressNotFoundError
+        ADR     r11, PhysicalAddressNotFoundError
         B       %BT95
 
 ; ***********************************************************************************
@@ -112,35 +85,21 @@ MovePageAtR0ToR1WithAccessR6ReturnPageNumber Entry "r3-r5,r11"
 ;       r0,r1,r3,r6-r12 preserved
 ;       r4,r5 corrupted
 
-MoveCAMatR0toR3 Entry "r0,r1,r6,r7"
-        LDR     r5, =L2PT
-        ADD     r4, r5, r0, LSR #10             ; r4 -> L2PT for log addr r0
-        MOV     r2, r4, LSR #12
-        LDR     r2, [r5, r2, LSL #2]            ; r2 = L2PT entry for r4
-        TST     r2, #3                          ; if no page there
-        BEQ     %FT90                           ; then cam corrupt
-
-        LDR     r4, [r4]                        ; r4 = L2PT entry for r0
-        TST     r4, #3                          ; check entry is valid too
-        BEQ     %FT91
-        MOV     r4, r4, LSR #12                 ; r4 = phys addr >> 12
-
-        LDR     r2, =ZeroPage
-        LDR     r6, [r2, #MaxCamEntry]
-        ADD     r5, r2, #PhysRamTable
-      [ ZeroPage <> 0
-        MOV     r2, #0
-      ]
-10
-        CMP     r2, r6                          ; if page we've got to is > max
-        BHI     %FT92                           ; then corrupt
-        LDMIA   r5!, {r7, lr}                   ; get phys.addr, size
-        SUB     r7, r4, r7, LSR #12             ; number of pages into this bank
-        CMP     r7, lr, LSR #12                 ; if too many
-        ADDCS   r2, r2, lr, LSR #12             ; then advance physical page no.
-        BCS     %BT10                           ; and loop
-
-        ADD     r2, r2, r7                      ; add on number of pages within bank
+MoveCAMatR0toR3
+        Entry   "r0,r1,r6,r7"
+        Push    "r3,r8-r11"
+        ; Get page number of R0, so we know what we're dealing with
+        MOV     r4, r0
+        BL      logical_to_physical
+        BCS     %FT91
+        LDR     r4, =ZeroPage
+        LDR     r7, [r4, #MaxCamEntry]
+        BL      physical_to_ppn
+        ; r3 = page number
+        MOVCC   r2, r3
+        Pull    "r3,r8-r11"
+        BCS     %FT92
+        ; r2, r3, r9, r11 are ready for BangCamUpdate
         BL      BangCamUpdate
         CLRV
         EXIT
@@ -155,6 +114,7 @@ MoveCAMatR0toR3 Entry "r0,r1,r6,r7"
         MOV     pc, lr
 
 91
+        Pull    "r3,r8-r11"
         ADR     lr, PageBeingRemovedNotPresentError
         B       %BT95