diff --git a/VersionASM b/VersionASM
index 7dd1a283275e20fa14d8ff82a443fa7868a5b00a..ab802e478b693c124f68a800eb9303330817a06b 100644
--- a/VersionASM
+++ b/VersionASM
@@ -13,11 +13,11 @@
GBLS Module_ComponentPath
Module_MajorVersion SETS "5.35"
Module_Version SETA 535
-Module_MinorVersion SETS "4.79.2.286"
-Module_Date SETS "01 Sep 2015"
-Module_ApplicationDate SETS "01-Sep-15"
+Module_MinorVersion SETS "4.79.2.287"
+Module_Date SETS "06 Sep 2015"
+Module_ApplicationDate SETS "06-Sep-15"
Module_ComponentName SETS "Kernel"
Module_ComponentPath SETS "castle/RiscOS/Sources/Kernel"
-Module_FullVersion SETS "5.35 (4.79.2.286)"
-Module_HelpVersion SETS "5.35 (01 Sep 2015) 4.79.2.286"
+Module_FullVersion SETS "5.35 (4.79.2.287)"
+Module_HelpVersion SETS "5.35 (06 Sep 2015) 4.79.2.287"
END
diff --git a/VersionNum b/VersionNum
index a0eac04cd33730ef18a9f7225f74c20a2775c8ba..d2e0a0e62f5d2e566bb8eb7f7dec63c2d9bfd04d 100644
--- a/VersionNum
+++ b/VersionNum
@@ -5,19 +5,19 @@
*
*/
#define Module_MajorVersion_CMHG 5.35
-#define Module_MinorVersion_CMHG 4.79.2.286
-#define Module_Date_CMHG 01 Sep 2015
+#define Module_MinorVersion_CMHG 4.79.2.287
+#define Module_Date_CMHG 06 Sep 2015
#define Module_MajorVersion "5.35"
#define Module_Version 535
-#define Module_MinorVersion "4.79.2.286"
-#define Module_Date "01 Sep 2015"
+#define Module_MinorVersion "4.79.2.287"
+#define Module_Date "06 Sep 2015"
-#define Module_ApplicationDate "01-Sep-15"
+#define Module_ApplicationDate "06-Sep-15"
#define Module_ComponentName "Kernel"
#define Module_ComponentPath "castle/RiscOS/Sources/Kernel"
-#define Module_FullVersion "5.35 (4.79.2.286)"
-#define Module_HelpVersion "5.35 (01 Sep 2015) 4.79.2.286"
+#define Module_FullVersion "5.35 (4.79.2.287)"
+#define Module_HelpVersion "5.35 (06 Sep 2015) 4.79.2.287"
#define Module_LibraryVersionInfo "5:35"
diff --git a/s/AMBControl/Workspace b/s/AMBControl/Workspace
index 79e2d3d6433b3ae29f3f76538c3528d43d76427f..91efdb5b91dd87c435c321573d99afcb9d8d3fb0 100644
--- a/s/AMBControl/Workspace
+++ b/s/AMBControl/Workspace
@@ -44,6 +44,9 @@ AMBMappedInNode # 4 ;node ptr of mapped-in task, or 0 for non
AMBNodeHandles # 4 ;ptr to node handle array (1 word per entry)
AMBPhysBin # 4 ;ptr to physical page bin array
AMBPhysBinEntries # 4 ;no. of entries in physical page bin array
+ [ AMB_LazyMapIn
+AMBPageFlags # 4 ;L2PT page flags to use when (lazily) mapping in pages
+ ]
AMBAnchorNode # AMBNode_HdrSize ;dummy node - see note (1) below
;
[ ChocolateAMB
diff --git a/s/AMBControl/allocate b/s/AMBControl/allocate
index f04d1823cbcb29adb541a52ad1e9f16fa6712d09..44e55c0af346bfd59c8c79933e8a1a48c539791f 100644
--- a/s/AMBControl/allocate
+++ b/s/AMBControl/allocate
@@ -65,9 +65,10 @@ allocate
MOV R4,#ApplicationStart
STR R4,[R2,#AMBNode_startaddr]
LDR R4,=ZeroPage+AppSpaceDANode
- LDR R4,[R4,#DANode_Flags]
- AND R4,R4,#&7F
- STR R4,[R2,#AMBNode_PPL] ;PPL from bottom 8 bits of DA flags
+ LDR R4,[R4,#DANode_Flags] ;Get the page flags from the DA.
+ LDR LR,=DynAreaFlags_AccessMask;Note that this is rather academic
+ AND R4,R4,LR ;because various bits of code ignore
+ STR R4,[R2,#AMBNode_PPL] ;or overwrite these flags!
;do the actual MMU page allocation (grow from 0), for R1 pages, using node R2
BL growpages
diff --git a/s/AMBControl/growp b/s/AMBControl/growp
index aa56fb2e93bf862931e00922a6808c54b3d6662a..067ed8e225c4c3494b450d43a6772e1fc30b2b6b 100644
--- a/s/AMBControl/growp
+++ b/s/AMBControl/growp
@@ -55,17 +55,19 @@ growpages ROUT
LDR R5,[R1,#DANode_PMP]
LDR LR,[R1,#DANode_PMPSize]
ADD R5,R5,LR,LSL #2 ;current end of FreePool
- SUB R5,R5,R3,LSL #2 ;R5 := first required page in PMP
;R3 = no. of pages, R4 -> buffer for page entries,
- ;R5 := start page in PMP
+ ;R5 -> end of free pool PMP
+ ; Reverse the order as we copy in order to match OS_ChangeDynamicArea
+ ; (helps ensure pages are physically contiguous - to help with any
+ ; potential DMA)
MOV R2,R3
MOV R6,#-1
10
- LDR LR,[R5]
+ LDR LR,[R5,#-4]!
SUBS R2,R2,#1
STR LR,[R4],#4
- STR R6,[R5],#4
+ STR R6,[R5]
BNE %BT10
SUB R4,R4,R3,LSL #2
LDR R2,=ZeroPage+AppSpaceDANode ;R2 := dest for pages
diff --git a/s/AMBControl/main b/s/AMBControl/main
index 30ff2e77c8101fc278b1346e89a0f402a9bf6a1a..e363f5190a1e4ed85c5bcc729e9f1ff6a6f7089e 100644
--- a/s/AMBControl/main
+++ b/s/AMBControl/main
@@ -98,6 +98,22 @@ AMBControl_Init
TST R0,#CPUFlag_AbortRestartBroken ;but wait! can't use for bugged chips (eg. pre rev T StrongARM)
MOVNE R1,#AMBFlag_LazyMapIn_disable
STR R1,AMBFlags
+
+; Calculate default page flags
+ LDR r2,=ZeroPage
+ [ MEMM_Type = "VMSAv6"
+ ADRL r1,PPLTrans
+ |
+ LDR r1, [r2, #ProcessorFlags]
+ TST r1, #CPUFlag_ExtendedPages
+ ADREQL r1, PPLTrans
+ ADRNEL r1, PPLTransX
+ ]
+ LDR r3,[r1] ; Page type + access flags
+ LDR r2,[r2,#MMU_PCBTrans]
+ LDRB r2,[r2] ; Cacheability + other attribs
+ ORR r3,r3,r2
+ STR r3,AMBPageFlags
|
MOV R1,#AMBFlag_LazyMapIn_disable
STR R1,AMBFlags
diff --git a/s/AMBControl/memmap b/s/AMBControl/memmap
index cd413bdb3edf8e337b361d9fea516a2f6452c937..55b661889507b747733ade69506b56977d8f86cd 100644
--- a/s/AMBControl/memmap
+++ b/s/AMBControl/memmap
@@ -108,15 +108,8 @@ AMB_LazyFixUp ROUT
ADD r1,r1,r0,LSL #2 ;r1 -> page involved, in node page list
LDR r2,AMBPhysBin
-; Calculate the L2PT protection bits in a nice way that won't produce broken code if we change MMU model
-; This should match the AP_Full entry from the PPLTrans table that gets used by BangCam (plus C+B bits)
- [ MEMM_Type = "VMSAv6"
- MOV r3,#(AP_Full*L2X_APMult)+L2_ExtPage+L2_C+L2_B
- |
- ASSERT (AP_Full*L2_APMult)+L2_SmallPage+L2_C+L2_B = &FFE
- MOV r3,#&FF0
- ORR r3,r3,#&E
- ]
+; Get the correct default page flags
+ LDR r3,AMBPageFlags
LDR r4,[r1]
MOV r6,r4
PageNumToL2PT r4,r2,r3,r5
diff --git a/s/AMBControl/shrinkp b/s/AMBControl/shrinkp
index e53bb7595a75d54c3c987c8464d0d1a059f92339..a5816c95c879ed3427b49570262ec3547742bdd9 100644
--- a/s/AMBControl/shrinkp
+++ b/s/AMBControl/shrinkp
@@ -85,9 +85,13 @@ shrinkpages
LDR R7,=ZeroPage
LDR R7,[R7,#CamEntriesPointer]
ADD R7,R7,#CAM_PMP
+ ADD R4,R4,R3,LSL #2
MOV R0,R3
+ ; Reverse the page order as we copy, to match the reverse we performed
+ ; on grow (try and keep free pool pages in optimal order for future
+ ; grows)
10
- LDR LR,[R4],#4
+ LDR LR,[R4,#-4]!
SUBS R0,R0,#1
STR LR,[R5,R6,LSL #2] ;add to free pool PMP
ADD LR,R7,LR,LSL #CAM_EntrySizeLog2
diff --git a/s/ChangeDyn b/s/ChangeDyn
index 0e052e7c7807123e874338672e033ef8301b14c7..40997138da809c3afea0b9a9f298a49ba41a12b3 100644
--- a/s/ChangeDyn
+++ b/s/ChangeDyn
@@ -2518,7 +2518,7 @@ DynArea_Locate Entry "r2-r5"
B %BT50
60
LDR r1, [r10, #DANode_Flags]
- LDR r0, [r10, #DANode_Size]
+ LDR r0, [r10, #DANode_MaxSize]
TST r1, #DynAreaFlags_DoublyMapped
LDR r1, [r10, #DANode_Base]
ADD r2, r1, r0 ; r1:=base r2:=top
@@ -2539,11 +2539,11 @@ DynArea_Locate Entry "r2-r5"
;
; in: r0 = reason code (21)
; r1 = area number
-; r2 = pointer to array of (PMP page index, phys page index, PMP page flag) tuples
+; r2 = pointer to array of (PMP page index, phys page index, page flag) tuples
; phys page index -1 to release
; phys page index -2 to let kernel pick page
; otherwise page number to use
-; PMP page flags are defined by DynAreaFlags_PMPPhysOpAccessMask
+; page flags are defined by DynAreaFlags_PMPPhysOpAccessMask
; r3 = number of entries
;
; out: r0-r1 preserved (error if not all of region successfully updated)
@@ -3528,17 +3528,13 @@ DynArea_PMP_GetInfo ROUT
;
; Internal routine called by DynamicAreaSWI
;
-; Although designed for use with PMPs, this call works with regular DAs
-; too (just returns zero for r6 & r7)
-;
; in: r0 = reason code (25)
; r1 = area number
; r2 = pointer to input/output array:
-; +0: PMP page index (filled in on entry)
-; +4: phys page index (filled in on exit, -1 if none)
-; +8: PMP page flags (filled in on exit, 0 if none)
-; +12: DA page index (filled in on exit, -1 if not mapped)
-; +16: page flags (filled in on exit, 0 if not mapped)
+; +0: PMP page index
+; +4: phys page number
+; +8: DA page index
+; +12: page flags
; r3 = number of entries
;
; out: r0-r3 preserved
@@ -3546,6 +3542,16 @@ DynArea_PMP_GetInfo ROUT
; All other registers preserved
; Array updated with page details
;
+; On entry, for each array entry either the PMP page index, phys page number, or
+; DA page index must be provided, with the other indices set to -1 (page flags
+; are ignored).
+;
+; On exit, if the page is a member of the PMP, the entries will be filled in as
+; appropriate. If the page isn't mapped in (and it was a lookup by PMP page
+; index/phys page number) the DA page index will be set to -1. If no physical
+; page is allocated (or the page isn't a member of the PMP) the page flags will
+; be set to 0.
+;
DynArea_PMP_GetPages ROUT
Entry "r0-r9"
@@ -3556,52 +3562,125 @@ DynArea_PMP_GetPages ROUT
]
BCC %FT90 ; [it doesn't]
; r10 -> DANode
- LDR r8, [r10, #DANode_PMP]
- CMP r8, #0
+ LDR r6, [r10, #DANode_PMP]
+ CMP r6, #0
BEQ %FT90
LDR r9, [r10, #DANode_PMPMaxSize]
BEQ %FT90
- LDR r7, =ZeroPage
+ LDR r11, =ZeroPage
LDR r5, [r10, #DANode_Base]
- LDR r7, [r7, #CamEntriesPointer]
- LDR r11, =DynAreaFlags_PMPLogOpAccessMask
- LDR r12, =Nowhere
+ LDR r7, [r11, #MaxCamEntry]
+ LDR r8, =L2PT
+ LDR r11, [r11, #CamEntriesPointer]
+ LDR r12, =DynAreaFlags_PMPLogOpAccessMask
; Usage in main loop:
; r2 -> input page list
; r3 = length
- ; r4 = current entry PMP index
; r5 -> DA base
- ; r7 -> CAM
- ; r8 -> PMP
+ ; r6 -> PMP
+ ; r7 = MaxCamEntry
+ ; r8 -> L2PT
; r9 = PMP size
; r10 -> DANode
- ; r11 = PMPLogOpAccessMask
- ; r12 = Nowhere
- ; r0, r1, r5, r6 temp
+ ; r11 -> CAM
+ ; r12 = DynAreaFlags_PMPLogOpAccessMask
+ ; r0, r1, r4 temp
10
SUBS r3, r3, #1
BLT %FT80
- LDR r4, [r2], #4
+ ; Get the entry
+ LDMIA r2, {r0, r1, r4}
+ ; PMP page provided?
+ CMP r0, #-1
+ BNE %FT50
+ ; Phys page provided?
+ CMP r1, #-1
+ BNE %FT20
+ ; DA page provided
+ ; n.b. skipping any range check here since it won't hurt if the page
+ ; doesn't belong to us
+ Push "r3, r5, r9-r11"
+ ADD r4, r5, r4, LSL #12
+ BL logical_to_physical
+ BLCC physical_to_ppn
+ MOV r0, r3
+ Pull "r3, r5, r9-r11"
+ BCS %FT15
+ ; r0 = PPN, check to see if it belongs to us
+ ADD r1, r11, r0, LSL #CAM_EntrySizeLog2
+ ASSERT CAM_PageFlags=4
+ ASSERT CAM_PMP=8
+ ASSERT CAM_PMPIndex=12
+ LDMIB r1, {r1, r4, lr}
+ TST r1, #DynAreaFlags_PMP
+ BEQ %FT15
+ CMP r4, r10
+ BNE %FT15
+ STR lr, [r2], #4 ; Store PMP page index
+ AND r1, r1, r12
+ STR r0, [r2], #8 ; Store phys page number, skip DA page index
+ STR r1, [r2], #4 ; Store page flags
+ B %BT10
+15
+ ; Bad DA page index
+ ; PMP page index & phys page number are already known to be -1, so just
+ ; store flags
+ MOV r0, #0
+ STR r0, [r2, #12]
+ ADD r2, r2, #16
+ B %BT10
+
+20
+ ; Check for silly phys page number
+ CMP r1, r7
+ BHI %FT91
+ ADD r1, r11, r1, LSL #CAM_EntrySizeLog2
+ ASSERT CAM_LogAddr=0
+ ASSERT CAM_PageFlags=4
+ ASSERT CAM_PMP=8
+ ASSERT CAM_PMPIndex=12
+ LDMIA r1, {r0, r1, r4, lr}
+ TST r1, #DynAreaFlags_PMP
+ BEQ %FT25
+ CMP r4, r10
+ BNE %FT25
+ LDR r4, =Nowhere
+ STR lr, [r2], #8 ; Store PMP page index, skip phys page number
+ TEQ r0, r4
+ B %FT55
+
+25
+ ; Bad phys page number
+ ; PMP page index known to be -1, so store DA page index + flags
+ ADD r2, r2, #8
+ MOV r0, #-1
+ MOV r1, #0
+ STMIA r2!, {r0-r1}
+ B %BT10
+
+50
; Check for silly PMP page index
- CMP r4, r9
+ CMP r0, r9
BHS %FT91
; Look up the page that's currently in the PMP
- LDR r0, [r8, r4, LSL #2]
- MOV r1, #0 ; Currently, no flags
- STMIA r2!, {r0-r1}
+ LDR r0, [r6, r0, LSL #2]
+ ADD r2, r2, #4
+ STR r0, [r2], #4 ; Store phys page number
; Does the page exist?
CMP r0, #-1
- ADDNE r0, r7, r0, LSL #CAM_EntrySizeLog2
+ LDR r4, =Nowhere
+ ADDNE r0, r11, r0, LSL #CAM_EntrySizeLog2
+ MOVEQ r1, #0 ; No physical page, so no flags
ASSERT CAM_LogAddr=0
ASSERT CAM_PageFlags=4
LDMNEIA r0, {r0-r1} ; Get log addr, flags from CAM
- TEQNE r0, r12
+ TEQNE r0, r4
+55
MOVEQ r0, #-1 ; No physical page, or not mapped
SUBNE r0, r0, r5
- MOVEQ r1, #0
MOVNE r0, r0, LSR #12
- AND r1, r1, r11 ; Mask returned flags
- STMIA r2!, {r0-r1}
+ AND r1, r1, r12 ; Mask returned flags
+ STMIA r2!, {r0-r1} ; Store DA page index, flags
B %BT10
80
@@ -3619,6 +3698,7 @@ DynArea_PMP_GetPages ROUT
|
SETV
]
+ FRAMSTR r0
EXIT
@@ -4447,11 +4527,9 @@ DynArea_AddrLookup_loop
]
; Now that the system heap is initialised we can create a page list for the
-; free pool and start pushing the free pages into it. We want the pages at the
-; start of the list to be the VRAM block, followed by all the other pages in
-; order of increasing speed. However it's highly unlikely that we'll be able to
-; build the full page list without having to grow the system heap - for which
-; we'd want the fast pages to be available.
+; free pool and start pushing the free pages into it. However it's highly
+; unlikely that we'll be able to build the full page list without having to
+; grow the system heap - for which we'd want the fast pages to be available.
; So to cope with this we start by putting the fast pages into the page list,
; growing the system heap for every page we insert (a bit slow but reliable).
@@ -4459,8 +4537,6 @@ DynArea_AddrLookup_loop
; on success we then switch to a different algorithm which fills the main page
; list.
-; TODO - Make sure pages are inserted in an order which keeps them in consecutive physical order when being transferred to a DA (and make sure shrink/grow preserves order!)
-
SUB sp, sp, #4 ; Store the initial list on the stack
LDR r5, =ZeroPage
LDR r6, =ZeroPage+FreePoolDANode
@@ -4482,14 +4558,12 @@ DynArea_AddrLookup_loop
ADD r9, r5, #PhysRamTable
LDMIA r9!, {r0, r10} ; get VRAM info
MOV r10, r10, LSR #12 ; r10 = current page number
+ LDMIA r9!, {r0, r11} ; get first regular RAM chunk
+ SUB r10, r10, #1 ; set things up so the first call to NextFreePage will return the first page of the block
+ MOV r11, r11, LSR #12
+ ADD r11, r11, #1
LDR r4, [r5, #CamEntriesPointer]
10
- LDMIA r9!, {r0, r11} ; get next block
- MOVS r11, r11, LSR #12 ; if no more blocks left...
- MOVEQ r10, #0
- ADDEQ r9, r5, #PhysRamTable ; ...panic and use the VRAM
- BEQ %BT10
-15
; See if we have enough space
LDR r3, [r5, #MaxCamEntry]
ADD r3, r3, #1
@@ -4498,22 +4572,14 @@ DynArea_AddrLookup_loop
MOV r0, #HeapReason_Desc
BL DoSysHeapOpWithExtension ; HACK - check space before calling, to avoid crashing when the grow fails and tries to generate an error (vector table not initialised yet, so crashes when UKSWIV is invoked in order to call MessageTrans)
Pull "r3"
- SUB r2, r2, #4096 ; Paranoia
+ SUB r2, r2, #4096 ; Paranoia
CMP r2, r3
BLT %FT20
BL ClaimSysHeapNode
BVC %FT40
- ; Find a page we can use to grow the system heap
20
- CMP r10, r7
- CMPHS r8, r10
- BHS %FT30 ; page is in statics
- ; Check the CAM map to see if the page is already taken - this will detect the DMA regions, which aren't included in InitUsedStart/InitUsedEnd
- ADD r0, r4, r10, LSL #CAM_EntrySizeLog2
- LDR lr, [r0, #CAM_PageFlags]
- TST lr, #PageFlags_Unavailable
- BNE %FT30
- ; Found a page, add it to the free pool
+ ; Find a page we can use to grow the system heap
+ BL NextFreePage ; n.b. no out-of-pages check
STR r10, [sp]
LDR lr, =AP_FreePool :AND: DynAreaFlags_AccessMask
STR lr, [r0, #CAM_PageFlags]
@@ -4526,12 +4592,8 @@ DynArea_AddrLookup_loop
MOV r0, #ChangeDyn_SysHeap
MOV r1, #4096
SWI XOS_ChangeDynamicArea
-30
- ; Move on to next page
- SUBS r11, r11, #1
- ADD r10, r10, #1
- BEQ %BT10
- B %BT15
+ B %BT10
+
40
; We've successfully allocated the memory for the PMP - start filling
; it in. To ensure the pages are in the correct order we need to fill
@@ -4548,34 +4610,10 @@ DynArea_AddrLookup_loop
MOV r1, r3
STR r2, [r6, #DANode_PMP]
45
- CMP r10, r7
- CMPHS r8, r10
- BHS %FT50 ; page is in statics
- ; Check the CAM map to see if the page is already taken - this will detect the DMA regions, which aren't included in InitUsedStart/InitUsedEnd
- ADD r0, r4, r10, LSL #CAM_EntrySizeLog2
- LDR lr, [r0, #CAM_PageFlags]
- TST lr, #PageFlags_Unavailable
- BNE %FT50
- ; Found a page, add it to the free pool
- STR r10, [r3, #-4]!
-50
- ; Move on to next page
- SUBS r11, r11, #1
- ADD r10, r10, #1
- BNE %BT45
- ADD lr, r5, #PhysRamTable+8
- CMP lr, r9 ; if we've just processed the VRAM chunk, we're done
- BEQ %FT55
- LDMIA r9!, {r0, r11} ; else get next block
- MOVS r11, r11, LSR #12 ; if no more blocks left...
- BNE %BT45
- MOV r10, #0
- MOV r9, lr
- LDMDB r9, {r0, r11} ; ...then process VRAM
- MOVS r11, r11, LSR #12 ; And if no VRAM...
- BNE %BT45
- ; ...then we're done
-55
+ BL NextFreePage
+ CMP r10, #-1
+ STRNE r10, [r3, #-4]!
+ BNE %BT45 ; Keep going until we run out of pages
; Left with:
; r1 -> end of memory block
; r2 -> start of memory block
@@ -4621,6 +4659,83 @@ DynArea_AddrLookup_loop
]
EXIT
+;
+; NextFreePage - Find next page to insert into the free pool on startup
+;
+; In:
+; r4 -> CAM
+; r7 = page number of start of static chunk
+; r8 = page number of end of static chunk
+; r9 -> next PhysRamTable entry
+; r10 = Current page number
+; r11 = Number of pages left in current chunk
+; Out:
+; r0 -> CAM entry for page
+; r10 = Next free page in optimal order, -1 if no more pages
+; r9, r11 updated
+;
+; We have to move all free pages (ie ones not occupied by the static pages)
+; into the free pool.
+; By default, pages will get taken from the end of the free pool when other
+; dynamic areas are initialised or grown. So make sure that the slowest RAM
+; is at the start of the free pool and the fastest is at the end; this is the
+; reverse of the order in PhysRamTable. Also, within each group of pages (i.e.
+; PhysRamTable entry), we want the pages to be in decreasing physical address
+; order - so that when they are moved to a DA they end up in increasing address
+; order, leading to more optimal DMA transfer lists.
+;
+; Also note that the VRAM block is kept at the start of the free pool, mainly
+; to match old behaviour (it's not clear whether moving it elsewhere will have
+; any significant impact on the system - especially when you consider that
+; shrinking screen memory will end up adding the pages to the end of the pool
+; rather than the start).
+;
+; Over time this optimal ordering will be lost, so at a later date it might be
+; nice to re-sort pages as they are added back into the free pool (and move the
+; VRAM block to the end of PhysRamTable, so that it's in order fast RAM -> slow
+; RAM -> fast DMA -> slow DMA -> VRAM, so that sorting by page number is
+; all that's required to deal with both contiguity and desirability)
+;
+; In terms of this routine, we fill the free pool from the highest entry down,
+; so we want the first page returned to be the lowest-numbered page from the
+; first (non-VRAM) PhysRamTable entry.
+;
+NextFreePage ROUT
+ Entry
+10
+ SUBS r11, r11, #1
+ ADD r10, r10, #1
+ BEQ %FT30
+20
+ CMP r10, r7
+ CMPHS r8, r10
+ BHS %BT10 ; page is in statics
+ ; Check the CAM map to see if the page is already taken - this will detect the DMA regions, which aren't included in InitUsedStart/InitUsedEnd
+ ADD r0, r4, r10, LSL #CAM_EntrySizeLog2
+ LDR lr, [r0, #CAM_PageFlags]
+ TST lr, #PageFlags_Unavailable
+ BNE %BT10
+ ; Page is good
+ EXIT
+
+30
+ ; Advance to next block
+ LDR lr, =ZeroPage+PhysRamTable+8
+ CMP lr, r9 ; if we've just processed the VRAM block, we're done
+ BEQ %FT90
+ LDMIA r9!, {r0, r11} ; else get next block
+ MOVS r11, r11, LSR #12 ; if no more blocks left...
+ BNE %BT20
+ MOV r10, #0
+ MOV r9, lr
+ LDMDB lr, {r0, r11} ; ...then process VRAM
+ MOVS r11, r11, LSR #12 ; And if no VRAM...
+ BNE %BT20
+90 ; ...then we're done
+ MOV r10, #-1
+ EXIT
+
+
LTORG
InitFreePoolTable
@@ -6009,7 +6124,7 @@ DoTheGrowPagesSpecified ROUT
LDR r6, [r8, #4] ;logical address of src page
; If the required page is in the free pool, we don't need to preserve its contents
- ; TODO - have 'volatile' PMP page flag which can be used to indicate that pages can just be taken? (so will work with any PMP)
+ ; TODO - have 'volatile' page flag which can be used to indicate that pages can just be taken? (so will work with any PMP)
TST r2, #DynAreaFlags_PMP
BEQ %FT73
CMP r3, r11