Mirror OS_AMBControl changes from Pyromaniac

* Create new header file defining symbolic name for OS_AMBControl
  reason codes and flags
* Implement OS_AMBControl 9 (used to determine required size of buffer
  passed to OS_AMBControl 8 - potential thread safety issue not addressed)
* Return allocated error numbers in various failure cases

Version 6.38. Tagged as 'Kernel-6_38'

Makefile

@@ -32,7 +32,8 @@ ASFLAGS        += -PD "FreezeDevRel SETL {${FREEZE_DEV_REL}}"
 CUSTOMROM       = custom
 CUSTOMEXP       = custom
 CUSTOMSA        = custom
-EXPORTS         = ${EXP_HDR}.DBellDevice \
+EXPORTS         = ${EXP_HDR}.AMBControl \
+                  ${EXP_HDR}.DBellDevice \
                   ${EXP_HDR}.EnvNumbers \
                   ${EXP_HDR}.HALDevice \
                   ${EXP_HDR}.HALEntries \
@@ -98,6 +99,9 @@ ${KERNEL_MODULE}: ${ROM_OBJECT} ${DIRS}
 export: ${EXPORTS}
 	@${ECHO} ${COMPONENT}: export complete
 
+${EXP_HDR}.AMBControl: hdr.AMBControl
+	${CP} hdr.AMBControl $@ ${CPFLAGS}
+
 ${EXP_HDR}.EnvNumbers: hdr.EnvNumbers
 	${CP} hdr.EnvNumbers $@ ${CPFLAGS}
 

VersionASM

@@ -9,12 +9,12 @@
                         GBLS    Module_ApplicationDate
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
-Module_MajorVersion     SETS    "6.37"
-Module_Version          SETA    637
+Module_MajorVersion     SETS    "6.38"
+Module_Version          SETA    638
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "23 Mar 2020"
-Module_ApplicationDate  SETS    "23-Mar-20"
+Module_Date             SETS    "23 May 2020"
+Module_ApplicationDate  SETS    "23-May-20"
 Module_ComponentName    SETS    "Kernel"
-Module_FullVersion      SETS    "6.37"
-Module_HelpVersion      SETS    "6.37 (23 Mar 2020)"
+Module_FullVersion      SETS    "6.38"
+Module_HelpVersion      SETS    "6.38 (23 May 2020)"
                         END

VersionNum

-/* (6.37)
+/* (6.38)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  *
  */
-#define Module_MajorVersion_CMHG        6.37
-#define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                23 Mar 2020
+#define Module_MajorVersion_CMHG        6.38
+#define Module_MinorVersion_CMHG
+#define Module_Date_CMHG                23 May 2020
 
-#define Module_MajorVersion             "6.37"
-#define Module_Version                  637
+#define Module_MajorVersion             "6.38"
+#define Module_Version                  638
 #define Module_MinorVersion             ""
-#define Module_Date                     "23 Mar 2020"
+#define Module_Date                     "23 May 2020"
 
-#define Module_ApplicationDate          "23-Mar-20"
+#define Module_ApplicationDate          "23-May-20"
 
 #define Module_ComponentName            "Kernel"
 
-#define Module_FullVersion              "6.37"
-#define Module_HelpVersion              "6.37 (23 Mar 2020)"
-#define Module_LibraryVersionInfo       "6:37"
+#define Module_FullVersion              "6.38"
+#define Module_HelpVersion              "6.38 (23 May 2020)"
+#define Module_LibraryVersionInfo       "6:38"

hdr/AMBControl

+; Copyright 2020 RISC OS Open Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+
+OldOpt  SETA    {OPT}
+        OPT     OptNoList+OptNoP1List
+
+; Reason codes to OS_AMBControl
+
+                                ^       0
+AMBControl_Allocate             #       1       ; 0  R0,R1->R1,R2
+AMBControl_Deallocate           #       1       ; 1  R0,R2->
+AMBControl_GrowShrink           #       1       ; 2  R0,R1,R2->R1,R2,R3
+AMBControl_MapSlot              #       1       ; 3  R0,R1,R2,R3,R4->
+AMBControl_ReadInfo             #       1       ; 4  R0,R2->R1,R3
+AMBControl_Laziness             #       1       ; 5  R0,R1->R1
+                                #       1       ; 6  reserved
+                                #       1       ; 7  reserevd
+AMBControl_SystemInfo           #       1       ; 8  R0,R1->
+AMBControl_CurrentInfo          #       1       ; 9  R0->R2,R3
+
+; Flag bits in OS_AMBControl 3
+
+AMBControl_MapSlot_MapSome      *       1 :SHL: 8
+
+        OPT     OldOpt
+        END

s/AMBControl/deallocate

@@ -96,7 +96,7 @@ badhandle
         ADR     R0,err_badhandle
         B       SLVK_SetV
 err_badhandle
-        DCD     0
+        DCD     ErrorNumber_AMBBadHandle
         DCB     "AMBControl bad handle",0
         ALIGN
       ]

s/AMBControl/growshrink

@@ -92,7 +92,7 @@ growshrink
         CMP     R1,#0                  ; if shrunk to zero
         LDR     R2,[R2,#AMBNode_handle-AMBNode_DANode]
         BNE     gs_done
-        MOV     R0,#1
+        MOV     R0,#AMBControl_Deallocate
         SWI     XOS_AMBControl         ; then completely free the node
         MOV     R2,#0
         STR     R2,[SP,#4]               ;poke freed handle to saved R2

s/AMBControl/main

@@ -116,6 +116,7 @@ reasons0
         B       reserved     ;6
         B       reserved     ;7
         B       mjs_info     ;8 - system reason code, dumps info to buffer
+        B       current_info ;9
 reasons1
         ADR     R0,err_badreason
         B       SLVK_SetV
@@ -147,7 +148,7 @@ laziness ROUT
        CMP     R3,#0
        BEQ     %FT10
        Push    "R0-R3"
-       MOV     R0,#3
+       MOV     R0,#AMBControl_MapSlot
        MOV     R1,#-1
        LDR     R2,[R3,#AMBNode_handle]
        SWI     XOS_AMBControl                   ;map out current node
@@ -157,7 +158,7 @@ laziness ROUT
        CMP     R3,#0
        BEQ     %FT20
        Push    "R0-R3"
-       MOV     R0,#3
+       MOV     R0,#AMBControl_MapSlot
        MOV     R1,#0
        LDR     R2,[R3,#AMBNode_handle]
        SWI     XOS_AMBControl                   ;map in current node
@@ -212,6 +213,24 @@ mjs_info
        Pull    "R1-R7,LR"
        B       SLVK
 
+;entry: R0=9 (reason)
+;exit: R2=current AMB id, R3=number of tasks present (use this to size the buffer passed to AMBControl 8)
+current_info
+       Push    "R7,LR"
+       LDR     R2,AMBMappedInNode
+       CMP     R2,#0
+       LDRNE   R2,[R2,#AMBNode_handle]
+       MOV     R3, #0
+       ADR     LR,AMBAnchorNode
+       MOV     R7,LR
+01
+       LDR     LR,[LR,#AMBNode_next]
+       CMP     LR,R7
+       ADDNE   R3,R3,#1
+       BNE     %BT01
+       Pull    "R7,LR"
+       B       SLVK
+
 reserved
        ADR     R0,err_reserved
        B       SLVK_SetV
@@ -219,17 +238,17 @@ reserved
 ;;; errors (sod internationalisation)
 
 err_badreason
-        DCD     0
+        DCD     ErrorNumber_AMBBadReason
         DCB     "bad AMBControl reason code",0
         ALIGN
 
 err_reserved
-        DCD     0
+        DCD     ErrorNumber_AMBBadReason
         DCB     "reserved AMBControl reason code",0
         ALIGN
 
 err_nomorehandles
-        DCD     0
+        DCD     ErrorNumber_AMBNoHandles
         DCB     "AMBControl handles exhausted",0
         ALIGN
 

s/AMBControl/mapslot

@@ -29,7 +29,7 @@
 ;
 mapslot ROUT
 
-        TST     R0,#&100   ;if bit 8 set, then mapsome
+        TST     R0,#AMBControl_MapSlot_MapSome   ;if bit 8 set, then mapsome
         BNE     mapsome
 
         Push    "R0-R6,LR"

s/GetAll

@@ -79,6 +79,7 @@
         GET     Hdr:OSMisc
         GET     Hdr:OSRSI6
         GET     Hdr:PL310
+        GET     Hdr:AMBControl
 
 ; now the main parts of the MOS