Ensure IO memory is marked as non-executable

Detail:
  s/HAL - The VMSAv6/v7 memory model allows speculative instruction fetches from any memory (including device/strongly-ordered), unless the memory is marked as non-executable. So to prevent interference with read-sensitive devices we must make sure all appropriate IO memory is marked as non-executable.
Admin:
  Tested on IGEPv5
  Fixes data corruption seen when reading from SD card


Version 5.35, 4.79.2.265. Tagged as 'Kernel-5_35-4_79_2_265'

VersionASM

@@ -13,11 +13,11 @@
                         GBLS    Module_ComponentPath
 Module_MajorVersion     SETS    "5.35"
 Module_Version          SETA    535
-Module_MinorVersion     SETS    "4.79.2.264"
-Module_Date             SETS    "19 Apr 2015"
-Module_ApplicationDate  SETS    "19-Apr-15"
+Module_MinorVersion     SETS    "4.79.2.265"
+Module_Date             SETS    "14 Jun 2015"
+Module_ApplicationDate  SETS    "14-Jun-15"
 Module_ComponentName    SETS    "Kernel"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/Kernel"
-Module_FullVersion      SETS    "5.35 (4.79.2.264)"
-Module_HelpVersion      SETS    "5.35 (19 Apr 2015) 4.79.2.264"
+Module_FullVersion      SETS    "5.35 (4.79.2.265)"
+Module_HelpVersion      SETS    "5.35 (14 Jun 2015) 4.79.2.265"
                         END

VersionNum

@@ -5,19 +5,19 @@
  *
  */
 #define Module_MajorVersion_CMHG        5.35
-#define Module_MinorVersion_CMHG        4.79.2.264
-#define Module_Date_CMHG                19 Apr 2015
+#define Module_MinorVersion_CMHG        4.79.2.265
+#define Module_Date_CMHG                14 Jun 2015
 
 #define Module_MajorVersion             "5.35"
 #define Module_Version                  535
-#define Module_MinorVersion             "4.79.2.264"
-#define Module_Date                     "19 Apr 2015"
+#define Module_MinorVersion             "4.79.2.265"
+#define Module_Date                     "14 Jun 2015"
 
-#define Module_ApplicationDate          "19-Apr-15"
+#define Module_ApplicationDate          "14-Jun-15"
 
 #define Module_ComponentName            "Kernel"
 #define Module_ComponentPath            "castle/RiscOS/Sources/Kernel"
 
-#define Module_FullVersion              "5.35 (4.79.2.264)"
-#define Module_HelpVersion              "5.35 (19 Apr 2015) 4.79.2.264"
+#define Module_FullVersion              "5.35 (4.79.2.265)"
+#define Module_HelpVersion              "5.35 (14 Jun 2015) 4.79.2.265"
 #define Module_LibraryVersionInfo       "5:35"

s/HAL

@@ -2058,11 +2058,11 @@ RISCOS_AccessPhysicalAddressUnchecked                   ; well OK then, I trust
  ]
         LDR     ip, =L1PT + (PhysicalAccess:SHR:18)     ; ip -> L1PT entry
  [ MEMM_Type = "VMSAv6"
-        LDR     a4, =(AP_None * L1_APMult) + L1_Section
+        LDR     a4, =(AP_None * L1_APMult) + L1_Section + L1_XN
  |
         LDR     a4, =(AP_None * L1_APMult) + L1_U + L1_Section
  ]
-        ORR     a1, a4, a1                              ; a1 = flags for 2nd level descriptor
+        ORR     a1, a4, a1                              ; a1 = flags for 1st level descriptor
         MOV     a4, a2, LSR #20                         ; rounded to section
         ORR     a1, a1, a4, LSL #20                     ; a1 = complete descriptor
         TEQ     a3, #0
@@ -2371,6 +2371,9 @@ RISCOS_MapInIO ROUT
         LDR     ip, =ZeroPage
         LDR     a4, =L1PT
         AND     a1, a1, v7                              ; only allow bufferable as flags option
+ [ MEMM_Type = "VMSAv6"
+        ORR     a1, a1, #L1_XN                          ; force non-executable to prevent speculative instruction fetches
+ ]
         LDR     v2, =IO                                 ; logical end (exclusive) of currently mapped IO
         LDR     v1, [ip, #IOAllocPtr]                   ; logical start (inclusive)