1. 13 Feb, 2021 8 commits
    • Jeffrey Lee's avatar
      [RISCOS_]AccessPhysicalAddress uses page flags · 7924aae2
      Jeffrey Lee authored
      Currently RISCOS_AccessPhysicalAddress allows the caller to specify the
      permissions/properties of the mapped memory by directly specifying some
      of the L1 page table entry flags. This will complicate things when
      adding support for more page table formats, so change it so that
      standard RISC OS page flags are used instead (like the alternate entry
      point, RISCOS_AccessPhysicalAddressUnchecked, already uses).
      Also, drop the "RISCOS_" prefix from RISCOS_AccessPhysicalAddress and
      RISCOS_ReleasePhysicalAddress, and remove the references to these
      routines from the HAL docs. These routines have never been exposed to
      the HAL, so renaming them and removing them from the docs should make
      their status clearer.
      Version 6.52. Tagged as 'Kernel-6_52'
    • Jeffrey Lee's avatar
      Remove unused BangCam routine · 5dbb8207
      Jeffrey Lee authored
      Somewhere along the way, BangCam became redundant. Get rid of it.
    • Jeffrey Lee's avatar
      Remove more direct page table access · 858949b6
      Jeffrey Lee authored
      RISCOS_LogToPhys and OS_Memory 20 (compatibility page) changed to use
      suitable subroutines for reading the page tables instead of accessing
      them directly.
    • Jeffrey Lee's avatar
      DecodeL1/L2Entry -> LoadAndDecodeL1/L2Entry · 846eee02
      Jeffrey Lee authored
      Change the DecodeL1/L2Entry routines so that instead of accepting a page
      table entry as input, they accept a (suitable-aligned) logical address
      and fetch the page table entry themselves. This helps insulate the
      calling code from the finer details of the page table format.
    • Jeffrey Lee's avatar
      More code uses logical_to_physical & physical_to_ppn · 9a82cb28
      Jeffrey Lee authored
      GetPageFlagsForR0IntoR6 & MoveCAMatR0toR3 changed to use
      logical_to_physical & physical_to_ppn, to reduce the number of routines
      which are performing direct page table access.
    • Jeffrey Lee's avatar
      OS_FindMemMapEntries now uses logical_to_physical · b60d3a70
      Jeffrey Lee authored
      Reduce the number of routines which directly examine the page tables, by
      changing OS_FindMemMapEntries to use logical_to_physical.
    • Jeffrey Lee's avatar
      Start moving page table code into s.ShortDesc · ca69793c
      Jeffrey Lee authored
      In preparation for the addition of long descriptor page table support,
      start moving low-level page table routines into their own file
      (s.ShortDesc) so that we can add a corresponding long descriptor
      implementation in the future.
      * logical_to_physical, MakePageTablesCacheable,
      MakePageTablesNonCacheable, AllocateBackingLevel2, AMB_movepagesin_L2PT,
      AMB_movecacheablepagesout_L2PT, AMB_moveuncacheablepagesout_L2PT
      routines, and PageNumToL2PT macros, all moved to s.ShortDesc with no
      * Add new UpdateL1PTForPageReplacement routine (by splitting some code
      out of s.ChangeDyn)
    • Jeffrey Lee's avatar
      Prepare logical_to_physical for 64bit phys addrs · 4fd2dd01
      Jeffrey Lee authored
      ppn_to_physical, logical_to_physical, physical_to_ppn & ppn_to_physical
      have now all been changed to accept/receive 64bit physical addresses in
      R8,R9 instead of a 32bit address in R5. However, where a phys addr is
      being provided as an input, they may currently only pay attention to the
      bottom 32 bits of the address.
  2. 10 Feb, 2021 2 commits
    • Timothy E Baldwin's avatar
      Fix OS_EvaluateExpression · fd66eeef
      Timothy E Baldwin authored
      OS_EvaluateExpression is documented as applying GSTrans to any strings
      within the expression, but did instead GSTrans the entire expression.
      This would result in a sequence such as:
          *Set Alias$@RunType_FD1 "Basic -quit ""%0"" %*1"
          *If "<Alias$@RunType_FD1>"="" Then Set Alias$@RunType_FD1 @RunType_FFB %*0
      raising a "Unknown operand" error as the quote in the variable
      were interpreted as expression syntax. See
      Unfortunately skipping the initial GSTrans breaks common code such as:
          If "<StrED_cfg$Dir>" = "" AND <Ctrl$Pressed> = 0 Then ...
          If "<Zap$OSVsn>" <> "" Then SetEval ZapFonts$OSVsn <Zap$OSVsn>
      Fix by applying a GSTrans transformation over unquoted parts of the
      expression, then applying GSTrans over the quoted strings.
      Version 6.51. Tagged as 'Kernel-6_51'
    • Timothy E Baldwin's avatar
      Fix GSTrans of quoted macro variable · 0eeb16a7
      Timothy E Baldwin authored
          *SetMacro Macro Test
          SYS "OS_GSTrans", """<Macro>""", &10000, &100
      Would result in an erroneous "String not recognised" error as the
      end of macro variable was reached before closing quote.
      Fix by reordering the checks.
  3. 30 Jan, 2021 3 commits
    • Jeffrey Lee's avatar
      Expose ABTSTK via OS_ReadSysInfo 6 · 02e5e4dc
      Jeffrey Lee authored
      It's the only privileged-mode stack which doesn't have its address
      exposed via OS_ReadSysInfo 6. Expose it so that software which wants to
      know its address can read it instead of relying on hardcoded values.
      Tested on Raspberry Pi 4
      Version 6.50. Tagged as 'Kernel-6_50'
    • Jeffrey Lee's avatar
      Remove some quirks from the memory map · d0c4b0c1
      Jeffrey Lee authored
      The correct amount of space is now reserved for Kbuffs, and there's no
      need to have a 1MB gap where the old PhysicalAccess window was.
      Tested on Raspberry Pi 4
    • Jeffrey Lee's avatar
      More declarative memory map · ee6d31a3
      Jeffrey Lee authored
      Although storage maps are useful for allowing the fixed areas of the
      memory map to be relocated, it isn't clear in the current definition
      what the size of each area is, and it's hard to ensure that all the
      areas are kept at the correct alignment.
      Replace the current basic workspace definition with one which makes use
      of the new ASpace macro, to allow addresses to be calculated
      automatically based on the size & alignment of each area. Also output
      the address of each area in the build log for easy
      Binary unchanged.
  4. 23 Jan, 2021 1 commit
    • Timothy E Baldwin's avatar
      Preserve LR and CPSR in DebugTX · 59d9f948
      Timothy E Baldwin authored
      This ensures that the debug macros may be freeley placed without
      concern for if LR and CPSR contain important values, and avoid the
      of code only working because the debug code changes the flags with
      the effect of a bug appearing when debugging is enabled.
      Version 6.49. Tagged as 'Kernel-6_49'
  5. 16 Jan, 2021 5 commits
    • Jeffrey Lee's avatar
      Make supervisor stack inaccessible to user mode · bbc7ad20
      Jeffrey Lee authored
      Previously the supervisor stack was read-only in user mode, but since
      the supervisor stack is typically empty when the CPU is in user mode,
      it's questionable whether any software actually makes use of this
      To simplify support for the long descriptor page table format (which
      doesn't support the user-RO + privileged-RW access mode), let's
      try and remove usermode SVC stack access completely.
      Tested on Raspberry Pi 4
      Version 6.48. Tagged as 'Kernel-6_48'
    • Timothy E Baldwin's avatar
      Allow ZeroPage at any 64K aligned address · 4341900a
      Timothy E Baldwin authored
      Change ZeroPage calculation so that ZeroPage can be at
      any 64K aligned address.
      Version 6.47. Not tagged
    • Timothy E Baldwin's avatar
      Fix ROM check for callbacks · 4a56c45f
      Timothy E Baldwin authored
      Check now works if ROMLimit is precisely at the end
      of ROM causing ROMLimit to not be a valid immediate.
    • Timothy E Baldwin's avatar
      Move ROM constant and add ASSERT · afd37607
      Timothy E Baldwin authored
      Move ROM constant to KernelWS with the reset of the memory layout.
      Add ASSERT to guard against workspace colliding with ROM.
    • Timothy E Baldwin's avatar
      Allow the kernel workspace to be easily relocated · ebc97877
      Timothy E Baldwin authored
      Rather than specifing absolute addresses for the workspace,
      use ObjASM's storage layout support.
  6. 19 Dec, 2020 1 commit
  7. 23 Nov, 2020 1 commit
    • Julie Stamp's avatar
      Increase RamFS limit to 2GB · a81fa868
      Julie Stamp authored
      RamFS now supports disc sizes up to 2GB-4KB, so raise the dynamic area limit from 508MB.
      Tested with a disc size up to 928MB
      Version 6.46. Tagged as 'Kernel-6_46'
  8. 28 Oct, 2020 1 commit
    • John Ballance's avatar
      Build fix to DebugTerminal · 070ae73d
      John Ballance authored
      Changes in Kernel-6_44 left an undefined symbol in s.HAL in DebugTerminal_Rdch. These mods resolve that, and also add a note in s.Kernel to reflect this usage.
      Version 6.45. Tagged as 'Kernel-6_45'
  9. 24 Oct, 2020 3 commits
    • Timothy E Baldwin's avatar
      Eliminate callback check to Portable_Idle races · 994cc0d9
      Timothy E Baldwin authored
      Previously both `RdchInkey` and `PageTest` enabled interrupts after
      running callbacks before calling Portable_Idle with the result that
      callback could be delayed until the next interrupt.
      * Change `process_callback_chain` to leave interrupts disabled, and
        rename accordingly.
      * Remove redundant check of CallBack_Flag.
      * In `PageTest` move running calbacks into `CtrlShiftTest`, so that
        it is immediately before the test.
      * Re-enable interrupts at appropriate locations.
      Tested on StrongARM Risc PC.
      Version 6.44. Tagged as 'Kernel-6_44'
    • Timothy E Baldwin's avatar
    • Timothy E Baldwin's avatar
      Remove remains of led setting from PageTest · e1c04167
      Timothy E Baldwin authored
      This was introduced on 2002-10-07 in Kernel-5_35-4_79_2_48
      the removed on 2002-11-30 in Kernel-5_35-4_79_2_51 as it
      was "liable to crash".
  10. 19 Oct, 2020 2 commits
  11. 19 Sep, 2020 1 commit
    • Jeffrey Lee's avatar
      OS_DynamicArea 22 fixes · 88219988
      Jeffrey Lee authored
      Multiple fixes, mostly related to error handling.
      1. Ensure R1 is initialised correctly when generating BadPageNumber
      errors (labels 94 & 95). Generally this involves setting it to zero to
      indicate that no call to LogOp_MapOut is required. Failing to do this
      would typically result in a crash.
      2. When branching back to the start of the loop after calling
      GetNonReservedPage, ensure R0 is reset to zero. Failing to do this would
      have a performance impact on LogOp_MapOut, but shouldn't be fatal.
      3. In the main routine, postpone writing back DANode_Size until after
      the call to physical_to_ppn (because we may decide to abort the op
      and return an error without moving a page).
      4. Fix stack offset when accessing PMPLogOp_GlobalTBLFlushNeeded.
      Getting this wrong could potentially result in some TLB maintenance
      being skipped when moving uncacheable pages.
      5. Fix stack imbalance at label 94
      Version 6.43. Tagged as 'Kernel-6_43'
  12. 15 Aug, 2020 1 commit
    • Timothy E Baldwin's avatar
      Fix cleaning · 5e131c13
      Timothy E Baldwin authored
      Move .gitignore file to root and populate with all temporary paths.
      This fixes .gitignore files being deleted during a ROM build.
      Version 6.42. Not tagged
  13. 25 Jul, 2020 1 commit
    • Timothy E Baldwin's avatar
      Disable interrupts whilst checking for keys in OS_ReadC / INKEY · 9d5ab8de
      Timothy E Baldwin authored
      This ensures that on exit from OS_ReadC / INKEY either
      a character is returned or the input buffer is empty,
      and that Portable_Idle is only called when the input
      buffer is empty.
      This avoids a 10 microsecond delay and relying on timer
      interrupts to make progress and allows reliably waiting
      for input and another event by:
      Disable Interrupts
        Call INKEY(0), exit loop if key pressed
        Check other event, exit loop if key pressed
        Call Portable_Idle
      Version 6.42. Tagged as 'Kernel-6_42'
  14. 11 Jul, 2020 1 commit
    • Jeffrey Lee's avatar
      Fix OS_Memory 7 for discontiguous RAM · fb127e47
      Jeffrey Lee authored
      The current OS_Memory 7 implementation uses an address range structure
      returned by HAL_PhysInfo to decide which part of the physical address
      arrangement table to overwrite with RAM information. I suspect the
      original intention was for OS_Memory to use this address range to avoid
      marking the VRAM as DRAM (HAL_PhysInfo is expected to fill in the VRAM
      itself). But by overwriting everything between the start and the end
      address, OS_Memory will also overwrite any non-RAM areas which are
      sandwiched between RAM banks, e.g. the VideoCore-owned RAM on Pi models
      with >1GB RAM. There's also the problem that the address range returned
      by the HAL is using 32bit addresses, so it won't work as-is for RAM
      located above the 4GB barrier.
      Fix these issues by reworking the routine so that it ignores the address
      range returned by the HAL and instead detects VRAM by checking the
      IsVRAM flag in the PhysRamTable entry. And for detecting if the ROM is
      running from RAM, instead of using the address range we can rely on the
      flag available via OS_ReadSysInfo 8 (i.e. HAL_PlatformInfo), like
      OS_Memory 8 does.
      Also add a simple BASIC program (Dev.PhysInfo) to allow easy checking of
      HAL & OS physical address arrangement tables.
      Version 6.41. Tagged as 'Kernel-6_41'
  15. 01 Jul, 2020 6 commits
    • Jeffrey Lee's avatar
      Add missing AMBControl appspace shrink check · 0634b535
      Jeffrey Lee authored
      Fix GrowFreePoolFromAppSpace (i.e. appspace shrink operation) to issue
      UpCall_MemoryMoving / Service_Memory when attempting to shrink PMP-based
      appspace (i.e. AMBControl nodes). This fixes (e.g.) BASIC getting stuck
      in an abort loop if you try and use OS_ChangeDynamicArea to grow the
      free pool.
      Version 6.40. Tagged as 'Kernel-6_40'
    • Jeffrey Lee's avatar
      Fix PMP appspace size check · 5014117d
      Jeffrey Lee authored
      Fix AreaGrow to read appspace size correctly when appspace is a PMP
      (i.e. an AMBControl node). Reading DANode_Size will only report the
      amount of memory currently paged in (e.g. by lazy task swapping),
      causing AreaGrow to underestimate how much it can potentially take from
      the area.
    • Jeffrey Lee's avatar
      Fix GrowFreePool · 1a3c927f
      Jeffrey Lee authored
      Buggy since its introduction in Kernel-5_35-4_79_2_284, GrowFreePool was
      attempting to grow the free pool by shrinking application space, an
      operation which OS_ChangeDynamicArea doesn't support. Change it to grow
      the free pool instead, and fix a couple of other issues that would have
      caused it to work incorrectly (register corruption causing it to request
      a size change of zero, and incorrect assumption that
      OS_ChangeDynamicArea returns the amount unmoved, when really it returns
      the amount moved)
    • Jeffrey Lee's avatar
      Fix combined freepool + appspace shrink · 76d04b25
      Jeffrey Lee authored
      When a DA tries to grow by more than the free pool size, the kernel
      should try to take the necessary remaining amount from application
      space. Historically this was handled as a combined "take from freepool
      and appspace" operation, but with Kernel-5_35-4_79_2_284 this was
      changed to use a nested call to OS_ChangeDynamicArea, so first appspace
      is shrunk into the free pool and then the target DA is grown using just
      the free pool.
      However the code was foolishly trying to use ChangeDyn_AplSpace as the
      argument to OS_ChangeDynamicArea, which that call doesn't recognise as a
      valid DA number. Change it to use ChangeDyn_FreePool ("grow free pool
      from appspace"), and also fix up a stack imbalance that would have
      caused it to misbehave regardless of the outcome.
    • Jeffrey Lee's avatar
      Fix shrinkables check in AreaGrow · 86fe0712
      Jeffrey Lee authored
      TryToShrinkShrinkables_Bytes expected both R1 and R2 to be byte counts,
      but AreaGrow was calling with R1 as a byte count and R2 as a page count.
      This would have caused it to request the first-found shrinkable to
      shrink more than necessary, and also confuse the rest of AreaGrow when
      the page-based R2 result of TryToShrinkShrinkables gets converted to a
      byte count (when AreaGrow wants it as a page count)
    • Jeffrey Lee's avatar
      Fix Service_Memory when shrinking appspace · 323e88c6
      Jeffrey Lee authored
      Update AreaShrink so that (when shrinking appspace) CheckAppSpace is
      passed the change amount as a negative number, so that Service_Memory is
      issued with the correct sign.
      Fixes issue reported on the forums, where BASIC was getting confused
      because appspace shrinks were being reported as if they were a grow
      It looks like this bug was introduced in Kernel-5_35-4_79_2_284
      (introduction of PMPs), where the logic for appspace shrinks (which must
      be performed via a grow of the free pool or some other DA) were moved
      out of AreaGrow and into AreaShrink (because appspace shrinks are now
      internally treated as "shrink appspace into free pool")
  16. 22 Jun, 2020 1 commit
    • Jeffrey Lee's avatar
      Fix OS_Byte 166 for high ZeroPage, make read-only · 0595a541
      Jeffrey Lee authored
      Despite never being properly documented in the RISC OS PRMs, there's
      evidence that Acorn were recommending that third-parties used OS_Byte
      166 for locating the OS_Byte variables well into the mid-1990's:
      Currently OS builds which use zero page relocation will only return the
      low 16 bits of the address from OS_Byte 166, most likely breaking any
      third-party software which is trying to use it. Attempt to restore
      compatibility by having OS_Byte 166 add the missing high address bits
      into the "next location" value returned in R2, and fix OS_Byte 167 in a
      similar manner (adding into R1).
      Additionally, make the values read-only, because the kernel is littered
      with code that uses hard-coded OsbyteVars addresses and so is unlikely
      to do anything sensible if someone was to modify the OsbyteVars address
      that's stored in workspace.
      Version 6.39. Tagged as 'Kernel-6_39'
  17. 23 May, 2020 1 commit
    • Ben Avison's avatar
      Mirror OS_AMBControl changes from Pyromaniac · 2991e2df
      Ben Avison authored
      * 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'
  18. 23 Mar, 2020 1 commit
    • ROOL's avatar
      Resync with allocations database · b5d0e2dc
      ROOL authored
      Edits to the RISCOS header file should really have gone through the
      allocations system. Fortunately, no harm was done in this case, but a
      minor syntactical change is required in order to bring it in line with
      the automatic redaction scripts used when exporting the header from the
      allocations database.
      Version 6.37. Not tagged