GitLab

OS_CLI permits commands to be prefixed with a temporary filing
system, for example "ADFS:Format"

It also passes commands unrecognised to FileSwitch to be executed,
so "ADFS::HardDisc4.$.!Boot" first sets the temporary filing to
ADFS then executes ":HardDisc4.$.!Boot".

This does not work if the path contains a special field,
currently this results in an error as the special filed
would be lost.

Unfortunately many programs, including the RISC OS source
fail because of this.

Instead if a filing system prefix with special field
is found switch to the Temporary filing system and
treat the whole command as a path to execute. For example
passing "IXFS#W:$.HardDisc4.!Boot" sets the temporary filing
system to "IXFS" then executes "IXFS#W:$.HardDisc4.!Boot".

Version 6.30. Tagged as 'Kernel-6_30'

OS_DynamicArea 27 is the same as OS_DynamicArea 5 ("return free
memory"), except the result is measured in pages instead of bytes,
allowing it to behave sensibly on machines with many gigabytes of RAM.

Similarly, OS_DynamicArea 28 is the same as OS_DynamicArea 7 (internal
DA enumeration call used by TaskManager), except the returned size
values are measured in pages instead of bytes. A flags word has also
been added to allow for more expansion in the future.

Hdr:OSMem now also contains some more definitions which external code
will find useful.

Version 6.29. Tagged as 'Kernel-6_29'

Version 6.28. Not tagged

This change adds a new OS_Memory reason code, 23, for reserving memory
without actually assigning it to a dynamic area. Other dynamic areas can
still use the memory, but only the code that reserved it will be allowed
to claim exclusive use over it (i.e. PageFlags_Unavailable).

This is useful for systems such as the PCI heap, where physically
contiguous memory is required, but the memory isn't needed all of the
time. By reserving the pages, it allows other regular DAs to make use of
the memory when the PCI heap is small. But when the PCI heap needs to
grow, it guarantees that (if there's enough free memory in the system)
the previously reserved pages can be allocated to the PCI heap.

Notes:

* Reservations are handled on an honour system; there's no checking that
the program that reserved the memory is the one attempting to map it in.

* For regular NeedsSpecificPages DAs, reserved pages can only be used if
the special "RESV" R0 return value is used.

* For PMP DAs, reserved pages can only be made Unavailable if the entry
in the page block also specifies the Reserved page flag. The actual
state of the Reserved flag can't be modified via PMP DA ops, the flag is
only used to indicate the caller's permission/intent to make the page
Unavailable.

* If a PMP DA tries to make a Reserved page Unavailable without
specifying the Reserved flag, the kernel will try to swap it out for a
replacement page taken from the free pool (preserving the contents and
generating Service_PagesUnsafe / Service_PagesSafe, as if another DA
had claimed the page)

Version 6.28. Tagged as 'Kernel-6_28'

 * MinAplWork isn't used.
 * SuperMode isn't used and is less well known than "SWI OS_EnterOS".
 * MEMCADR is now only a magic value returned by OS_UpdateMEMC,
   so it is clearer to include it literally with comment.

Added a comment to explain the baffling combination of
the MEMC1 control register's address with it's value.


Version 6.27. Not tagged

This makes SVLK and NVECTORS available.

Version 6.27. Tagged as 'Kernel-6_27'

Version 6.26. Tagged as 'Kernel-6_26'

Version 6.25. Tagged as 'Kernel-6_25'

Between RISC OS 3.6 and 3.7 the directory was renamed from
Doc to Docs and was duplicated during CVS import.

Fix by deleting Doc. Identical files remain in Docs.


Version 6.24. Not tagged

Detail:
This adds a new OS_DynamicArea reason code, 26, for adjusting
AplWorkMaxSize at runtime. This allows compatibility tools such as
Aemulor to adjust the limit without resorting to patching the kernel.
Any adjustment made to the value will affect the upper limit of
application space, and the lower limit of dynamic area placement.
Attempting to adjust beyond the compile-time upper/default limit, or
such that it will interfere with existing dynamic areas / wimpslots,
will result in an error.

Relevant forum thread:
https://www.riscosopen.org/forum/forums/11/topics/14734

Admin:
Tested on BB-xM, desktop active & inactive

Version 6.24. Tagged as 'Kernel-6_24'

Detail:

- s/HAL - Fix ADD v. SUB muddle that could prevent addresses from being rounded down correctly. Fix incorrect logical address being returned to caller on pre-ARMv6 machines due to PageTableSync corrupting a1.
- s/NewReset - Initialising the CMOS RAM cache while in the middle of setting up the processor vectors feels a bit silly. Move the code to just afterwards so that it feels a bit safer, and so that early crashes are easier to debug (processor vectors in stable state)

Admin:

Tested on Iyonix.
Fixes ROM softload failure reported on forums:
https://www.riscosopen.org/forum/forums/11/topics/14749

Version 6.23. Tagged as 'Kernel-6_23'

To achieve this:
* DecodeL1Entry and DecodeL2Entry return 64-bit physical addresses in
  r0 and r1, with additional return values shuffled up to r2 and r3
* DecodeL1Entry now returns the section size, so callers can distinguish
  section- from supersection-mapped memory
* PhysAddrToPageNo now accepts a 64-bit address (though since the physical
  RAM table is currently still all 32-bit, it will report any top-word-set
  addresses as being not in RAM)

Version 6.22. Tagged as 'Kernel-6_22'

ControlList_Interlaced is taken to have meant "output interlaced sync on H/V" and "configure DMA to show alternate lines in the framestore on alternate fields", therefore SyncPol flags mean:
b43
 00 = 'normal' progressive scan
 01 = interlaced sync, but both fields show the same image
 10 = (invalid)
 11 = interlaced sync, fields use alternate lines from the image

Version 6.21. Tagged as 'Kernel-6_21'

Without this, some CPUs (including Cortex-A72) take the undefined instruction
trap when encountering any CP15-encoded barrier instructions.

Requires RiscOS/Sources/Programmer/HdrSrc!1

Version 6.20. Tagged as 'Kernel-6_20'

Detail:
  s/vdu/vdudriver - When mapping external framestores, only double-map them if the driver supports hardware scrolling. Avoids wasting IO address space, and reduces IO space fragmentation if the framestore address changes
Admin:
  Tested on Raspberry Pi 3


Version 6.19. Tagged as 'Kernel-6_19'

Detail:
  s/vdu/vdupalxx:
  - Fix conditional code sequence in PV_BulkWrite which meant that the greyscale palette flag was being recalculated when the border or pointer colour was changed.
  - Change PV_1stFlashState / PV_2ndFlashState to act as NOPs in true colour modes, which helps to avoid regular redundant gamma table updates (due to the flashing colour logic in the VSync handler).
Admin:
  Tested on Raspberry Pi 3


Version 6.18. Tagged as 'Kernel-6_18'

Detail:
  s/vdu/legacymodes - Make the Service_ModeExtension implementation automatically use ExtraBytes to request that the row length is a multiple of a word (since things fail with non-word aligned rows)
  hdr/VIDCList - Un-deprecate SyncPol bits 2 & 3 and improve the comments to indicate the difference between SyncPol interlace and control list interlace
Admin:
  Tested on BB-xM


Version 6.17. Tagged as 'Kernel-6_17'

Detail:
  s/vdu/vduswis - Fix 18 year old register corruption bug in FindOKMode which would prevent it from falling back to Service_ModeTranslation if Service_ModeExtension returned a VIDC list but the VIDC list was rejected by the GraphicsV driver
  s/vdu/vdudriver - Also, change a couple of error cases in ModeChangeSub so that they use the "Screen mode not available" error instead of the incorrect "Not enough screen memory" error.
Admin:
  Tested on Raspberry Pi 3
  Fixes issue reported on forums where if AnyMode is loaded, numbered modes in unsupported colour depths weren't being replaced with substitutes (although note that there are still some AnyMode-related issues to resolve)
  https://www.riscosopen.org/forum/forums/4/topics/12773


Version 6.16. Tagged as 'Kernel-6_16'

Detail:
  s/ARMops - If the ICacheInvalidate macro was told to pull a2, it would pull it before invoking ICache_InvalidateRange, causing the end address of the range to be lost. Avoid this by only pulling the registers after the ranged call.
  Also optimise MMU_ChangingEntry to go straight to ICache_InvalidateRange instead of doing a redundant range size check.
Admin:
  Tested on OMAP5
  Potentially fixes lockup/long stall seen when using PhotoDesk, reported by Willi Theiss


Version 6.15. Tagged as 'Kernel-6_15'

Detail:
  Over the years the OS's substitute screen mode selection logic has grown to be a tangled mess, and the logic it does implement isn't always very useful. Additionally, the kernel is structured in such a way that it can be hard for modules to override it.
  This set of changes aims to fix the many of the problems, by doing the following:
  - Moving all substitute mode selection logic out of the core VDU driver code and into a Service_ModeTranslation handler. This means you now only have one place in the kernel to look instead of several, and modules can override the behaviour by claiming/blocking the service call as appropriate.
  - Moving handling of the built-in VIDC lists out of the core VDU driver code and into a Service_ModeExtension handler. This means programs can now inspect these VIDC lists by issuing the right service call (although you are essentially limited to lists which the GraphicsV driver is OK with)
  - Moving *TV interlace & offset adjustment logic into the Service_ModeExtension handler, since they're legacy things which can be handled more cleanly for MDF/EDID (and the old code was poking memory the kernel didn't own)
  - Adding a Service_EnumerateScreenModes implementation, so that if you end up in the desktop with ScreenModes non-functional, the display manager at least has something useful to show you
  - Enhancing the handling of the built-in numbered modes so that they are now available in any colour depth; the Service_ModeExtension handler (and related handlers) treat the builtin VIDC lists as a set of mode timings, not a discrete set of modes
  - Substitute mode selection logic is a complete re-write. Instead of trying a handful of numbered fallback modes, it now tries:
    - Same mode but at higher colour depths
    - Same mode but at lower colour depths
    - Alternate resolutions (half-width mode with no double-pixel if original request was for double-pixel, and default resolution for monitor type)
  - Combined with the logic to allow the builtin VIDC lists to be used at any colour depth, this means that the kernel should now be able to find substitute modes for machines which lack support for <=8bpp modes (e.g. OMAP5)
  - Additionally the mode substitution code will attempt to retain as many properties of the originally requested mode as possible (eigen values, gap mode type, etc.)
  Other improvements:
  - The kernel now actually vets the builtin VIDC lists instead of assuming that they'll work (which also means they'll have the correct ExtraBytes value, where applicable)
  - The kernel now uses GraphicsV 19 (VetMode2) to vet the mode during the mode switch process, using the result to detect where the framebuffer will be placed. This allows for GraphicsV drivers to switch between DA 2 and external framestores on a per-mode basis.
  - The kernel now supports mode selectors which specify LineLength values which are larger than necessary; this will get translated to a suitable ExtraBytes control list item (+ combined with whatever padding the driver indicates is necessary via the VetMode2 result)
  File changes:
  - hdr/KernelWS - Reserve space for a VIDC list, since the Service_ModeExtension implementation typically can't use the built-in list as-is
  - s/Arthur3 - Issue Service_ModeFileChanged when the configured monitor type is changed, so that DisplayManager + friends are aware that the set of available modes has changed
  - s/GetAll - Fiddle with GETs a bit
  - s/MemMap2 - Extra LTORG
  - s/NewIRQs - Small routine to install/uninstall false VSync routine (previously from PushModeInfo, which wasn't really the appropriate place for it)
  - s/Utility - Hook up the extra service call handlers
  - s/vdu/legacymodes - New file containing the new service call implementations, and some related code
  - s/vdu/vdudecl - Move mode workspace definition here, from vdumodes
  - s/vdu/vdudriver - Remove assorted bits of mode substitution code. Plug in new bits for calling GraphicsV 19 during mode set, and deal with ExtraBytes/LineLength during PushModeInfo
  - s/vdu/vdumodes - Move some workspace definitions to s/vdu/vdudecl. Tweak how the builtin VIDC lists are stored.
  - s/vdu/vduswis - Rip out more mode substitution code. Issue Service_ModeFileChanged when monitor type is changed by OS_ScreenMode.
Admin:
  Tested on Raspberry Pi 3, Iyonix, IGEPv5


Version 6.14. Tagged as 'Kernel-6_14'

Detail:
  s/vdu/vdudriver - When using mode selector blocks, don't allow the system to switch into double-vertical, double-pixel, or BBC-gap modes which are in colour depths unsupported by the kernel
Admin:
  Tested on BB-xM


Version 6.13. Tagged as 'Kernel-6_13'

Detail:
  s/HAL - OS_Hardware 3 (remove HAL device) will now re-scan the device list for the device following the Service_Hardware call, so that the device list won't become corrupt if the service call triggers addition/removal of devices.
Admin:
  Tested on iMX6
  *HDMIOff now correctly removes the HDMI audio device and SoundDMA's software mixer device (SoundDMA removes mixer in response to the HDMI audio device vanishing, but re-entrancy bug meant that the HDMI device was left on the list)
  Note that this only covers re-entrancy via Service_Hardware. OS_Hardware 2/3/4/5 are not re-entrant from other locations (e.g. IRQ handlers or memory allocation service calls).


Version 6.12. Tagged as 'Kernel-6_12'

Detail:
  ECFIndex and PalIndex claim to be mode variables, but it's impossible for extension modes to specify their values.
  Since they're easy to calculate from the ModeFlags and Log2BPP values, drop them from the mode workspace (+ table of builtin modes) and calculate them on the fly instead.
  File changes:
  - hdr/KernelWS - Drop ECFIndex & PalIndex from workspace
  - s/vdu/vdumodes - Adjust workspace definition, drop ECFIndex & PalIndex values from VWSTAB
  - s/vdu/vdudriver - Remove now-redundant copy loop from ModeChangeSub. Remove code from GenerateModeSelectorVars that sets up the ECFIndex & PalIndex values on the stack
  - s/vdu/vdugrafl - Adjust copy loop in SwitchOutputToSprite/Mask
  - s/vdu/vdupalette, s/vdu/vdupalxx - Add GetPalIndex routine to generate PalIndex on the fly. Drop the obsolete 16bpp palette/gamma table and shuffle the other entries to simplify GetPalIndex a bit.
  - s/vdu/vduplot - Add GetECFIndex routine to generate ECFIndex on the fly. Also, fix things so that mode 0 isn't the only rectangular-pixel mode which uses the special rectangular-pixel ECF patterns (index 0 vs. index 4). Fiddle with ExportedHLine a bit to avoid an out-of-range ADR.
  - s/NewReset - Fix UAL warning for MOV R0, AppSpaceStart. Adjust memset to not assume 512KB is the correct amount
Admin:
  Tested on Raspberry Pi 3


Version 6.11. Tagged as 'Kernel-6_11'

Detail:
  s/MemInfo - The wrapper around OS_Memory 0 introduced in Kernel-5_35-4_79_2_311 was preserving the wrong PSR field on exit, causing any error generated by the core code to be lost.
Admin:
  Tested on Iyonix
  Fixes *screensave saving mostly white pixels (address translation for "external" VRAM should have failed and caused ADFS to fall back to a bounce buffer)
  Is also likely to be the cause of https://www.riscosopen.org/forum/forums/5/topics/11713 (address translation should have failed for soft ROM)


Version 6.10. Tagged as 'Kernel-6_10'

Detail:
  hdr/Options - The setting of the SMP switch can now be controlled by specifying the correct ASFLAGS, e.g. ASFLAGS="-PD \"SMP SETL {FALSE}\""
Admin:
  Untested


Version 6.08, 4.129.2.10. Tagged as 'Kernel-6_08-4_129_2_10'

Detail:
  As the application slot is now a normal dynamic area, there's no need to manipulate the CAM directly. Convert FudgeSomeAppSpace into a OS_ChangeDynamicArea SWI followed by memset().
  ChangeDyn.s: Offset by 32k to account for the -32k that dynamic area -1 has.
  NewReset.s: Delete FudgeSomeAppSpace and replace as above.
Admin:
  Submission from Timothy Baldwin.

Version 6.08. Tagged as 'Kernel-6_08'

Detail:
  NewReset.s: Remove warning about soft reset, this is not supported any longer
  MsgCode.s: Reload LR after potentially changing mode
  PMF/osinit.s: Delete vestiges of soft reset support
Admin:
  Submission from Timothy Baldwin.

Version 6.07. Tagged as 'Kernel-6_07'

Detail:
  hdr/VduExt:
  - Introduce mode variable 13, for specifying the minimum number of screen banks that are guaranteed to be available. Eventually the kernel will make use of this during mode vetting & selection, to give programs a simple and reliable way of selecting banked screen modes. Currently however it's only supported by VideoOverlay and the corresponding GraphicsV overlay APIs.
  - Extend the mode flags to allow display rotation & flipping to be specified. This is used to indicate that the framebuffer accessed by the CPU is not in the same orientation as what the user is seeing. Again, currently this is only supported by VideoOverlay and the corresponding GraphicsV overlay APIs.
Admin:
  Tested on OMAP3, OMAP4


Version 6.06. Tagged as 'Kernel-6_06'

Detail:
Admin:


Version 6.05. Tagged as 'Kernel-6_05'

Detail:
  The error block checks introduced in Kernel-5_35-4_79_2_313 are generating a few too many false positives and edge cases, so take the safe option of just disabling them rather than trying to tweak the rules further. Error pointers will still be checked, but the content of the error blocks will not.
  hdr/Options - Add CheckErrorBlocks switch so we can easily turn the code back on again in the future if necessary
  s/Kernel - Switch out all the code relating to error number checks, except for the dummy load of the first word of the error block, since that's still useful as a pointer validity check
  hdr/KernelWS - Revise SWIDespatch_Size definition so it's easier for it to cope with the various factors which may affect the despatcher size
Admin:
  Tested on PandaBoard
  Relevant discussion:
  https://www.riscosopen.org/forum/forums/11/topics/11133


Version 6.04. Tagged as 'Kernel-6_04'

Version 6.03. Tagged as 'Kernel-6_03'

Version 6.02. Tagged as 'Kernel-6_02'

Detail:
  Resolve allocation clash for vector &2C.  It appears that RISCOS Ltd used
  this vector in RISC OS 6 without getting it allocated - they really should
  have known better, since Hdr:RISCOS has always one of the header files
  centrally managed and coordinated between the two forks of RISC OS.
  Resolved by moving SeriousErrorV to &2D since it is a relatively recent
  addition (April 2016) and hasn't yet featured in a stable RISC OS 5
  release.
  Also correct some comments elsewhere in Hdr:RISCOS.


Version 6.01. Tagged as 'Kernel-6_01'

Detail:
  s/ChangeDyn - Due to the way that some page flags map to the same bits as (different) DA flags, the Batcall that PMP_PreGrow makes in order to claim the requested page was getting confused and thinking that the special DMA PreGrow handler should be used instead of the DA-specific one (which in this case is a custom one responsible for claiming the right page). Modify PMP_PreGrow so that it only supplies DA flags to the Batcall, and patches in any custom page flags afterwards.
  Also swap magic number for appropriate symbol in PMPGrowHandler.
Admin:
  Tested on BB-xM
  Fixes CAM corruption when a PMP claims a specific page, due to the PMP code and DA code disagreeing about which page should be used


Version 6.00. Tagged as 'Kernel-6_00'

The default OS_Byte value enabled num lock, but this was passed to the keyboard *before* a decision to wipe the CMOS (and hence potentially override it) was made.
This left the LED on until a key was pressed, regardless of the configured state.
Change the default OS_Byte value to be off so there's only one transition (off->on, or off->off), and refresh the keyboard after the validity of CMOS has been made.
Ref: https://www.riscosopen.org/forum/forums/4/topics/10400

Version 5.99. Tagged as 'Kernel-5_99'

Detail:
  s/Middle - Tweak register dump generation so that it'll attempt to provide sensible R13 & R14 values if the abort came from the same mode that we're handling the abort in. R13 will be adjusted by however much data we've pushed onto the stack, and R14 will be set to &DEADDEAD to indicate that the CPU has corrupted it and we don't know what the original value was.
Admin:
  Tested on BB-xM


Version 5.98. Tagged as 'Kernel-5_98'

When SyncLib-0_04 is used in conjunction with SDIODriver, the exclusive access instructions (instead of SWP) abort when the cache is off, causing the machine to hang if *Cache Off is used.
See A15 TRM section 6.4.5 for the logic.
Copy the A53's known CPU flags to prevent the D cache being turned off.

Version 5.97. Tagged as 'Kernel-5_97'

Detail:
  s/vdu/vdudriver - On startup, initialise all palettes to 0, not just Pal_Blank. Ensures that entries which might not always be explicitly initialised (e.g. pointer) are self-consistent. Also make sure InitialiseMode communicates the pointer palette to the new GV driver, since some components tend to program it in a lazy manner (e.g. Hourglass)
  s/vdu/vdupalxx - Fix UpdateAllPalette setting R4 to 0 on exit. Fix PV_BlankScreen R0 return value to be 0/1 as the comment suggests instead of always being 0 due to GraphicsV calls.
Admin:
  Tested on wandboard
  Fixes incorrect hourglass colours after reset, due to software RAM clear not wiping the kernel's palette (kernel + Hourglass thought old colours were still in use, but IMXVideo hadn't been told any colours yet so was using defaults of 0)


Version 5.96. Tagged as 'Kernel-5_96'

Newly born boards have all 0xFF's in their CMOS (EEPROM), but the new order of keyboard scan did
  Init -> Scan keyboard -> Check (or wipe) CMOS
and would therefore leave 0xFF's in a select few kernel workspace areas and OS_Byte values.
Defer the init which reads CMOS until after the check/wipe step. Only the screen area size is now done early, but MassageScreenSize clamps that properly anyway.

Arthur3.s: Relocate stranded function SetupPrinterBuffer to osinit.
PMF/key.s: Drop support for SoftReset.
PMF/osinit.s: Stuff in hardcoded defaults at early init. Retrieve the proper ones later. Take ownership of SystemSprite/RamFS/Font Manager dynamic areas (deferrable).
vdudriver.s: Use symbolic name.
NewReset.s: Defer SystemSprite/RamFS/Font Manager area creation, MouseInit, Read(Hard)CMOSDefaults until later.
hdr/Options: Delete unused IgnoreVRAM. Remove MaxRAMFS_Size now PMPs make it not useful. Shuffle ARM6Support/XScaleMiniCache/XScaleJTAGDebug to be adjacent to their definitions.

Tested by filling first 256 bytes with 0xFF and powering up. Reset now completes, OS_Byte variables look sensible.

Version 5.95. Tagged as 'Kernel-5_95'

Detail:
  s/vdu/vdugrafl - Disable hardware scrolling if we're in a teletext mode with a border. Quick fix in lieu of adding some code to make sure the relevant border areas are cleared when scrolling.
  s/vdu/vduttx - Ignore VDU 23,18,<n> sequences when outside of teletext. Fixes a crash when screen update suspend/resume sequences are used.
Admin:
  Tested on RiscPC


Version 5.94. Tagged as 'Kernel-5_94'