GitLab

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/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'

Detail:
  The ExtraBytes control list item can be used to add padding between framebuffer rows.
  When the kernel sees a VIDC list containing this item, it will now adjust the LineLength and ScreenSize mode variables accordingly, with the end result that the correct amount of memory will be allocated for the framebuffer and the OS will render into it correctly.
  Files changed:
  - hdr/KernelWS - Add DisplayLineLength variable to allow the correct LineLength value to be preserved when screen output is redirected to a sprite
  - s/vdu/vdudriver - Make ModeChangeSub initialise DisplayLineLength before calling SwitchOutputToSprite. Update PushModeInfo to take ExtraBytes into account when calculating LineLength and ScreenSize.
  - s/vdu/vdugrafl - Adjust SwitchOutputToSprite to use DisplayLineLength when restoring screen output
  - s/vdu/vduwrch - Fix full-screen CLS to not write to the padding bytes
Admin:
  Tested on Raspberry Pi 3


Version 5.82. Tagged as 'Kernel-5_82'

Detail:
  s/vdu/vdugrafl, s/vdu/vduttx - Adjust initialisation & shutdown of TTX workspace to fix workspace being erroneously freed/reinitialised when redirecting output to a sprite
  s/vdu/vdugrafk - If ScreenLoad needs to load one row at a time (e.g. when graphics window width != sprite width), allocate a block from the RMA instead of assuming that ScrLoaBuffer is large enough
  hdr/KernelWS - Get rid of ScrLoaBuffer, and shrink LargeCommon to a suitable size. Frees about 2K of VDU workspace.
  s/GetAll - Move Hdr:Sprite earlier in list of GETs
Admin:
  Tested on Raspberry Pi


Version 5.75. Tagged as 'Kernel-5_75'

Detail:
  This set of changes:
  * Adds support for the T, TX and TY mode string elements (as per RISCOS Ltd)
  * Adds support for entering arbitrary-resolution teletext modes by using mode selector blocks with the Teletext mode flag set
  * ScrRCol and ScrBRow mode variables can be provided in the mode selector in order to restrict the number of text rows/columns in teletext modes (as per RISCOS Ltd)
  * If the rows / columns are restricted in this manner then the text window will be centered on the screen, to try and avoid things looking too ugly (no variable text scaling implemented)
  * For HiResTTX, all colour depths >= 4bpp are now supported by teletext. This essentially makes the TTX256 switch obsolete.
  * If the "native" mode 7 is unavailable then the kernel will try a series of fallback resolutions & colour depths in an effort to find a combination that works
  Known bugs/issues:
  * Teletext column count has a max limit of 255 due to TTXDoubleCounts being a byte array
  * If there's a border around the text window, the border will not be refreshed when changing transparency modes using a VDU 23,18,0 sequence
  * ScreenLoad looks like it can overflow the LargeCommon buffer (no buffer size check) - needs fixing before LargeCommon can be safely shrunk below (Old)TTXMapSize
  File changes:
  - hdr/KernelWS - Make CharWidth non-conditional. Adjust handling of teletext workspace; it's now allocated from the system heap to allow it to cope with arbitrary screen sizes
  - s/vdu/vdu23 - Make CharWidth non-conditional
  - s/vdu/vducursoft - Make CursorTeletext cope with arbitrary colour depths, make CharWidth non-conditional, remove hard-coded teletext values
  - s/vdu/vdudriver - Deal with teletext workspace allocation during ModeChangeSub. Deal with selecting teletext modes (and validating colour depth) in GenerateModeSelectorVars.
  - s/vdu/vdugrafl - Make CharWidth non-conditional. Calculate offset required for text window centering.
  - s/vdu/vdumodes - Remove TTX256
  - s/vdu/vduswis - Try other teletext modes if native mode 7 not available. Extend OS_ScreenMode reason codes to cope with teletext mode strings.
  - s/vdu/vduttx - Update to use dynamic workspace. Replace various hardcoded values with variable lookups. Update character plotting + colour/palette selection to work with true-colour modes if HiResTTX.
  - s/vdu/vduwrch - Move some useful code into a subroutine. Update FastCLS to cope with true-colour teletext. Update AddressR0R1 to cope with text window centering offset. Make CharWidth non-conditional.
Admin:
  Tested on Raspberry Pi, BB-xM
  VDU 23,18,0 in 256-colour teletext now works correctly (previously 64-colour mode was in use, causing palette update to be ruined by VIDC1-mangling)


Version 5.74. Tagged as 'Kernel-5_74'

Detail:
  This change gets rid of the following switches from the source (picking appropriate code paths for a desktop build):
  * STB
  * RO371Timings
  * NormalSpeedROMS
  * AutoSpeedROMS
  * RISCPCBurstMode
  * InterlacedPointer
  * ParallelFlashUpgrade (and s/FlashROM file)
  * Embedded_UI
  Some of the deleted code might be worth revisiting in future:
  * OS_ReadSysInfo 4 support for storing the MAC in alternate CMOS locations (including 2nd copy for error checking) or fetching via Service_MachineAddress
  * Mouse handling changes, possibly aimed at hiding the mouse pointer if a mouse isn't connected
  * More strict CMOS validation in s/NewReset
Admin:
  Identical binary to previous revision for IOMD & Raspberry Pi builds


Version 5.50. Tagged as 'Kernel-5_50'

ModeFlag_GreyscalePalette handling improvements. Issue service calls on certain GraphicsV events. Sprite tweaks and fixes.

Detail:
  hdr/VduExt - Add reason codes used by Service_DisplayChanged & Service_DisplayStatus
  s/vdu/vdugrafg - Remove dependency on SpriteReason_BadReasonCode; just use the size of our lookup table instead. Alter SpriteOp lookup table so that unimplemented ops return an error instead of doing nothing. Fix PutSprite incorrectly using the slow GCOL action plotter if a request was made to plot a sprite using its mask but the sprite has none.
  s/vdu/vdugrafl - Update screen redirection handling to set ModeFlag_GreyscalePalette if switching output to a sprite with a greyscale palette or a RISC OS Select alpha mask. Restore the flag to its correct value when restoring screen output.
  s/vdu/vdupalxx - Update ModeFlag_GreyscalePalette in realtime as the palette is changed
  s/vdu/vduswis - Issue Service_DisplayChanged during OS_ScreenMode 11. Issue Service_DisplayStatus during OS_ScreenMode 65 & 66.
Admin:
  Tested on Iyonix, BB-xM


Version 5.35, 4.79.2.210. Tagged as 'Kernel-5_35-4_79_2_210'

Add support for the new RISC OS 5 style sprite mode word. Add partial support for alpha channel sprite masks. Implement OS_ScreenMode reasons 13-15

Detail:
  ECFShift/ECFYOffset:
  - hdr/PublicWS - Add ECFShift and ECFYOffset to list of public exports (SpriteExtend was using hardcoded values). Rearrange exports so that VduWorkspace exports are now labelled as such.
  - hdr/KernelWS - Make sure ECFShift & ECFYOffset match their exported locations
  - hdr/OSRSI6, s/Middle - Add OS_ReadSysInfo 6 items 83 & 84, for reading ECFYOffset and ECFShift locations
  Mode flags/VDU variables:
  - Makefile - Add hdr/VduExt to the C header exports
  - hdr/VduExt - Get rid of NotRVVTBarWobblyBits macro and defined VDU variables manually so that Hdr2H will handle them. Begin replacing overly generic 'Flag_*' mode flag definitions with 'ModeFlag_*' instead. Define new flags as required by the new screen/sprite modes. Add OS_ScreenMode reason codes and mode selector format (from s.vdu.vdudecl)
  - NewModes/NEWF2, NewModes/OldPSSrc, NewModes/PSSrc, s.vdu.vdu23, s.vdu.vducursoft, s.vdu.vdudriver, s.vdu.vdugrafg, s.vdu.vdugrafj, s.vdu.vdugrafl, s.vdu.vdumodes, s.vdu.vdupal10, s.vdu.vdupal20, s.vdu.vdupalette, s.vdu.vdupalxx, s.vdu.vduwrch - Renaming Flag_* to ModeFlag_*
  - s.vdu.vdudecl - Remove OS_ScreenMode reason codes & mode selector format definitions; these are now in hdr/VduExt. Flag_* -> ModeFlag_* renaming.
  - s.vdu.vdupalxx - Apply a greyscale palette in PV_SetDefaultPalette if the greyscale mode flag is set
  New sprite types:
  - s.vdu.vdudriver - Extend GenerateModeSelectorVars to deal with the wide mask flag, 64K sprites, and the new RISC OS 5 sprite mode word format.
  - s.vdu.vdugrafdec - Store more information about the sprite in the SprReadNColour ... SprLog2BPC block.
  - s.vdu.vdugrafg - Update SpriteVecHandler to be able to detect whether RISC OS 5 format sprites are allowed palettes. Update SetupSprModeData to store the extra sprite info that's defined in vdugrafdec. Update PutSprite to fault any sprites with wide masks - SpriteExtend must be used for that (once implemented!)
  - s.vdu.vdugrafh - Update WritePixelColour to avoid temporary poking of NColour VDU variable for 8bpp sprites. Correctly replicate data when writing to RISC OS 5 format sprites. Update ReadPixelMask, WritePixelMask, SpriteMaskAddr, GetMaskspWidth to deal with wide masks. Delete obsolete bounce_new_format_masks routine.
  - s.vdu.vdugrafi - Comment updated to reflect new reality
  - s.vdu.vdugrafj - Get rid of unused code block in CreateHeader/PostCreateHeader. Update SanitizeSGetMode to generate RISC OS 5 style sprite mode words where applicable. Update DecideMaskSize to rely on GetMaskspWidth for calculating mask width.
  - s.vdu.vdugrafl - Update SwitchOutputToSprite/SwitchOutputToMask to deal with the new sprite formats. Allow PushModeInfoAnyMonitor to fail.
  - s.vdu.vduswis - Extended OS_ReadModeVariable to cope with new sprite types
  Misc:
  - s.vdu.vdudriver - Fixed bug with VIDCList copying where any -1 value in the structure would terminate the copy, instead of only -1 as a control item number
  - s.vdu.vduswis - Implemented OS_ScreenMode 13 (Mode string to specifier), 14 (mode specifier to string), and 15 (set mode by string). Mostly as per ROL's specs, but minus support for teletext attributes, and plus support for new RISC OS 5 attributes (L... layout specifier, 4096 & 24bpp packed modes, etc.)
  - s.vdu.vduwrch - Pick correct default text colours for the new modes
Admin:
  Tested on BB-xM
  Part of an implementation of the Extended Framebuffer Format spec:
  http://www.riscosopen.org/wiki/documentation/show/Extended%20Framebuffer%20Format%20Specification


Version 5.35, 4.79.2.194. Tagged as 'Kernel-5_35-4_79_2_194'

Expand tabs.
Swap DCI for instructions now Objasm 4 is out.
Symbols for FSControl_CAT/RUN/OPT changed to non Arthur definitions.
Still boots on IOMD class, no other testing.

Version 5.35, 4.79.2.124. Tagged as 'Kernel-5_35-4_79_2_124'

Detail:
  A whole mass of changes to add high processor vectors + zero page relocation support to the Cortex branch of the kernel
  At the moment the code can only cope with two ZeroPage locations, &0 and &FFFF0000. But with a bit more tweaking those restrictions can probably be lifted, allowing ZeroPage to be hidden at almost any address (assuming it's fixed at compile time). If I've done my job right, these restrictions should all be enforced by asserts.
  There's a new option, HiProcVecs, in hdr/Options to control whether high processor vectors are used. When enabling it and building a ROM, remember:
  * FPEmulator needs to be built with the FPEAnchor=High option specified in the components file (not FPEAnchorType=High as my FPEmulator commit comments suggested)
  * ShareFS needs unplugging/removing since it can't cope with it yet
  * Iyonix users will need to use the latest ROOL boot sequence, to ensure the softloaded modules are compatible (OMAP, etc. don't really softload much so they're OK with older sequences)
  * However VProtect also needs patching to fix a nasty bug there - http://www.riscosopen.org/tracker/tickets/294
  The only other notable thing I can think of is that the ProcessTransfer code in s/ARM600 & s/VMSAv6 is disabled if high processor vectors are in use (it's fairly safe to say that code is obsolete in HAL builds anyway?)
  Fun challenge for my successor: Try setting ZeroPage to &FFFF00FF (or similar) so its value can be loaded with MVN instead of LDR. Then use positive/negative address offsets to access the contents.
  File changes:
  - hdr/ARMops - Modified ARMop macro to take the ZeroPage pointer as a parameter instead of 'zero'
  - hdr/Copro15ops - Corrected $quick handling in myISB macro
  - hdr/Options - Added ideal setting for us to use for HiProcVecs
  - s/AMBControl/allocate, s/AMBControl/growp, s/AMBControl/mapslot, s/AMBControl/memmap, s/AMBControl/service, s/AMBControl/shrinkp, s/Arthur2, s/Arthur3, s/ArthurSWIs, s/ChangeDyn, s/ExtraSWIs, s/HAL, s/HeapMan, s/Kernel, s/MemInfo, s/Middle, s/ModHand, s/MoreSWIs, s/MsgCode, s/NewIRQs, s/NewReset, s/Oscli, s/PMF/buffer, s/PMF/IIC, s/PMF/i2cutils, s/PMF/key, s/PMF/mouse, s/PMF/osbyte, s/PMF/oseven, s/PMF/osinit, s/PMF/osword, s/PMF/oswrch, s/SWINaming, s/Super1, s/SysComms, s/TickEvents, s/Utility, s/vdu/vdu23, s/vdu/vdudriver, s/vdu/vdugrafl, s/vdu/vdugrafv, s/vdu/vdupalxx, s/vdu/vdupointer, s/vdu/vduswis, s/vdu/vduwrch - Lots of updates to deal with zero page relocation
  - s/ARM600 - UseProcessTransfer option. Zero page relocation support. Deleted pre-HAL ClearPhysRAM code to tidy the file up a bit.
  - s/ARMops - Zero page relocation support. Set CPUFlag_HiProcVecs when high vectors are in use.
  - s/KbdResPC - Disable compilation of dead code
  - s/VMSAv6 - UseProcessTransfer option. Zero page relocation support.
Admin:
  Tested with OMAP & Iyonix ROM softloads, both with high & low zero page.
  High zero page hasn't had extensive testing, but boot sequence + ROM apps seem to work.


Version 5.35, 4.79.2.98.2.48. Tagged as 'Kernel-5_35-4_79_2_98_2_48'

Added 256-colour version of the (high-resolution only) teletext code, and support for teletext when hardware scroll is disabled. Both are required for Tungsten.

Turned off the module init/final service calls, since we still don't have an
allocation for them.
Upped the OS version number to 5.01.

Version 5.35, 4.79.2.53. Tagged as 'Kernel-5_35-4_79_2_53'

Version 5.35, 4.79.2.48. Tagged as 'Kernel-5_35-4_79_2_48'

Version 5.35, 4.79.2.10. Tagged as 'Kernel-5_35-4_79_2_10'

Added compile-time support for full-resolution teletext characters in teletext emulation mode (MODE 7) for that authentic BBC Micro feel.

  Also introduced a few useful teletext control features via VDU 23,18.
  Unrelatedly, fixed *ScreenLoad to work for interlaced displays.

Detail:
  The new typeface is designed on a 16x20 grid (previously we had used 8x10),
  so it uses a screen resolution of 640x500 pixels (rather than 320x250).
  Since we have been unable to source a genuine teletext font, and since
  examination of a BBC Micro suggests that the genuine font may not have been
  a power-of-2 pixels wide, I have designed one specially, based upon the one
  supplied in Zap distributions (a 12x20 font). Rather than increase the
  amount of workspace that the kernel requires for cacheing graphic
  characters, it now generates them on the fly, as they are required; this
  should only add about 25% to their rendering time.

  The new VDU 23 sequences are as follows:

  VDU 23,18,0,mode,0,0,0,0,0,0
    Switch transparency mode
      mode = 0: "Text" mode: the whole display is set opaque
      mode = 1: "Mix" mode: foreground colours, and both foreground and
        background of boxed text are opaque; non-boxed background colours are
        all transparent
      mode = 2: "Box" mode: boxed regions are opaque, others are transparent
      mode = 3: "TV" mode: the whole display is set transparent
    Default is mode = 0.

  VDU 23,18,1,suspend,0,0,0,0,0,0
    Suspend or resume bitmap updates
    This call allows an application to request that the kernel suspends
    updates to the framebuffer bitmap. This allows for a significant speed
    increase in the rendering time for a large amount of text, for example
    when redrawing a complete teletext page, because each time you plot a
    single character, it can cause the whole of the rest of the line to be
    re-rendered. When you switch out of suspend mode, the whole screen is
    refreshed in a single pass. Note that the appearance of the display is
    undefined is you cause a hardware scroll while in suspend mode.
      suspend = 0: screen update is enabled
      suspend = 1: screen update is suspended
    Default is suspend = 0.

  VDU 23,18,2,reveal,0,0,0,0,0,0
    Reveal/conceal
      reveal = 0: characters between the Conceal control code and the next
        colour control code are replaced by spaces
      reveal = 1: all characters are displayed
    Default is reveal = 0.

  VDU 23,18,3,black_emable,0,0,0,0,0,0
    Enable/disable black foreground colour control codes
      black_enable = 0: control codes &80 and &90 do nothing
      black_enable = 1: control code &80 selects black text, control code
        &90 selects black graphics
    Default is black_enable = 0.

  I have performed some timing tests on the rendering of complete teletext
  pages grabbed from the teletext server. These show that the new code
  generally imposes a 2x speed hit. However, when using the VDU 23,18,1
  suspend function, this improves to a 20% speed increase when compared to
  the old low-resolution code. Better still, because the framebuffer is only
  being updated for the final stage of this process, the screen *appears* to
  be updated some 3x faster than with the old code!

  A comment on the VDU variable Log2BPC is in order: in previous kernels,
  this was able unambiguously to refer to both the framebuffer width of a
  character in bytes, and the framebuffer width of an "addressable pixel" in
  bits; this no longer works with the 16-pixel wide teletext font. Bearing
  in mind that future kernels may support Unicode system fonts where the
  width varies from character to character, I have chosen to fix Log2BPC to
  the "addressable pixel" definition.

Admin:
  Requires HdrSrc 0.89 and (for non-desktop builds) Interlace 0.61. A monitor
  definition file containing a definition for a 640x500 screen mode is also
  required; version 0.40 of ModeFiles contains a suitable mode for STB-400.

  Tested fairly rigourously on an Ursula build, a Lazarus build and an
  STB-400 build, using genuine teletext pages and Yellow River Kingdom.

Version 5.30. Tagged as 'Kernel-5_30'

Details:
  The Kernel will now compile to produce a pure 32-bit system if No26bitCode is
  set to TRUE.
  If No26bitCode is FALSE, then the Kernel will be a standard 26-bit Kernel,
  although some internal changes have taken place to minimise compile
  switches between the two cases. See Docs.32bit for more technical info.

  The hardest part was the flood-fill...

Other changes:
  Pointer shape changes now take place on the next VSync, rather than actually
  WAITING for the VSync. Turning the Hourglass on shouldn't slow your machine
  down by 5% now :)

  Lots of really crusty pre-IOMD code removed.

Admin:
  Tested in 32 and 26-bit forms in a limited desktop build. Basically, this
  will need to see a lot of use to iron out difficulties. I'd like anyone who
  has a non-frozen project to at least attempt using this Kernel.

Version 5.23. Tagged as 'Kernel-5_23'