GitLab

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'

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:
  Accept a monitortype of 'EDID' (as distinct from 'Auto', which uses the ID pins) to force the kernel, via ScrModes, to use the native screen mode prior to executing the boot sequence.
  Required for discless boot, this also helps if the boot sequence fails, the desktop will be entered in the monitor's native resolution, or a fallback if GraphicsV rejects that.
  The allocation of the EDID monitor type has been carefully selected to degrade to 'Auto' when used with an older OS. That way the configuration in CMOS is safe to use with softloads on top of older physical ROMs.
  When OS_ScreenMode is queried return the 'Auto' type, ie. at an API level there's no distinction.
Admin:
  Requires HdrSrc-2_67.
  Submission for the EDID bounty.

Version 5.80. Tagged as 'Kernel-5_80'

Detail:
  This change gets rid of the following switches from the source (picking appropriate code paths for a 32bit HAL build):
  * FixCallBacks
  * UseProcessTransfer
  * CanLiveOnROMCard
  * BleedinDaveBell
  * NewStyleEcfs
  * DoVdu23_0_12
  * LCDPowerCtrl
  * HostVdu
  * Print
  * EmulatorSupport
  * TubeInfo
  * AddTubeBashers
  * TubeChar, TubeString, TubeDumpNoStack, TubeNewlNoStack macros
  * FIQDebug
  * VCOstartfix
  * AssemblingArthur (n.b. still defined for safety with anything in Hdr: which uses it, but not used explicitly by the kernel)
  * MouseBufferFix
  * LCDInvert
  * LCDSupport
  * DoInitialiseMode
  * Interruptible32bitModes
  * MouseBufferManager
  * StrongARM (new CacheCleanerHack and InterruptDelay switches added to hdr/Options to cover some functionality that StrongARM previously covered)
  * SAcleanflushbroken
  * StrongARM_POST
  * IrqsInClaimRelease
  * CheckProtectionLink
  * GSWorkspaceInKernelBuffers
  * EarlierReentrancyInDAShrink
  * LongCommandLines
  * ECC
  * NoSPSRcorruption
  * RMTidyDoesNowt
  * RogerEXEY
  * StorkPowerSave
  * DebugForcedReset
  * AssembleKEYV
  * AssemblePointerV
  * ProcessorVectors
  * Keyboard_Type
  Assorted old files have also been deleted.
Admin:
  Identical binary to previous revision for IOMD & Raspberry Pi builds


Version 5.51. Tagged as 'Kernel-5_51'

Variously the call to TranslateError was either followed (outside the switch) by an unnecessary SETV, or missing SETV for the non international case.
Added DMA controller HAL device for IOMD.

Version 5.35, 4.79.2.174. Tagged as 'Kernel-5_35-4_79_2_174'

STB default = off, desktop default = on.
Collapsed single use of 'ErrorsInR0' switch.

Version 5.35, 4.79.2.167. Tagged as 'Kernel-5_35-4_79_2_167'

The kernel already looks after all other aspects of the ARM CPU, so can look after the cache control command too.
 HelpStrs.s:New tokens for help and syntax
 CmdHelp.s:UK help and syntax
 Arthur3.s:Tables updates for *CONFIGURE/STATUS, lined some stuff up, default error text sync'd with Hdr:NewErrors
 MoreComms.s:Parsing and doing of *CACHE
 Utility.s:Hashing table updated for *CACHE
Other minor changes
 hdr/Options:Bring 'MosVer' into the private header
 hdr/RISCOS:aasm aliases for SP removed, MainVars and MosVer made private, added definition of the start of application space
 HeapMan.s:Use of GRAB changed to Pull
 Offset of TutuCMOS changed for more informative PrintSoundCMOS
 PMF/osbyte.s:Use OsBytes header file in place of MainVars

Version 5.35, 4.79.2.151. Tagged as 'Kernel-5_35-4_79_2_151'

Detail:
  * As noted in recent commits to ADFS, the *Configure options Dir and NoDir
    haven't done anything since RISC OS 2, so ADFS has stopped reading the
    CMOS bit. Unusually, these options are implemented by the kernel, so this
    is the accompanying change to remove the *Configure options. This frees
    up a bit of CMOS for future re-use.
  * Now exports a C version of Hdr:ModHand.
Admin:
  Builds OK, but not tested in a ROM build yet (should be fairly safe though)

Version 5.35, 4.79.2.143. Tagged as 'Kernel-5_35-4_79_2_143'

Improve heap manager. Add heap testbed. Add dummy implementation of some OS_ScreenMode reason codes.

Detail:
  s/HeapMan, hdr/KernelWS - Heap manager improvements:
    - Errors generated by interrupted heap operations that are forced to complete by a OS_Heap call from the background are now cached in kernel workspace until the foreground task is resumed. This prevents them from being potentially overwritten by MessageTrans running out of background error buffers.
    - Added new OS_Heap reason code, #7 - Get area aligned. This allows areas of memory to be allocated at specific (power-of-2) alignments, and optionally without crossing a given (power-of-2) boundary. Alignment & boundary calculations are performed using logical addresses.
    - Removed the limitation that all free and allocated blocks must be a multiple of 8 bytes in length. This change was required in order to allow OS_Heap 7 to function correctly. Now the only requirements are that blocks must be multiples of 4 bytes in length, at 4 byte alignment, with a minimum length of 8 bytes. 4 extra padding bytes may still be added to the end of allocations in order to avoid creating 4-byte free blocks.
  s/HeapMan, TestSrc/HeapTest/Makefile, TestSrc/HeapTest/c/testbed, TestSrc/HeapTest/s/asm - Added heap testbed program. Can either use the OS_Heap SWI or directly include a copy of the Kernel's heap manager sources.
  s/vdudecl, s/vduswis - Added dummy implementations of OS_ScreenMode 4, 5 and 6. This prevents the Wimp generating lots of "Unknown OS_ScreenMode reason code" errors when redrawing the screen.
  s/Arthur3, s/Oscli - Moved dotstring closer to where it's used to avoid "ADRL out of range" errors in Tungsten build
Admin:
  Tested in OMAP3 ROM & Tungsten ROM softload.
  Heap testbed successfully performed over 400 million heap ops, so there shouldn't be any serious bugs in the new code (touch wood)


Version 5.35, 4.79.2.128. Tagged as 'Kernel-5_35-4_79_2_128'

Detail:
  s/Arthur3, s/ChangeDyn, s/HAL, s/HeapMan, s/Middle, s/MoreSWIs, s/NewIRQs, s/Utility, s/VMSAv6, s/PMF/key, s/PMF/osbyte, s/PMF/osword, s/vdu/vdudecl, s/vdu/vdudriver, s/vdu/vduplot, s/vdu/vduwrch - Tweaked lots of LDM/STM instructions in order to get rid of the depracation/performance warnings
Admin:
  Tested on rev A2 BB-xM


Version 5.35, 4.79.2.98.2.53. Tagged as 'Kernel-5_35-4_79_2_98_2_53'

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'

*Configure ANYTHINGsize was broken due to not setting R0 to ReadUnsigned
IIC ack message uninternationalised
OS_Memory was saying we only had 4M of RAM
VDU4 scrolling when output was switched to sprite was causing corruption
on use of CTRL-J and CTRL-K
Default SystemSize CMOS set to 32k

Version 5.35, 4.79.2.55. Tagged as 'Kernel-5_35-4_79_2_55'

Detail:
  Lots of changes since last version, at least the following:
  * Updated OS timestamp, removed alpha status
  * Negative INKEY OS version changed to &AA
  * GraphicsV is now alocated vector number &2A
  * ROM moved up to &FC000000
  * Max application slot increased to 512 Mbytes (for now)
  * Max size of RMA increased to 256 Mbytes
  * RMA is now first-created dynamic area (so it gets lowest address after
    top of application slot)
  * OS_Memory 10 reimplemeted
  * New OS_ReadSysInfo 6 values 18-22 added
  * OS_ReadSysInfo 8 gains flag bit to indicate soft power-off
  * Misc internal top-bit-set-address fixes
  * *ChangeDynamicArea can take sizes in megabytes or gigabytes
  * Magic word "&off" in R0 passed to OS_Reset powers down if possible
  * Added acceleration: block copy; CLS; text window scroll up; rectangle
    fill
  * Disabled LED flashing in page mode (liable to crash)
  * Masked sprite plot and VDU 5 text avoids reading the screen if possible
  * Framestore made USR mode accessible
  * Fix for VDU 5,127 bug - now relies on font definitions being in extreme
    quarters of memory, rather than bottom half
  * Allocated 64-bit OS_Convert... SWIs
  * IIC errors use allocated error numbers
  * Looks for Dallas RTC before Philips RTC because we're using a Philips
    NVRAM device with the same ID
  * Fix to bug that meant the oscillator in the Dallas RTC wasn't enabled
  * Default mouse type (USB) changed to allocated number
  * Ram disc max size increased to 128 Mbytes (Ursula merge) and made
    cacheable for StrongARMs (not XScale)
  * Branch through zero handler now works in USR mode, by use of a
    trampoline in the system stack to allow PC-relative register storage
  * Address exception handler changed to not use 0 as workspace
  * OS_Memory 13 extended to allow specification of cacheability and access
    privileges
  * Added OS_Memory 16 to return important memory addresses
  * RISCOS_MapInIO() takes cacheable flag in bit 3, access permissions in
    bits 10 and 11, doubly-mapped flag in bit 20, and access permissions
    specified flag in bit 21
  * Bug fix in last version for application abort handlers didn't quite
    work; register shuffle required
  * "Module is not 32-bit compatible" error now reports the module name
  * Default configured language changed from 10 to 11 (now Desktop again)

Version 5.35, 4.79.2.51. Tagged as 'Kernel-5_35-4_79_2_51'

Look for LongCommandLine flag, command line size currently
set at 1k.
For HAL/32bit builds, the kernel buffer space is at high
(top bit set) address, which may break some code using signed
comparisons. So *beware* that there may be some latent
bugs in old kernel code using these buffers, not yet found.
One such bug, in s.Arthur2 found and fixed.
Tested moderately on ARM9 desktop build.
Lovely to reimplement things I did two and half years ago.

Version 5.35, 4.79.2.37. Tagged as 'Kernel-5_35-4_79_2_37'

First attempt at ARM9 support, and general clean-up of old ARM-specific code, now using vectored ARMops.

Not tested.

Version 5.35, 4.79.2.14. Tagged as 'Kernel-5_35-4_79_2_14'

* Added ARM_IMB and ARM_IMBRange SWIs as recommended by ARMv5.
* Some early prototype HAL bits popped in - a lot of source restructuring still
  to come.
* New debug target creates an AIF image with debug information, and translates
  this into an ASCII object file for the 16702B logic analyser.

Version 5.35, 4.79.2.1. Tagged as 'Kernel-5_35-4_79_2_1'

  Removed DriversInKernel conditional.
Detail:
  If the territory changes or the resource file changes, the kernel
    will now decache all the cached error blocks so that next time
    they are required, they will be looked up again.
  The error cacheing is now a kernel build option and is always set
    to on.
  Removed one of the 5 error messages to be cached - it never seems
    to happen.  The remaining 4 are more frequent.
Admin:
  Tested in Ursula build.
  Cannot be used with HdrSrc 0.94.  HdrSrc 0.95 and later is required
    (or HdrSrc 0.93 and earlier subject to other kernel requirements)
  Requires MessageTrans 0.42 or later for correct operation when a
    replacement messages file is loaded.

Version 5.32. Tagged as 'Kernel-5_32'

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'