Our legacy KD module is slowly being phased out for the more recent KD64
Kernel Debugger that supports WinDbg, but at the same time we must retain
support for GCC debugging and the KDBG interface.
For the time being few #ifdef _WINKD_ have been introduced in KD64 so that
some of its code/data does not completely get shared yet with the legacy KD,
until the latter becomes phased out.
KD Modifications:
=================
- Remove the implementation of NtQueryDebugFilterState() /
NtSetDebugFilterState() that now comes entirely from KD64.
- Remove KD variables that are now shared with KD64.
- Share common code with KD64: KdpMoveMemory(), KdpZeroMemory(),
KdpCopyMemoryChunks(), KdpPrint(), KdpPrompt().
- KDBG: Remove the duplicated KdpCopyMemoryChunks() function.
- In KdpServiceDispatcher() and KdpEnterDebuggerException(), call the
KdpPrint() worker function that correctly probes and captures its arguments.
- Temporarily stub out KdEnterDebugger() and KdExitDebugger() that is used
by the shared code, until KD is removed and only the KD64 version of these
functions remain.
- Re-implement the KD/KDBG KdpPrompt() function using a custom KdpPromptString()
helper compatible with KD64, that is called by the KD64 implementation of
KdpPrompt(). This KdpPromptString() helper now issues the prompt on all
the KD loggers: e.g. if you use both at the same time COM-port and SCREEN
debugging, the prompt will appear on both. Before that the prompt was always
being displayed on COM port even if e.g. a SCREEN-only debug session was used...
- ppc_irq.c: Fix the prototype of KdpServiceDispatcher().
KD64 Fixes:
===========
- Initialize the MaximumLength member of the counted STRING variables
before using them elsewhere.
- Get rid of alloca() within SEH block in KdpPrint() (addendum to 7b95fcf9).
- Add the ROS-specific handy dump commands in KdSystemDebugControl().
- Import KdpCopyMemoryChunks() from kd64/kdapi.c, and re-implement
KdbpSafeReadMemory() and KdbpSafeWriteMemory() around it.
Note that these functions read virtual memory and are equivalent of
the kd64 KdpReadVirtualMemory() and KdpWriteVirtualMemory()
respectively.
- Get rid of the KdpEnableSafeMem() call in KdInitSystem().
- Adjust kd gdbstub.c wrapper in accordance.
Instead move to a threading model like the Windows one.
We'll queue several work items to be executed in a system thread (Cc worker)
when there are VACB that have been marked as dirty. Furthermore, some delay
will be observed before action to avoid killing the system with IOs.
This new threading model opens way for read ahead and write behind implementation.
Also, moved the initialization of the lazy writer to CcInitializeCacheManager()
it has nothing to do with views and shouldn't be initialized there.
Also, moved the lazy writer implementation to its own file.
Modified CcDeferWrite() and CcRosMarkDirtyVacb() to take into account the new threading model.
Introduced new functions:
- CcPostWorkQueue(): post an item to be handled by Cc worker and spawn a worker if required
- CcScanDpc(): called after some time (not to have lazy writer always running) to queue a lazy scan
- CcLazyWriteScan(): the lazy writer we used to have
- CcScheduleLazyWriteScan(): function to call when you want to start a lazy writer run. It will make a DPC after some time and queue execution
- CcWorkerThread(): the worker thread that will handle lazy write, read ahead, and so on
