System Loader Logging Facility

The system loader provides optional logging and checking under the debug kernel. These optional facilities may be activated selectively by setting bits in the _LdrDebugFlags flags double-word as follows:

Note:

The flags described are those implemented in OS/2 Warp V3.0. Slightly different, similar messages are generated for earlier releases of OS/2.

0x00000001

This will cause the Loader to break into the debugger using an INT 3 instruction if any of the following error conditions are detected:
Not enough memory
Caching error
Invalid Ordinal
Procedure not found
Bad EXE format
Invalid segment number
Invalid CALLGATE
Network Disconnected
0x00000002
This will generate log entries when LDRGetPage exits with a non-zero return code. LDRGetPage is called to demand load a page within a object of a load module. The message logged is of the following form:

      ldrGP bad cr2=nnnnnnnn rc=mmmmmmmm

cr2= is the page fault address and rc= is the LDRGetPage return code.

0x00000004
This generates log entries when LDRGetPage is called to demand load a page within a object of a load module. The message logged is of the form:

      ldrGP cr2=nnnnnnnn hMTE=hhhh bno=oo
            name=pppppppppppppppp

cr2=

is the page fault address,
hMTE=
is the module's hmte,
bno=
is page number with in the module
name=
is the module's full name taken from the SMTE.
0x00000018
This switch causes log information to be generated when DLL modules are loaded and initialised. The following messages are logged:

      ldrDLM entry - slot ssss ptda pppppppp

      ldrDLM name  - slot ssss name nnnnnnnn

      ldrDLM free  - slot ssss

      ldrDLM exit  - slot ssss

      tk SD has-init slot=ssss

      tk SD no-init slot=ssss

      tk SD pre-inc slot=ssss cnest=nnnn

      tk IN pre-dec slot=ssss cnest=nnnn

      tk LIn slot=ssss cnest=nnnn

slot

is the thread slot in which the DLL is being processed,
ptda
is the address of the PTDA for this slot
name
is the DLL module name
cnest
Nesting counter for TKLibiStartDispatch
ldrDLM entry
marks entry to w_loadmodule, the DosLoadModule worker routine.
ldrDLM name
marks the successful request for the DLL initialisation mutex semaphore (ptda_DLMsem (PTDA +0x4ac (H/R: +0x4a8))).
ldrDLM free
marks the release of the mutex semaphore. Exit marks the exiting of w_loadmodule.
ldrDLM exit
marks the exit from w_loadmodule.
tk SD
marks events in TKLibiStartDispatch.
tk IN and tk LIn
Mark events in TKLiniInitNextDLL
0x00000080
This switch requests import initialisation be recorded. Messages of the following format are generated:

      lpi, Recording init hMTE=hhhh, flags1=ffffffff, name=nnnnnnnnn

      lpi, Skipping init hMTE=hhhh, flags1=ffffffff, name=nnnnnnnnn

      lpi, Processing imports slot=ssss, module=nnnnnnnnn

      lrm, Recording init hMTE=hhhh, flags1=ffffffff, name=nnnnnnnn

      lrm, Skipping init hMTE=hhhh, flags1=ffffffff, name=nnnnnnnnn

hMTE

is the module handle
flags1
are the flags MTE flags field. (See the .LM command for details).
name
is the full module name taken from the SMTE.
module
is the full module name taken from the SMTE.
lpi, Recording init
Logs the processing of system DLL imports from the system DLL names table in EXE file loading.
lpi, Skipping init
Logs system DLL names not imported in EXE file loading.
lpi, Processing imports
Logs the processing of DLL initialisation as the result of imports being present in an EXE module.
lrm, Recording init
Logs imported DLL initialisation being recorded.
lrm, Skipping init
Logs imported DLLs skipping initialisation.
0x00000100
Logs when the loader cannot load an object at the compiler/linker designated base address. The message logged appears as:

      Cannot load nnnnnnnn at the requested base address

where nnnnnnnn is the module name.

0x00000800
Logs the processing of the DLL import tree. The following messages appear:

      lpi, Processing imports slot=ssss, module=nnnnnnnnn

      ldr walking tree hMTE=hhhh, name=nnnnnnnn

      ldr walking tree going down

      ldr walking tree going up

lpi, Processing imports

marks the initiation of the process for slot ssss and module nnnnnnnn.
ldr walking tree hMTE=hhhh, name=nnnnnnnn
marks the processing of an imported DLL, whose handle is hhhh and name is nnnnnnnn
ldr walking tree going up
marks a backward progression through the import tree.
ldr walking tree going down
marks a forward progression through the import tree.

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