
 About
 
 HXHELP is a trap file for Open Watcom's debugger WD. Two versions
 are created, HXHELP.EXE and HXHP16.EXE, the first for 32bit HX binaries,
 the latter for 16bit binaries.

 
 Files
 
 HX.TRP: DOS overlay which will load HXHELP.EXE. This binary is loaded
     by WD.EXE when debugging locally or by WINSERV.EXE/VDMSERV.EXE when
     debugging remotely.
 HX16.TRP: same as HX.TRP for 16bit clients, will load HXHP16.EXE.
 HXHELP.EXE: the trap file for 32bit clients.
 HXHP16.EXE: the trap file for 16bit clients.
 RMDBGHLP.BIN: file which will be loaded by HXHELP.EXE/HXHP16.EXE on
     startup. Will trap real-mode exceptions. Will be searched in the
     directory where HXHELP.EXE/HXHP16.EXE was loaded from.
 HXHELP.CFG: configuration file for HXHELP.EXE. Will be searched in current
     directory and then in directory where HXHELP.EXE was loaded from.
 HXHP16.CFG: configuration file for HXHP16.EXE
 HXHELP.LOG: a log file which will be created if option Debug=1 is set
     in HXHELP.CFG/HXHP16.CFG.
 
 
 History

 __.10.2025, V1.6

 - moved some tables to .data? to reduce size of binary.
 - fixed: protect read from memory addresses with PL3 GDT selector.

 15.07.2022, V1.5

 - last byte of a segment wasn't read because the segment limit was interpreted
   incorrectly.
 - adjusted to dpmild16/32 v3.11 - hxhelp is no longer visible to int 41h.
 - fixed: hx.trp/hx16.trp: removed .obj files; dosxlink.c: a second location to
   adjust was missing and "EXTENDER_NAMES" was changed from "dpmild32.exe" to
   "hxhelp.exe".
 - request map_addr: if real-mode app, ignore offset.

 07/15/2018, V1.4

 - added a few error checks.
 - bugfix: HXHELP does modify the DPMILDxx flags to ensure the loader won't
   start another instance of itself (DPMILDR=8). However, HXHELP didn't reset
   this value after the debuggee has been loaded; this caused the debuggee
   to behave differently if it launched another program.
 - bugfix: the 16-bit trap file HXHP16.EXE assumed hiword of ESP to be
   zeroed when loading XMM register values, causing a crash.

 12/16/2012, V1.3

 - will allow the debugger to get and set XMM registers.
 - bugfix: section mapping didn't work reliably.
 - linked with stub dpmildxx.bin (contains the HX DPMI loader)

 06/30/2006, V1.2.2
 
 - previous version had a bug which may have caused a GPF on some conditions

 06/14/2006, V1.2.1

 - trap helper was changed to a PE dll and then changed back to HXHELP.EXE
 - symbolic debugging didn't work for 32bit MZ binaries if
   debuggee's real-mode startup code was debugged.
             
 08/28/2005: V1.2:
 
 - bugfix: symbolic debugging with 32bit MZ format made the disassembler
   to show code in 16bit.
 - HXHELP now displays error msg if RMDBGHLP.BIN cannot be opened.
 
 08/14/2005, V1.1:

 08/26/2004, V1.0:

