pushbx wiki

User Tools

Site Tools

Trace: • lDOS boot CL signature mismatch, lDebug immasm branch • 95LX file transfer woes and backup battery tray
blog:pushbx:2023:0903_august:september_work

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Next revision 		Previous revision
blog:pushbx:2023:0903_august:september_work [2023-09-03 20:14:53 +0200 Sep Sun]
ecm created 		blog:pushbx:2023:0903_august:september_work [2023-12-04 20:47:07 +0100 Dec Mon] (current)
ecm [Notes from debugging lDebug]
Line 98: Line 98:
 The workaround is to run a single run command (T, TP, P, or G -- but not TTEST) before enabling the breakpoint on the interrupt 2Dh entrypoint. This will give the debugger the chance to hook the DPMI entrypoint before the breakpoint is enabled. The workaround is to run a single run command (T, TP, P, or G -- but not TTEST) before enabling the breakpoint on the interrupt 2Dh entrypoint. This will give the debugger the chance to hook the DPMI entrypoint before the breakpoint is enabled.
  
-Another choice would be to ''uninstall int2F'' before setting the breakpoint. In particular, if no DPMI host is installed the debugger may retry the DPMI entrypoint hook on every run instruction. However, it seems that this won't actually work because the DCO4 flag is checked too late into the function, where the int 2Dh and int 2Fh calls already happened.+Another choice would be to ''uninstall int2F'' before setting the breakpoint. In particular, if no DPMI host is installed the debugger may retry the DPMI entrypoint hook on every run command. However, it seems that this won't actually work because the DCO4 flag is checked too late into the function, where the int 2Dh and int 2Fh calls already happened.
  
  
Line 117: Line 117:
   * (In outer debugger:)   * (In outer debugger:)
   * Enter a TSR command   * Enter a TSR command
-  * Enter a G comman+  * Enter a G command
   * (On the DOS command line:)   * (On the DOS command line:)
   * Run a ''keephook 8'' command   * Run a ''keephook 8'' command
Line 131: Line 131:
 A similar trick was used [[blog:pushbx:2023:0828_late_august_work#freedos_kernel|to debug the FreeDOS kernel bug]] in order to load the second debugger near the top of the Low Memory Area. This also had the second debugger run a TSR command then a G command, returning to the PRA of the first debugger in the debuggee context of the second debugger. In that case, the first debugger was simply quit to leave only the second debugger resident. A similar trick was used [[blog:pushbx:2023:0828_late_august_work#freedos_kernel|to debug the FreeDOS kernel bug]] in order to load the second debugger near the top of the Low Memory Area. This also had the second debugger run a TSR command then a G command, returning to the PRA of the first debugger in the debuggee context of the second debugger. In that case, the first debugger was simply quit to leave only the second debugger resident.
  
-{{tag>edrdos testhook ldebug}}+{{tag>edrdos testhook ldebug heatshrink}}
  
  
 ~~DISCUSSION~~ ~~DISCUSSION~~
  
blog/pushbx/2023/0903_august/september_work.1693764893.txt.gz · Last modified: 2023-09-03 20:14:53 +0200 Sep Sun by ecm

Page Tools

Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution 4.0 International
CC Attribution 4.0 International Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki