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

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blog:pushbx:2023:0903_august:september_work [2023-09-03 21:40:44 +0200 Sep Sun]
ecm 		blog:pushbx:2023:0903_august:september_work [2023-12-04 20:47:07 +0100 Dec Mon] (current)
ecm [Notes from debugging lDebug]
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 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.
  
  
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 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.1693770044.txt.gz · Last modified: 2023-09-03 21:40:44 +0200 Sep Sun by ecm

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