DOS ain't dead - User exception handler in C

User exception handler in C (Developers)

posted by tkchia , 24.07.2020, 20:47

Hello RayeR,

> Hi, is it possible/how to install user exception handler in user program in
> DJGPP (DOS) and MinGW (Windows) to catch CPU exception before OS/program
> will crash? Does DJGPP have it's own hander or is it catched by DPMI server
> or other memory manager in v86 mode like JEMM? Is it possible to resume
> from exception and continue normally? Eg. in case of RDMSR of nonexisting

Apparently DJGPP supports the POSIX-ish signal(...) and sigaction(...) interface for catching exceptions such as these --- see http://www.delorie.com/djgpp/doc/libc/libc_724.html . (Myself though, I have only tried using it on Linux, not on DJGPP.)

If it works, a way to use it would be to do a sigsetjmp(...) before doing the RDMSR. Meanwhile you also arrange for your signal handler to do a siglongjmp(...) if it is invoked. The place where the program siglongjmp(...)'s to can then handle the failed RDMSR.

Thank you!

---
https://gitlab.com/tkchia · https://codeberg.org/tkchia · 😴 "MOV AX,0D500H+CMOS_REG_D+NMI"

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Complete thread:

User exception handler in C - RayeR, 24.07.2020, 13:15 (Developers)
- User exception handler in C - Japheth, 24.07.2020, 18:07
- User exception handler in C - Rugxulo, 24.07.2020, 18:39
- User exception handler in C - tkchia, 24.07.2020, 20:47
  - User exception handler in C - RayeR, 30.07.2020, 13:18
    - User exception handler in C - tom, 30.07.2020, 23:54
      - User exception handler in C - RayeR, 01.08.2020, 02:13
        User exception handler in C - Laaca, 16.08.2020, 21:27
        User exception handler in C - Laaca, 16.08.2020, 22:38
        User exception handler in C - Rugxulo, 17.08.2020, 22:35
        User exception handler in C - marcov, 18.08.2020, 12:23
        User exception handler in C - Laaca, 18.08.2020, 20:15
        User exception handler in C - Rugxulo, 19.08.2020, 19:44
        User exception handler in C - Laaca, 19.08.2020, 21:50
        User exception handler in C - Rugxulo, 23.08.2020, 17:32
        User exception handler in C - Japheth, 23.08.2020, 20:36
        User exception handler in C - Rugxulo, 17.08.2020, 22:26
        User exception handler in C - tkchia, 19.08.2020, 18:52
        User exception handler in C - marcov, 20.08.2020, 00:00
        User exception handler in C - Laaca, 20.08.2020, 15:31
    - User exception handler in C - tkchia, 31.07.2020, 19:36
      - User exception handler in C - RayeR, 01.08.2020, 02:16
- User exception handler in C - Guti, 27.07.2020, 08:22