DOS ain't dead - indirect far jmp - calling old INT problem

indirect far jmp - calling old INT problem (Developers)

posted by bretjohn , Rio Rancho, NM, 13.05.2012, 17:05

In general, I pass the entire original callers flags register, unchanged, to the old interrupt handler (whether I CALL it or JMP to it). I don't assume that the only thing that matters is one or two of the flags (like CF or ZF). In particular, modifying the Interrupt Flag or Direction flag can cause all kinds of problems, though modifying any flag other than the one(s) used to pass parameter(s) as defined by the API are potentially disastrous.

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Complete thread:

indirect far jmp in NASM - RayeR, 10.05.2012, 10:46 (Developers)
- indirect far jmp in NASM - RayeR, 10.05.2012, 13:16
  - indirect far jmp - ecm, 10.05.2012, 13:26
  - indirect far jmp in NASM - Rugxulo, 10.05.2012, 13:26
    - indirect far jmp in NASM - RayeR, 10.05.2012, 14:07
      - indirect far jmp - ecm, 10.05.2012, 15:17
        indirect far jmp - RayeR, 11.05.2012, 00:47
        indirect far jmp - ecm, 11.05.2012, 12:46
        indirect far jmp - bretjohn, 11.05.2012, 18:53
        indirect far jmp - RayeR, 11.05.2012, 19:31
        indirect far jmp - bretjohn, 11.05.2012, 22:31
        indirect far jmp - ecm, 11.05.2012, 22:33
        indirect far jmp - RayeR, 12.05.2012, 00:33
        indirect far jmp - Arjay, 12.05.2012, 01:07
        indirect far jmp - ecm, 12.05.2012, 01:27
        indirect far jmp - Arjay, 12.05.2012, 11:09
        indirect far jmp - ecm, 12.05.2012, 21:18
        indirect far jmp - RayeR, 12.05.2012, 21:17
        indirect far jmp/call - Chaining Interrupt Service Routines - Arjay, 13.05.2012, 13:16
        indirect far jmp - calling old INT problem - RayeR, 13.05.2012, 04:01
        indirect far jmp - calling old INT problem - ecm, 13.05.2012, 04:27
        indirect far jmp - calling old INT problem - RayeR, 13.05.2012, 15:33
        indirect far jmp - calling old INT problem - bretjohn, 13.05.2012, 17:05
        indirect far jmp - calling old INT problem - RayeR, 13.05.2012, 17:15
        indirect far jmp - calling old INT problem - RayeR, 13.05.2012, 19:19
        indirect far jmp - calling old INT problem - Rugxulo, 13.05.2012, 20:02
        indirect far jmp - calling old INT problem - RayeR, 13.05.2012, 20:49
        indirect far jmp - calling old INT problem - ecm, 13.05.2012, 23:49
        indirect far jmp - calling old INT problem - ecm, 13.05.2012, 23:40
        indirect far jmp - calling old INT problem - ecm, 14.05.2012, 00:07
        indirect far jmp - calling old INT problem - RayeR, 14.05.2012, 01:19
        indirect far jmp - calling old INT problem - ecm, 13.05.2012, 23:44
        indirect far jmp - calling old INT problem - bretjohn, 14.05.2012, 18:30
        redundant override in "ss:bp" for clarity - ecm, 14.05.2012, 18:47
        indirect far jmp - calling old INT problem - RayeR, 14.05.2012, 18:50
        indirect far jmp - calling old INT problem - bretjohn, 14.05.2012, 20:16
        indirect far jmp - calling old INT problem - ecm, 14.05.2012, 20:21
        indirect far jmp - calling old INT problem - bretjohn, 14.05.2012, 21:42
        indirect far jmp - calling old INT problem - bretjohn, 15.05.2012, 18:45
        indirect far jmp - calling old INT problem - ecm, 15.05.2012, 18:53
        indirect far jmp - calling old INT problem - bretjohn, 15.05.2012, 20:13
        indirect far jmp - calling old INT problem - RayeR, 17.05.2012, 01:25