Add support for os2dump compatibility

[Steven Levine]

os2dump tends to fail on systems using the os2ahci.add driver. This occurs because os2dump is invoked with the AHCI controller in a state where BIOS int13 I/O will not work.

This ticket is related to

​http://bugs.ecomstation.nl/view.php?id=3201

[Markus Thielen]

We will add an IDC entry point to OS2AHCI that allows to switch back to BIOS mode.

[Markus Thielen]

Version 1.23 contains the promised IDC entry point; more on this can be found here.

[Steven Levine]

We have discovered a better solution for system dump support. There is an undocumented DevHelp_RegisterKrnlExit option that registers a kernel exit designed specifically for this task.

== RegisterKrnlExit 6F - Register Kernel Exit ==

MOV AX,Action 0x1000 = add, 0x2000 = delete
MOV CX,Type 0 = NMI 1 = SFF 2 = ProcDump 3 = dyn 4 = int13
MOV BX,selector Selector of routine to be called
MOV SI,address Offset of routine to be called
MOV DL,DevHlp_RegisterKrnlExit
CALL [Device_Help]

The CX = 4 request registers an exit routine that will be called while the kernel is preparing to invoke os2dump. The routine is supposed to return the disk controller to a state where int13 IO functions normally.

Please implement support for this exit and verify that it functions as we would like. It should be sufficient to generate a system dump with Ctrl-Alt-Numlock-Numlock or Ctrl-Alt-F10-F10 to verify that the feature works as we think it should.

[Markus Thielen]

Version 1.25 contains the kernel exit handler for trap dumps

[Markus Thielen]

I attached version 1.25 to this ticket; it contains the kernel exit handler as you described above. I successfully tested it on an Intel ICH8 machine (Ctrl+Alt+NumLock+NumLock).

-- Markus

[David Azarewicz]

Milestone milestone1 deleted