DOS ain't dead

VESAMTTR (recovered from Google) (DOSX)

posted by DOS386, 23.07.2007, 02:42

Japheth wrote:

> VESAMTRR "switches" to ring 0 to run the privileged instructions.

I wrote:

> * VERY * interesting source

Japheth wrote:

> Rayer's switches to "real-mode" and runs the instructions.
> But since "real-mode" very often is "v86-mode"

I wrote:

> Looks like very bad design He uses DGJPP, and then goes "real" for
> the relevant activity ... 500 Bytes of real mode assembly could probably
> replace the 100 KB from DGJPP

> Had thought that Rayer found out how to execute privileged
> instructions under DPMI ... but he didn't ... but you did

> Seem to be at least 4 ways how to execute privileged instruction from DPMI code:

> - Go "real" (bad hack needed to switch ?) ... bad
> - Emulate them in the DPMI host (CR accesses & HLT in HDPMI32)
> - Run "client" in Ring0 (CWSDPR0, DOS/32A, other "WATCOM" extenders ?)
> - Shoot a hole into the protection and jump to Ring0 (VESAMTRR)

Complete thread:

• VESAMTTR (recovered from Google) - DOS386, 23.07.2007, 02:42 (DOSX)
  • VESAMTTR (recovered from Google) - RayeR, 03.09.2007, 20:45
  • VESAMTTR (recovered from Google) - RayeR, 03.09.2007, 20:58
    • VESAMTTR (recovered from Google) - Rugxulo, 04.09.2007, 02:01
      • VESAMTTR (recovered from Google) - RayeR, 04.09.2007, 12:59
        • VESAMTTR (recovered from Google) - Japheth, 04.09.2007, 16:41
          • VESAMTTR (recovered from Google) - RayeR, 04.09.2007, 20:25
            • VESAMTTR (recovered from Google) - Japheth, 04.09.2007, 22:32
              • VESAMTTR (recovered from Google) - DOS386, 05.09.2007, 02:17
              • VESAMTTR (recovered from Google) - RayeR, 05.09.2007, 09:53
                • VESAMTTR (recovered from Google) - Japheth, 06.09.2007, 08:27
                  • VESAMTTR (recovered from Google) - DOS386, 11.09.2007, 06:54
                    • VESAMTTR (recovered from Google) - RayeR, 12.09.2007, 20:31
                      • VESAMTTR (recovered from Google) - DOS386, 13.09.2007, 02:21
        • VESAMTTR (recovered from Google) - Rugxulo, 05.09.2007, 14:51
          • VESAMTTR (recovered from Google) - RayeR, 05.09.2007, 16:22
            • VESAMTTR (recovered from Google) - Rugxulo, 05.09.2007, 20:56
              • VESAMTTR (recovered from Google) - RayeR, 06.09.2007, 01:08
                • VESAMTTR (recovered from Google) - Rugxulo, 06.09.2007, 04:40
                  • VESAMTTR (recovered from Google) - rr, 06.09.2007, 16:56
                    • VESAMTTR (recovered from Google) - Rugxulo, 07.09.2007, 04:12
                  • VESAMTTR (recovered from Google) - RayeR, 06.09.2007, 22:35
                    • VESAMTTR (recovered from Google) - Rugxulo, 07.09.2007, 04:14
                      • VESAMTTR (recovered from Google) - RayeR, 07.09.2007, 10:18
                        • VESAMTTR (recovered from Google) - rr, 07.09.2007, 10:45
                          • VESAMTTR (recovered from Google) - RayeR, 08.09.2007, 01:46
                            • VESAMTTR (recovered from Google) - Rugxulo, 08.09.2007, 07:03
                              • VESAMTTR (recovered from Google) - RayeR, 08.09.2007, 22:03
                                • VESAMTTR (recovered from Google) - rr, 08.09.2007, 22:49
                                  • VESAMTTR (recovered from Google) - RayeR, 10.09.2007, 14:18
                • VESAMTTR (recovered from Google) - Japheth, 06.09.2007, 07:17
                  • VESAMTTR (recovered from Google) - RayeR, 06.09.2007, 22:34
                • VESAMTTR (recovered from Google) - rr, 06.09.2007, 16:51
                  • VESAMTTR (recovered from Google) - RayeR, 06.09.2007, 22:33
                    • VESAMTTR (recovered from Google) - Rugxulo, 07.09.2007, 05:11
                      • VESAMTTR (recovered from Google) - rr, 07.09.2007, 10:40
                    • VESAMTTR (recovered from Google) - rr, 07.09.2007, 10:40