DOS ain't dead - VESAMTTR (recovered from Google)

VESAMTTR (recovered from Google) (DOSX)

posted by RayeR , CZ, 04.09.2007, 12:59

I dopn't need anything extra, just if here someone knows AT&T inline ASM for DJGPP:

My ring0 code is this shor function:

void ring0_rdmsr(void) // GCC bohuzel nepodporuje __attribute__ ((naked)) na x86 { // takze misto pointeru na funkci pouzijeme ASM label asm __volatile__ ( "rdmsr_label:\n" // label at start of pure code behind C-function prologue "rdmsr\n" // read CPU MSR register value to EDX:EAX "movl %eax,(%ebx)\n" // mov dword ptr [ebx],eax "movl %edx,(%edi)\n" // mov dword ptr [edi],edx "lret\n" // far return from ring 0 ); // C-function epilogue will be never reached

and callgate is called:

asm __volatile__ ( // volani CallGate // "pushal\n" // store all registers to stack "cli\n" // disable interrupts "movl %0,%%ebx\n" // store pointer to low DWord "movl %1,%%edi\n" // store pointer to high DWord "movl %2,%%ecx\n" // store MSR index "lcall *%3\n" // far call the CallGate to enter ring 0, require code far return "sti\n" // enable interrupts // "popal\n" // restore all registers from stack : // no outputs (readed data overwrites input arguments) : "g" (eax), "g" (edx), "g" (ecx), "m" (ldt_callgate_ptr) // inputs );

If I have pushal/popal around the call, then DJGPP crashes (but mingw32 not) so i commented it. Is it really needed? Or can I ommit it? Or any idea to improve this inline asm?

EDIT by rr: added {code} tags

---
DOS gives me freedom to unlimited HW access.

Post reply

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