🚀 go-pugleaf

In article <1992Oct5.184133.13502@mnemosyne.cs.du.edu> kconnors@nyx.cs.du.edu (Keith Connors) writes:
>
>Help!  I think we've been ripped off!  The family just purchased a
>486 33 MHz system, but there is reason to believe that it may be
>actually a 386 33 MHz machine!!  Could someone please uuencode and mail
>me (or better yet, refer to an anonymous FTP site) a program that 
>displays the CPU in the machine?!  We'd rather not take it apart until
>we can be sure that we've been had!!!  
>
>Thanks so much for your time......
  
  The following program will test to see if the executing processor
  is behaving like a 386 or like a 486, without resorting to
  hardware methods (a dangerous thing is a software-engineer
  with a screw-driver):
----------------------------------------------------------
#include <stdio.h>

#define UNKNOWN 2

char* cpu_names[] = { "i386", "i486", "????" };
main()
{
   int cpu;

   cpu = cpu_type();

   if ( cpu < 0 || cpu > 1)
      cpu = UNKNOWN;

   printf ( "%s\n", cpu_names[cpu]);
}

/*
 * cpu_type  --  guess the type of the cpu by checking
 *               if the alignment-check flag gets set
 *               returns 1 if set (i.e., i486) or 0 if
 *               not set (i.e., i386)
 */
int
cpu_type()
{
   asm("pushfl");               /* get flags into eax */
   asm("mov 0(%esp),%eax");
   asm("movl %eax,%ecx");       /* save flag register in ecx */
   asm("xorl $0x40000,%eax");   /* toggle alignment-check (ac) flag */
   asm("mov %eax,0(%esp)");     /* copy eax to flag register */
   asm("popfl");                /* (potentially changes ac flag) */
   asm("pushfl");               /* get flags into eax */
   asm("mov 0(%esp),%eax");
   asm("shrl $0x12,%eax");      /* ac flag -> LSbit */
   asm("andl $0x1,%eax");       /* clear rest of register */
   asm("mov %ecx,0(%esp)");
   asm("popfl");                /* restore flag register from ecx */
}
----------------------------------------------------------


  Roy
--
Roy Phillips
A+F System-Entwicklung
DW-4030 Ratingen
Germany
roy@alfrat.de