//-------------------------------------------------------------------
//	findsvga.cpp
//
//	This utility invokes PCI Bios Services in virtual-8086 mode
//	to locate the SVGA display devices installed in the system.
//	For each such device the PCI Configuration Header is shown.  
//	
//	  compile with:  $ g++ findsvga.cpp int86.cpp -o findsvga
//
//	Note: to execute this utility, our 'dosio.c' driver must be
//	installed, and the '/dev/dos' device-file must be writable. 
//
//	programmer: ALLAN CRUSE
//	written on: 02 AUG 2005
//-------------------------------------------------------------------

#include <stdio.h>		// for printf() 
#include "int86.h"		// for init8086(), int86()

#define CLASS_SVGA 0x030000	// PCI Display Device class

struct vm86plus_struct	vm;

int main( int argc, char **argv )
{
	init8086();		// setup simulated 8086 environment

	vm.regs.eax = 0xB101;	// detect presence of the PCI Bios
	int86( 0x1A, vm );
	int	version = vm.regs.ebx;
	printf( "\nPCI Bios version: %X.%X  ", version >> 8, version & 0xFF );
	printf( "Number of PCI buses: %d \n\n", vm.regs.ecx & 0xFF );
	
	for (int i = 0; i < 0xFFFF; i++) 
		{
		vm.regs.eax = 0xB103;	// find PCI Class
		vm.regs.ecx = CLASS_SVGA;
		vm.regs.esi = i;	// device index
		int86( 0x1A, vm );
		if ( ( vm.regs.eax & 0xFF00 ) == 0x8600 ) break;

		printf( "VGA display device #%d:  ", i );
		printf( "bus=%d  ", (vm.regs.ebx >> 8) & 0xFF );
		printf( "device=%d  ", ( vm.regs.ebx >> 3 )&0x1F );
		printf( "function=%d  ", (vm.regs.ebx >> 0 )&0x07 );

		for (int j = 0; j < 256; j+=4)
			{
			if ( ( j % 32 ) == 0 ) printf( "\n%02X: ", j );
			vm.regs.eax = 0xB10A;	// read PCI Config Dword
			vm.regs.edi = j;
			int86( 0x1A, vm );
			printf( "%08X ", vm.regs.ecx );
			}

		printf( "\n\n" );
		}
}