isvesa.c

gumstiz u-boot loader in linux

/****************************************************************************
*
*                   SciTech OS Portability Manager Library
*
*  ========================================================================
*
*    The contents of this file are subject to the SciTech MGL Public
*    License Version 1.0 (the "License"); you may not use this file
*    except in compliance with the License. You may obtain a copy of
*    the License at http://www.scitechsoft.com/mgl-license.txt
*
*    Software distributed under the License is distributed on an
*    "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
*    implied. See the License for the specific language governing
*    rights and limitations under the License.
*
*    The Original Code is Copyright (C) 1991-1998 SciTech Software, Inc.
*
*    The Initial Developer of the Original Code is SciTech Software, Inc.
*    All Rights Reserved.
*
*  ========================================================================
*
* Language:     ANSI C
* Environment:  any
*
* Description:  Test program to check the ability to allocate real mode
*               memory and to call real mode interrupt handlers such as
*               the VESA VBE BIOS from protected mode. Compile and link
*               with the appropriate command line for your DOS extender.
*
*               Functions tested:   PM_getVESABuf()
*                                   PM_mapRealPointer()
*                                   PM_int86x()
*
****************************************************************************/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "pmapi.h"

/* SuperVGA information block */

#pragma pack(1)

typedef struct {
    char    VESASignature[4];       /* 'VESA' 4 byte signature          */
    short   VESAVersion;            /* VBE version number               */
    ulong   OEMStringPtr;           /* Far pointer to OEM string        */
    ulong   Capabilities;           /* Capabilities of video card       */
    ulong   VideoModePtr;           /* Far pointer to supported modes   */
    short   TotalMemory;            /* Number of 64kb memory blocks     */
    char    reserved[236];          /* Pad to 256 byte block size       */
    } VgaInfoBlock;

#pragma pack()

int main(void)
{
    RMREGS          regs;
    RMSREGS         sregs;
    VgaInfoBlock    vgaInfo;
    ushort          *mode;
    uint            vgLen;
    uchar           *vgPtr;
    unsigned        r_vgseg,r_vgoff;

    printf("Program running in ");
    switch (PM_getModeType()) {
	case PM_realMode:
	    printf("real mode.\n\n");
	    break;
	case PM_286:
	    printf("16 bit protected mode.\n\n");
	    break;
	case PM_386:
	    printf("32 bit protected mode.\n\n");
	    break;
	}

    /* Allocate a 256 byte block of real memory for communicating with
     * the VESA BIOS.
     */
    if ((vgPtr = PM_getVESABuf(&vgLen,&r_vgseg,&r_vgoff)) == NULL) {
	printf("Unable to allocate VESA memory buffer!\n");
	exit(1);
	}

    /* Call the VESA VBE to see if it is out there */
    regs.x.ax = 0x4F00;
    regs.x.di = r_vgoff;
    sregs.es = r_vgseg;
    memcpy(vgPtr,"VBE2",4);
    PM_int86x(0x10, &regs, &regs, &sregs);
    memcpy(&vgaInfo,vgPtr,sizeof(VgaInfoBlock));
    if (regs.x.ax == 0x4F && strncmp(vgaInfo.VESASignature,"VESA",4) == 0) {
	printf("VESA VBE version %d.%d BIOS detected\n\n",
	    vgaInfo.VESAVersion >> 8, vgaInfo.VESAVersion & 0xF);
	printf("Available video modes:\n");
	mode = PM_mapRealPointer(vgaInfo.VideoModePtr >> 16, vgaInfo.VideoModePtr & 0xFFFF);
	while (*mode != 0xFFFF) {
	    printf("    %04hXh (%08X)\n", *mode, (int)mode);
	    mode++;
	    }
	}
    else
	printf("VESA VBE not found\n");
    return 0;
}