fb.h

extern int get_fbdev_addr(void);

#if defined(__linux__)
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <linux/fb.h>
#include <linux/fs.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <iostream>
using namespace std;

#define DEVICE_NAME "/dev/fb0"
#define DIV_BYTE 8

#define X_PIXEL_MAX 320
#define Y_LINE_MAX  240

#define BORDER1 80
#define BORDER2 160

#define COLOR_RED    0xf800
#define COLOR_GREEN  0x07e0
#define COLOR_BLUE   0x001f
#define COLOR_WHITE  0xffff
#define COLOR_BLACK  0x0000
#define COLOR_YELLOW 0xffe0

/* function prototype */
void send_current_error_msg(char *ptr);
void send_current_information(char *ptr);

int get_fbdev_addr(void)
{
        int fd_framebuffer ;
        struct fb_var_screeninfo vinfo;
        struct fb_fix_screeninfo finfo;
        long int screensize ;
        //long int location;
        char *fbptr ;
        char tmp[DIV_BYTE*10];

        //int x , y ;
        int xres,yres,vbpp,line_len;
        //unsigned short tcolor ;

        /* Æɤ߽ñ¤­ÍѤ˥ե¡¥¤¥ë¤ò³«¤¯ */
        fd_framebuffer = open( DEVICE_NAME , O_RDWR);
        if ( !fd_framebuffer ) {
                send_current_error_msg("Framebuffer device open error !");
                exit(1);
        }
        send_current_information("The framebuffer device was opened !");

        /* ¸ÇÄꥹ¥¯¥ê¡¼¥ó¾ðÊó¼èÆÀ */
        if ( ioctl( fd_framebuffer , FBIOGET_FSCREENINFO , &finfo ) ) {
                send_current_error_msg("Fixed information not gotton !");
                exit(2);
        }

        /* ÊÑÆ°¥¹¥¯¥ê¡¼¥ó¾ðÊó¼èÆÀ */
        if ( ioctl( fd_framebuffer , FBIOGET_VSCREENINFO , &vinfo ) ) {
                send_current_error_msg("Variable information not gotton !");
                exit(3);
        }
        xres = vinfo.xres ;
        yres = vinfo.yres ;
        vbpp = vinfo.bits_per_pixel ;
        line_len = finfo.line_length ;
        sprintf( tmp , "%d(pixel)x%d(line), %dbpp(bits per pixel)",xres,yres,vbpp);
        send_current_information( tmp );

        /* ¥Ð¥¤¥Èñ°Ì¤Ç¤Î¥¹¥¯¥ê¡¼¥ó¤Î¥µ¥¤¥º¤ò·×»» */
        screensize = xres * yres * vbpp / DIV_BYTE ;

        /* ¥Ç¥Ð¥¤¥¹¤ò¥á¥â¥ê¤Ë¥Þ¥Ã¥×¤¹¤ë */
        fbptr = (char *)mmap(0,screensize,PROT_READ | PROT_WRITE,MAP_SHARED,fd_framebuffer,0);
        if ( (int)fbptr == -1 ) {
                send_current_error_msg("Don't get framebuffer device to memory !");
                exit(4);
        }
        send_current_information("The framebuffer device was mapped !");

        printf("fb: 0x%x \n", (unsigned int)fbptr);
        return (int)fbptr;
        //munmap(fbptr,screensize);
        //close(fd_framebuffer);
        //return 0;
}

void send_current_error_msg(char *ptr)
{
        fprintf( stderr , "%s\n" , ptr );
}

void send_current_information(char *ptr)
{
        fprintf( stdout , "%s\n" , ptr );
}
#else /* __linux__ */
int get_fbdev_addr(void) {return 0;}
#endif /* __linux__ */

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