学步园

主机：VM - redhat 9.0

开发板：FL2440，linux-2.6.12

arm-linux-gcc：3.4.1

对应的LCD设备驱动参见：http://blog.csdn.net/gzliu_hit/article/details/6738659

#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <linux/fb.h>
#include <sys/mman.h>

#define RED_COLOR565    0x0F100
#define GREEN_COLOR565  0x007E0
#define BLUE_COLOR565   0x0001F

int main(void)
{
    int fd_fb = 0;
    struct fb_var_screeninfo vinfo;
    struct fb_fix_screeninfo finfo;
    long int screen_size = 0;
    short *fbp565 = NULL;

    int x = 0, y = 0;

    fd_fb = open("/dev/fb0", O_RDWR);
    if (!fd_fb)
    {
        printf("Error: cannot open framebuffer device.\n");
        exit(1);
    }

    // Get fixed screen info
    if (ioctl(fd_fb, FBIOGET_FSCREENINFO, &finfo))
    {
        printf("Error reading fixed information.\n");
        exit(2);
    }

    // Get variable screen info
    if (ioctl(fd_fb, FBIOGET_VSCREENINFO, &vinfo))
    {
        printf("Error reading variable information.\n");
        exit(3);
    }

    // the size of the screen in bytes
    screen_size = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;

    printf("%dx%d, %dbpp, screen_size = %d\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel, screen_size );

    // map framebuffer to user memory
    fbp565 = (short *)mmap(0, screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);

    if ((int)fbp565 == -1)
    {
        printf("Error: failed to map framebuffer device to memory.\n");
        exit(4);
    }

    if(vinfo.bits_per_pixel == 16)
    {
        printf("16 bpp framebuffer\n");

        // Red Screen
        printf("Red Screen\n");
        for(y = 0; y < vinfo.yres/3;  y++)
        {
            for(x = 0; x < vinfo.xres ; x++)
            {
                *(fbp565 + y * vinfo.xres + x) = RED_COLOR565;
            }
        }

        // Green Screen
        printf("Green Screen\n");
        for(y = vinfo.yres/3; y < (vinfo.yres*2)/3; y++)
        {
            for(x = 0; x < vinfo.xres; x++)
            {
                *(fbp565 + y * vinfo.xres + x) =GREEN_COLOR565;
            }
        }

        // Blue Screen
        printf("Blue Screen\n");
        for(y = (vinfo.yres*2)/3; y < vinfo.yres; y++)
        {
            for(x = 0; x < vinfo.xres; x++)
            {
                *(fbp565 + y * vinfo.xres + x) = BLUE_COLOR565;
            }
        }
    }
    
    else
    {
        printf("warnning: bpp is not 16\n");
    }

    munmap(fbp565, screen_size);
    close(fd_fb);
    return 0;
}

测试结果，由上往下颜色分别为红、绿、蓝，图像有色差。