TB-RK3399ProX Debian10系统与内存映射FrameBuffer出错 - Toybrick

static int width; //LCD X 分辨率
static int height; //LCD Y 分辨率
static unsigned short *screen_base = NULL; //映射后的显存基地址
int main(int argc, char *argv[])
{
struct fb_fix_screeninfo fb_fix;
struct fb_var_screeninfo fb_var;
unsigned int screen_size;
int fd;
/* 打开 framebuffer 设备 */
if (0 > (fd = open("/dev/fb0", O_RDWR))) {
perror("open error");
exit(EXIT_FAILURE);
}
/* 获取参数信息 */
ioctl(fd, FBIOGET_VSCREENINFO, &fb_var);
ioctl(fd, FBIOGET_FSCREENINFO, &fb_fix);
screen_size = fb_fix.line_length * fb_var.yres;
printf("screen_size:%d\r\n",screen_size);
width = fb_var.xres;
height = fb_var.yres;
/* 将显示缓冲区映射到进程地址空间 */
screen_base = mmap(NULL, screen_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if (MAP_FAILED == (void *)screen_base) {
perror("mmap error");
close(fd);
exit(EXIT_FAILURE);
}
memset(screen_base, 0xFF, screen_size);
munmap(screen_base, screen_size); //取消映射
close(fd); //关闭文件
exit(EXIT_SUCCESS); //退出进
}