linux下 lcd显示程序

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

int main() {
    int fbfd = open("/dev/fb0", O_RDWR);
    if (fbfd == -1) {
        perror("Error: cannot open framebuffer device");
        return 1;
    }

    struct fb_var_screeninfo vinfo;
    if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) {
        perror("Error reading variable information");
        return 1;
    }

    long screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
    char *fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fbfd, 0);
    if ((int)fbp == -1) {
        perror("Error: failed to map framebuffer device to memory");
        return 1;
    }

    memset(fbp, 0, screensize); // Clear the screen

    // Example: Draw a simple text string
    const char *text = "Hello, LCD!";
    int x = 10, y = 20;
    // ... (Here you would implement text rendering logic)

    munmap(fbp, screensize);
    close(fbfd);
    return 0;
}