linux lcd文字库

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

int main() {
    int fbfd;
    struct fb_var_screeninfo vinfo;
    struct fb_fix_screeninfo finfo;
    long screensize;
    char *fbp;

    // 打开framebuffer设备
    fbfd = open("/dev/fb0", O_RDWR);
    if (fbfd == -1) {
        perror("Error: cannot open framebuffer device");
        exit(1);
    }

    // 获取framebuffer信息
    if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo) == -1) {
        perror("Error reading fixed information");
        exit(2);
    }
    if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo) == -1) {
        perror("Error reading variable information");
        exit(3);
    }

    // 计算屏幕大小
    screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;

    // 映射framebuffer到内存
    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");
        exit(4);
    }

    // 设置颜色（例如白色）
    long int screens[ vinfo.xres * vinfo.yres ];
    memset(fbp, 0, screensize);
    for (int i = 0; i < vinfo.xres * vinfo.yres; i++)
        screens[i] = 0xffffff;

    // 在LCD上显示文字
    char text[] = "Hello, LCD!";
    int x = 10, y = 10;
    for (int i = 0; text[i] != '\0'; i++) {
        // 这里需要实现字符绘制逻辑，具体实现取决于LCD驱动程序和硬件
        // 假设每个字符占用8x16像素，并且已经有一个函数draw_char来绘制字符
        draw_char(fbp, text[i], x, y);
        x += 8; // 假设每个字符宽度为8像素
    }

    // 解除映射并关闭framebuffer设备
    munmap(fbp, screensize);
    close(fbfd);

    return 0;
}