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复制代码到目录下
root@xiliang-desktop:/home/bw-1788/framebuffer# cp /mnt/hgfs/share/framebuffer.c .
编译
root@xiliang-desktop:/home/bw-1788/framebuffer# /home/lpc1788/linux-cortexm-1.4.1/tools/arm-2010q1/bin/arm-uclinuxeabi-gcc -Os -mcpu=cortex-m3 -mthumb -o framebuffer framebuffer.c
把可执行文件复制到根文件系统下
root@xiliang-desktop:/home/bw-1788/framebuffer# cp framebuffer /home/bw-1788/rootfs/
在开发板上执行程序
# ./framebuffer
程序源码:
/* framebuffer.c */- #include <unistd.h>
- #include <stdio.h>
- #include <fcntl.h>
- #include <linux/fb.h>
- #include <sys/mman.h>
- int main()
- {
- int fbfd = 0;
- struct fb_var_screeninfo vinfo;
- struct fb_fix_screeninfo finfo;
- long int screensize = 0;
- char *fbp = 0;
- int x = 0, y = 0;
- long int location = 0;
- // Open the file for reading and writing
- fbfd = open("/dev/fb0", O_RDWR);
- if (!fbfd) {
- printf("Error: cannot open framebuffer device.\n");
- exit(1);
- }
- printf("The framebuffer device was opened successfully.\n");
- // Get fixed screen information
- if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo)) {
- printf("Error reading fixed information.\n");
- exit(2);
- }
- // Get variable screen information
- if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) {
- printf("Error reading variable information.\n");
- exit(3);
- }
- printf("%dx%d, %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);
- // Figure out the size of the screen in bytes
- screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
- // Map the device to memory
- fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED,
- fbfd, 0);
- if ((int)fbp == -1) {
- printf("Error: failed to map framebuffer device to memory.\n");
- exit(4);
- }
- printf("The framebuffer device was mapped to memory successfully.\n");
- x = 100; y = 100; // Where we are going to put the pixel
- // Figure out where in memory to put the pixel
- for (y = 100; y < 300; y++)
- for (x = 100; x < 300; x++) {
- location = (x+vinfo.xoffset) * (vinfo.bits_per_pixel/8) +
- (y+vinfo.yoffset) * finfo.line_length;
- if (vinfo.bits_per_pixel == 32) {
- *(fbp + location) = 100; // Some blue
- *(fbp + location + 1) = 15+(x-100)/2; // A little green
- *(fbp + location + 2) = 200-(y-100)/5; // A lot of red
- *(fbp + location + 3) = 0; // No transparency
- } else { //assume 16bpp
- int b = 10;
- int g = (x-100)/6; // A little green
- int r = 31-(y-100)/16; // A lot of red
- unsigned short int t = r<<11 | g << 5 | b;
- *((unsigned short int*)(fbp + location)) = t;
- }
- }
- munmap(fbp, screensize);
- close(fbfd);
- return 0;
- }
复制代码 |
阿莫论坛20周年了!感谢大家的支持与爱护!!
该献的血还是要献的。你不献他不献。难道让我去献? --- 出自坛友:lovejp1981
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