linux操作fb文件节点刷纯色

代码

#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <linux/fb.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <string.h>#define RED    0xF800
#define YELLOW    0xFFE0
#define BLUE     0x001F
#define WHITE    0xFFFF
#define BLACK    0x0000void fill_color16(short *fb_addr, short bit_map, int psize)
{int i;for(i=0; i<psize; i++) {*fb_addr = bit_map;fb_addr++;}
}int main ()
{int fp=0;struct fb_var_screeninfo vinfo;struct fb_fix_screeninfo finfo;long screensize=0;char *fbp = NULL, *test_fbp=NULL;int x = 0, y = 0;long location = 0;int i;int num = 5;int pix_size=0;//fp = open("/dev/graphics/fb0", O_RDWR);fp = open("/dev/fb0", O_RDWR);if(fp < 0) {printf("Error : Can not open framebuffer device/n");exit(1);}if(ioctl(fp, FBIOGET_FSCREENINFO, &finfo)){printf("Error reading fixed information/n");exit(2);}if(ioctl(fp, FBIOGET_VSCREENINFO, &vinfo)){printf("Error reading variable information/n");exit(3);}screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;printf("The phy mem = 0x%x, total size = %d(byte)\n", finfo.smem_start, finfo.smem_len);printf("xres =  %d, yres =  %d, bits_per_pixel = %d\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);printf("So the screensize = %d(byte), using %d frame\n", screensize, finfo.smem_len/screensize);printf("vinfo.xoffset = %d, vinfo.yoffset = %d\n", vinfo.xoffset, vinfo.yoffset);printf("vinfo.vmode is :%d\n", vinfo.vmode);printf("finfo.ypanstep is :%d\n", finfo.ypanstep);printf("vinfo.red.offset=0x%x\n", vinfo.red.offset);printf("vinfo.red.length=0x%x\n", vinfo.red.length);printf("vinfo.green.offset=0x%x\n", vinfo.green.offset);printf("vinfo.green.length=0x%x\n", vinfo.green.length);printf("vinfo.blue.offset=0x%x\n", vinfo.blue.offset);printf("vinfo.blue.length=0x%x\n", vinfo.blue.length);printf("vinfo.transp.offset=0x%x\n", vinfo.transp.offset);printf("vinfo.transp.length=0x%x\n", vinfo.transp.length);fbp =(char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fp,0);if ((int)fbp == -1){printf ("Error: failed to map framebuffer device to memory./n");exit (4);}printf("Get virt mem = %p\n", fbp);pix_size = vinfo.xres * vinfo.yres;/* using first frame, for FBIOPAN_DISPLAY* 当刷新需要调用FBIOPAN_DISPLAY， 要告知驱动刷哪块帧， 用到下面两个参数* 如果使用第二帧buffer -> vinfo.xoffset = 0; vinfo.yoffset = vinfo.yres;*/vinfo.xoffset = 0;vinfo.yoffset = 0;/* show color loop */while(num--) {printf("\ndrawing YELLOW......\n");fill_color16((short *)fbp, YELLOW, pix_size);//ioctl(fp, FBIOPAN_DISPLAY, &vinfo);sleep(3);printf("\ndrawing BLUE......\n");fill_color16((short *)fbp, BLUE, pix_size);//ioctl(fp, FBIOPAN_DISPLAY, &vinfo);sleep(3);printf("\ndrawing RED......\n");fill_color16((short *)fbp, RED, pix_size);//ioctl(fp, FBIOPAN_DISPLAY, &vinfo);sleep(3);}
#if 1/*这是你想画的点的位置坐标,(0，0)点在屏幕左上角*/x = 10;y = 10;location = x * (vinfo.bits_per_pixel / 8) + y  *  finfo.line_length;test_fbp = fbp + location;printf("draw line.......\n");for(i = 0; i < (vinfo.xres - x); i++)*test_fbp++ = i+30;//ioctl(fp, FBIOPAN_DISPLAY, &vinfo);
#endifmunmap(fbp, screensize); /*解除映射*/close (fp);return 0;
}