上代码
import fcntl import struct import mmap import contextlib import os import time import numpy as np import cv2 src = cv2.imread('./1.bmp', cv2.IMREAD_COLOR) img = src#[0:100, 0:400] print img.shape with open('/dev/fb0', 'r+b') as fbfd: fb_fix_screeninfo = struct.pack('16sLIIIIIIIILIIHHH', '0000000000000000', 0L, 0,0,0,0,0,0,0,0, 0L, 0, 0, 0, 0, 0) ''' struct fb_fix_screeninfo { char id[16]; /* identification string eg "TT Builtin" */ unsigned long smem_start; /* Start of frame buffer mem */ /* (physical address) */ __u32 smem_len; /* Length of frame buffer mem */ __u32 type; /* see FB_TYPE_* */ __u32 type_aux; /* Interleave for interleaved Planes */ __u32 visual; /* see FB_VISUAL_* */ __u16 xpanstep; /* zero if no hardware panning */ __u16 ypanstep; /* zero if no hardware panning */ __u16 ywrapstep; /* zero if no hardware ywrap */ __u32 line_length; /* length of a line in bytes */ unsigned long mmio_start; /* Start of Memory Mapped I/O */ /* (physical address) */ __u32 mmio_len; /* Length of Memory Mapped I/O */ __u32 accel; /* Indicate to driver which */ /* specific chip/card we have */ __u16 capabilities; /* see FB_CAP_* */ __u16 reserved[2]; /* Reserved for future compatibility */ }; ''' fb_fix_screeninfo = fcntl.ioctl(fbfd, 0x4602, fb_fix_screeninfo) fb_fix_screeninfo = struct.unpack('16sLIIIIIIIILIIHHH', fb_fix_screeninfo) lineLength = fb_fix_screeninfo[8] fb_var_screeninfo = struct.pack('IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) ''' struct fb_bitfield { __u32 offset; /* beginning of bitfield */ __u32 length; /* length of bitfield */ __u32 msb_right; /* != 0 : Most significant bit is */ /* right */ }; struct fb_var_screeninfo { __u32 xres; /* visible resolution */ __u32 yres; __u32 xres_virtual; /* virtual resolution */ __u32 yres_virtual; __u32 xoffset; /* offset from virtual to visible */ __u32 yoffset; /* resolution */ __u32 bits_per_pixel; /* guess what */ __u32 grayscale; /* 0 = color, 1 = grayscale, */ /* >1 = FOURCC */ struct fb_bitfield red; /* bitfield in fb mem if true color, */ struct fb_bitfield green; /* else only length is significant */ struct fb_bitfield blue; struct fb_bitfield transp; /* transparency */ __u32 nonstd; /* != 0 Non standard pixel format */ __u32 activate; /* see FB_ACTIVATE_* */ __u32 height; /* height of picture in mm */ __u32 width; /* width of picture in mm */ __u32 accel_flags; /* (OBSOLETE) see fb_info.flags */ /* Timing: All values in pixclocks, except pixclock (of course) */ __u32 pixclock; /* pixel clock in ps (pico seconds) */ __u32 left_margin; /* time from sync to picture */ __u32 right_margin; /* time from picture to sync */ __u32 upper_margin; /* time from sync to picture */ __u32 lower_margin; __u32 hsync_len; /* length of horizontal sync */ __u32 vsync_len; /* length of vertical sync */ __u32 sync; /* see FB_SYNC_* */ __u32 vmode; /* see FB_VMODE_* */ __u32 rotate; /* angle we rotate counter clockwise */ __u32 colorspace; /* colorspace for FOURCC-based modes */ __u32 reserved[4]; /* Reserved for future compatibility */ };''' fb_var_screeninfo = fcntl.ioctl(fbfd, 0x4600, fb_var_screeninfo) fb_var_screeninfo = struct.unpack('IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', fb_var_screeninfo) screen_x = fb_var_screeninfo[0] screen_y = fb_var_screeninfo[1] bitPerPix = fb_var_screeninfo[6] print("%d*%d, %dbpp" %(fb_var_screeninfo[0], fb_var_screeninfo[1], fb_var_screeninfo[6])) screensize = fb_var_screeninfo[0] * fb_var_screeninfo[1] * fb_var_screeninfo[6] / 8 print 'screensize=' + str(screensize) with contextlib.closing(mmap.mmap(fbfd.fileno(), screensize, flags=mmap.MAP_SHARED, access=mmap.ACCESS_WRITE)) as fbp: ## print fbp.size() loc = 0 linex = 0 for y in range(img.shape[0]): for x in range(img.shape[1]): loc = (y*lineLength) + (x*bitPerPix/8) fbp[loc] = chr(img[y][x][0]) fbp[loc+1] = chr(img[y][x][1]) fbp[loc+2] = chr(img[y][x][2]) fbp[loc+3] = chr(255) ## ## r = fbp.flush() ## time.sleep(3)
资料
获取framebuffer设备信息.ioctl(int fb,FBIOGET_FSCREENINFO,&finfo);
ioctl函数是实现对设备的信息获取和设定，第一个参数为文件描述符，第二个参数为具体设备的参数，对于framebuffer,参数在linux/fb.h中定义的。
#define FBIOGET_VSCREENINFO 0x4600 //获取设备无关的数据信息fb_var_screeninfo
#define FBIOPUT_VSCREENINFO 0x4601 //设定设备无关的数据信息
#define FBIOGET_FSCREENINFO 0x4602 //获取设备无关的常值信息fb_fix_screeninfo
#define FBIOGETCMAP 0x4604 //获取设备无关颜色表信息
#define FBIOPUTCMAP 0x4605 //设定设备无关颜色表信息
#define FBIOPAN_DISPLAY 0x4606
#define FBIO_CURSOR _IOWR('F', 0x08, struct fb_cursor)
第三个参数是存放信息的结构体或者缓冲区