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作者：yuweixian4230@163.com
博客：yuweixian4230.blog.chinaunix.net 网址 http://www.cnblogs.com/cute/archive/2011/04/20/2022114.html 有一程序关于 framebuffer，现在我对他进行测试，然后进行分析
代码附件：
xx.rar 现在 将 程序贴出来
- #include <stdlib.h>
-
#include <unistd.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <linux/fb.h>
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#include <linux/kd.h>
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#include <sys/mman.h>
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#include <sys/ioctl.h>
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#include <sys/time.h>
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#include <string.h>
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#include <errno.h>
-
-
-
struct fb_var_screeninfo vinfo;
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struct fb_fix_screeninfo finfo;
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char *frameBuffer = 0;
-
-
-
//打印fb驱动中fix结构信息，注：在fb驱动加载后，fix结构不可被修改。
-
void printFixedInfo ()
-
{
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printf ("Fixed screen info:\n"
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"\tid: %s\n"
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"\tsmem_start: 0x%lx\n"
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"\tsmem_len: %d\n"
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"\ttype: %d\n"
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"\ttype_aux: %d\n"
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"\tvisual: %d\n"
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"\txpanstep: %d\n"
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"\typanstep: %d\n"
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"\tywrapstep: %d\n"
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"\tline_length: %d\n"
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"\tmmio_start: 0x%lx\n"
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"\tmmio_len: %d\n"
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"\taccel: %d\n"
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"\n",
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finfo.id, finfo.smem_start, finfo.smem_len, finfo.type,
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finfo.type_aux, finfo.visual, finfo.xpanstep, finfo.ypanstep,
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finfo.ywrapstep, finfo.line_length, finfo.mmio_start,
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finfo.mmio_len, finfo.accel);
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}
-
-
-
//打印fb驱动中var结构信息，注：fb驱动加载后，var结构可根据实际需要被重置
-
void printVariableInfo ()
-
{
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printf ("Variable screen info:\n"
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"\txres: %d\n"
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"\tyres: %d\n"
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"\txres_virtual: %d\n"
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"\tyres_virtual: %d\n"
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"\tyoffset: %d\n"
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"\txoffset: %d\n"
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"\tbits_per_pixel: %d\n"
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"\tgrayscale: %d\n"
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"\tred: offset: %2d, length: %2d, msb_right: %2d\n"
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"\tgreen: offset: %2d, length: %2d, msb_right: %2d\n"
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"\tblue: offset: %2d, length: %2d, msb_right: %2d\n"
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"\ttransp: offset: %2d, length: %2d, msb_right: %2d\n"
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"\tnonstd: %d\n"
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"\tactivate: %d\n"
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"\theight: %d\n"
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"\twidth: %d\n"
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"\taccel_flags: 0x%x\n"
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"\tpixclock: %d\n"
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"\tleft_margin: %d\n"
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"\tright_margin: %d\n"
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"\tupper_margin: %d\n"
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"\tlower_margin: %d\n"
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"\thsync_len: %d\n"
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"\tvsync_len: %d\n"
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"\tsync: %d\n"
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"\tvmode: %d\n"
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"\n",
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vinfo.xres, vinfo.yres, vinfo.xres_virtual, vinfo.yres_virtual,
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vinfo.xoffset, vinfo.yoffset, vinfo.bits_per_pixel,
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vinfo.grayscale, vinfo.red.offset, vinfo.red.length,
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vinfo.red.msb_right, vinfo.green.offset, vinfo.green.length,
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vinfo.green.msb_right, vinfo.blue.offset, vinfo.blue.length,
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vinfo.blue.msb_right, vinfo.transp.offset, vinfo.transp.length,
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vinfo.transp.msb_right, vinfo.nonstd, vinfo.activate,
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vinfo.height, vinfo.width, vinfo.accel_flags, vinfo.pixclock,
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vinfo.left_margin, vinfo.right_margin, vinfo.upper_margin,
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vinfo.lower_margin, vinfo.hsync_len, vinfo.vsync_len,
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vinfo.sync, vinfo.vmode);
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}
-
-
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//画大小为width*height的同色矩阵，8alpha+8reds+8greens+8blues
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void
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drawRect_rgb32 (int x0, int y0, int width, int height, int color)
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{
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const int bytesPerPixel = 4;
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const int stride = finfo.line_length / bytesPerPixel;
-
-
-
int *dest = (int *) (frameBuffer)
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+ (y0 + vinfo.yoffset) * stride + (x0 + vinfo.xoffset);
-
-
-
int x, y;
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for (y = 0; y < height; ++y)
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{
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for (x = 0; x < width; ++x)
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{
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dest[x] = color;
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}
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dest += stride;
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}
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}
-
-
-
//画大小为width*height的同色矩阵，5reds+6greens+5blues
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void
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drawRect_rgb16 (int x0, int y0, int width, int height, int color)
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{
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const int bytesPerPixel = 2;
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const int stride = finfo.line_length / bytesPerPixel;
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const int red = (color & 0xff0000) >> (16 + 3);
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const int green = (color & 0xff00) >> (8 + 2);
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const int blue = (color & 0xff) >> 3;
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const short color16 = blue | (green << 5) | (red << (5 + 6));
-
-
-
short *dest = (short *) (frameBuffer)
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+ (y0 + vinfo.yoffset) * stride + (x0 + vinfo.xoffset);
-
-
-
int x, y;
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for (y = 0; y < height; ++y)
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{
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for (x = 0; x < width; ++x)
-
{
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dest[x] = color16;
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}
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dest += stride;
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}
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}
-
-
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//画大小为width*height的同色矩阵，5reds+5greens+5blues
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void drawRect_rgb15 (int x0, int y0, int width, int height, int color)
-
{
-
const int bytesPerPixel = 2;
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const int stride = finfo.line_length / bytesPerPixel;
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const int red = (color & 0xff0000) >> (16 + 3);
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const int green = (color & 0xff00) >> (8 + 3);
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const int blue = (color & 0xff) >> 3;
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const short color15 = blue | (green << 5) | (red << (5 + 5)) | 0x8000;
-
-
-
short *dest = (short *) (frameBuffer)
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+ (y0 + vinfo.yoffset) * stride + (x0 + vinfo.xoffset);
-
-
-
int x, y;
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for (y = 0; y < height; ++y)
-
{
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for (x = 0; x < width; ++x)
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{
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dest[x] = color15;
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}
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dest += stride;
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}
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}
-
-
-
void drawRect (int x0, int y0, int width, int height, int color)
-
{
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switch (vinfo.bits_per_pixel)
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{
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case 32:
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drawRect_rgb32 (x0, y0, width, height, color);
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break;
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case 16:
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drawRect_rgb16 (x0, y0, width, height, color);
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break;
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case 15:
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drawRect_rgb15 (x0, y0, width, height, color);
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break;
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default:
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printf ("Warning: drawRect() not implemented for color depth %i\n",
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vinfo.bits_per_pixel);
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break;
-
}
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}
-
-
-
#define PERFORMANCE_RUN_COUNT 5
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void performSpeedTest (void *fb, int fbSize)
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{
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int i, j, run;
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struct timeval startTime, endTime;
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unsigned long long results[PERFORMANCE_RUN_COUNT];
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unsigned long long average;
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unsigned int *testImage;
-
-
unsigned int randData[17] = {
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0x3A428472, 0x724B84D3, 0x26B898AB, 0x7D980E3C, 0x5345A084,
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0x6779B66B, 0x791EE4B4, 0x6E8EE3CC, 0x63AF504A, 0x18A21B33,
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0x0E26EB73, 0x022F708E, 0x1740F3B0, 0x7E2C699D, 0x0E8A570B,
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0x5F2C22FB, 0x6A742130
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};
-
-
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printf ("Frame Buffer Performance test...\n");
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for (run = 0; run < PERFORMANCE_RUN_COUNT; ++run)
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{
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/* Generate test image with random(ish) data: */
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testImage = (unsigned int *) malloc (fbSize);
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j = run;
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for (i = 0; i < (int) (fbSize / sizeof (int)); ++i)
-
{
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testImage[i] = randData[j];
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j++;
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if (j >= 17)
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j = 0;
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}
-
-
-
gettimeofday (&startTime, NULL);
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memcpy (fb, testImage, fbSize);
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gettimeofday (&endTime, NULL);
-
-
-
long secsDiff = endTime.tv_sec - startTime.tv_sec;
-
results[run] =
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secsDiff * 1000000 + (endTime.tv_usec - startTime.tv_usec);
-
-
-
free (testImage);
-
}
-
-
-
average = 0;
-
for (i = 0; i < PERFORMANCE_RUN_COUNT; ++i)
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average += results[i];
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average = average / PERFORMANCE_RUN_COUNT;
-
-
-
printf (" Average: %llu usecs\n", average);
-
printf (" Bandwidth: %.03f MByte/Sec\n",
-
(fbSize / 1048576.0) / ((double) average / 1000000.0));
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printf (" Max. FPS: %.03f fps\n\n",
-
1000000.0 / (double) average);
-
-
-
/* Clear the framebuffer back to black again: */
-
memset (fb, 0, fbSize);
-
}
-
-
-
int main (int argc, char **argv)
-
{
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const char *devfile = "/dev/fb0";
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long int screensize = 0;
-
int fbFd = 0;
-
-
-
-
-
-
/* Open the file for reading and writing */
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fbFd = open (devfile, O_RDWR);
-
if (fbFd == -1)
-
{
-
perror ("Error: cannot open framebuffer device");
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exit (1);
-
}
-
-
-
//获取finfo信息并显示
-
if (ioctl (fbFd, FBIOGET_FSCREENINFO, &finfo) == -1)
-
{
-
perror ("Error reading fixed information");
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exit (2);
-
}
-
printFixedInfo ();
-
//获取vinfo信息并显示
-
if (ioctl (fbFd, FBIOGET_VSCREENINFO, &vinfo) == -1)
-
{
-
perror ("Error reading variable information");
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exit (3);
-
}
-
printVariableInfo ();
-
-
-
/* Figure out the size of the screen in bytes */
-
screensize = finfo.smem_len;
-
-
-
/* Map the device to memory */
-
frameBuffer =
-
(char *) mmap (0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED,
-
fbFd, 0);
-
if (frameBuffer == MAP_FAILED)
-
{
-
perror ("Error: Failed to map framebuffer device to memory");
-
exit (4);
-
}
-
-
-
//测试virt fb的性能
-
performSpeedTest (frameBuffer, screensize);
-
-
-
printf ("Will draw 3 rectangles on the screen,\n"
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"they should be colored red, green and blue (in that order).\n");
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drawRect (vinfo.xres / 8, vinfo.yres / 8,
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vinfo.xres / 4, vinfo.yres / 4, 0xffff0000);
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drawRect (vinfo.xres * 3 / 8, vinfo.yres * 3 / 8,
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vinfo.xres / 4, vinfo.yres / 4, 0xff00ff00);
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drawRect (vinfo.xres * 5 / 8, vinfo.yres * 5 / 8,
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vinfo.xres / 4, vinfo.yres / 4, 0xff0000ff);
-
-
-
sleep (5);
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printf (" Done.\n");
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-
-
munmap (frameBuffer, screensize); //解除内存映射，与mmap对应
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-
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close (fbFd);
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return 0;
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}
显示效果
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