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Linux Frame Buffer Test
#include <linux/fb.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <sys/mman.h>
const char *FB_NAME = "/dev/fb0";
void* m_FrameBuffer;
struct fb_fix_screeninfo m_FixInfo;
struct fb_var_screeninfo m_VarInfo;
int m_FBFD;
int main() {
int iFrameBufferSize;
/* Open the framebuffer device in read write */
m_FBFD = open(FB_NAME, O_RDWR);
if (m_FBFD < 0) {
printf("Unable to open %s.\n", FB_NAME);
return 1;
}
/* Do Ioctl. Retrieve fixed screen info. */
if (ioctl(m_FBFD, FBIOGET_FSCREENINFO, &m_FixInfo) < 0) {
printf("get fixed screen info failed: %s\n",
strerror(errno));
close(m_FBFD);
return 1;
}
/* Do Ioctl. Get the variable screen info. */
if (ioctl(m_FBFD, FBIOGET_VSCREENINFO, &m_VarInfo) < 0) {
printf("Unable to retrieve variable screen info: %s\n",
strerror(errno));
close(m_FBFD);
return 1;
}
/* Calculate the size to mmap */
iFrameBufferSize = m_FixInfo.line_length * m_VarInfo.yres;
printf("Line length %d\n", m_FixInfo.line_length);
/* Now mmap the framebuffer. */
m_FrameBuffer = mmap(NULL, iFrameBufferSize, PROT_READ | PROT_WRITE,
MAP_SHARED, m_FBFD,0);
if (m_FrameBuffer == NULL) {
printf("mmap failed:\n");
close(m_FBFD);
return 1;
}
{
int *p = (int *) m_FrameBuffer;
int x,y,t=0;
while(1) {
for (y=0; y<m_VarInfo.yres; y++) {
for (x=0; x<m_VarInfo.xres; x++) {
p[x + y * m_VarInfo.xres] = 0x00100 * y + x + t;
}
}
t++;
}
}
}
@xhalo32

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commented Feb 25, 2018

Cool!

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