1) The driver is maintaining a 1 byte buffer.
memory_buffer = kmalloc(1, GFP_KERNEL);
2) Write operation always copies the last byte of user buffer to driver buffer.
tmp=buf+count-1;
copy_from_user(memory_buffer,tmp,1)
3) Read operation always returns the copied character from driver buffer on every read ignoring the count.
copy_to_user(buf,memory_buffer,1);
So, to me it seems everything is working fine.. what's the error here ? what am I missing something?
Regards,
Vikash Kumar
On Mon, May 9, 2011 at 4:56 PM, Aravind Vijayan <aravind1123@xxxxxxxxx> wrote:
Hi all,
Let me begin this post with thanx all to whom help me on
previous problem.I have completed jobs such as
writing,making,inserting the module.
i create a character special file using mknod in /dev directory.
i try to write data to my file by" echo -n "abcd" > /dev/memory "
and when i try to read from that file i get the last char was written
to that file that is "d"
here is my code:http://pastebin.com/9YsJetek
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