I am a beginner kernel programmer. I need to write a kernel code for a new system call called
int sys_printstr(void *buf);

This system call returns the usual success/failure codes. The buf argument that it gets is an encoded string as follows:

• the first byte in buf contains the length of the string in bytes
• the bytes that follow in buf contain the actual string, excluding the terminating null it should correctly printk this encoded string which is passed from user-land.

Any clue/suggestion?

Thanks in advance.

Yeah. I'd ask this question in a Linux-specific forum area. This is an OpenGL forum for platform agnostic 2D and 3D graphics processing.

If you're looking for help with the C code needed to implement the function, you may want to try the C programming language forum area.

http://www.gidforums.com/f-41.html

Basically, you will want to cast buf (if not NULL) to an unsigned char* (check your data type names for the actual typename to use). Then you will want to call printk with %s and pass-n-cast the address of buf[1] to a char* if the first byte is not zero.


MxB