On 2016?05?17? 23:21, Valdis.Kletnieks at vt.edu wrote:

On Tue, 17 May 2016 20:29:12 +0800, walkerlala said:

quoted

Can I just disable interrupts from hardwares? I know that, at the very
beginning, the kernel disable interrupt for convenient. So I wonder
whether we can do thing like this.

Sure you can do that.

But then, how do you get the kernel's attention?

quoted

Put it in another way:
	when we "interact" with a Linux Desktop, there are also many programs
running underneath as daemons, but we can still do our own works without
even noting their existing. So I wonder, is there a similar way that we
can use to interact with the kernel (without using a debugger) ?

Try this:

Start up Xorg and your preferred window manager.

Open an xterm or a Gnome-terminal or whatever.

 From that window, try to attach gdb to the Xorg process:

%  ps ax|grep Xorg
   1791 tty2     S+    69:42 /usr/libexec/Xorg vt2 -displayfd 3 -auth /run/user/967/gdm/Xauthority -nolisten tcp -background none -noreset -keeptty -verbose 3
  62036 pts/0    S+     0:00 grep Xorg
% gdb -p 1791

What happens?

Why does it happen?

Eventually, you'll figure out what Xorg and the kernel have in common here....

	Ok after trying what you said, I think I understand what you mean 
eventually. I try to use gdb to attach the window manager, which happen 
to be Compiz on my machine, then the whole GUI block. The only thing 
that I can see being able to react is the cursor(honestly I don't 
understand why the cursor can move....)
	This is my reasoning:
	when I attach gdb to Compiz, the window manager block, thus not being 
able to serving. The same with the kernel. If I block the kernel, then 
it would not be able to serve.....
	Is this what you mean ?

	So I have to wait for the kernel to finish and prompt me a console ?
	Actually, I am willing to do so, but I just can't get the raw kernel to 
run at Qemu. That is the reason why I tried to block the kernel......
	Any idea ?

Regards,