2007-02-17 15:55:22

by Mockern

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Subject: serial or tty driver

I have a question, what is really difference between serial and tty drivers?

As I understand tty is high level and communicates with user space.

Thank you


2007-02-17 19:29:57

by H. Peter Anvin

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Subject: Re: serial or tty driver

Mockern wrote:
> I have a question, what is really difference between serial and tty drivers?
> As I understand tty is high level and communicates with user space.

That's pretty much it, yes. When you're talking to a serial port, you
have a stack that looks roughly like:

(Userspace)
VFS layer
tty layer ----------------------\
serial core layer line discipline
serial driver
(Hardware)

There are other devices which can exist below the tty layer, like the
pty driver:

(Userspace)
VFS layer
tty layer ----------------------\
pty driver line discipline

-hpa