Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 2 Mar 1997 09:27:49 -0800 (PST)
From:      "Eric J. Schwertfeger" <ejs@bfd.com>
To:        freebsd-hackers@FreeBSD.ORG
Subject:   sio projects
Message-ID:  <Pine.BSF.3.95.970302091248.18611E-100000@harlie.bfd.com>

next in thread | raw e-mail | index | archive | help
Before I embark on my first FreeBSD kernel hacking project, does anyone
know if someone is already working on 16650/16750 UART support?  My plans
are for the following

1) Autodetect the UARTS, and use their deeper fifos.

2) Allow for the software-selectable divisor bit, for baud rates above
115k.

3) Throw in a flag to use the UART-driven hardware flow control methods.

4) Throw in a flag to tell the driver that the clock crystal has been
replaced (for those trying for more than 115K with 16550s).  Nothing
important, but the system really should know the real baud rate, if for no
other reason that the user doesn't have to remember to adjust it in his
head.

Also, I've found the info for #2 for the 16650, and some 16650 serial
cards (should arrive this week), but I would appreciate any pointers to
full data sheets on both UARTS, and a source for the 16750 UART chip.

Finally, my next project after this is to work on kernel PPP.  For this
project, I'm setting up two 486/33s side by side, connected by both a null
modem cable and ethernet, with one sysloging to the other, so I should
have a very good idea where things are going wrong.  Currently, with
kernel PPP, I'm seeing two problems.  The first is that every once in a
while, while the modems haven't dropped carrier, packets stop making it
across teh PPP link.  Second, at least with Linux PPP, lcp-echo-failure
doesn't work, as the remote end drops the FreeBSD end due to not seeing
any lcp-echos.  Not a problem between two linux boxes, so I suspect the
problem is in FreeBSD.





Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.95.970302091248.18611E-100000>