It is possible to run PPP over the serial port instead of using
rz and sz to transfer files. Running PPP gives you
full network support, so you can enable things like TELNET, FTP, SSH, and so
on.
First you will need to install a
kernel with PPP support.
(This beta7 kernel has IrDA as
well as PPP.) Use the emplode software or the upgclient tool
to install the kernel upgrade file. Note that you will need to re-install
this kernel image after any other upgrade (such as a new beta release)
unless those upgrades also provide PPP support in the kernel.
Next you will need a PPP daemon at both ends of the serial link. If you've created a Debian-like environment on your empeg, you can install this Debian ppp package.
If you don't have a Debian environment, you can use alien or just plain
ar x $package data.tar.gz
to extract a tarball from the Debian package. Note, however, that the
pppd binary in this package is linked against the
libcrypt shared library which is not included in the package,
and does not come with the empeg's developer images. (One possible source
is from the
Debian
ARM libc6 package.)
Next, make sure you are running at least one network service on the
empeg, or you won't be able to do much besides ping the unit.
:-) You may also want to check your /etc/hosts
and /etc/resolv.conf files for appropriate contents.
Then, run pppd on the empeg like this:
pppd ttyS1 115200 nocrtscts local noauth defaultroute passive
If you're connected to the empeg using a terminal, you'll need to disconnect at this point so PPP can take over.
Finally, at the other end of the serial link, run pppd
like this:
pppd$serial115200 nocrtscts local noauth :$ipaddr
where $serial is the name of your serial port
(e.g. ttyS0) and $ipaddr is the IP address to
assign to the empeg. A good choice if you don't have anything better to
assign would be an address from the private 10.0.0.0/8,
172.16.0.0/12, or 192.168.0.0/16 address blocks,
such as 10.0.0.1.
If the link is ever broken, you'll need to restart pppd on the
empeg, or you can add persist to the command options to keep it
running automatically. In the latter case, you may find it difficult to get
back to a shell prompt if you start pppd interactively.
If you are running the Debian /sbin/init on the empeg, you can
run pppd automatically by changing /etc/inittab to
contain these entries:
T1:2:respawn:/sbin/getty -L ttyS1 115200 vt100 P1:3:respawn:/usr/sbin/pppd ttyS1 115200 nocrtscts local noauth defaultroute passive
Runlevel 2 then gives you a login prompt, and runlevel 3 runs
pppd instead.