
MOL no longer accesses the hardware serial ports, so the following
information is outdated. To access open firmware as described below, 
recompile MOL with the file "emulation/escc.c" substituted with 
"emulation/escc_old.c".


Communicating with OpenFirmware
===============================

	The very first step in the booting process is starting
	OpenFirmware. This is normally an invisible process.
	Developers might want to interact with OF however. How this 
	is done is described below.

	To communicate with Open Firmware, hook up a terminal to the
	printer port, and set the nvram parameters accordingly
	(with the nvs utility, operating on the nvram image used).

		$nvs "auto-boot?" no
		$nvs "input-device" ttyb
		$nvs "output-device" ttyb
		$mol
		--- the debugger starts ---
		> [Meta-G] (go)
		--- OF should be up running at this point ---
		--- start the terminal software ---

	Currently Mac-on-Linux writes directly to the serial controller 
	(thus enabling primitive serial support although an actual 
	driver has not yet been written). The port (use ttyb) is left 
	in a undefined state, so don't count on using it for 
	other things.

	Note 1: OF defaults to the comm-parameters 38400-8N1.

	Note 2: The terminal software must be started *after* OF
	has booted (probably due to flow control problems).

	TIP: Use a null-modem cable between the modem and printer port,
	rather than an external terminal.

	Output to the printer port is mirrored to /dev/console.
	The debugger command "ofw" (OpenFirmware Write) can be
	used to send commands to OF without a physical serial
	line.


Any questions may be directed to <samuel@ibrium.se>.

