You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Michael Brown 82c4afcb32 Updated instructions to reflect current reality. 18 lat temu
..
.cvsignore Initial revision 19 lat temu
Makefile Initial revision 19 lat temu
README Updated instructions to reflect current reality. 18 lat temu
bochsrc.txt Hardcoded paths to ../../src/bin avoid one step in the instructions. 18 lat temu
serial-console Updated to syntax required by latest bochs CVS. 18 lat temu
serial-console.1 Initial revision 19 lat temu

README

Running Etherboot within Bochs
==============================

Michael Brown <mbrown@fensystems.co.uk>
Based on an idea suggested by H. Peter Anvin <hpa@zytor.com>.

$Id$

Bochs is a program that simulates a complete Intel x86 computer,
including hardware. It can be used to test Etherboot. There is a
special pseudo NIC ("pnic") implemented in Bochs, with a corresponding
driver in Etherboot. (There is also an NE2000 ISA driver in Bochs,
but it doesn't seem to quite work.)

To get bochs running is fairly simple:

1. Get the bochs source code:
cvs -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/bochs login
cvs -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/bochs co bochs

2. Configure bochs with
pushd bochs
./configure --enable-all-optimisations --enable-pci --enable-pnic
--enable-debugger --enable-magic-breakpoints --enable-disasm
popd

3. Build bochs:
make -C bochs

4. Set up a TAP virtual network device:
modprobe tun
tunctl -u <username> -t tap0
ifconfig tap0 up 10.254.254.2 netmask 255.255.255.0

5. Add the following fragment to /etc/dhcpd.conf:
subnet 10.254.254.0 netmask 255.255.255.252 {
range dynamic-bootp 10.254.254.1 10.254.254.1;
}
You will also need to add in any of your usual declarations for
Etherboot, e.g. 'filename "vmlinuz.ltsp";'. Note that this setup
assumes that your DHCP server, TFTP server etc. all live on the
machine you are using for running Bochs. If not, then you're on
your own.

6. Restart dhcpd
/etc/init.d/dhcpd restart

7. Build Etherboot images
pushd ../../src
make bin/pnic.dsk
popd

8. Start Bochs
./bochs/bochs -q
You should get to the debugger prompt "<bochs:1>". Type "c" to
start running Bochs.

You should see Bochs start up, load up Etherboot and attempt to boot
from the network.



Serial console
==============

You can use the program "serial-console" to obtain a virtual serial
console for Etherboot running within Bochs. Simply run
"./serial-console" on a spare tty (e.g. a separate xterm window)
before starting Bochs, and ensure that you have compiled Etherboot
with appropriate settings such as
CFLAGS+= -DCONSOLE_DUAL -DCOMCONSOLE=0x3F8 -DCONSPEED=9600

There is a manual page for "serial-console"; use
"man ./serial-console.1" to view it.



TODO
====

Packet forwarding/masquerading - document what must be set up.

Mention possibility of using RFB as the display device - in
conjunction with the serial console, gives you a test facility that
can be accessed remotely.

Mention use of BOCHSBP instruction (xchgw %bx,%bx) to avoid need to
calculate breakpoints.