This file contains directions for building guest kernels
from source.  The basic idea is that each guest, e.g.,
"hello", that is built from source gets its own entire
P4 build tree in, e.g.,  guests/hello.  When you type
"make" in your top-level directory, make will also be
run in the guests/hello directory, which will hopefully
cause a kernel to be built in guests/hello/kernel.  That
kernel image will then be included in your RAM disk, named
"hello".  For guests/hello to be built in this way the
STUDENTGUESTS directive in config.mk must include "hello"
(guests/ directories that are not so listed will be ignored).

Here is a step-by-step guide to building the "hello" guest
from source:

0. If you already have a test program called "hello",
   make sure to remove it from STUDENTTESTS in your
   config.mk.  Likewise, if you are running our pre-built
   "hello" binary, remove it from 410GUESTBINS.

1. edit config.mk so your STUDENTGUESTS directive
   contains "hello" (initially you will not have
   such a directive, so you will need to add one).

2. cd guests

3. Download a copy of the P4 tarball, proj4.tar.gz.
Note that some browsers will "helpfully" uncompress
the file for you but leave the filename unchanged.
So try one of the following two commands at random:

  tar xpvfz proj4.tar.gz
  tar xpvf proj4.tar.gz

4. mv p4 hello

5. (cd hello && ./update.sh)

Now you have a guests/hello directory that will build a
guest kernel, but one that does nothing interesting.  The
next step is to copy the source we gave you into that build
tree.

5. cd ..

6. (cd 410guests/hello && tar cf - .) | (cd guests/hello && tar xpf -)

7. Upgrade guests/hello/kern/hvstubs.S so it makes hypercalls.

8. make

In your top-level directory, the file "temp/hello" should
be created, and when you boot your kernel and do "ls" you
should see "hello".

If you happen to want to build a guest kernel from source
of your own (such as your P1), you would follow steps 1
through 5, insert a valid hvstubs.S, and then write the
rest of your guest kernel (perhaps starting from your P1
kernel source).