lguest: documentation I: Preparation

The netfilter code had very good documentation: the Netfilter Hacking HOWTO.
Noone ever read it.

So this time I'm trying something different, using a bit of Knuthiness.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 6 deletions

diff --git a/drivers/lguest/switcher.S b/drivers/lguest/switcher.S
index eadd4cc299d2..e7cb8c123558 100644
--- a/drivers/lguest/switcher.S
+++ b/drivers/lguest/switcher.S
@@ -1,10 +1,11 @@
-/* This code sits at 0xFFC00000 to do the low-level guest<->host switch.
+/*P:900 This is the Switcher: code which sits at 0xFFC00000 to do the low-level
+ * Guest<->Host switch.  It is as simple as it can be made, but it's naturally
+ * very specific to x86.
+ *
+ * You have now completed Preparation.  If this has whet your appetite; if you
+ * are feeling invigorated and refreshed then the next, more challenging stage
+ * can be found in "make Guest". :*/
 
-   There is are two pages above us for this CPU (struct lguest_pages).
-   The second page (struct lguest_ro_state) becomes read-only after the
-   context switch.  The first page (the stack for traps) remains writable,
-   but while we're in here, the guest cannot be running.
-*/
 #include <linux/linkage.h>
 #include <asm/asm-offsets.h>
 #include "lg.h"