update 83815 boot driver to recognise SiS controllers
and set their MAC adddresses (from ea= currently,
since it's a nuisance to dig it out of ROM).
also update load.c to make the above work by
probing ethers only after reading plan9.ini.

with these changes, I can boot through an sis controller,
giving ea= in plan9.ini.

--- added 1 Mar 2006 02:57 by geoff
Drat.  The change to load.c breaks 9pxeload.
I guess this needs more work.

Notes:
Thu Mar 2 13:25:30 EST 2006 rsc
    Is this the patch you mentioned on 9fans that made things crash?
    


Reference: /n/sources/patch/sorry/sis-boot
Date: Wed Mar  1 11:58:47 CET 2006
Reviewed-by: rsc

--- /sys/src/boot/pc/load.c	Wed Mar  1 08:36:40 2006
+++ /sys/src/boot/pc/load.c	Fri Mar  3 02:50:28 2006
@@ -282,15 +282,21 @@
 		panic("i'm too big\n");
 
 	readlsconf();
-	for(tp = types; tp->type != Tnil; tp++){
-		//if(tp->type == Tether)
-		//	continue;
-		if((mp = probe(tp->type, Fini, Dany)) && (mp->flag & Fini)){
+	/* first pass of probing, just non-ethers */
+	for(tp = types; tp->type != Tnil; tp++)
+		if(tp->type != Tether &&
+		    (mp = probe(tp->type, Fini, Dany)) && (mp->flag & Fini)){
 			print("using %s!%s!%s\n", mp->name, mp->part, mp->ini);
 			iniread = !dotini(mp->inifs);
 			break;
 		}
-	}
+	if(iniread)
+		/* now that we've read plan9.ini, probe ethers */
+		for(tp = types; tp->type != Tnil; tp++)
+			if(tp->type == Tether) {
+				probe(tp->type, Fini, Dany);
+				break;
+			}
 	apminit();
 
 	if((p = getconf("console")) != nil)