add tos changes, proto changes, fp tweaks. with this patch,
everything compiles properly for the rb.

Reference: /n/atom/patch/applied2013/rbcleanup
Date: Wed Jul 31 20:45:40 CES 2013
Signed-off-by: quanstro@quanstro.net

# rm /sys/src/libmp/mips/mpdigdiv.s

--- /sys/src/cmd/9l/compat.c	Wed Jul 31 20:44:27 2013
+++ /sys/src/cmd/9l/compat.c	Wed Jul 31 20:44:27 2013
@@ -48,3 +48,9 @@
 {
 	return sbrk(size);
 }
+
+void
+setmalloctag(void *v, ulong pc)
+{
+	USED(v, pc);
+}
--- /sys/src/ape/cmd/kill.c	Wed Jul 31 20:44:28 2013
+++ /sys/src/ape/cmd/kill.c	Wed Jul 31 20:44:28 2013
@@ -15,7 +15,7 @@
 
 main(int argc, char **argv)
 {
-	int signo, pid, res;
+	int signo, res;
 	int errlev;
 
 	errlev = 0;
--- /sys/src/mkfile.proto	Wed Jul 31 20:44:29 2013
+++ /sys/src/mkfile.proto	Wed Jul 31 20:44:29 2013
@@ -3,7 +3,7 @@
 #
 
 OS=56789qv	#12k
-CPUS=amd64 arm 386
+CPUS=amd64 arm mips 386
 #CPUS=arm alpha 386 amd64 power power64 mips
 CFLAGS=-FTVw
 LEX=lex
--- /sys/include/tos.h	Wed Jul 31 20:44:30 2013
+++ /sys/include/tos.h	Wed Jul 31 20:44:30 2013
@@ -19,6 +19,9 @@
 	ulong	pid;		/* might as well put the pid here */
 	ulong	clock;
 	uint	machno;		/* mp->machno */
+	/* scratch space for kernel use (e.g., mips fp delay-slot execution) */
+	ulong	kscr[4];
+
 	/* top of stack is here */
 };
 
--- /mips/include/u.h	Wed Jul 31 20:44:31 2013
+++ /mips/include/u.h	Wed Jul 31 20:44:31 2013
@@ -20,13 +20,13 @@
 typedef unsigned int	u32int;
 typedef unsigned long long u64int;
 
-/* FCR */
-#define	FPINEX	(1<<7)
+/* FCR (FCR31) */
+#define	FPINEX	(1<<7)		/* enables */
 #define	FPUNFL	(1<<8)
 #define	FPOVFL	(1<<9)
 #define	FPZDIV	(1<<10)
 #define	FPINVAL	(1<<11)
-#define	FPRNR	(0<<0)
+#define	FPRNR	(0<<0)		/* rounding modes */
 #define	FPRZ	(1<<0)
 #define	FPRPINF	(2<<0)
 #define	FPRNINF	(3<<0)
@@ -35,12 +35,15 @@
 #define	FPPSGL	0
 #define	FPPDBL	0
 #define	FPPMASK	0
-/* FSR */
-#define	FPAINEX	(1<<2)
+#define FPCOND	(1<<23)
+
+/* FSR (also FCR31) */
+#define	FPAINEX	(1<<2)		/* flags */
 #define	FPAOVFL	(1<<4)
 #define	FPAUNFL	(1<<3)
 #define	FPAZDIV	(1<<5)
 #define	FPAINVAL	(1<<6)
+
 union FPdbleword
 {
 	double	x;