--- /dev/null
+++ /sys/src/9/port/logpow.c
@@ -0,0 +1,41 @@
+/*
+ * log2 and pow2 routines.
+ */
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+
+/*
+ * these routines should be cheap enough that there will
+ * be no hesitation to use them.
+ *
+ * once 5c in-lines vlong ops, just use the vlong versions.
+ */
+
+int
+ispow2(uvlong uvl)
+{
+	return ISPOW2(uvl);
+}
+
+static int
+isulpow2(ulong ul)				/* temporary speed hack */
+{
+	return ISPOW2(ul);
+}
+
+/*
+ * return exponent of smallest power of 2 ≥ n
+ */
+int
+log2(ulong n)
+{
+	int i;
+
+	i = BI2BY*BY2WD - 1 - clz(n);
+	if (n == 0 || !ISPOW2(n))
+		i++;
+	return i;
+}
--- /sys/src/9/kw/archkw.c
+++ /sys/src/9/kw/archkw.c
@@ -227,27 +227,6 @@ praddrmap(void)
 		praddrwin(&map->win[i], i);
 }
 
-int
-ispow2(uvlong ul)
-{
-	/* see Hacker's Delight if this isn't obvious */
-	return (ul & (ul - 1)) == 0;
-}
-
-/*
- * return exponent of smallest power of 2 ≥ n
- */
-int
-log2(ulong n)
-{
-	int i;
-
-	i = 31 - clz(n);
-	if (!ispow2(n) || n == 0)
-		i++;
-	return i;
-}
-
 void
 cacheinfo(int level, int kind, Memcache *cp)		/* l1 only */
 {
--- /sys/src/9/kw/fns.h
+++ /sys/src/9/kw/fns.h
@@ -28,7 +28,6 @@ extern void cacheiinv(void);
 extern void cacheuwbinv(void);
 extern uintptr cankaddr(uintptr pa);
 extern void clockshutdown(void);
-extern int clz(ulong);
 int	cmpswap(long*, long, long);
 
 #define coherence barriers
@@ -47,7 +46,6 @@ extern u32int dacget(void);
 extern void dacput(u32int);
 extern u32int farget(void);
 extern u32int fsrget(void);
-extern int ispow2(uvlong);
 extern void l1cachesoff(void);
 extern void l1cacheson(void);
 extern void l2cachecfgoff(void);
@@ -60,7 +58,6 @@ extern void l2cacheuwbinv(void);
 extern void l2cacheuwbinvse(void*, int);
 extern void l2cacheuwbse(void*, int);
 extern void lastresortprint(char *buf, long bp);
-extern int log2(ulong);
 extern void mmuidmap(uintptr phys, int mbs);
 extern void mmuinvalidate(void);		/* 'mmu' or 'tlb'? */
 extern void mmuinvalidateaddr(u32int);		/* 'mmu' or 'tlb'? */

--- /sys/src/9/kw/mkfile
+++ /sys/src/9/kw/mkfile
@@ -25,6 +25,7 @@ PORT=\
 	latin1.$O\
 	mul64fract.$O\
 	rebootcmd.$O\
+	logpow.$O\
 	page.$O\
 	parse.$O\
 	pgrp.$O\
--- /sys/src/9/omap/archomap.c
+++ /sys/src/9/omap/archomap.c
@@ -347,27 +347,6 @@ archomaplink(void)
 {
 }
 
-int
-ispow2(uvlong ul)
-{
-	/* see Hacker's Delight if this isn't obvious */
-	return (ul & (ul - 1)) == 0;
-}
-
-/*
- * return exponent of smallest power of 2 ≥ n
- */
-int
-log2(ulong n)
-{
-	int i;
-
-	i = 31 - clz(n);
-	if (n == 0 || !ispow2(n))
-		i++;
-	return i;
-}
-
 void
 archconfinit(void)
 {
--- /sys/src/9/omap/fns.h
+++ /sys/src/9/omap/fns.h
@@ -25,7 +25,6 @@ extern void cacheuwbinv(void);
 extern uintptr cankaddr(uintptr pa);
 extern void chkmissing(void);
 extern void clockshutdown(void);
-extern int clz(ulong);
 extern int cmpswap(long*, long, long);
 extern void coherence(void);
 extern void configscreengpio(void);
@@ -54,13 +53,11 @@ extern u32int ifsrget(void);
 extern void intrsoff(void);
 extern int isaconfig(char*, int, ISAConf*);
 extern int isdmadone(int);
-extern int ispow2(uvlong);
 extern void kbdenable(void);
 extern void l2cacheuinv(void);
 extern void l2cacheuwb(void);
 extern void l2cacheuwbinv(void);
 extern void lastresortprint(char *buf, long bp);
-extern int log2(ulong);
 extern void machinit(void);
 extern void mmuidmap(uintptr phys, int mbs);
 extern void mmuinvalidate(void);		/* 'mmu' or 'tlb'? */
--- /sys/src/9/omap/mkfile
+++ /sys/src/9/omap/mkfile
@@ -25,6 +25,7 @@ PORT=\
 	latin1.$O\
 	mul64fract.$O\
 	rebootcmd.$O\
+	logpow.$O\
 	page.$O\
 	parse.$O\
 	pgrp.$O\
--- /sys/src/9/pc/devarch.c
+++ /sys/src/9/pc/devarch.c
@@ -51,6 +51,8 @@ enum {				/* cpuid standard function codes */
 
 typedef long Rdwrfn(Chan*, void*, long, vlong);
 
+int	bsr(ulong n);		/* l.s */
+
 static Rdwrfn *readfn[Qmax];
 static Rdwrfn *writefn[Qmax];
 
@@ -1260,3 +1262,11 @@ timerset(Tval x)
 	if(doi8253set)
 		(*arch->timerset)(x);
 }
+
+int
+clz(ulong n)			/* count leading zeroes */
+{
+	if (n == 0)
+		return BI2BY*BY2WD;
+	return BI2BY*BY2WD - 1 - bsr(n);
+}
--- /sys/src/9/pc/l.s
+++ /sys/src/9/pc/l.s
@@ -878,6 +878,13 @@ TEXT islo(SB), $0
 	RET
 
 /*
+ * Miscellany
+ */
+TEXT bsr(SB), $0
+	BSRL	word+0(FP), AX		/* return bit index of leftmost 1 bit */
+	RET
+
+/*
  * Test-And-Set
  */
 TEXT tas(SB), $0
--- /sys/src/9/pc/mkfile
+++ /sys/src/9/pc/mkfile
@@ -29,6 +29,7 @@ PORT=\
 	edf.$O\
 	fault.$O\
 	latin1.$O\
+	logpow.$O\
 	page.$O\
 	parse.$O\
 	pgrp.$O\
--- /sys/src/9/pc/mtrr.c
+++ /sys/src/9/pc/mtrr.c
@@ -131,12 +131,6 @@ sanity(Mtrreg *mtrr)
 	mtrr->mask &= Paerange - 1;
 }
 
-static int
-ispow2(uvlong ul)
-{
-	return (ul & (ul - 1)) == 0;
-}
-
 /* true if mtrr is valid */
 static int
 mtrrdec(Mtrreg *mtrr, uvlong *ptr, uvlong *size, int *type)
--- /sys/src/9/pcboot/bootmkfile
+++ /sys/src/9/pcboot/bootmkfile
@@ -19,6 +19,7 @@ PORT=\
 	dev.$O\
 	edf.$O\
 	latin1.$O\
+	logpow.$O\
 	page.$O\
 	parse.$O\
 	pgrp.$O\
--- /sys/src/9/pcboot/l32v.s
+++ /sys/src/9/pcboot/l32v.s
@@ -540,6 +540,13 @@ TEXT islo(SB), $0
 	RET
 
 /*
+ * Miscellany
+ */
+TEXT bsr(SB), $0
+	BSRL	word+0(FP), AX			/* count leading zeros */
+	RET
+
+/*
  *  basic timing loop to determine CPU frequency
  */
 TEXT	aamloop(SB),$0
--- /sys/src/9/port/portfns.h
+++ /sys/src/9/port/portfns.h
@@ -38,6 +38,7 @@ void		closefgrp(Fgrp*);
 void		closepgrp(Pgrp*);
 void		closergrp(Rgrp*);
 long		clrfpintr(void);
+int		clz(ulong);
 void		cmderror(Cmdbuf*, char*);
 int		cmount(Chan**, Chan*, int, char*);
 void		confinit(void);
@@ -146,6 +146,8 @@ int		islo(void);
 Segment*	isoverlap(Proc*, ulong, int);
 int		ispages(void*);
 int		isphysseg(char*);
+#define		ISPOW2(i) (((i) & ((i) - 1)) == 0) /* see Hacker's Delight */
+int		ispow2(uvlong);
 void		ixsummary(void);
 int		kbdcr2nl(Queue*, int);
 int		kbdgetmap(uint, int*, int*, Rune*);
@@ -163,6 +165,7 @@ ulong		l2be(long);
 long		latin1(Rune*, int);
 int		lock(Lock*);
 void		logopen(Log*);
+int		log2(ulong);
 void		logclose(Log*);
 char*		logctl(Log*, int, char**, Logflag*);
 void		logn(Log*, int, void*, int);
--- a/sys/src/9/teg2/fns.h
+++ b/sys/src/9/teg2/fns.h
@@ -33,7 +33,6 @@ extern uintptr cankaddr(uintptr pa);
 extern void chkmissing(void);
 extern void clockprod(Ureg *);
 extern void clockshutdown(void);
-extern int clz(ulong);
 extern int cmpswap(long*, long, long);
 extern void coherence(void);
 extern void configscreengpio(void);
@@ -79,11 +78,9 @@ extern void intrshutdown(void);
 extern void intrsoff(void);
 extern int isaconfig(char*, int, ISAConf*);
 extern int isdmadone(int);
-extern int ispow2(uvlong);
 extern void kbdenable(void);
 extern void l1diag(void);
 extern void l2pl310init(void);
-extern int log2(ulong);
 extern void machoff(uint cpu);
 extern void machon(uint cpu);
 extern void memdiag(ulong *);
--- /sys/src/9/teg2/mkfile
+++ /sys/src/9/teg2/mkfile
@@ -26,6 +26,7 @@ PORT=\
 	latin1.$O\
 	mul64fract.$O\
 	rebootcmd.$O\
+	logpow.$O\
 	page.$O\
 	parse.$O\
 	pgrp.$O\
--- /sys/src/9/teg2/ts
+++ /sys/src/9/teg2/ts
@@ -57,7 +57,6 @@ misc
 	pci
 	rdb
 	coproc
-	v7-arch
 	caches
 	caches-v7
 	cache-l2-pl310
--- /sys/src/9/teg2/v7-arch.c
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * arm arch v7 routines other than cache-related ones.
- *
- * calling this arch-v7.c would confuse the mk scripts,
- * to which a filename arch*.c is magic.
- */
-#include "u.h"
-#include "../port/lib.h"
-#include "mem.h"
-#include "dat.h"
-#include "fns.h"
-#include "../port/error.h"
-#include "io.h"
-#include "arm.h"
-
-/*
- * these routines should be cheap enough that there will
- * be no hesitation to use them.
- *
- * once 5c in-lines vlong ops, just use the vlong versions.
- */
-
-/* see Hacker's Delight if this isn't obvious */
-#define ISPOW2(i) (((i) & ((i) - 1)) == 0)
-
-int
-ispow2(uvlong uvl)
-{
-	/* see Hacker's Delight if this isn't obvious */
-	return ISPOW2(uvl);
-}
-
-static int
-isulpow2(ulong ul)				/* temporary speed hack */
-{
-	return ISPOW2(ul);
-}
-
-/*
- * return exponent of smallest power of 2 ≥ n
- */
-int
-log2(ulong n)
-{
-	int i;
-
-	i = BI2BY*BY2WD - 1 - clz(n);
-	if (n == 0 || !ISPOW2(n))
-		i++;
-	return i;
-}