bcm: use extended small pages so XN bit can work

the change to support no-execute bits broke the original
raspberry pi1, as it uses backwards compatible page table
format.

to use the XN bit, subpage AP bits have to be disabled
using the XP bit in CP15 Control Register c1 Bit 23.

7 files changed, 5 insertions, 17 deletions

diff --git a/sys/src/9/bcm/archbcm.c b/sys/src/9/bcm/archbcm.c
index dd480bc43..d2e138330 100644
--- a/sys/src/9/bcm/archbcm.c
+++ b/sys/src/9/bcm/archbcm.c
@@ -116,12 +116,6 @@ archbcmlink(void)
 }
 
 int
-l2ap(int ap)
-{
-	return (AP(3, (ap))|AP(2, (ap))|AP(1, (ap))|AP(0, (ap)));
-}
-
-int
 cmpswap(long *addr, long old, long new)
 {
 	return cas32(addr, old, new);
diff --git a/sys/src/9/bcm/archbcm2.c b/sys/src/9/bcm/archbcm2.c
index 05c7e9d55..510abdb8f 100644
--- a/sys/src/9/bcm/archbcm2.c
+++ b/sys/src/9/bcm/archbcm2.c
@@ -221,12 +221,6 @@ archbcm2link(void)
 	addclock0link(wdogfeed, HZ);
 }
 
-int
-l2ap(int ap)
-{
-	return (AP(0, (ap)));
-}
-
 void
 cpustart(int cpu)
 {
diff --git a/sys/src/9/bcm/arm.h b/sys/src/9/bcm/arm.h
index cc032cccd..3a1f10860 100644
--- a/sys/src/9/bcm/arm.h
+++ b/sys/src/9/bcm/arm.h
@@ -123,6 +123,7 @@
 #define CpCha		(1<<17)		/* HA: hw access flag enable */
 #define CpCdz		(1<<19)		/* DZ: divide by zero fault enable */
 #define CpCfi		(1<<21)		/* FI: fast intrs */
+#define CpCxp		(1<<23)		/* XP: subpage AP bits disabled */
 #define CpCve		(1<<24)		/* VE: intr vectors enable */
 #define CpCee		(1<<25)		/* EE: exception endianness */
 #define CpCnmfi		(1<<27)		/* NMFI: non-maskable fast intrs. */
@@ -309,8 +310,8 @@
 
 #define F(v, o, w)	(((v) & ((1<<(w))-1))<<(o))
 #define AP(n, v)	F((v), ((n)*2)+4, 2)
-#define L1AP(ap)	(AP(3, (ap)))
-/* L2AP differs between armv6 and armv7 -- see l2ap in arch*.c */
+#define L1AP(ap)	AP(3, (ap))
+#define L2AP(ap)	AP(0, (ap))
 #define DAC(n, v)	F((v), (n)*2, 2)
 
 #define HVECTORS	0xffff0000
diff --git a/sys/src/9/bcm/armv6.s b/sys/src/9/bcm/armv6.s
index 68714f924..3eae17b83 100644
--- a/sys/src/9/bcm/armv6.s
+++ b/sys/src/9/bcm/armv6.s
@@ -57,7 +57,7 @@ _ramZ:
 	 * enable caches, mmu, and high vectors
 	 */
 	MRC	CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
-	ORR	$(CpChv|CpCdcache|CpCicache|CpCpredict|CpCmmu), R0
+	ORR	$(CpCxp|CpChv|CpCdcache|CpCicache|CpCpredict|CpCmmu), R0
 	MCR	CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
 	ISB
 
diff --git a/sys/src/9/bcm/fns.h b/sys/src/9/bcm/fns.h
index 125dd4f4c..a2b8d16f8 100644
--- a/sys/src/9/bcm/fns.h
+++ b/sys/src/9/bcm/fns.h
@@ -99,7 +99,6 @@ extern void wdogoff(void);
 extern void wdogfeed(void);
 extern void writeconf(void);
 extern void vtable(void);
-extern int l2ap(int);
 extern uint getcputemp(void);
 extern char *cputype2name(char *buf, int size);
 extern uint getboardrev(void);
diff --git a/sys/src/9/bcm/mkfile b/sys/src/9/bcm/mkfile
index 7ce2c07ff..eb7cad035 100644
--- a/sys/src/9/bcm/mkfile
+++ b/sys/src/9/bcm/mkfile
@@ -112,6 +112,7 @@ armv7.$O: cache.v7.s
 main.$O: errstr.h init.h reboot.h
 devmouse.$O mouse.$O screen.$O: screen.h
 usbdwc.$O: dwcotg.h ../port/usb.h
+arch.$O archbcm.$O archbcm2.$O clock.$O coproc.$O fpiarn.$O mmu.$O trap.$O vfp3.$O: arm.h mem.h
 
 init.h:D:	../port/initcode.c init9.s
 	$CC ../port/initcode.c
diff --git a/sys/src/9/bcm/mmu.c b/sys/src/9/bcm/mmu.c
index 7de489456..864757079 100644
--- a/sys/src/9/bcm/mmu.c
+++ b/sys/src/9/bcm/mmu.c
@@ -9,7 +9,6 @@
 #define FEXT(d, o, w)	(((d)>>(o)) & ((1<<(w))-1))
 #define L1X(va)		FEXT((va), 20, 12)
 #define L2X(va)		FEXT((va), 12, 8)
-#define L2AP(ap)	l2ap(ap)
 #define L1ptedramattrs	soc.l1ptedramattrs
 #define L2ptedramattrs	soc.l2ptedramattrs
 #define PTEDRAM		(PHYSDRAM|Dom0|L1AP(Krw)|Section|L1ptedramattrs)