From 410dc4af7f267b132c5c0d5a73090b692e5b370d Mon Sep 17 00:00:00 2001
From: cognet <cognet@FreeBSD.org>
Date: Wed, 29 Feb 2012 12:44:34 +0000
Subject: [PATCH] Make sure we do not provide the page 0 to the VM. It can't
 handle it properly, because pmap_extract() returns 0 when there's no mapping.

PR:		arm/154227
MFC after:	1 week
---
 sys/arm/mv/mv_machdep.c             | 16 +++++++++++++---
 sys/arm/xscale/i8134x/crb_machdep.c |  4 ++--
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/sys/arm/mv/mv_machdep.c b/sys/arm/mv/mv_machdep.c
index 8839740ee940..9afd29af2780 100644
--- a/sys/arm/mv/mv_machdep.c
+++ b/sys/arm/mv/mv_machdep.c
@@ -287,9 +287,19 @@ physmap_init(void)
 		    availmem_regions[i].mr_start + availmem_regions[i].mr_size,
 		    availmem_regions[i].mr_size);
 
-		phys_avail[j] = availmem_regions[i].mr_start;
-		phys_avail[j + 1] = availmem_regions[i].mr_start +
-		    availmem_regions[i].mr_size;
+		/* 
+		 * We should not map the page at PA 0x0000000, the VM can't
+		 * handle it, as pmap_extract() == 0 means failure.
+		 */
+		if (availmem_regions[i].mr_start > 0 ||
+		    availmem_regions[i].mr_size > PAGE_SIZE) {
+			phys_avail[j] = availmem_regions[i].mr_start;
+			if (phys_avail[j] == 0)
+				phys_avail[j] += PAGE_SIZE;
+			phys_avail[j + 1] = availmem_regions[i].mr_start +
+			    availmem_regions[i].mr_size;
+		} else
+			j -= 2;
 	}
 	phys_avail[j] = 0;
 	phys_avail[j + 1] = 0;
diff --git a/sys/arm/xscale/i8134x/crb_machdep.c b/sys/arm/xscale/i8134x/crb_machdep.c
index 8f2c43eb3572..b368c1988c7a 100644
--- a/sys/arm/xscale/i8134x/crb_machdep.c
+++ b/sys/arm/xscale/i8134x/crb_machdep.c
@@ -381,8 +381,8 @@ initarm(void *arg, void *arg2)
 	
 	i = 0;
 #ifdef ARM_USE_SMALL_ALLOC
-	phys_avail[i++] = 0x00000000;
-	phys_avail[i++] = 0x00001000; 	/*
+	phys_avail[i++] = 0x00001000;
+	phys_avail[i++] = 0x00002000; 	/*
 					 *XXX: Gross hack to get our
 					 * pages in the vm_page_array
 					 . */