diff --git a/lang/cem/libcc.ansi/malloc/calloc.c b/lang/cem/libcc.ansi/malloc/calloc.c
new file mode 100644
index 000000000..2e9d3be16
--- /dev/null
+++ b/lang/cem/libcc.ansi/malloc/calloc.c
@@ -0,0 +1,23 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+
+void* calloc(size_t nmemb, size_t size)
+{
+    size_t bytes = nmemb * size;
+    void* ptr;
+    
+    /* Test for overflow.
+     * See http://stackoverflow.com/questions/1815367/multiplication-of-large-numbers-how-to-catch-overflow
+     */
+
+    if ((nmemb == 0) || (size == 0) || (nmemb > (SIZE_MAX / size)))
+        return NULL;
+    
+    ptr = malloc(bytes);
+    if (!ptr)
+        return NULL;
+
+    memset(ptr, 0, bytes);
+    return ptr;
+}
diff --git a/plat/cpm/include/unistd.h b/plat/cpm/include/unistd.h
index 2af9db921..ea4f51c0f 100644
--- a/plat/cpm/include/unistd.h
+++ b/plat/cpm/include/unistd.h
@@ -37,7 +37,7 @@ extern char** environ;
 
 extern void _exit(int);
 extern pid_t getpid(void);
-extern void* sbrk(intptr_t increment);
+extern void* sbrk(int increment);
 extern int isatty(int d);
 extern off_t lseek(int fildes, off_t offset, int whence);
 extern int close(int d);
diff --git a/plat/cpm/libsys/brk.c b/plat/cpm/libsys/brk.c
index e29dc565b..0b83b2523 100644
--- a/plat/cpm/libsys/brk.c
+++ b/plat/cpm/libsys/brk.c
@@ -28,7 +28,7 @@ int brk(void* newend)
 	return 0;
 }
 
-void* sbrk(intptr_t increment)
+void* sbrk(int increment)
 {
 	char* old;
 	
diff --git a/plat/linux/libsys/brk.c b/plat/linux/libsys/brk.c
deleted file mode 100644
index 7ce5c5fc8..000000000
--- a/plat/linux/libsys/brk.c
+++ /dev/null
@@ -1,17 +0,0 @@
-/* $Source: /cvsroot/tack/Ack/plat/linux386/libsys/brk.c,v $
- * $State: Exp $
- * $Revision: 1.1 $
- */
-
-#include <stdlib.h>
-#include <unistd.h>
-#include <errno.h>
-#include "libsys.h"
-
-int brk(void* end)
-{
-	int e = _syscall(__NR_brk, (quad) end, 0, 0);
-	if (e == -1)
-		errno = ENOMEM;
-	return e;
-}
diff --git a/plat/linux/libsys/sbrk.c b/plat/linux/libsys/sbrk.c
index 35810ef89..7aeeecb86 100644
--- a/plat/linux/libsys/sbrk.c
+++ b/plat/linux/libsys/sbrk.c
@@ -12,7 +12,17 @@
 
 static char* current = NULL;
  
-void* sbrk(intptr_t increment)
+int brk(void* end)
+{
+	int e = _syscall(__NR_brk, (quad) end, 0, 0);
+	if (e == -1)
+		errno = ENOMEM;
+	else
+		current = end;
+	return e;
+}
+
+void* sbrk(int increment)
 {
 	char* old;
 	char* new;
diff --git a/plat/linux386/include/unistd.h b/plat/linux386/include/unistd.h
index 715e321d7..35dc8dde7 100644
--- a/plat/linux386/include/unistd.h
+++ b/plat/linux386/include/unistd.h
@@ -67,7 +67,7 @@ extern char** environ;
 extern void _exit(int);
 extern pid_t getpid(void);
 extern int brk(void* ptr);
-extern void* sbrk(intptr_t increment);
+extern void* sbrk(int increment);
 extern int isatty(int d);
 
 /* Signal handling */
diff --git a/plat/linux68k/include/unistd.h b/plat/linux68k/include/unistd.h
index 5cbdc1b5d..307192f77 100644
--- a/plat/linux68k/include/unistd.h
+++ b/plat/linux68k/include/unistd.h
@@ -65,7 +65,7 @@ extern char** environ;
 extern void _exit(int);
 extern pid_t getpid(void);
 extern int brk(void* ptr);
-extern void* sbrk(intptr_t increment);
+extern void* sbrk(int increment);
 extern int isatty(int d);
 
 /* Signal handling */
diff --git a/plat/linuxppc/include/unistd.h b/plat/linuxppc/include/unistd.h
index 5cbdc1b5d..307192f77 100644
--- a/plat/linuxppc/include/unistd.h
+++ b/plat/linuxppc/include/unistd.h
@@ -65,7 +65,7 @@ extern char** environ;
 extern void _exit(int);
 extern pid_t getpid(void);
 extern int brk(void* ptr);
-extern void* sbrk(intptr_t increment);
+extern void* sbrk(int increment);
 extern int isatty(int d);
 
 /* Signal handling */
diff --git a/plat/pc86/include/unistd.h b/plat/pc86/include/unistd.h
index 2af9db921..ea4f51c0f 100644
--- a/plat/pc86/include/unistd.h
+++ b/plat/pc86/include/unistd.h
@@ -37,7 +37,7 @@ extern char** environ;
 
 extern void _exit(int);
 extern pid_t getpid(void);
-extern void* sbrk(intptr_t increment);
+extern void* sbrk(int increment);
 extern int isatty(int d);
 extern off_t lseek(int fildes, off_t offset, int whence);
 extern int close(int d);
diff --git a/plat/pc86/libsys/brk.c b/plat/pc86/libsys/brk.c
index 02e213399..952a9c747 100644
--- a/plat/pc86/libsys/brk.c
+++ b/plat/pc86/libsys/brk.c
@@ -28,7 +28,7 @@ int brk(void* newend)
 	return 0;
 }
 
-void* sbrk(intptr_t increment)
+void* sbrk(int increment)
 {
 	char* old;
 	
diff --git a/plat/qemuppc/include/unistd.h b/plat/qemuppc/include/unistd.h
index 5cbdc1b5d..307192f77 100644
--- a/plat/qemuppc/include/unistd.h
+++ b/plat/qemuppc/include/unistd.h
@@ -65,7 +65,7 @@ extern char** environ;
 extern void _exit(int);
 extern pid_t getpid(void);
 extern int brk(void* ptr);
-extern void* sbrk(intptr_t increment);
+extern void* sbrk(int increment);
 extern int isatty(int d);
 
 /* Signal handling */
diff --git a/plat/qemuppc/libsys/brk.c b/plat/qemuppc/libsys/brk.c
index 02e213399..952a9c747 100644
--- a/plat/qemuppc/libsys/brk.c
+++ b/plat/qemuppc/libsys/brk.c
@@ -28,7 +28,7 @@ int brk(void* newend)
 	return 0;
 }
 
-void* sbrk(intptr_t increment)
+void* sbrk(int increment)
 {
 	char* old;
 	
diff --git a/plat/qemuppc/tests/brk_c.c b/plat/qemuppc/tests/brk_c.c
new file mode 100644
index 000000000..aa0f7ef99
--- /dev/null
+++ b/plat/qemuppc/tests/brk_c.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <limits.h>
+#include "test.h"
+
+int main(int argc, const char* argv[])
+{
+    void* p;
+
+    ASSERT(-1 == (intptr_t)brk((void*)0xffffffff));
+    ASSERT(ENOMEM == errno);
+
+    p = sbrk(0);
+    ASSERT(p == sbrk(0));
+    ASSERT(p == sbrk(8));
+    ASSERT(p != sbrk(0));
+    ASSERT(p != sbrk(-8));
+    ASSERT(p == sbrk(0));
+
+    /* We assume the test environment has less than 2GB of RAM. */
+    ASSERT(-1 == (intptr_t)sbrk(INT_MAX));
+    ASSERT(-1 == (intptr_t)sbrk(INT_MIN));
+
+    finished();
+}
+
diff --git a/plat/qemuppc/tests/calloc_c.c b/plat/qemuppc/tests/calloc_c.c
new file mode 100644
index 000000000..518aa7e49
--- /dev/null
+++ b/plat/qemuppc/tests/calloc_c.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "test.h"
+
+int main(int argc, const char* argv[])
+{
+    const char* p;
+    int i;
+
+    ASSERT(0 == calloc(0, 0));
+    ASSERT(0 == calloc(0, 1));
+    ASSERT(0 == calloc(1, 0));
+    ASSERT(0 == calloc(SIZE_MAX/2, 3));
+    ASSERT(0 == calloc(SIZE_MAX/2, 2));
+    ASSERT(0 != calloc(1, 1));
+
+    p = calloc(10, 1);
+    for (i=0; i<10; i++)
+        ASSERT(0 == p[i]);
+
+    finished();
+}
diff --git a/plat/rpi/include/unistd.h b/plat/rpi/include/unistd.h
index a4d0c4507..196b823c4 100644
--- a/plat/rpi/include/unistd.h
+++ b/plat/rpi/include/unistd.h
@@ -59,7 +59,7 @@ extern char** environ;
 
 extern void _exit(int);
 extern pid_t getpid(void);
-extern void* sbrk(intptr_t increment);
+extern void* sbrk(int increment);
 extern int isatty(int d);
 extern off_t lseek(int fildes, off_t offset, int whence);
 extern int close(int d);
diff --git a/plat/rpi/libsys/brk.c b/plat/rpi/libsys/brk.c
index 36c7d4a6f..171b8e5cf 100644
--- a/plat/rpi/libsys/brk.c
+++ b/plat/rpi/libsys/brk.c
@@ -30,7 +30,7 @@ int brk(void* newend)
 	return 0;
 }
 
-void* sbrk(intptr_t increment)
+void* sbrk(int increment)
 {
 	char* old;