Add sys_vumap() kernel call

This new call is a vectored version of sys_umap(). It supports batch
lookups, non-contiguous memory, faulting in memory, and basic access
checks.

lib/libsys/Makefile

@@ -109,6 +109,7 @@ SRCS=  \
 	sys_voutw.c \
 	sys_vsafecopy.c \
 	sys_vtimer.c \
+	sys_vumap.c \
 	taskcall.c \
 	tickdelay.c \
 	timers.c \

lib/libsys/sys_vumap.c

@@ -0,0 +1,34 @@
+#include "syslib.h"
+
+/*===========================================================================*
+ *				sys_vumap				     *
+ *===========================================================================*/
+PUBLIC int sys_vumap(
+  endpoint_t endpt,			/* source process endpoint, or SELF */
+  struct vumap_vir *vvec,		/* virtual (input) vector */
+  int vcount,				/* number of elements in vvec */
+  size_t offset,			/* offset into first vvec element */
+  int access,				/* requested safecopy access flags */
+  struct vumap_phys *pvec,		/* physical (output) vector */
+  int *pcount				/* (max, returned) nr of els in pvec */
+)
+{
+  message m;
+  int r;
+
+  m.VUMAP_ENDPT = endpt;
+  m.VUMAP_VADDR = (vir_bytes) vvec;
+  m.VUMAP_VCOUNT = vcount;
+  m.VUMAP_OFFSET = offset;
+  m.VUMAP_ACCESS = access;
+  m.VUMAP_PADDR = (vir_bytes) pvec;
+  m.VUMAP_PMAX = *pcount;
+
+  r = _kernel_call(SYS_VUMAP, &m);
+
+  if (r != OK)
+	return r;
+
+  *pcount = m.VUMAP_PCOUNT;
+  return OK;
+}