Add crossystem arch (reports x86 or arm, depending on platform)

host/arch/arm/lib/crossystem_arch.c

 /* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <stdio.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ skipping 57 matching lines @@
   } else if (!strcasecmp(name,"savedmem_size")) {
   }
 
   return -1;
 }
 
 
 const char* VbGetArchPropertyString(const char* name, char* dest, int size) {
   /* TODO: IMPLEMENT ME!  For now, return reasonable defaults for
    * values where reasonable defaults exist. */
-  if (!strcasecmp(name,"hwid")) {
+  if (!strcasecmp(name,"arch")) {
+    return StrCopy(dest, "arm", size);
+  } else if (!strcasecmp(name,"hwid")) {
     return StrCopy(dest, "UnknownArmHwid", size);
   } else if (!strcasecmp(name,"fwid")) {
     return StrCopy(dest, "UnknownArmFwid", size);
   } else if (!strcasecmp(name,"ro_fwid")) {
     return StrCopy(dest, "UnknownArmRoFwid", size);
   } else if (!strcasecmp(name,"mainfw_act")) {
     return StrCopy(dest, "A", size);
   } else if (!strcasecmp(name,"mainfw_type")) {
     return StrCopy(dest, "developer", size);
   } else if (!strcasecmp(name,"ecfw_act")) {
     return StrCopy(dest, "RO", size);
   }
 
   return NULL;
 }
 
 
 int VbSetArchPropertyInt(const char* name, int value) {
   /* TODO: IMPLEMENT ME! */
   return -1;
 }
 
 
 int VbSetArchPropertyString(const char* name, const char* value) {
   /* If there were settable architecture-dependent string properties,
    * they'd be here. */
   return -1;
 }