update_kernel: first cut at arm support

remote_access.sh

Index: remote_access.sh
diff --git a/remote_access.sh b/remote_access.sh
index 70d6058b0242f2f0315f6926ba7e66b1b5af04dc..c7152cc832e5a6f3b3c05812dfe029ad631052dc 100644
--- a/remote_access.sh
+++ b/remote_access.sh
@@ -66,6 +66,17 @@ function learn_board() {
   info "Target reports board is ${FLAGS_board}"
 }
 
+function learn_arch() {
+  [ -n "${FLAGS_arch}" ] && return
+  remote_sh uname -m
+  FLAGS_arch=$(echo "${REMOTE_OUT}" | sed s/armv7l/arm/g)
+  if [ -z "${FLAGS_arch}" ]; then
+    error "Arch required"
+    exit 1
+  fi
+  info "Target reports arch is ${FLAGS_arch}"
+}
+
 function remote_reboot {
   info "Rebooting."
   remote_sh "touch /tmp/awaiting_reboot; reboot"