Add 'reboot bootloader' to bootloader_message.

 Add 'reboot bootloader' capability to the bootloader_message.

BUG: https://issuetracker.google.com/issues/32474515

Change-Id: I01e8b2fad978bf7c8fc96ff6b08ad3e52533f504
Author: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Reviewed-on: https://android.intel.com/548519
diff --git a/bootloader_message/bootloader_message.cpp b/bootloader_message/bootloader_message.cpp
index 59c2b2e..f6f8005 100644
--- a/bootloader_message/bootloader_message.cpp
+++ b/bootloader_message/bootloader_message.cpp
@@ -163,6 +163,19 @@
   return write_bootloader_message(boot, err);
 }
 
+bool write_reboot_bootloader(std::string* err) {
+  bootloader_message boot;
+  if (!read_bootloader_message(&boot, err)) {
+    return false;
+  }
+  if (boot.command[0] != '\0') {
+    *err = "Bootloader command pending.";
+    return false;
+  }
+  strlcpy(boot.command, "bootonce-bootloader", sizeof(boot.command));
+  return write_bootloader_message(boot, err);
+}
+
 bool read_wipe_package(std::string* package_data, size_t size, std::string* err) {
   package_data->resize(size);
   return read_misc_partition(&(*package_data)[0], size, WIPE_PACKAGE_OFFSET_IN_MISC, err);
@@ -173,6 +186,11 @@
                               WIPE_PACKAGE_OFFSET_IN_MISC, err);
 }
 
+extern "C" bool write_reboot_bootloader(void) {
+  std::string err;
+  return write_reboot_bootloader(&err);
+}
+
 extern "C" bool write_bootloader_message(const char* options) {
   std::string err;
   return write_bootloader_message({options}, &err);