Support non-ubifs layout

Add ubifs_layout as config argument, so a build could select if it
needs ubifs_layout feature or not.

Add code to update non-ubifs layout image by
1. Putting the bmc image in /run/initramfs;
2. Set its state as Active when it is ready to update
3. Let user to initiate the reboot request

Tested: Generate a tarball with Romulus bmc image and manifest,
        update it with REST API (image upload, activation, and reboot)
        Verify the code update works well in WebUI.

Change-Id: I5b122211fafb7cb9d96ee67317db139ed0b7d0a7
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/static/flash.cpp b/static/flash.cpp
new file mode 100644
index 0000000..59c7a67
--- /dev/null
+++ b/static/flash.cpp
@@ -0,0 +1,43 @@
+#include <experimental/filesystem>
+
+#include "activation.hpp"
+#include "config.h"
+#include "flash.hpp"
+#include "image_verify.hpp" // For bmcImages
+
+namespace
+{
+constexpr auto PATH_INITRAMFS = "/run/initramfs";
+} // anonymous
+
+namespace phosphor
+{
+namespace software
+{
+namespace updater
+{
+
+namespace fs = std::experimental::filesystem;
+
+void Activation::flashWrite()
+{
+    // For static layout code update, just put image in /run/initramfs.
+    // It expects user to trigger a reboot and an updater script will program
+    // the image to flash during reboot.
+    fs::path uploadDir(IMG_UPLOAD_DIR);
+    fs::path toPath(PATH_INITRAMFS);
+    for (auto& bmcImage : phosphor::software::image::bmcImages)
+    {
+        fs::copy_file(uploadDir / versionId / bmcImage, toPath / bmcImage,
+                      fs::copy_options::overwrite_existing);
+    }
+}
+
+void Activation::onStateChanges(sdbusplus::message::message& /*msg*/)
+{
+    // Empty
+}
+
+} // namespace updater
+} // namespace software
+} // namepsace phosphor