Release notes for 1.4.0-rc1

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/README.md b/README.md
index e2bf5e5..fb7e9fa 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 [coverity]: https://scan.coverity.com/projects/mcuboot
 [travis]: https://travis-ci.org/JuulLabs-OSS/mcuboot
 
-This is mcuboot, version 1.3.1
+This is mcuboot, version 1.4.0-rc1
 
 MCUboot is a secure bootloader for 32-bit MCUs.   The goal of MCUboot is to
 define a common infrastructure for the bootloader, system flash layout on
diff --git a/docs/release-notes.md b/docs/release-notes.md
index dbaa3ad..c42e7bc 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -3,6 +3,26 @@
 - Table of Contents
 {:toc}
 
+## Version 1.4.0
+
+The 1.4.0 release of MCUboot primarily adds support for multi-image
+booting.  With this release, MCUboot can manage two images that can be
+updated independently.  With this, it also supports additions to the
+TLV that allow these dependencies to be specified.
+
+Multi-image support adds backward-incompatible changes to the format
+of the images: specifically adding support for protected TLV entries.
+If multiple images and dependencies are not used, the images will be
+compatible with previous releases of MCUboot.
+
+### About this release
+
+- Fixed CVE-2019-5477.  This fixes an issue with a dependency used in
+  the generation of the documentation on github.
+- Numerous code cleanups and refactorings
+- Documentation updates for multi-image features
+- Update imgtool.py to support the new features
+
 ## Version 1.3.1
 
 The 1.3.1 release of MCUboot consists mostly of small bug fixes and updates.
diff --git a/repository.yml b/repository.yml
index 83e4670..93e5c25 100644
--- a/repository.yml
+++ b/repository.yml
@@ -26,6 +26,7 @@
     "1.2.0": "v1.2.0"
     "1.3.0": "v1.3.0"
     "1.3.1": "v1.3.1"
+    "1.4.0": "v1.4.0-rc1"
 
     "0-dev": "0.0.0"        # master
     "0-latest": "1.3.1"     # latest stable release