Initial creation of the end-user recovery tool.

user_tools/README_recovery.txt

+
+The recovery tool assists the user in creating a bootable USB drive that can
+recover a non-functional Chromium OS device. It generally operates in three
+steps.
+
+1. Download a config file from a known URL. This file describes the
+   available images and where they can be found.
+
+2. Ask the user to select the appropriate image, download it, and verify
+   that it matches what the config file describes.
+
+3. Ask the user to select a USB drive, and write the recovery image to it.
+
+
+Here's the format of the config file:
+
+The config file is a text file containing at least two paragraphs or
+stanzas, which are separated by at least one blank line. Lines beginning
+with '#' are completely ignored and do not count as blank lines. Non-blank
+lines must consist of a non-blank key and non-blank value separated by a '='
+with no spaces on either side. The key may not contain whitespace. The value
+may contain spaces, but all trailing whitespace is discarded.
+
+The first stanza must contain a key named "recovery_tool_version'. Its value
+must match the version of the recovery tool. If the value does not match,
+then the key 'recovery_tool_update', if it exists in the first stanza,
+should contain a string to display to the user. Regardless, if the version
+doesn't match, the recovery tool should exit.
+
+The second and remaining stanzas describe recovery images to put on the USB
+drive.
+
+For recovery_tool_version=1.0, each image stanza must contain:
+
+* One and only one of these keys:
+
+   display_name    - string to show to the user
+   file            - the name of the file to extract from the tarball
+   size            - size in bytes of the tarball
+
+* One or more of these keys:
+
+   url             - where to find the tarball to download
+
+* One or both of these keys:
+
+   md5             - md5sum of the tarball
+   sha1            - sha1sum of the tarball
+
+* Any other keys are informational only and are not used by the recovery tool.
+
+
+
+NOTE: This is still in flux. Possible additional keys are
+
+  hwid
+  name
+  channel