generate files/etc/{banner, firmware} from repository state

The new script ./name_firmware is used to generates two files in
openwrt/$REPO/files/ during `make image/...`:
- /etc/firmware (see documentation on firmware id)
- /etc/banner (login banner; generated from the template in
  /files/common/etc/banner)

1 files changed, 10 insertions, 4 deletions

diff --git a/doc/overview.org b/doc/overview.org
index 78bf230..40fe441 100644
--- a/doc/overview.org
+++ b/doc/overview.org
@@ -103,12 +103,18 @@ digraph {
        verified
 
     Once this state is reached the update is performed.
-  
+    
 * Components
 ** Firmware ID
-   /etc/firmware stores sha256 of the current firmware. If a node is
-   intensively modified after flashing the value is replaced (e.g. by
-   "custom").
+   /etc/firmware stores a string identifying the current firmware. It
+   consists of
+   1. the date of the git commit of the FFJ config
+   2.   a hash of the git commit of the FFJ config
+   3. the OpenWRT major version
+   4. the OpenWRT revision
+
+   Example:
+   2011-12-06_a4fa439-modified_backfire-29460
 ** Router IDs
    - unique ID :: all routers use /proc/sys/kernel/random/boot_id as
                   unique ID