README.md: mention nvramtool

README.md

@@ -47,6 +47,7 @@ Planned:
 Ownerboot includes two nixpkgs-style packages:
 
 * `em100`: a nix expression for the [coreboot project's open-source driver](https://www.coreboot.org/EM100pro) for the em100 flash chip emulator.
+* `nvramtool`: a nix expression for the coreboot utility which manipulates the battery-backed (RTC) memory on x86 motherboards.
 * `flashrom-wp`: adds an out-of-tree patch to flashrom to configure which range of bytes are protected by the write-protect pin.  Upstream [does not have this feature](https://github.com/flashrom/flashrom/issues/142#issuecomment-793548441).  There [appears to be adding some work towards adding it](https://review.coreboot.org/q/topic:more_wp).  Work on this [began in 2016](https://mail.coreboot.org/pipermail/flashrom/2016-July/014737.html).  There is a [separate fork](https://chromium.googlesource.com/chromiumos/third_party/flashrom) maintained by Google for their chromebooks which implements this functionality on them; it is enabled by the `forChromebook` parameter.
 
 I'm not sure either of these really belongs in nixpkgs, but they are useful to the same kinds of people who might be interested in ownerboot.  So this is a good place for them.