doc: Document how to flash with filesystem

README.md

@@ -85,7 +85,13 @@ https://github.com/tillitis/tkey-libs
 
 but keep our own copy of it in the repo. See below.
 
-## Building
+## Building & flashing
+
+You need a [TKey
+Unlocked](https://shop.tillitis.se/products/tkey-not-provisioned) and
+a [TKey Programmer
+Board](https://shop.tillitis.se/products/tkey-dev-kit) to use this on
+real hardware.
 
 Building is probably easiest using make and Podman. Do this to see all
 targets:
@@ -103,6 +109,18 @@ cd contrib
 make run-make
 ```
 
+To flash the bitstream, the testloadapp in app slot 0 and the
+partition table copies in one go, place the TKey Unlocked in the TP1,
+then do:
+
+```
+make flash
+```
+
+This uses the make target `prog_flash` in
+`hw/application_fpga/Makefile` behind the scenes, but mounts your TP1
+device into the container.
+
 See the [Tillitis Developer Handbook](https://dev.tillitis.se) for
 more.
 

hw/application_fpga/fw/README.md

@@ -765,6 +765,26 @@ initiated before starting for the first time. You need a [TKey
 Programmer Board](https://shop.tillitis.se/products/tkey-dev-kit) for
 this part.
 
+If you just want to build and flash the bitstream, the testloadapp in
+app slot 0, and the partition table copies in one go, place the TKey
+Unlocked in the TP1, then:
+
+Using Podman, from the top level directory:
+
+```
+cd contrib
+make flash
+```
+
+Using native tools:
+
+```
+cd hw/application_fpga
+make prog_flash
+```
+
+If you want to prepare the filesystem yourself:
+
 1. Choose your pre-loaded app. You *must* have a pre-loaded app, for
    example `testloadapp`. Build it with the OCI image we use. The
    binary needs to produce the BLAKE2s digest in `allowed_app_digest`