FLASHFILE is now set to RIOTBOOT_EXTENDED_BIN, changing the meaning of
make all`, `flash`, `flash-only`.
This commits updates the documentation accordingly.
riotboot looks for valid, available slots and compares its
version. The slot with the highest version is booted, otherwise
if no valid slot is found it loops on `while(1);`
riotboot is introduced here and makes use of riotboot_hdr,
which indentifies the images encapsulated as slots.
The slot size and offset is configurable, which makes
slots extendable if needed, e.g. 2 or more slots can be
transparently added.
Co-authored-by: Kaspar Schleiser <kaspar@schleiser.de>
Co-authored-by: Gaëtan Harter <gaetan.harter@fu-berlin.de>
