To make the creation of a bootstrap medium for most ARM platforms more
comfortable this tool shall bundle all the different U-Boot source
states, patches, and MMC preparation rules that we gathered over the
year for that purpose. As input, the tool merely needs the targeted
platform (analogous to the platform parameter of 'create_builddir'). By
now, 'hw_wand_quad' is the only supported platform. Further platforms
can be added successively. As output, the tool creates a head image file
of small size (8MiB) that can be copied (dd) with offset 0 to the MMC.
Fixes#1730
