now both partitions (bootloader and application) use a commonly
defined memory location to shared the DFU state (which includes
the magic value to know which part to start), instead of using
a hard coded value.
the bootloader size has now also been restricted to 16 kB.
this limitation is enforced so to not be able to create larger
images, which could be corrupted when flashing the application.
bootloader and application flashing have been successfully tested
on qmod st12 and st34.
Change-Id: I204bed7e9391602672ed894decec1fc12e879275
We need to refer to g_dfu as a pointer from all code. In DFU mode, it
gets assigned to the address of _g_dfu, which is placed by the linker
script at the start of RAM. In runtime mode, the pointer is statically
defined to point at the start of RAM. The linker script for the runtime
(dfu environment) is adjusted to save the first 32 bytes for the _g_dfu
structure.
This way we can easily check with 'diff' for differences in our code and
Atmel softpack. Also, this layout is more suitable for building various
different firmware images (e.g. factory-test, dfu-loader, main
application) for a variety of different boards (simtrace, owhw, qmod).
