4370 USB boot DFU header question

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by MikeSimmonds on Thu Sep 18 15:36:40 MST 2014
I am just starting with the 4370 (LPC-Link2 board) and I have a question about the 16 byte header that has to be
prefixed to the DFU download image.

Does the image size field (i.e the 512-byte block count) have to include the DFU header itself.
With the rounding going on, in most cases it will not matter if the header is included or not,
but imagine this ...

The actual code image is EXACTLY 512 bytes and (by definition) the DFU header is 16 bytes.
Would the 'HASH_SIZE' be 1 (= 512) or 2 (512+16 round up to 1024)?

Secondly, I suppose that the code image will start with a vector table (with initial SP and reset address etc.)
Can you confirm this and indicate if the code image should be based a zero (and rely on the Boot ROM setting
the M4MEMMAP to hex 10000000) or base the image at absolute hex 10000000?

The 4370 is not an AES capable device, and the 'HASH_VALUE' will be zero.

Regards, Mike