Flashing ProjectTrellis ECP5_evn multiboot example failes

[feldim2425]

I recently tried to flash the ECP5 multiboot example in the ProjectTrellis Repo for the ECP5 evaluation board (LFE5UM5G-85F-EVN) but it failed during the "Refresh" step and the FPGA was not able to load the bitstream from th SPI flash (The Red LED D3 lit up and stayed on util I flashed a new program).
I used the following command:
openFPGALoader -c ft2232 -b ecp5_evn -f multiboot.mcs

Refresh: FAIL
displayReadReg
	Config Target Selection : 0
	SPIm Fail1
	Preamble ERR
	EXEC Error

I also tried flashing the blinky1.bit and blinky2.bit Bitstreams using the same command (to the onboard SPI Flash) which worked without problem.
I was also able to flash the multiboot.mcs file from ProjectTrellis with the official Lattice Diamond programmer util also without any problems.

[feldim2425]

Ok. I figured it out. It seems like Lattice Diamond programmer ignores the preamble in the mcs file and adds it's own or does some error correction. The problem is that the ProjectTrellis Multiboot example removes all 0xFF bytes at the beginning and that messes up the preamble. Simply removing the -unfill 0xFF parameter in the Makefile fixes it.

[trabucayre]

Thanks for this information.
Maybe I need to check if this preample is present (or not) and adapt content accordingly.
I suppose it's the better approach to avoid this issue