Generating random content with size:

head -c 524288 </dev/urandom > random.bin

Never trust autodetect, specify the flash name explicitly with -c. (My SST25LF040A was not detectable with autodetect)

Assert CS at the begining of spi_master::command and deassert befor leaving it.

Yes someone welded a ovoid chainring to his cowrushing bike :D

Put the Igo to the Navitel folder on the flash.
Rename Navitel.exe to Navitel.old.exe
Rename Igo.exe to Navitel.exe

Put the following to the sys.txt:
https://gist.github.com/martonmiklos/6f35582765ecb1957ab7d66b79c23e12

I have bought a sunken PH1 around a year ago, managed to get it fly, but it is not able to see the GPS signal properly.

I have hooked up the board to my saleae and I have wrapped this tool to read the Saleae logic analyzer output CSV:
https://github.com/aanjhan/ubx

It turned out that it see some satellites, but the link quality is very poor: CNO (Carrier to Noise ratio) was mostly 0 and sometimes 28-30.

So I have replaced the ublox receiver module (to an uBlox 6T), it see more satellites, with better CNo (27-33) but still no signal lock in the system.

I have ordered today a ANT1575-2540A from the TME and we will see.
There is a ALM-1912-BLKG in the antenna path, but I have not been able to source it yet. And my hopes to the antenna is pretty high :D.