The SPI pins are flipped

[maloneymr]

You have:

#set_io SPI_SCK 70
#set_io SPI_SI 68
#set_io SPI_SO 67
#set_io SPI_SS_B 71

But after several hours of debugging and wondering why my SPI flash memory wasn't working , I happened to notice that it should be:

set_io SPI_SCK 70
set_io SPI_SI 67
set_io SPI_SO 68
set_io SPI_SS_B 71

with the SO and SI pins flipped.