I have board which loads filesystem and kernel to RAM from spi flash when booting, because we do not want to use sd card for filesystem and kernel. It is 45 Mbytes big and it needs about 25 sec to be read with sf read command to RAM. I have tried to speed up but I could not find the right solution. Spi flash is The Cypress S25FL512S and it is big 64 MBytes and in documentation it has max speed Quad Read Speed (SDR) of 52 MB/s. How can I setup in boot that I have such speed. I tried to increase the clock:
CONFIG_SF_DEFAULT_SPEED = 100000000
but it fails.
I am stuck with it. The boot time is about 30s, and it should be 5.
Thanks, regards, Ivan.