The SiFive HiFive1 Rev B is a SBC funded on Crowd Supply featuring the Freedom Everywhere FE310-G002 RISC-V processor capable of being clocked at 320+ MHz.
The FE310-G002 jumps to 0x2001_0000
in the external SPI Flash memory on the HiFive1 Rev B. The FE310-G002 can boot from other sources, controlled by the Mode Select (MSEL[1:0]
) pins. The default value appears to be 01
, which is a jump to 0x2000_0000
in external SPI Flash. It may also be defaulting to 10
, a jump to the OTP (One-Time Programmable) memory at 0x0002_0000
, which could then jump to one of the previous locations in external Flash. The other two options are 11
for the fixed mask ROM, which contains an instruction at 0x0001_0000
to jump to the OTP memory, and 00
, which jumps to 0x0000_1004
and loops forever waiting for a debugger.