Yeah, I solved problem with SATP register. It was caused by generating page faults when dirty and accessed flags are not set in PTEs. Unlike emulators where flags are managed automatically, on HiFive Unmatched flags need to be set by software.
Freedom U740-C000 Manual says:
It is important to note the U74 does not automatically set the accessed ( A ) and dirty ( D ) bits in a
Sv39 Page Table Entry (PTE). Instead, the U74 MMU will raise a page fault exception for a read
to a page with PTE.A=0 or a write to a page with PTE.D=0 .
Now kernel is running: UART log.