dffinit - set INIT param on FF cells

yosys> help dffinit

dffinit [options] [selection]

This pass sets an FF cell parameter to the the initial value of the net it
drives. (This is primarily used in FPGA flows.)

-ff <cell_name> <output_port> <init_param>

operate on the specified cell type. this option can be used
multiple times.

-highlow

use the string values "high" and "low" to represent a single-bit
initial value of 1 or 0. (multi-bit values are not supported in this
mode.)

-strinit <string for high> <string for low>

use string values in the command line to represent a single-bit
initial value of 1 or 0. (multi-bit values are not supported in this
mode.)

-noreinit

fail if the FF cell has already a defined initial value set in other
passes and the initial value of the net it drives is not equal to
the already defined initial value.