6i25 Error: BootSector is invalid

$ sudo mesaflash --device 5i25 --readhmid ERROR: no HOSTMOT2 firmware found. FFFFFFFF Configuration Name: General configuration information:   BoardName :   FPGA Size: 0 KGates   FPGA Pins: 0   Number of IO Ports: 0   Width of one I/O port: 0   Clock Low frequency: 0.0000 MHz   Clock High frequency: 0.0000 MHz   IDROM Type: 0   Instance Stride 0: 0   Instance Stride 1: 0   Register Stride 0: 0   Register Stride 1: 0 Modules in configuration: Configuration pin-out:

 sudo mesaflash --device 5i25 --fallback --write 5i25_7i85sx2.bit Checking file... OK   File type: BIT file Error: BootSector is invalid

$ sudo mesaflash --device 5i25 --fix-boot-block --write 5i25_7i85sx2.bit Checking file... OK   File type: BIT file Erasing sector 0 for boot block

$ sudo mesaflash --device 5i25 --fix-boot-block --fallback --write 5i25_fallback.bit