PC_CKS_LOC
expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
__nvram_read_byte(PC_CKS_LOC+1);
__nvram_write_byte(sum >> 8, PC_CKS_LOC);
__nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);