linux /zImage netif_num=1 earlycon=uart8250,io,0x3f8,115200n8 syno_hdd_powerup_seq=1 syno_hdd_detect=0 elevator=elevator root=/dev/md0 loglevel=15 log_buf_len=32M mac1=xxxxxxxxxxx vid=0xxxxx pid=0xxxxx console=ttyS0,115200n8 DiskIdxMap=00 SataPortMap=4 SasIdxMap=0 sn=xxxxxxxxxxx earlyprintk syno_port_thaw=1 HddHotplug=0 withefi syno_hw_version=DS918+ vender_format_version=2
That is my config. I copy SataPortMap=4 from my previous (6.2.3) config. As for DiskIdxMap=00 SasIdxMap=0 I set them to 0 just for check.
So i dont know what the SataPortMap DiskIdxMap SasIdxMap value needed to be. I suppose i am lucky