Its not needed. But the SD card users tend to flash the exact same image (from a PC) to multiple SDs, therefore cloning the mac address.
If your devices are already using different mac addresses, don't worry.
Thanks for clarify.
I just flashed an S9J with ssh image successfully and am going to do the rest of my miners
Need a little help here,
At the end of the operation it print out "Content of U-Boot configuration" as bellow:
Content of U-Boot configuration:
miner_pool_host=stratum+tcp://stratum.slushpool.com
miner_pool_port=3333
miner_pool_user=!non-existent-user!
load_addr=0x2000000
fdt_high=0x7FFFFFF
initrd_high=0x7FFFFFF
bitstream_addr=0x2100000
bootenv=uEnv.txt
set_bootargs=setenv bootargs console=ttyPS0,115200 root=/dev/ram0 r rootfstype=squashfs ${mtdparts} earlyprintk
uenv_load=load mmc 0 ${load_addr} ${bootenv} && echo Loaded environment from ${bootenv} && env import -t ${load_addr} ${filesize}
load_fpga=nand read ${load_addr} ${bitstream_off} ${bitstream_size} && unzip ${load_addr} ${bitstream_addr} && fpga loadb 0 ${bitstream_addr} ${bitstream_size}
nandboot=echo Copying FIT from NAND flash to RAM... && run uenv_load; test x${sd_boot} = xyes && run sdboot; run set_bootargs && run load_fpga && nand read ${load_addr} ${kernel_off} ${kernel_size} && bootm ${load_addr}
sdboot=echo Copying FIT from SD to RAM... && run set_bootargs && run uenv_load; load mmc 0 ${load_addr} fit.itb && bootm ${load_addr}
mtdids=nand0=pl35x-nand
mtdparts=mtdparts=pl35x-nand:512k(boot),2560k(uboot),2m(fpga1),2m(fpga2),512k(uboot_env),512k(miner_cfg),22m(recovery),95m(firmware1),95m(firmware2)
bootcmd=run $modeboot
bitstream_off=0x300000
bitstream_size=0x74a74
kernel_off=0xB000000
kernel_size=0x6b5274
stage2_off=0x3D00000
stage2_size=0x1076b99
stage2_mtd=8
ethaddr=0c:19:d1:fc:4e:a9
miner_hwid=TKGqkuaOSqj1UIaz
miner_freq=550
miner_voltage=0706
net_ip=192.168.1.81
net_mask=255.255.255.0
net_gateway=192.168.1.1
net_dns_servers=192.168.1.1
And then:
Upgrade was successful!
Where can I find "U-Boot configuration" to edit so I dont need to manually edit all the other miners after flash.