This is what I am running (with 23.05.0-rc2)
root@MX60-1:~# fw_printenv
bootdelay=1
baudrate=115200
loads_echo=
preboot=echo;echo Set serverpath and run meraki_netboot to netboot;echo
nload=${netloadmethod} 200000 ${serverpath}u-boot-nand.bin
nupdate=nand erase 0 0x00200000 ;nand write 200000 0 0x00100000
nupd=run nload nupdate
kernel_addr=fc000000
fdt_addr=fc1e0000
ramdisk_addr=fc200000
pciconfighost=1
pcie_mode=RP:RP
pcie=enabled
netdev=eth0
netloadmethod=dhcp
ethact=ppc_4xx_eth0
ethaddr=00:01:73:01:23:41
boardtype=pcie
mtd_addr_r=0x4000000
kernel_size=0x400000
fdt_size=0x25000
meraki_bootargs=setenv bootargs root=/dev/ram console=ttyS0,${baudrate} ubi.mtd=ubi MERAKI_BOARD=buck mtdoops.mtddev=oops ${extra_bootargs}
meraki_bootfile=buck.bin
meraki_bootlinux=bootm ${meraki_loadaddr_kernel} ${meraki_loadaddr_ramdisk} ${meraki_loadaddr_fdt}
meraki_boot=run meraki_ubi meraki_bootargs ; run meraki_load1 meraki_checkpart meraki_bootlinux; run meraki_load2 meraki_checkpart2 meraki_bootlinux
meraki_checkpart=meraki checkpart ${meraki_loadaddr}
meraki_checkpart2=meraki checkpart ${meraki_loadaddr} skiphash
meraki_netboot=run meraki_load_net meraki_bootargs meraki_checkpart2 meraki_bootlinux
meraki_part_fdt_index=0
meraki_loadaddr_fdt=800400
meraki_loadaddr_kernel=810000
meraki_loadaddr_ramdisk=a00000
meraki_load1=ubi read ${meraki_loadaddr} part1
meraki_load2=ubi read ${meraki_loadaddr} part2
meraki_load_net=${netloadmethod} ${meraki_loadaddr} ${serverpath}${meraki_bootfile}
meraki_ubi=ubi part ubi
meraki_ubifile=buck-ubi.bin
meraki_ubi_loadfile=${netloadmethod} 200000 ${serverpath}${meraki_ubifile}
meraki_ubi_update_nand=nand erase 0x00240000 0x3fdc0000 ; nand write 200000 0x00240000 ${filesize}
meraki_ubi_update=run meraki_ubi_loadfile meraki_ubi_update_nand
meraki_update_part1=run meraki_ubi meraki_load_net meraki_write1
meraki_update_part2=run meraki_ubi meraki_load_net meraki_write2
meraki_write1=ubi write ${meraki_loadaddr} part1 ${filesize}
meraki_write2=ubi write ${meraki_loadaddr} part2 ${filesize}
mtdids=nand0=nand0
mtdparts=mtdparts=nand0:0x00200000@0(firmware),0x00040000@0x00200000(panic),0x3fdc0000@0x00240000(ubi)
serverpath=10.1.30.240:tftpboot/
ipaddr=192.168.1.1
serverip=192.168.1.101
gatewayip=192.168.1.1
netmask=255.255.255.0
factory_cmdline=setenv bootargs root=/dev/ram ramdisk_size=${factory_ramdisk_size} rw ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}:${netdev}:off panic=1 console=ttyS1,${baudrate}
factory_ramdisk_file=uRamdisk
factory_bootfile=uImage
factory_fdt_file=bluestone.dtb
factory_kernel_addr_r=0x400000
factory_fdt_addr_r=0x800000
factory_mtd_addr_r=0x4000000
factory_ramdisk_size=0x200000
factory_boot=tftp ${factory_kernel_addr_r} ${factory_bootfile};tftp ${factory_fdt_addr_r} ${factory_fdt_file};tftp ${factory_mtd_addr_r} ${factory_ramdisk_file};run factory_cmdline;bootm ${factory_kernel_addr_r} ${factory_mtd_addr_r} ${factory_fdt_addr_r}
stdin=serial
stdout=serial
stderr=serial
ver=U-Boot 2009.08-00049-g0ee25dd Meraki MX60 (Jul 27 2012 - 14:59:20)
owrt_load1=ubi read ${meraki_loadaddr} kernel
owrt_load2=ubi read ${meraki_loadaddr} recovery
lede_bootkernel=bootm ${meraki_loadaddr_kernel} - ${meraki_loadaddr_fdt}
owrt_bootkernel=bootm ${meraki_loadaddr}
owrt_bootargs=setenv bootargs console=ttyS0,${baudrate} rootfstype=squashfs mtdoops.mtddev=oops
owrt_boot=run meraki_ubi owrt_bootargs; run owrt_load1 meraki_checkpart lede_bootkernel; run owrt_load2 owrt_bootkernel
owrt510_boot=run meraki_ubi owrt_bootargs; run owrt_load1 owrt_bootkernel; run owrt_load2 owrt_bootkernel
bootcmd=run owrt510_boot
meraki_loadaddr=1000000
Note that if fw_printenv does not work for you (shows "CRC Error, using default environment), you need to configure it as described here: