Can't Modify U-Boot Environment Variables on Updated Firmware

[eli-osr]

I am trying to get up and running with the R-Car H3 Starter Kit Premier Board (h3ulcb). I first followed the instructions here http://elinux.org/R-Car/Boards/Yocto-Gen3 to build Yocto 2.19 for the board. When I attempted to run the built Yocto image on the board, I received a kernel panic message. The limited resources on the internet indicated this was likely due to outdated firmware. I then followed the instructions here http://elinux.org/R-Car/Boards/H3SK#Flashing_firmware to update the firmware on the board. Now when I turn the board on, I am not given the option of cancelling autoboot. The board simply attempts to read from the specified boot file and I am not able to follow the usual process of cancelling autoboot and changing U-Boot's environment variables. Any help would be greatly appreciated!

Output of boot sequence is below:

user@user-linux:~$ sudo picocom -b 115200 --send-cmd "ascii-xfr -vvs" /dev/ttyUSB0
[sudo] password for user:
picocom v1.7

port is : /dev/ttyUSB0
flowcontrol : none
baudrate is : 115200
parity is : none
databits are : 8
escape is : C-a
local echo is : no
noinit is : no
noreset is : no
nolock is : no
send_cmd is : ascii-xfr -vvs
receive_cmd is : rz -vv
imap is :
omap is :
emap is : crcrlf,delbs,

Terminal ready
[ 0.000194] NOTICE: BL2: R-Car Gen3 Initial Program Loader(CA57) Rev.1.0.14
[ 0.005761] NOTICE: BL2: PRR is R-Car H3 Ver2.0
[ 0.010335] NOTICE: BL2: Board is unknown Rev0.0
[ 0.015006] NOTICE: BL2: Boot device is HyperFlash(80MHz)
[ 0.020445] NOTICE: BL2: LCM state is CM
[ 0.024423] NOTICE: BL2: AVS setting succeeded. DVFS_SetVID=0x52
[ 0.030611] NOTICE: BL2: DDR3200(rev.0.22)NOTICE: [COLD_BOOT]NOTICE: ..0
[ 0.091270] NOTICE: BL2: DRAM Split is 4ch
[ 0.095155] NOTICE: BL2: QoS is default setting(rev.0.14)
[ 0.100655] NOTICE: BL2: Lossy Decomp areas
[ 0.104832] NOTICE: Entry 0: DCMPAREACRAx:0x80000540 DCMPAREACRBx:0x570
[ 0.111917] NOTICE: Entry 1: DCMPAREACRAx:0x40000000 DCMPAREACRBx:0x0
[ 0.118829] NOTICE: Entry 2: DCMPAREACRAx:0x20000000 DCMPAREACRBx:0x0
[ 0.125743] NOTICE: BL2: v1.3(release):4eef9a2
[ 0.130233] NOTICE: BL2: Built : 17:35:56, Jul 13 2017
[ 0.135420] NOTICE: BL2: Normal boot
[ 0.139062] NOTICE: BL2: dst=0xe6320190 src=0x8180000 len=512(0x200)
[ 0.145608] NOTICE: BL2: dst=0x43f00000 src=0x8180400 len=6144(0x1800)
[ 0.152070] NOTICE: BL2: dst=0x44000000 src=0x81c0000 len=65536(0x10000)
[ 0.159295] NOTICE: BL2: dst=0x44100000 src=0x8200000 len=524288(0x80000)
[ 0.169775] NOTICE: BL2: dst=0x50000000 src=0x8640000 len=1048576(0x100000)