Booting to single user mode:
pcib0: <Marvell Armada 3700 PCIe Bus Controller> mem 0xd0070000-0xd008ffff irq 5 on simplebus0
pcib0: link never came up
pci0: <OFW PCI bus> on pcib0
pci0: domain=0, physical bus=0
pcib0: a37x0_pcie_check_pio_status: Posted PIO Response Status: CA, 0xe00 @ 0
pcib0: a37x0_pcie_check_pio_status: Posted PIO Response Status: CA, 0xe00 @ 0
pcib0: a37x0_pcie_check_pio_status: Posted PIO Response Status: CA, 0xe00 @ 0xc
ofw_firmware0: <armada-3700-rwtm> compat marvell,armada-3700-rwtm-firmware (no driver attached)
gpioled0: <GPIO LEDs> on ofwbus0
crypto: assign cryptosoft0 driver id 0, flags 0x6000000
armv8crypto0: <AES-CBC,AES-XTS,AES-GCM>
crypto: assign armv8crypto0 driver id 1, flags 0xe000000
Device configuration finished.
procfs registered
Timecounters tick every 1.000 msec
enc0: bpf attached
lo0: bpf attached
vlan: initialized, using hash tables with chaining
mvneta0: link state changed to UP
usbus0: 5.0Gbps Super Speed USB v3.0
usbus1: 480Mbps High Speed USB v2.0
IPsec: Initialized Security Association Processing.
tcp_init: net.inet.tcp.tcbhashsize auto tuned to 8192
ugen0.1: <Generic XHCI root HUB> at usbus0
uhub0 on usbus0
uhub0: <Generic XHCI root HUB, class 9/0, rev 3.00/1.00, addr 1> on usbus0
ugen1.1: <Marvell EHCI root HUB> at usbus1
uhub1 on usbus1
uhub1: <Marvell EHCI root HUB, class 9/0, rev 2.00/1.00, addr 1> on usbus1
pflog0: bpf attached
pfsync0: bpf attached
spibus0: <OFW SPI bus> on spi0
mx25l0: <M25Pxx Flash Family> at cs 0 mode 0 on spibus0
mx25l0: device type mx25u3235f, size 4096K in 64 sectors of 64K, erase size 4K
sdhci_xenon1: Powering up sd/mmc
sdhci_xenon1-slot0: Divider 500 for freq 400000 (base 400000000)
**mmc0: Probing bus
GEOM: new disk flash/spi0
mmc0: SD probe: failed
mmc0: MMC probe: OK (OCR: 0x40ff8080)
mmc0: Current OCR: 0x00ff8080
mmc0: Probing cards
mmc0: New card detected (CID 1501004d384731474303f49149fc7000)
mmc0: New card detected (CSD d02701320f5903fff6dbffef8e404000)
mmc0: Card at relative address 0x0002 added:
mmc0: card: MMCHC M8G1GC 0.3 SN F49149FC MFG 07/2013 by 21 0x0000
mmc0: quirks: 0
mmc0: bus: 4bit, 200MHz (HS200 timing)
mmc0: memory: 15269888 blocks, erase sector 1024 blocks
mmc0: setting transfer rate to 52.000MHz (high speed timing)
sdhci_xenon1-slot0: Divider 4 for freq 50000000 (base 400000000)
mmc0: setting bus width to 4 bits high speed timing
mmc0: Failed to set VCCQ for card at relative address 2
mmcsd0: taking advantage of TRIM
mmcsd0: cache size 65536KB
mmcsd0: 8GB <MMCHC M8G1GC 0.3 SN F49149FC MFG 07/2013 by 21 0x0000> at mmc0 50.0MHz/4bit/65535-block
uhub0: 2 ports with 2 removable, self powered
mmcsd0boot0: 4MB partition 1 at mmcsd0
mmcsd0boot1: 4MB partition 2 at mmcsd0
mmcsd0rpmb: 524kB partition 3 at mmcsd0**
pci0: driver added
CPU 0: ARM Cortex-A53 r0p4 affinity: 0
Cache Type = <64 byte D-cacheline,64 byte I-cacheline,VIPT ICache,64 byte ERG,64 byte CWG>
Instruction Set Attributes 0 = <CRC32,SHA2,SHA1,AES+PMULL>
Instruction Set Attributes 1 = <>
Instruction Set Attributes 2 = <>
Processor Features 0 = <GIC,AdvSIMD,FP,EL3 32,EL2 32,EL1 32,EL0 32>
Processor Features 1 = <>
Processor Features 2 = <>
Memory Model Features 0 = <TGran4,TGran64,SNSMem,BigEnd,16bit ASID,1TB PA>
Memory Model Features 1 = <8bit VMID>
Memory Model Features 2 = <32bit CCIDX,48bit VA>
Memory Model Features 3 = <>
Memory Model Features 4 = <>
Debug Features 0 = <DoubleLock,2 CTX BKPTs,4 Watchpoints,6 Breakpoints,PMUv3,Debugv8>
Debug Features 1 = <>
Auxiliary Features 0 = <>
Trying to mount root from ufs:/dev/ufs/pfSense_Install [ro,noatime]...
Auxiliary Features 1 = <>
AArch32 Instruction Set Attributes 5 = <CRC32,SHA2,SHA1,AES+VMULL,SEVL>
AArch32 Media and VFP Features 0 = <FPRound,FPSqrt,FPDivide,DP VFPv3+v4,SP VFPv3+v4,AdvSIMD>
AArch32 Media and VFP Features 1 = <SIMDFMAC,FPHP DP Conv,SIMDHP SP Conv,SIMDSP,SIMDInt,SIMDLS,FPDNaN,FPFtZ>
L1 cache: 32KB (instruction), 32KB (data)
L2 cache: 256KB (unified)
TCP_ratelimit: Is now initialized
regulator: shutting down unused regulators
regulator: shutting down vcc_sd1... ok
GEOM: new disk mmcsd0
GEOM: new disk mmcsd0boot0
GEOM: new disk mmcsd0boot1
uhub1: 1 port with 1 removable, self powered
e6000sw0port1: link state changed to DOWN
e6000sw0port2: link state changed to DOWN
e6000sw0port3: link state changed to UP
Root mount waiting for: usbus0
ugen0.2: <SanDisk Cruzer Blade> at usbus0
umass0 on uhub0
umass0: <SanDisk Cruzer Blade, class 0/0, rev 2.00/1.26, addr 1> on usbus0
umass0:0:0: Attached to scbus0
pass0 at umass-sim0 bus 0 scbus0 target 0 lun 0
pass0: <SanDisk Cruzer Blade 1.26> Removable Direct Access SPC-3 SCSI device
pass0: Serial Number 200443230002CF812081
pass0: 40.000MB/s transfers
da0 at umass-sim0 bus 0 scbus0 target 0 lun 0
da0: <SanDisk Cruzer Blade 1.26> Removable Direct Access SPC-3 SCSI device
da0: Serial Number 200443230002CF812081
da0: 40.000MB/s transfers
da0: 7633MB (15633408 512 byte sectors)
da0: quirks=0x2<NO_6_BYTE>
da0: Delete methods: <NONE(*),ZERO>
GEOM: new disk da0
Warning: no time-of-day clock registered, system time will not be set accurately
Dual Console: Video Primary, Serial Secondary
start_init: trying /sbin/init
Enter full pathname of shell or RETURN for /bin/sh: random: unblocking device.
Which appears to show the MMC there, but I'm not sure what to do.