This is the log initializing the board with debug info enabled and with a thumb driver connected to USB1 port:
usbhost_drivers_initialize: Register class drivers
usbhost_registerclass: Registering class:0x20200174 nids:1
usbhost_registerclass: Registering class:0x20200174 nids:1
imxrt_usbhost_vbusdrive: RHPort1: enable=1
usbmonitor_start: Started: 5
usbhost_waiter: Running 0x20200458
usbmonitor_daemon: Running: 5
NuttShell (NSH) NuttX-12.10.0
nsh> usbhost_waiter: connected
usbhost_enumerate: maxpacksetsize: 64
usbhost_devdesc: class:0 subclass:0 protocol:0 vid:346d pid:5678
usbhost_enumerate: sizeof config data: 32
usbhost_enumerate: Parsing interface: 0
usbhost_configdesc: cfg len:9 total len:32
usbhost_configdesc: class:8 subclass:6 protocol:80
usbhost_findclass: Looking for class:8 subclass:6 protocol:80 vid:346d pid:5678
usbhost_findclass: Checking class:0x20200174 nids:1
usbhost_idmatch: Compare to class:8 subclass:6 protocol:80 vid:0000 pid:0000
usbhost_classbind: usbhost_findclass: 0x20200174
usbhost_allocclass: Allocated: 0x2020276c
usbhost_classbind: CLASS_CREATE: 0x2020276c
usbhost_cfgdesc: Interface descriptor
usbhost_cfgdesc: Endpoint descriptor
usbhost_cfgdesc: Bulk OUT EP addr:1 mxpacketsize:64
usbhost_cfgdesc: Endpoint descriptor
usbhost_cfgdesc: Bulk IN EP addr:2 mxpacketsize:64
usbhost_cfgdesc: Endpoints allocated
usbhost_initvolume: Get max LUN
usbhost_maxlunreq: Request maximum logical unit number
usbhost_initvolume: Test unit ready, retries=0
usbhost_dumpcbw: CBW:
usbhost_dumpcbw: signature: 43425355
usbhost_dumpcbw: tag: 00000000
usbhost_dumpcbw: datlen: 00000000
usbhost_dumpcbw: flags: 00
usbhost_dumpcbw: lun: 00
usbhost_dumpcbw: cdblen: 06
usbhost_dumpcbw: CDB:
usbhost_dumpcbw: 00 00 00 00 00 00 00 00
usbhost_dumpcsw: CSW:
usbhost_dumpcsw: signature: 53425355
usbhost_dumpcsw: tag: 00000000
usbhost_dumpcsw: residue: 00000000
usbhost_dumpcsw: status: 00
usbhost_initvolume: Read capacity
usbhost_dumpcbw: CBW:
usbhost_dumpcbw: signature: 43425355
usbhost_dumpcbw: tag: 00000000
usbhost_dumpcbw: datlen: 00000008
usbhost_dumpcbw: flags: 80
usbhost_dumpcbw: lun: 00
usbhost_dumpcbw: cdblen: 0a
usbhost_dumpcbw: CDB:
usbhost_dumpcbw: 25 00 00 00 00 00 00 00
usbhost_dumpcbw: 00 00 00 00 00 00 00 00
usbhost_dumpcsw: CSW:
usbhost_dumpcsw: signature: 53425355
usbhost_dumpcsw: tag: 00000000
usbhost_dumpcsw: residue: 00000000
usbhost_dumpcsw: status: 00
usbhost_initvolume: Inquiry
usbhost_dumpcbw: CBW:
usbhost_dumpcbw: signature: 43425355
usbhost_dumpcbw: tag: 00000000
usbhost_dumpcbw: datlen: 00000024
usbhost_dumpcbw: flags: 80
usbhost_dumpcbw: lun: 00
usbhost_dumpcbw: cdblen: 06
usbhost_dumpcbw: CDB:
usbhost_dumpcbw: 12 00 00 00 24 00 00 00
usbhost_dumpcsw: CSW:
usbhost_dumpcsw: signature: 53425355
usbhost_dumpcsw: tag: 00000000
usbhost_dumpcsw: residue: 00000000
usbhost_dumpcsw: status: 00
usbhost_initvolume: Register block driver
usbhost_classbind: Returning: 0
EHCI Initializing EHCI Stack
EHCI HCIVERSION 1.00
EHCI nports=1, HCSPARAMS=0011
EHCI HCCPARAMS=000006
EHCI USB EHCI Initialized
EHCI Interrupt: 000004
EHCI PORTSC1: 1803
EHCI Connect Status Change: 001803
EHCI RHPort1 connected, pscwait: 1
EHCI RHPort1 connected: 1
EHCI Interrupt: 000004
EHCI PORTSC1: 1805
EHCI Hub port 0: Enumerate the device
EHCI CTRLIN/OUT: RHPort1 req: 06
EHCI Async transfer EP0 buflen=8
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP0 TOKEN=8c00
EHCI CTRLIN/OUT: RHPort1 req: 06
EHCI Async transfer EP0 buflen=18
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP0 TOKEN=8c00
EHCI CTRLIN/OUT: RHPort1 req: 05
EHCI Async transfer EP0 buflen=0
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP0 TOKEN=8d00
EHCI CTRLIN/OUT: RHPort1 req: 06
EHCI Async transfer EP0 buflen=9
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP0 TOKEN=8c00
EHCI CTRLIN/OUT: RHPort1 req: 06
EHCI Async transfer EP0 buflen=32
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP0 TOKEN=8c00
EHCI CTRLIN/OUT: RHPort1 req: 09
EHCI Async transfer EP0 buflen=0
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP0 TOKEN=8d00
EHCI EPALLOC: EP1 TYPE=2
EHCI EPALLOC: EP2 TYPE=2
EHCI CTRLIN/OUT: RHPort1 req: fe
EHCI Async transfer EP0 buflen=1
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP0 TOKEN=8c00
EHCI Async transfer EP1 buflen=31
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP1 TOKEN=8c00
EHCI Async transfer EP2 buflen=13
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP2 TOKEN=8d00
EHCI Async transfer EP1 buflen=31
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP1 TOKEN=8c00
EHCI Async transfer EP2 buflen=8
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP2 TOKEN=8d00
EHCI Async transfer EP2 buflen=13
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP2 TOKEN=8d00
EHCI Async transfer EP1 buflen=31
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP1 TOKEN=8c00
EHCI Async transfer EP2 buflen=36
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP2 TOKEN=8d00
EHCI Async transfer EP2 buflen=13
EHCI Interrupt: 000001
EHCI USB Interrupt (USBINT) Interrupt: 000001
EHCI IOC EP2 TOKEN=8d00
nsh> ls /dev
/dev:
console
null
sda
ttyS0
zero
nsh>