Bootcode.bin-only boot mode, latest version?

I've been booting a couple of old Pi2 v1.1 (armv7) hosts
using the bootcode.bin method to run freebsd from usb
mechanical hard disks.

The hardware documentation page link for the "latest"
bootcode.bin for this purpose appears to be at least a
couple years old, placed on Github under the handle
popcornmix. The URL is
https://github.com/raspberrypi/firmware/blob/master/boot/bootcode.bin
 

Does anybody know of a more recent version of the file? Recent
boot attempts have failed to find the USB disk, but the disk
and SATA-to_USB adapter are recognized without a problem on
both FreeBSD and RasPiOS Bookworm, suggesting both are ok.

At this point the machine falls into a loop of netboot attempts.
Alternatively, is there some way to break out of the netboot
loop via the serial console? That might let me look around.

Thanks for reading,

bob prohaska