From everything I have read, it should "Just Work" as long as the disk is dedicated to FreeBSD. Since I accepted all of the defaults, I assume that this is what was set up.
I have run lots of tests. Can someone who understands this tell me what information I might post, or what I might try, or tell me "Clearly this will never work because xyz" ?
Thanks.
I have tried the following permutations of BIOS settings and Geometry:
AUTO (Disk Config) and LBA
USER (Disk Config) and LBA with 3148 16 63 (I changed to a 1.6G disk)
USER (Disk Config) and LBA with 787 64 63
AUTO (Disk Config) and NORMAL
With AUTO, 3148 16 63 was offered and accepted in the PFSense "Select Geometry" dialog in both cases.
I always put the same geometry in the BIOS and the PFSense "Select Geometry" dialog.
For each of these four permutations, I tried the default Boot Boot configuration (No Packet, no Grub), with "Packet", and with "Grub"
In all cases the Default Boot configuration and the Packet install fine then fail on boot as described previously with the one second Beep every 10 seconds.
In all cases the Grub configuration failed installation, saying "Cannot mount selected partition".