fat16 has a 2 gigabtye partition size limit

The original BIOS used on the PC could access hard disk drives only up to 7.84 GB

ATA interface uses a 28-bit variable to address sectors under LBA mode, creating a 128 GB
(or 137 GB if you use the wrong definition of gigabyte) limit (2^28 x 512 bytes).

check

/mnt/f/CODE                      2011 era

/mnt/e/downloads/award-bios/     1999 era

/mnt/e/downloads/bios-8088       1987 era

/mnt/f/masm

MASM611 to assemble award-bios
some parts are Masm 5.10 DMIFUNC.ASM
Intel/i810

check *.BIN files

PPPBIOS.PDF for pentium pro bios guidelines

coreboot.rom 256k build for gigabyte