Felix Held has posted comments on this change. ( https://review.coreboot.org/17669 )
Change subject: superio/fintek: Add support for Fintek F71889A. ......................................................................
Patch Set 9:
or for that matter, why 0x07ff signifies one byte
the leftmost '1' bit says what the highest address is that can be assigned to a peripheral in the io space. the number of zeros from the right side says how much bytes are needed to be allocated for the peripheral; the zeros on the right are basically the address mask, that masks the 2^n bytes being reserved with N being the number of zeros.
Maybe have a look at the function pnp_get_ioresource in pnp_device.c and/or diagram in f71869ad/superio.c