[LinuxBIOS] difference between uint16_t and u16

[matt]

i have noticed several patches signed off on the list that change data
types from uint16_t to u16 and the like (8 .. 32 bit signed and
unsigned) and was wondering why ?  i thought uint16_t was c99
standard ?  i asked the same thing on sdl's mailing list and was told
that not all compilers support it.  with sdl that seems right since its
a platform independent lib.  with linuxbios it seems that is not the
case, i assume most or all would be using gcc.

only reason i ask is that a standard header was added years ago and i
still see custom data types.  just trying to understand that better.

thanks

matt