[base16] Generalise base16_decode() to hex_decode()
Provide a generic hex_decode() routine which can be shared between the
Base16 code and the "hex" and "hexhyp" settings parsers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Don't implement strtoul() on top of strtoull() as strtoull() is much
bigger and only used on linux currently. Instead refactor most of the
logic out of strtoul() into static inlines and reuse that. Also put it
in a separate object so it won't get linked in.
Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>