We plan to increase the default serial rate to 115200 (see review
D36295) but early boot components that use BIOS interfaces do not
support higher rates. Add a note to that effect.
Reported by: imp
Sponsored by: The FreeBSD Foundation
This shouldn't be an option (and I added it in the first place back in
4ae4202e70 and
83f4b92050). However, unlike the other
knobs I added back then, this really shouldn't be a knob since it is
hardcoded in the source.
This really shouldn't even be an option given it is hardcoded as a
constant named ORIGIN in the assembly. mbr.S also uses 0x600 and
hardcodes it in both the assembly and the Makefile.
And thus has a limited range of supported baud rates. Also add that
setting BOOT_BOOT0_COMCONSOLE_SPEED=0 will leave it unchanged which
sometimes can give you 115200 if the BIOS initialized things outside of
the normal BIOS baud rates (which many x86 enbedded-targetted boards
do).
Sponsored by: Netflix
Reviewed by: emaste, manu (earlier versions)
Suggestions by: jhb
Differential Revision: https://reviews.freebsd.org/D36300
MK_CTF, MK_SSP, MK_PROFILE, NO_PIC, and INTERNALLIB are always the
same, so set them in defs.mk. MAN= is common, so set it here too.
This removes a lot of boring repetition from the Makefiles that added
almost no value.