and assume that the BIOS has set it up for us. This allows folks with a
serial-aware BIOS to set the BIOS to speeds above 9600 and allow boot0 to
just use the existing settings.
- Purge some gratuitous cpp comments as per style(9).
Submitted by: Danny Braniss danny at cs dot huji dot ac dot il (1)
MFC after: 1 month
boot0sio.s was repo-copied to boot0.S.
- Rename boot0ext.s to boot0ext.S, to stay consistent
with other preprocessed asm files around here, and
for better portability.
Repocopied by: joe
Merge boot0.s and boot0sio.s into boot0_512.s controlled by "#ifdef SIO".
Add Makefile magic to generate boot0.s and boot0sio.s from boot0_512.s.
The compile boot0 and boot0sio have unchanged MD5 checksums.
- Now that bsd.prog.mk deals with programs linked with -nostdlib
better, and has a notion of an "internal" program, use PROG
where possible. This has a good impact on the contents of
.depend files and causes programs to be linked with cc(1).
XXX: boot2 couldn't be converted as it's actually two programs.
Tested on: i386, amd64
- do not use PROG for what's not a real C program,
- use sys.mk transformation rules where possible,
- only create the "machine" symlink on AMD64,
- removed MAINTAINER lines in individual makefiles,
- added the LIBSTAND defitinion to <bsd.libnames.mk>,
- somewhat better contents in .depend files.
Tested on: i386, amd64
Prodded by: bde
under way to move the remnants of the a.out toolchain to ports. As the
comment in src/Makefile said, this stuff is deprecated and one should not
expect this to remain beyond 4.0-REL. It has already lasted WAY beyond
that.
Notable exceptions:
gcc - I have not touched the a.out generation stuff there.
ldd/ldconfig - still have some code to interface with a.out rtld.
old as/ld/etc - I have not removed these yet, pending their move to ports.
some includes - necessary for ldd/ldconfig for now.
Tested on: i386 (extensively), alpha
backing out the 1024 sector boot0, but revision 1.12 had nothing to do with
that. Instead, it documented various compile time options for boot0 and
allowed them to be overridden via make.conf or options on the make
command line.
Taking over the sector following the MBR causes problems on some
machines, and the actual gains are fairly small in terms of how
the space is presently used.
Since we need a number of further features (eg. handling extended
partitions) that can't be readily accommodated in the basic boot0
design anyway, rather choose to implement the additional stuff
separately and concentrate on compatibility rather than features
here.
to 0x600 via a 'rep movsw'. Once that was done, %cx was zero, so we could
simply use 'movb' to update the lower byte of %cx in preparation for
zeroing out the fake partition entry used to boot to other drives via F5.
Well, in the new boot0, we don't actually relocate ourselves, instead it
is easier to create the fake partition entry first and then just use it to
get the BIOS to load all of boot0 into memory at 0x600. However, since we
aren't doing the relocate code anymore, we don't know that %cx == 0 when
we hit the 'movb' to setup %cx for clearning the fake partition entry.
Thus, if %ch != 0 when the BIOS started boot0, then it would end up zeroing
a lot more memory than just 8 words. The solution is to do a word move of
$8 into %cx.
Debugging help from: David Wolfskill <dhw@whistle.com>
- Autodetection and support of the BIOS EDD extensions to work around the
1024 cylinder limit on all but really ancient BIOS's.
- To work around some BIOS's which break when EDD is used with older drives,
we only attempt to use EDD if the cylinder is > 1023.
- Since this new code required more space than we had left, expand boot0 to
2 sectors (1024 bytes) in length.
- Add support for boot0 being multiple sectors using predefined constants.
If boot0 needs to be extended in the future, all that is required is
bumping the NUM_SECTORS constant.
- Now that we have more room to work with, add a few more fs type
descriptions while making others more verbose.
with the new binutils. Now that we have a decent assembler, all the old
m4 macros are no longer needed. Instead, straight assembly can be used
since as(1) now understands 16-bit addressing, branches, etc. Also,
several bugs have been fixed in as(1), allowing boot0.s to be further
cleaned up.
code instead of using 32-bit code and having to just "know" that it's
really 16-bit instructions when things run. This also allows the code
to use fewer macros and more actual assembly statements, which eases
maintenance. Unfortunately, due to as(1) brokenness, we still use m4
macros for all 16-bit addresses, and all short jumps (i.e., 8-bit
relative addresses in the jump instruction) must be wrapped in .code32
directives to avoid useless bloat by as(1). This also fixes a few
problems that were preventing boot0 from compiling with the latest
and greatest version of as(1).
