GCC forwards the -N flag directly to ld. This flag is not documented and
not supported by (for example) Clang. Just use -Wl,-N.
Submitted by: Pawel Worach
and re-enable it as default.
In particular:
+ re-enable the 'update' flag in the Makefile (of course!);
+ commit Warner's patch "orb $NOUPDATE,_FLAGS(%bp)"
to avoid writing to disk in case of a timeout/default choice;
+ fix an off-by-one count in the partition scan code that would
print the wrong name for unknown partitions;
+ unconditionally change the boot prompt to 'Boot:' instead of 'Default:'
to make room for the extra code/checks/messages. Some of the changes
listed below are also made to save space;
+ rearrange and fix comments for known partition types. Right now we
explicitly recognise *BSD, Linux, FAT16 (type 6, used on many USB keys),
NTFS (type 7), FAT32 (type 11).
Depending on other options we also recognise Extended (type 5),
FAT12 (type 1) and FAT16 < 32MB (type 4).
+ Add an entry "F6 PXE" when the code is built with -DPXE (which is
a default now). Technically, F6 boots through INT18, so the prompt 'PXE'
is a bit misleading. Unfortunately the name INT18
is too long and does not fit in - we could use ROM perhaps.
The reason I picked 'PXE' is that on many (I believe) new systems
INT18 calls PXE.
Apart from the choice of the name for PXE/ROM/INT18, this should close
pending issues on the 1-sector boot0 code and we should be able to
move the code to RELENG_7 when it reopens.
No boot0cfg changes are necessary.
MFC after: 3 weeks
boot0.S changes:
+ import a patch from Christoph Mallon to rearrange the various
print functions and save another couple of bytes;
+ implement the suggestion in PR 70531 to enable booting from
any valid partition because even the extended partitions that
were previously in our kill list may contain a valid boot loader.
This simplifies the code and saves some bytes;
+ followwing up PR 127764, implement conditional code to preserve
the 'Volume ID' which might be used by other OS (NT, XP, Vista)
and is located at offset 0x1b8. This requires a relocation of the
parameter block within the boot sector -- there is no other
possible workaround.
To address this, boot0cfg has been updated to handle both
versions of the boot code;
+ slightly rearrange the strings printed in the menus to make
the code buildable with all options. Given the tight memory
budget, this means that with certain options we need to
shrink or remove certain labels.
and especially:
make -DVOLUME_LABEL -DPXE the default options.
This means that the newly built boot0 block will preserve the
Volume ID, and has the (hidden) option F6 to boot from INT18/PXE.
I think the extra functionality is well worth the change.
The most visible difference here is that the 'Default: ' string
now becomes 'Boot: ' (it can be reverted to the old value
but then we need to nuke 1/2 partition name or entries to
make up for the extra room).
boot0cfg changes:
+ modify the code to recognise the new boot0 structure (with the
relocated options block to make room for the Volume id).
+ add two options, '-i xxxx-xxxx' to set the volume ID, -e c
to modify the character printed in case of bad input
PR: 127764 70531
Submitted by: Christoph Mallon (portions)
MFC after: 4 weeks
of the boot0.S code, with a number of compile-time selectable options,
the most interesting one being the ability to select PXE booting.
The code is completely compatible with the previous one, and with
the boot0cfg program. Even the actual code is largely unmodified,
with only minor rearrangements or fixes to make room for the new
features.
The behaviour of the standard build differs from the previous
version in the following, minor things:
+ 'noupdate' is the default, which means the code does not
write back the selection to disk. You can enable the feature
at runtime with boot0cfg, or changing the flags in the Makefile.
+ a drive number of 0x00 (floppy, or USB in floppy emulation) is
now accepted as valid. Previously, it was overridden with 0x80,
meaning that the partition table coming from the media was
used to access sectors on a possibly different media.
You can revert to the previous mode building with -DCHECK_DRIVE,
and you can always use the 'setdrv' option in boot0cfg
+ certain FAT or NTFS partitions are listed as WIN instead of DOS.
+ the 'bel' character on a bad selection is replaced by a '#' to
make it clear that the system is not hang even if the machine
does not have a speaker. This can be reverted back at compile
time, or at runtime with an upcoming boot0cfg option.
Additional features are available as compile time options,
and may be become the default if deemed useful. In particular:
+ INT18/PXE boot (make -DPXE)
This option enables booting through INT 18h (which on certain
BIOSes can be hooked to PXE) by pressing F6. There is unfortunately
no room to print the additional menu option.
Also, to make room for the code, the 'Default: ' string is
changed to 'Boot: '
+ print current drive number (make -DTEST)
Prints a line indicating the current drive number.
This is useful to figure out what is going on for machines/bioses
which remap drives in sometimes surprising ways.
+ disable numeric keys in console mode (make -DONLY_F_KEYS)
Not really a significant option, but it is needed to make
room for the -DTEST mode.
+ disable floppy support (make -DCHECK_DRIVE)
Revert to the old behaviour of only accepting 0x80 and above
as valid drive numbers.
MFC after: 6 weeks
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.
- 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.
