MFC Loader Fixes Final: r327612,r327703,r327704,r327878,r327879,r327881,
r328007,r328029,r328030,r328031,r328061,r328156,r328169,r328288,r328289,
r328290,r328291,r328292,r328411,r328536,r328603,r328614,r328642,r328769,
r328779,r328780,r328781,r328782,r328783,r328806,r328808,r328826,r328835,
r328911,r328986,r328987,r328990,r328999,r329000,r329019,r329050,r329054,
r329060

r327612: Invent new #defines for the biospci_{read,write}_config function

r327703: Define __dmadat after #include'ing ufsread.c.

r327704: Fix printf missing format variables warnings.

r327878: Add GUID for UEFI boot manager variables.

r327879: Report the boot order and where we are in that boot order.

r327881: Allow this file to be included

r328007: Fix booting on some arm64 systems after r327879 by fixing the call
to utf8_to_ucs2

r328029: When returning an error and freeing allocated memory from
ucs2_to_utf8, NULL the return pointer.

r328030: Check the return value from utf8_to_ucs2 instead of whether or not
uv is NULL.

r328031: Need to free uv after we're done using it.

r328061: utf8_to_ucs2() should check for malloc failure

r328156: stand: Move sections around to fix stand/ build with ld.lld on
armv7

r328169: Remove extra copy of bootinfo.c. It's a bit rotted copy of the one
in efi/loader.

r328288: Fix some resource leaks.

r328289: Don't leak memory when displaying help.

r328290: On malloc failure, be sure to close the include file that triggered
it.

r328291: getenv does not return tainted data in the boot loader. Attempt to
clue Coverity into that fact.

r328292: There's no tainted data here, tag it as such to avoid false
positives.

r328411: loader.efi: add missing EFI GUIDs

r328536: loader: support for mixed-endianness ELF/loader and POWER8

r328603: Add missing non-POWERPC case to give the scr value something
non-zero.

r328614: Move libstand.3 to libsa.3. Update libsa.3 to include functions

r328642: Break out the interpreters (simple and forth) w/o ifdefs.

r328769: Centralize several variables.

r328779: Retire pnp.4th and the code needed only for 4th words used here.

r328780: These 4th words were an attempt to allow integration into the boot
loader scripts. However, that path won't be taken after all it
seems.

r328781: Remove pcibios forth support.

r328782: Now that we no longer conditionally compile some files outside of
ficl

r328783: Invent new LDR_INTERP for the loader interpreter to use.

r328806: We need more heap space to properly load newer powerpc kernels.

r328808: Implement strcoll as strcmp.

r328826: Make cross-endian loader changes apply only to powerpc

r328835: Fix regression introduced in r328806, preventing boot on many
platforms.

r328911: Ignore relocation tables for non-memory-resident sections.

r328986: Fix relative location of USB sources after recent move.

r328987: A more definitions to kernel emulation shim in order to build
stand/usb.

r328990: Move the stand/usb test loader into its own directory.

r328999: Fix indentation to FreeBSD standard for interp files

r329000: Move simple interpreter 'perform' into interp.c and call it

r329019: Move to tabs for indentation and to 8-space notches, per style(9).

r329050: Fix build of userboot.so

r329054: Set script.lang in the environment to either 'forth' or 'simple' to
reflect what scripting language was compiled into the loader.

r329060: loader: fix endianness conversion

PR: 225323

MFC r325834,r325997,326502: Move sys/boot to stand/

This is effectively a direct commit to stable/11, due to differences between
stable/11 and head. Changes to DTS in sys/boot/fdt/dts were often
accompanied by kernel changes. Many of these were also risc-v updates that
likely had many more dependencies to MFC.

Because of this, sys/boot/fdt/dts remains as-is while everything else in
sys/boot relocates to stand/.

r325834: Move sys/boot to stand. Fix all references to new location

r325997: Remove empty directories.

r326502: Document the sys/boot -> stand move in hier.7 and the top-level README.

MFC Loader Fixes 2017q4p6: r324649,r324650,r324651,r324652,r324653,r324654,
r324700,r324702,r324709,r324717,r324719,r324841,r324842,r324843,r324845,
r324850,r324876,r324877,r324878,r324879,r324880,r324881,r324883,r324980,
r324981,r324982,r324995,r325014,r325093,r325094,r325114,r325170,r325171,
r325172,r325173,r325174,r325175,r325176,r325248,r325286,r325310,r325332,
r325338,r325339,r325376,r325377,r325379,r325380,r325382,r325478,r325479,
r325480,r325482,r325483,r325484,r325485,r325556,r325641,r325681,r325685,
r325686,r325687,r325688,r325689,r325690,r325691,r325692,r325693,r325694,
r325743,r325744,r325748,r325775,r325779,r325780

r324649: Move common/Makefile.inc to sys/boot/loader.mk.

r324650: tweak style

r324651: create defs.mk for common definitions

r324652: Move all the ficl common code into ficl.mk

r324653: LOADER_foo_SUPPORTED

r324654: Explicitly inlcude SYSDIR in the include path

r324700: loader: initialize dv_cleanup in md.c to eliminate clang warning

r324702: We need to include disk.o in libuboot.a when we're building with
support for disk access.

r324709: Revert "Unify boot1 with loader" change r324646

r324717: libsa/ip.c: misplaced comment, ip_v is half char, not ip_p

r324719: libsa/ip: stop read loop on bad fragments

r324841: Use BOOTDIR more consistently in defs.mk rather than repeat
sys/boot.

r324842: Introduce BOOTOBJ: The top level object directory for the boot tree

r324843: Stopgap fix to the mistmatch between LOADER_GELI_SUPPORT and
LOADER_NO_GELI_SUPPORT.

r324845: Use BOOTOBJ and BOOTDIR to find geli includes and libraries.

r324850: Define LIBSA32 to LIBSA on i386 to fix build.

r324876: Move fdt and uboot defines into common uboot.mk.

r324877: End source directories with SRC rather than a hodgepodge of names

r324878: Make at91 boot loader compile again.

r324879: Prefer SRCTOP paths for bits we're grabbing from libc.

r324880: Use BOOTSRC here.

r324881: Use SYSDIR instead of ${.CURDIR}/../..<etc>/sys.

r324883: Use preferred defined paths, rather than relative paths in fdt.

r324980: Use BOOTDIR consistently.

r324981: Move BINDIR definition to defs.mk, and override where it isn't
/boot

r324982: Remove sys/boot/arm/at91 and ixp425

r324995: loader.efi: Make framebuffer commands available for arm64

r325014: Add a 'place holder' arm struct efi_fb until a real one comes

r325093: Define new EFI variables

r325094: Cleanup non-arch Makefiles

r325114: Use defs.mk defins in most MD code

r325170: Use defs.mk values for userboot

r325171: Use defs.mk name and prefer bsd.init.mk

r325172: Remove the -nostdlib stuff I added. Instead, fix LDFLAGS to be
honored correctly with the new Makefile.inc include order.

r325173: We don't need to build a special ficl for userboot.

r325174: Minor cleanup

r325175: For amd64, compile both zfs and zfs32 libraries.

r325176: Actually add zfs32/Makefile

r325248: loader ptblread() is broken with >512B sectors

r325286: efipart_strategy is using wrong offset with >512B sectors

r325310: zfs.c:vdev_read() needs to be careful about large sectors

r325332: loader: re-enable gzip support for x86

r325338: loader: fix BOOTSRC -> BOOTOBJ in a library path

r325339: This used to have bzip2 support too.

r325376: WIP: centralize machine links

r325377: mostly libsa

r325379: Revert "mostly libsa"

r325380: Revert "WIP: centralize machine links"

r325382: Cleanup stray libstand names to be libsa names.

r325478: Powerpc is a 32-bit boot loader.

r325479: Define LIBFICL32 to be libficl.a on i386 and libficl32.a on amd64.

r325480: Use DO32 for all the places that we need to flag we're building a
32-bit version of a library.

r325482: Move machine and other link creation to defs.mk

r325483: MACHINE can never be powerpc64, so cleanup code that thinks it can.

r325484: Prefer bsd.init.mk to src.opts.mk

r325485: Centralize all 32-bit builds on 64-bit platform stuff.

r325556: loader: set options before including bsd.init.mk

r325641: loader.efi: efi_devpath_is_prefix should return bool

r325681: boot1: avoid using NULL device path

r325685: libsa32 isn't needed for i386. It's already a 32-bit platform.

r325686: Simplify this if to a direct assignment.

r325687: Remove all the empty help files from the powerpc build.

r325688: FDT support doesn't make sense for ps3, remove it.

r325689: Remove LOADER_FDT_SUPPORT as a Makefile variable.

r325690: Remove LOADER_ZFS_SUPPORT as a Makefile variable

r325691: Remove useless PNP define here.

r325692: Replace LOADER_FIREWIRE_SUPPORT variable

r325693: Move LOADER_{NO,}_GELI_SUPPORT to MK_LOADER_GELI

r325694: Install the 4th files in sys/boot/forth instead of each loader

r325743: Make sure the proper loader.rc gets installed.

r325744: boot1: also check for NULL device

r325748: Use proper include file.

r325775: Add loader.conf to the list of files that are MD.

r325779: Add /boot/dts to the list of default modules.

r325780: Don't add /boot/dt*s* but /boot/dt*b*. Stupid think-o.

MFC Loader Fixes 2017q2: r316437,r316577,r316578,r316585,r316590,r316612,
r316625,r316628,r316654,r316682,r316704,r316771,r317092,r317097,r317099,
r317652,r317785,r317886,r317887,r318142,r318320,r318356,r318678,r318754,
r318982,r318986,r318987,r318988,r318989,r318990,r318991,r318992,r318993,
r318994,r318999,r319083,r319084,r319085,r320011,r320234,r320288,r320304,
r320467,r320482

r316437: Small cleanup to make i386/loader match efi/loader boot environment
code

r316577: loader: part.c cstyle cleanup

r316578: loader: want mechanism to avoid RA with bcache

r316585: loader: zfs reader should check all labels

r316590: libstand/dosfs: cache FAT32 in 128 Kb blocks to save loader memory

r316612: In r298230 the value of HEAP_MIN was changed from 3MB to 64MB.
Correct a comment.

r316625: Do not use -msoft-float with intention of disabling FP on aarch64

r316628: Silence GCC warning by initializing the local variable.

r316654: loader: r316585 did miss userboot update

r316682: loader: r316585 did miss sparc/ofw

r316704: loader.efi: only fetch zfs pool guid for the actual boot device

r316771: loader: Avoid possible overflow via environment variable

r317092: loader: zfs reader vdev_probe should check for minimum device size

r317097: loader: F_READ/F_WRITE should be checked against masked flag

r317099: loader: uboot disk ioctl should call disk_ioctl

r317652: loader.efi: ResetSystem does not use data with EFI_SUCCESS

r317785: zfsboot: drvsize() may be unusable on some systems

r317886: distinguish NFS versus TFTP boot by rootpath

r317887: loader: network read rework

r318142: libstand: NULL pointer dereference in rarp

r318320: loader: add ip layer code into libstand

r318356: libstand: increase nfs max read size to 16k

r318678: Replacing iterating over rootpath by strsep(3).

r318754: Pass -N directly to ld via -Wl rather than passing it to the
compiler driver.

r318982: Pass a "FREEBSD" user-class in PXE dhcp request

r318986: add a comment on vendor index 19 and 20 to avoid confusion

r318987: Support URI scheme for root-path in netbooting

r318988: Always build tftpfs support along with nfs for pxeboot

r318989: Always issue the pxe request

r318990: Partially revert r314948

r318991: Document recent changes on pxeboot

r318992: Capitalize DHCP

r318993: Use the usual FreeBSD spelling for the DHCP user class

r318994: Catch with the change in the user class

r318999: Update the comments concerning net_parse_rootpath to reflect what
it is now

r319083: Followup on the user-class changes

r319084: Small cleanup in dev_net.c

r319085: use the same option list for dhcp discovery and request

r320011: Add chain loader support for loader

r320234: Make structure padding explicit in EFI_MEMORY_DESCRIPTOR

r320288: Allow Clang's integrated assembler to assemble boot0

r320304: loader.efi: Disable smbios for arm

r320467: loader: chain load relocate data declaration is bad

r320482: As with arm64 mark the EFI PE header as allocated on arm.

PR: 218473

MFC r303555,r303556,r303936,r303962,r304317,r304532,r305026,r305107,r305132,
r305178,r305353,r305814,r306159,r306380,r306504: Loader fixes, 2016q3

r303555: bcache should support reads shorter than sector size

r303556: Improve boot loader quote parsing

r303936: Add kernel environment variables under smbios.system

r303962: Add the missing space between .asciz directive and opening quote
for some lines with #ifdef BTXLDR_VERBOSE/#endif

r304317: boot1.efi Free() should check for NULL to provide consistent
behavior

r304532: Replace sprintf -> snprintf for command_errbuf provisioned from
dynamic content.

r305026: Emulate efi_cons_poll when WaitForKey is not available

r305107: Create a hook 'post-initialize' for people that want to define
something to read in .conf files after all other .conf files for the purpose
of overriding.

r305132: Remove accidentally committed stray comment.

r305178: bd_int13probe() should check extended info if sector info is bad

r305353: Don't use -N to set the OMAGIC with data and text writeable and
data not page aligned.

r305814: ufsread: Do not cast struct direct from void *

r306159: Consistently declare getsecs(void) with proper return type and void
when no arguments are present.

r306380: loader command interpreter should reset command_errmsg

r306504: Fix a cluster of bugs in list EFI environment variables

PR: 204602, 211958, 211958
Relnotes: yes ("Improve boot loader quote parsing")

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Implement (ACFLAGS|CFLAGS|CXXFLAGS).SRC globally.

Sponsored by: EMC / Isilon Storage Division

Remove disconnected boot0ext.

This was [re-]added in r127458 (apparently with disconnected history as well)
and never connected to the build.

It is no longer relevant for modern systems from the past 20 years.

Discussed with: jhb
Sponsored by: EMC / Isilon Storage Division

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

Define several extra macros in bsd.sys.mk and sys/conf/kern.pre.mk, to
get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.

Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang (disables -Werror)
- NO_WCAST_ALIGN.clang (disables -Wcast-align)
- NO_WFORMAT.clang (disables -Wformat and friends)
- CLANG_NO_IAS (disables integrated assembler)
- CLANG_OPT_SMALL (adds flags for extra small size optimizations)

As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf! For clang, use the following:

CC=clang
CXX=clang++
CPP=clang-cpp

MFC after: 2 weeks

Upgrade our copy of llvm/clang to r126079, from upstream's trunk.

This contains many improvements, primarily better C++ support, an
integrated assembler for x86 and support for -pg.

Use -Wl,-N instead of the undocumented -N option for GCC.

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

A number of small changes to make the 'save choice to disk' safer,
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

Another, hopefully final set of changes to boot0 and boot0cfg.

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

This commits brings in a lot of documentation and some enhancement
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

Allow BOOT_BOOT0_COMCONSOLE_SPEED to be derived from BOOT_COMCONSOLE_SPEED
at compile time.

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

In conjunction with having boot0cfg(8) default boot0 to packet mode.

Submitted by: Tor.Egge@cvsup.no.freebsd.org

Thanks to David's patches, we can now simplify these makefiles
further, and just use PROG directly (without FILES).

Suggested by: bde

- Properly merge boot0sio.s and boot0.s into boot0.S.
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

Temporary precaution measure until repocopy requests are
processed: don't forget to clean generated .s sources.

Change from '#' to "//" comment character to allow CPP preprocessing.

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.

Use a more compact syntax for passing the "binary" options to 'ld'.

Simplify the building of our i386 'binary' boot components by directly
producing them using 'ld' options rather than post-processing with 'objcopy'.

Idea by: Ryan Sommers <ryans@gamersimpact.com>

- Factor out -nostdlib to an upper level Makefile.inc.

- 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

First round of cleanups to sys/boot/ makefiles:

- 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

Inherit BINDIR from a parent Makefile.inc.

Allow one to specify the com port settings for boot0sio.

Hook boot0sio to the build. Use 'boot0cfg -b /boot/boot0sio' to use.

Add a serial console capable version of the FreeBSD boot manager. This has
been lying around my tree(s) for the past year or so. It could do with TLC.

Requested by: obrien
Sponsored by: Weyland-Yutani Corporation

Initiate deorbit burn for the i386-only a.out related support. Moves are
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

Unrevert revision 1.12. Revision 1.14 backed this out saying it was
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.

Unset MAINTAINER.

Go back to occupying just a single sector, reverting r1.17 - r1.20.
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.

Set MAINTAINER.

Cleanup warnings. Most of these are signed/unsigned warnings, as well as
some added const's.

The new and improved boot0, v1.1. This version adds the following:
- 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.

Clean up all of the 16-bit assembly code in the x86 bootstrap to work
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.

$Id$ -> $FreeBSD$

Provide for enabling/disabling each slice individually.

Make configurable (a) whether to use int 0x13 extensions; (b) timeout
value. Ignore failure to update mbr sector. Disable interrupts while
using extended registers. Default to F1 not F2.

Set BINMODE to 444.

Don't use an absolute path to objcopy.
Noticed by: Scott Mace <smace@intt.org>

Get this building as a.out or ELF.

With thanks to: jdp

Install in /boot.

This commit was generated by cvs2svn to compensate for changes in r39973,
which included commits to RCS files with non-trunk default branches.

boot0 is a booteasy (boot manager) workalike with EDD support.