Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC 261517,261520:
Convert the license on files where I am the sole copyright holder to
2 clause BSD licenses.

MFC r235281:

Fix sys/boot/i386/cdboot/cdboot.S compilation with clang after r235219.
This file uses .code16 directives, which are not yet supported by
clang's integrated assembler.

MFC r235219: cdboot, pxeldr: make use of bootargs.h instead of
redefining flag constants

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Remove duplicate "in".

Suggested by: Rob Farmer <rfarmer at predatorlabs.net>
MFC after: 3 days

Revert some of r177626. "in in" is valid in certain sentences.

PR: 121490
MFC after: 3 days

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

Fix some "in in" typos in comments.

PR: 121490
Submitted by: Anatoly Borodin <anatoly.borodin@gmail.com>
Approved by: rwatson (mentor), jkoshy
MFC after: 3 days

Add a trailing \0 to the read error string so that read errors don't print
out two error messages.

MFC after: 3 days

Fix the cdboot twiddle display.
I created and tested this with a custom FreeSBIE cd-image.

PR: i386/96452
Submitted by: Yuichiro Goto <y7goto at gmail dot com>
MFC after: 3 days
Approved by: imp (mentor)

Tweak comment.

Use the proper condition to determine that we matched an filename.
Otherwise, we could match on a filename that had the wrong last character
(such as /boot/loaded instead of /boot/loader).

PR: kern/95625
Submitted by: Oliver Fromme <olli@secnetix.de>
MFC after: 1 month

When enabling A20 put upper limit on amount of time we wait for the keyboard
controller to get ready (65K x ISA access time, visually around 1 second).
If we have wait more than that amount it's likely that the hardware is a
legacy-free one and simply doesn't have keyboard controller and doesn't
require enabling A20 at all.

This makes cdboot working for MacBook Pro with Boot Camp.

MFC after: 1 day

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

Update the copyright to use a 3 clause BSD license rather than one that
is less clear about allowing redistribution of modified copies.

Requested by: Tom Cosgrove tom dot cosgrove at arches-consulting dot com

Remove a bogus increment of %di when scanning the list of loader paths.
%di will already point to the character after the nul char when the
'repnz scasb' terminates.

Submitted by: Tom Cosgrove tom dot cosgrove at arches-consulting dot com

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

Suggested by: bde

Removed now redundant CLEANFILES assignments.

Not read enough of my patch by: obrien ;)

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.

- Use constant for shift when converting file length in bytes to a sector
count.
- Fix the twiddle output so that it actually spins.
- Save %cx around BIOS calls to read in sectors from the disc as at least
one BIOS trashes %cx when called to read off of a USB CD-ROM drive.

Submitted by: Martin Nilsson <martin@gneto.com>
MFC after: 1 week

- Change the lookup() function to report success or failure using the carry
flag rather than explicitly halting if a lookup failed.
- Add a loop around the call to lookup() to traverse an array of
nul-terminated strings for possible paths to the boot loader. A double
nul character denotes the end of the list.
- Add a new message to say that the boot failed if all of the path lookups
for a boot loader file failed.
- Add '/boot/loader' as a second boot path. If you build an ISO using
risky options to mkisofs such as -U then the loader will be called
'/boot/loader' rather than '/BOOT/LOADER;0'. This allows cdboot to work
with such risky ISO images.
- Bump version to 1.2 to denote added functionality.

The basic idea as well as some of the code were provided by the submitter,
but I added some extra code to use a loop rather than hard-code just 2
possible paths.

PR: misc/43543
Submitted by: kientzle
MFC after: 1 week

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

Remove a few more debugging bits and turn on twiddle output while reading
from the CD. This turns off the dual console output to COM1.

Trim all the extra debugging output including hexdumps, debug messages,
etc. The only bit of debugging left is performing dual output to both
the screen and COM1. Also, the twiddle is still disabled since it seems
to do weird things to the serial dump. cdboot now has 880 bytes to spare.

This is a new CD bootstrap utility designed to replace cdldr. According
to the El Torito standard for CD booting, a CD may boot in "No emulation"
mode without using a floppy image. In this mode, the BIOS loads a program
off of the CD into memory and creates a BIOS device using 2048 byte sectors
for the CD. According to the standard, this program can be up to 0xFFFF
virtual (512-byte) sectors long. The old cdldr depended on this by having
the BIOS load the entire loader and the small cdldr stub as one binary
similar to pxeboot so that cdldr didn't have to read the CD to find the
loader. However, the NT no emulation loader just uses 1 disk sector
(4 virtual sectors), so it seems that at least some BIOS writers just did
enough to get NT to boot by only loading 1 sector and ignoring the sector
count. Thus, while cdldr should have worked in theory, it doesn't in
practice. This replacment fits entirely in 1 sector and includes simple
ISO 9660 support. It looks for /boot/loader on the CD and loads it up
using the BIOS. This allows us to not have to depend on the limited size
of floppy images but use a full GENERIC kernel for CD-ROM installs in the
future, among other things.

This version of cdboot is a bit bloated as it includes some useful
debugging routines that people can pull to use in other x86 assembly
modules. Even with all the debugging cruft, we still have 272 bytes to
spare.

Allow for text section alignment to properly align the "end" symbol at the
actual end of the section. The new gas (binutils) puts in additional padding
which was misaligning the concatenated btx loader.

Reported by: Oliver Hartmann <ohartman@klima.physik.uni-mainz.de>,
Harti Brandt <brandt@fokus.gmd.de>
Tested by: Oliver Hartmann <ohartman@klima.physik.uni-mainz.de>,
David Wolfskill <dhw@whistle.com>, ps
Reviewed by: jhb
MFC after: 1 day

Trim trailing whitespace.

Grrr, fix a silly 'movl' -> 'movw' typo in both pxeldr and cdldr. Also,
remove unnecessary cruft from the Makefiles for both.

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.

Mega i386 loader commit.
- Don't hard code 0x10000 as the entry point for the loader. Instead add
src/sys/boot/i386/Makefile.inc which defines a make variable with the
entry point for the loader. Move the loader's entry point up to
0x20000, which makes PXE happy.
- Don't try to use cpp to parse btxldr for the optional BTXLDR_VERBOSE,
instead use m4 to achieve this. Also, add a BTXLDR_VERBOSE knob in the
btxldr Makefile to turn this option on.
- Redo parts of cdldr's Makefile so that it now builds and installs cdboot
instead of having i386/loader/Makefile do that. Also, add in some more
variables to make the pxeldr Makefile almost identical and thus to ease
maintainability.
- Teach cdldr about the a.out format. Cdldr now parsers the a.out header
of the loader binary and relocates it based on that. The entry point of
the loader no longer has to be hardcoded into cdldr. Also, the boot
info table from mkisofs is no longer required to get a useful cdboot.
- Update the lsdev function for BIOS disks to parse other file systems
(such as DOS FAT) that we currently support. This is still buggy as
it assumes that a floppy with a DOS boot sector actually has a MBR and
parses it as such. I'll be fixing this in the future.
- The biggie: Add in support for booting off of PXE-enabled network
adapters. Currently, we use the TFTP API provided by the PXE BIOS.
Eventually we will switch to using the low-level NIC driver thus
allowing both TFTP and NFS to be used, but for now it's just TFTP.

Submitted by: ps, alfred
Testing by: Benno Rice <benno@netizen.com.au>

Add the new cdldr CD bootstrap loader. This patch includes the following:

- Fix btxldr to preserve a NULL bootinfo pointer when it copies the kernel
arguments.
- Add the cdldr bootstrap program. This program is tacked onto the
beginning of the standard 3rd stage boot loader (/boot/loader) to form
the CD boot loader (/boot/cdboot). When a CD is booted, the cdboot file
is copied into memory instead and executed. The cdldr stub emulates the
environment normally provided by boot2 and then starts the loader. This
booting method does not emulate a floppy drive, but boots directly off of
the CD. This should fix the problems some BIOS's have with emulating a
2.88 MB floppy image.
- Add support to the loader to recognize that it has been booted by cdldr
instead of boot2 and use a simpler method of extracting the BIOS boot
device.