libsa: Remove redundant sys/cdefs.h

Sponsored by: Netflix

loader: Make MK_LOADER_BIOS_TEXTONLY work

Select between text-only and graphical frame buffer consoles for the
BIOS boot loader. Pull one or the other in with #ifdef in conf.c. Add
gfx_bios.c for the few routines that are needed for the BIOS support of
gfx. These are stubbed out for text-only mode. Move bi_load_vbe_data
here since it's only used for the graphical frame buffer.

Note: This setup also allows us to build multiple BIOS loaders if we
have to, some with text-only and some graphical. We don't do this today.
We may be forced to turn this on in the future if ZFS keeps growing.

The size savings is 41k, which helps a lot with some of our users that
want to enable more options in the BIOS boot loader than are normally
safe to do, and they don't need graphics.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D43917

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

stand: Remove i386-only support fire firewire

Remove support for booting off of firewire, and for having dcons via
firewire in the loader. Kernel support for these things is unchanged.
Discussed on arch@ and the current state is not working (and the build
was wrong to boot).

Sponsored by: Netflix
Discussed: https://lists.freebsd.org/archives/freebsd-arch/2022-November/000267.html
Reviewed by: kevans, melifaro, emaste
Differential Revision: https://reviews.freebsd.org/D37334

stand: s/libstand/libsa/g to catch up with rename

We renamed libstand to libsa years ago with the move from sys/boot to
stand. Catch up in the comments.

Sponsored by: Netflix

Remove NAND and NANDFS support

NANDFS has been broken for years. Remove it. The NAND drivers that
remain are for ancient parts that are no longer relevant. They are
polled, have terrible performance and just for ancient arm
hardware. NAND parts have evolved significantly from this early work
and little to none of it would be relevant should someone need to
update to support raw nand. This code has been off by default for
years and has violated the vnode protocol leading to panics since it
was committed.

Numerous posts to arch@ and other locations have found no actual users
for this software.

Relnotes: Yes
No Objection From: arch@
Differential Revision: https://reviews.freebsd.org/D20745

loader: implement map-vdisk and unmap-vdisk commands

illumos update: https://www.illumos.org/issues/10598

Add map-vdisk and unmap-vdisk commands to create virtual disk interface on top of file. This will allow to use disk image from file system to load and start the kernel.

By mapping file, we create vdiskX device, the device will be listed by lsdev [-v] and can be accessed directly as ls vdisk0p1:/path or can be used as value for currdev variable.

vdisk strategy function does not use bcache as we have bcache used with backing file. vdisk can be unmapped when all consumers have closed the open files.

In first iteration we do not support the zfs images because zfs pools do keep the device open (there is no "zpool export" mechanism). Adding zfs support is relatively simple, we just need to run zfs disk probe after mapping is done.

Differential Revision: https://reviews.freebsd.org/D19733

loader: create separate lists for fd, cd and hd, merge bioscd with biosdisk

Create unified block IO implementation in BIOS version, like it is done in UEFI
side. Implement fd, disk and cd device lists, this will split floppy devices
from disks and will allow us to have consistent, predictable device naming
(modulo BIOS issues).

Differential Revision: https://reviews.freebsd.org/D17888

Stop using ../zfs/libzfs.h but instead use libzfs.h.

While ../zfs/libzfs.h mostly works, there are a few situations where
it does not. Eliminate the problem by using plain libzfs.h, like we do
for ufs support. This fixes the weird cases, and is easier to
understand. It also follows the general style convetion of avoiding
../ in #includes.

Honor settings for including / excluding cd9660, ufs, ext2fs and msdos.

The Makefile gives the impression that ext2fs and msdos were excluded
(they weren't) and that you could exclude cd9660 and ufs support (you
couldn't). Allow those to be excluded.

We need to look, in the future, at trimming the number of supported
filesystems, and this will make that easier.

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

Sponsored by: Netflix