stand/lua: always allow overriding with local config files

Loader now also read configuration files listed in local_loader_conf_files.
Files listed here are the last ones read. And /boot/loader.conf.local was
moved from loader_conf_files to local_loader_conf_files leaving only
loader.conf and device.hints in loader_conf_files by default.

The idea is to ensure local_loader_conf_files, i.e., /boot/loader.conf.local,
can always be used to override other user defined settings.

So the sequencing is now as follow:

1. Bootstrap:
/boot/defaults/loader.conf

2. Read loader_conf_files files:
/boot/device.hints
/boot/loader.conf

3. Read loader_conf_dirs files:
/boot/loader.conf.d/*.conf

4. And finally, rread local_loader_conf_files files:
/boot/loader.conf.local

Reviewed by: imp, kevans
Pull Request: https://github.com/freebsd/freebsd-src/pull/759

stand/lua: per-product conf if requested via product_vars

If product_vars is set, it must be a space separated list of environment
variable names to walk through to guess the product. Each time a product can be
guessed (i.e., the corresponding variable is defined), prepend
/boot/loader.conf.d/PRODUCT/ to loader_conf_dirs.

It can be typically used as follow:

smbios.system.planar.maker="PLANAR_MAKER"
smbios.system.planar.product="PLANAR_PRODUCT"
smbios.system.product="PRODUCT"
uboot.m_product="M_PRODUCT"
product_vars="smbios.system.planar.maker smbios.system.planar.product smbios.system.product uboot.m_product"

to read files found in the following directories, in that order:

/boot/loader.conf.d/PLANAR_MAKER
/boot/loader.conf.d/PLANAR_PRODUCT
/boot/loader.conf.d/PRODUCT
/boot/loader.conf.d/M_PRODUCT

Reviewed by: imp, kevans
Pull Request: https://github.com/freebsd/freebsd-src/pull/759

Revert "stand/lua: per-product conf if requested via product_vars"

This reverts commit 754cac4b283eb024a3a6a194130199c860e32ebf. No mail
went out and commit message was wrong.

Sponsored by: Netflix

Revert "stand/lua: always allow overriding with local config files"

This reverts commit d3d0b735571d9562812ce5b343a6e91f7a795dbe. no mail
sent out, and the commit message was wrong.

Sponsored by: Netflix

stand/lua: always allow overriding with local config files

Loader now also read configuration files listed in local_loader_conf_files.
Files listed here are the last ones read. And /boot/loader.conf.local was
moved from loader_conf_files to local_loader_conf_files leaving only
loader.conf and device.hints in loader_conf_files by default.

The idea is to ensure local_loader_conf_files, i.e., /boot/loader.conf.local,
can always be used to override other user defined settings.

So the sequencing is now as follow:

1. Bootstrap:
/boot/defaults/loader.conf

2. Read loader_conf_files files:
/boot/device.hints
/boot/loader.conf

3. Read loader_conf_dirs files:
/boot/loader.conf.d/*.conf

4. And finally, rread local_loader_conf_files files:
/boot/loader.conf.local

stand/lua: per-product conf if requested via product_vars

If product_vars is set, it must be a space separated list of environment
variable names to walk through to guess the product. Each time a product can be
guessed (i.e., the corresponding variable is defined), prepend
/boot/loader.conf.d/PRODUCT/ to loader_conf_dirs.

It can be typically used as follow:

smbios.system.planar.maker="PLANAR_MAKER"
smbios.system.planar.product="PLANAR_PRODUCT"
smbios.system.product="PRODUCT"
uboot.m_product="M_PRODUCT"
product_vars="smbios.system.planar.maker smbios.system.planar.product smbios.system.product uboot.m_product"

to read files found in the following directories, in that order:

/boot/loader.conf.d/PLANAR_MAKER
/boot/loader.conf.d/PLANAR_PRODUCT
/boot/loader.conf.d/PRODUCT
/boot/loader.conf.d/M_PRODUCT

stand: Add 1440p to the list of known resolutions.

MFC after: 1 week
Reviewed by: manu, kevans, imp
Differential Revision: https://reviews.freebsd.org/D43391

Add kenv .Xr in kldload(8) and loader.conf(5)

Sponsored by: Netflix

Use 115200 bps by default for serial communication

9600 was a standard baud rate decades ago, but 115200 is now more common
so choose defaults that are useful to the largest number of users.

Note that boot0sio does not support rates above 9600 so it remains
unchanged.

Reviewed by: bz, imp, manu
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36295

Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

lualoader: add support for .lua configuration files

If a file is specified in loader_conf_files that ends in '.lua', lualoader
will now load and execute that file. These may be used in place of a
traditional loader.conf to use more complicated logic, where some values
may be set based on others or based on the environment that the C bits has
left us with.

Lua scripts are run in a limited environment. In particular, it does not get
access to any modules or, in-fact, anything except environment variable.

A config.buildenv hook has been added so that a local module can add
whatever it may need to to the environment.

When a global var is set in the lua script, it does not immediately alter
the loader environment. Instead, the script's environment is initially
empty and processed only if the whole script executes successfully.
Effectively, a lua configuration file either takes effect or it does not,
an error will not leave it in a half-baked state.

Reviewed by: bcr (manpages), imp
Differential Revision: https://reviews.freebsd.org/D28450

loader.conf(5): mention "efi" option for "console" parameter

PR: 213467
Reviewed by: imp
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D31368

loader: update autoboot description and move to loader.conf.5

Document "NO" special value for the autoboot_delay and move the
description to loader.conf.5.

imp reworked some of the wording from danger's patch.

Reviewed by: imp
PR: 85128
Differential Revision: https://reviews.freebsd.org/D11887

Fix date

It's 2021 already.

Reported by: delphij

Fix a couple of typos and formatting issues

loader: instead of hw.vga.textmode, use screen.textmode

hw.vga.textmode is directing VT VGA backend to use text mode.

The default screen mode for BIOS loader is text, and default
screen mode for VT VGA backend is graphics (unless we are running on
hypervisor or hw.vga.textmode is set to 1). Using hw.vga.textmode
for loader does remove possibility to have graphical mode VT VGA with
text mode loader.

screen.textmode can have possible values "0" to disable text mode,
and "1" to set text mode.

loader: implement framebuffer console

Draw console on efi.
Add vbe framebuffer for BIOS loader (vbe off, vbe on, vbe list,
vbe set xxx).
autoload font (/boot/fonts) based on resolution and font size.
Add command loadfont (set font by file) and
variable screen.font (set font by size). Pass loaded font to kernel.

Export variables:
screen.height
screen.width
screen.depth

Add gfx primitives to draw the screen and put png image on the screen.
Rework menu draw to iterate list of consoles to enamble device specific
output.

Probably something else I forgot...

Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D27420

lualoader: add loader_conf_dirs support (loader.conf.d)

loader_conf_dirs is the supporting mechanism for the included
/boot/loader.conf.d directory. When lualoader finishes processing all of
the loader_conf_files it finds after walking /boot/defaults/loader.conf,
it will now check any and all loader_conf_dirs and process files ending
in ".conf" as if they were a loader.conf.

Note that loader_conf_files may be specified in a loader.conf.d config
file, but loader_conf_dirs may *not*. It will only be processed as specified
in /boot/defaults/loader.conf and any loader_conf_files that were loaded
from there.

Reviewed by: allanjude, freqlabs, rpokala, tsoome
Includes suggestion from: imp
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D25608

Fix a few mandoc issues

- whitespace at end of input line
- skipping paragraph macro: Pp at the end of Sh
- new sentence, new line
- consider using OS macro: Fx
- AUTHORS section without An macro
- skipping paragraph macro: Pp before Ss

loader.conf(5): document that loader_conf_files may be clobbered

A future change in lualoader may take some liberties with the
loader_conf_files in the name of efficiency; namely, it may start omitting
it from the loader environment entirely so that it doesn't need to worry
about maintaining any specific value.

This variable has historically been incredibly volatile anyways, as it may
get set to completely different values in any given configuration file to
trigger a load of more files.

Document now that we may not maintain it in the future, but perhaps we'll
reserve the right to change our minds and eventually formally export all of
the loader configuration files that were read using this variable.

MFC after: 3 days

Fix a minor typo in loader.conf(5).

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

lualoader: Create a module blacklist, add DRM modules to it

This is a step in the process of easing migration into the new world order
of DRM drivers. Strongly encourage users towards loading DRM modules via
rc.conf(5) instead of loader.conf(5) by failing the load from loader(8).
Users so inclined may wipe out the blacklist via module_blacklist="" in
loader.conf(5), and it is expected that these modules will eventually be
removed from the blacklist. They may still be loaded as dependencies of
other modules or explicitly via the loader prompt, but this should not be a
major problem.

Approved by: re (rgrimes)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D16914

Document the cpu_microcode_* tunables.

Reviewed by: bcr (previous version), kib
Approved by: re (gjb)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16923

loader.conf(5): Convert list of values to much better looking table format

Discussed with: jhb, rpokala

loader.conf(5): Document efi_max_resolution

Amend missed reference to /boot/overlays, moved to /boot/dtb/overlays

loader.conf: remove obsolete non-x86 beastie menu statement

As of r330005 the same loader.conf defaults are used on all platforms.

Sponsored by: The FreeBSD Foundation

loader.conf(5): Document some other settings

These tend to have less coverage in other places and they don't have
defaults as of yet, so mention them here:
- fdt_overlays
- kernels_autodetect (lualoader only)

loader.conf is loader agnostic, so remove 4th references.

Go back to one loader.conf

We really only need one loader.conf. The other loader.conf was created
because the current one took forever to parse in FORTH. That will be
fixed in the next commit.