efibootmgr: Document -e command line switch

-e env will include `env` in the boot loader. Document that the boot
loader appends the `env` to the BootXXXX variable, and will parse it as
a series of a=b values to set in the boot loader's environment. These
assignments are separated by spaces. The env arg needs to be quoted if
more than one env var is to be set (we parse only the next argument on
the command line).

Sponsored by: Netflix

efibootmgr: support '-b bootXXXX' as an alias for '-b XXXX'

Sponsored by: Netflix

Remove $FreeBSD$: two-line nroff pattern

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

efibootmgr: Add --efidev (-u) to discover UEFI's device path to a dev or file

"efibootmgr --efidev unix-path" will return the UEFI device-path to the
file or device specified by unix-path. It's useful for debugging, but
may also be useful for scripting.

Sponsored by: Netflix
Reviewed by: corvink, manu
Differential Revision: https://reviews.freebsd.org/D38617

efibootmgr: Use the hier(7) ESP mount point in examples

MFC after: 1 week

efibootmgr: Add option to request booting to the firmware user interface

The OsIndications UEFI variable can request the firware to stop at
its UI instead of continuing with boot. Add flags for setting and
clearing this request.

Reviewed by: manu, bcr (manpages)
Approved by: scottl (implicit)
MFC after: 1 week
Sponsored by: Ampere Computing, Inc.
Differential Revision: https://reviews.freebsd.org/D25839

update example to make it active when creating a new boot method...

Clean up some of the sentences and grammar...

make igor happy..

Add --esp/-E argument to print the currently booted ESP

Add code to decode the BootCurrent and BootXXXX variable it points at
to deduce the ESP used to boot the system. By default, it prints the
path to that device. With --unix-path (-p) it will instead print the
current mount point for the ESP, if any (or an error). With
--device-path (-d) it wil print the UEFI device path for the ESP.

Note: This is the best guess based on the UEFI variables. If the ESP
is part of a gmirror, etc, that won't be reported. If by some weird
chance there was a complicated series of chain boots, this may not be
what you want. For setups that don't add layers on top of the raw
devices, it is accurate.

Differential Revision: https://reviews.freebsd.org/D22432

efibootmgr(8): fix markup and style issues

- split synopsis into separate options that can't be used together
- sort options
- fix (style) issues reported by mandoc lint

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D21710

Regularize the Netflix copyright

Use recent best practices for Copyright form at the top of
the license:
1. Remove all the All Rights Reserved clauses on our stuff. Where we
piggybacked others, use a separate line to make things clear.
2. Use "Netflix, Inc." everywhere.
3. Use a single line for the copyright for grep friendliness.
4. Use date ranges in all places for our stuff.

Approved by: Netflix Legal (who gave me the form), adrian@ (pmc files)

Update the efibootmgr(8) man page to document changes to options.

Improve the efibootmgr(8) man page

Fix formatting, typos, and attempt to improve the wording.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D18646

Add -b bootnum to allow creation of a specific boot number (rather
than the auotmatic selection). This is important in some scripting
environments.

Also, remove bogus checks for bootnum != 0. 0 is a valid bootnum.

Sponsored by: Netflix

efibootmgr.8: fix example

The example given was for the old, and now deleted, Linux
compatibility mode. Update the example for the current code.

Submitted by: Vlad Movchan

Import Netflix's efibootmgr to help manage UEFI boot variables

efibootmgr manages the UEFI BootXXXX variables that implement the UEFI
Boot Manager protocol defined in the UEFI standards. It is modeled
after the Linux program of the same name with a mostly compatible set
of command line options. Since there's a fair amount of OS specifioc
code due to differeing names and methods of doing things, the
compatibility isn't 100%.

Basic functionality is implemented, though the more advanced next boot
functionality that's been defined elsewhere is unimplemented.

Submitted by: Matt Williams (with unix / efi path xlate by me)
Sponsored by: Netflix