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 $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

loader: implement mount/unmount rootfs

We want to keep our root file system open to preserve bcache segment
between file accesses, thus reducing physical disk IO.

Reviewed by: imp, allanjude, kevans (previous version)
Differential Revision: https://reviews.freebsd.org/D30848
MFC after: 1 month

Work around cp breakage in current from last week

There was a small window cp was broken. Work around this by using :>
instead of cp /dev/null. Ideally, we'd keep the cp /dev/null in the
build as a regression test, but doing so breaks people that upgraded
during the cp breakage and this is simpler than bootstrapping a
working cp since there's no good __FreeBSD_version sign posts for
that.

Suggested by: lots of people
Too stubborn for his own good: imp

loader: zfs should support bootonce an nextboot

bootonce feature is temporary, one time boot, activated by
"bectl activate -t BE", "bectl activate -T BE" will reset the bootonce flag.

By default, the bootonce setting is reset on attempt to boot and the next
boot will use previously active BE.

By setting zfs_bootonce_activate="YES" in rc.conf, the bootonce BE will
be set permanently active.

bootonce dataset name is recorded in boot pool labels, bootenv area.

in case of nextboot, the nextboot_enable boolean variable is recorded in
freebsd:nvstore nvlist, also stored in boot pool label bootenv area.
On boot, the loader will process /boot/nextboot.conf if nextboot_enable
is "YES", and will set nextboot_enable to "NO", preventing /boot/nextboot.conf
processing on next boot.

bootonce and nextboot features are usable in both UEFI and BIOS boot.

To use bootonce/nextboot features, the boot loader needs to be updated on disk;
if loader.efi is stored on ESP, then ESP needs to be updated and
for BIOS boot, stage2 (zfsboot or gptzfsboot) needs to be updated
(gpart or other tools).

At this time, only lua loader is updated.

Sponsored by: Netflix, Klara Inc.
Differential Revision: https://reviews.freebsd.org/D25512

loader: create single zfs nextboot implementation

We should have nextboot feature implemented in libsa zfs code.
To get there, I have created zfs_nextboot() implementation based on
two sources, our current simple textual string based approach with added
structured boot label PAD structure from OpenZFS.

Secondly, all nvlist details are moved to separate source file and
restructured a bit. This is done to provide base support to add nvlist
add/update feature in followup updates.

And finally, the zfsboot/gptzfsboot disk access functions are swapped to use
libi386 and libsa.

Sponsored by: Netflix, Klara Inc.
Differential Revision: https://reviews.freebsd.org/D25324

Avoid using non-portable dd conv=osync option

The same thing can be achieved using the bs=$SIZE and conv=sync options.
Unlike conv=osync, conv=sync is support on both Linux and macOS.

Reviewed By: imp, jhb (earlier version)
Obtained from: CheriBSD
Differential Revision: https://reviews.freebsd.org/D24788

Link stand/i386 components using a linker script

LLD 10.0.0 changed the behavior of the -Ttext option, so that using
-Ttext=0x0 now causes linking of the loaders to fail with:

ld: error: output file too large: 18446744073707016908 bytes

I reported this in https://bugs.llvm.org/show_bug.cgi?id=44715, and
initially reverted the upstream change in r357259 to work around it.

However, after some discussion with Fangrui Song in the upstream ticket,
I think we can classify this as an unfortunate interaction between using
-Ttext=0 in combination with --no-rosegment. (We added the latter
in r332090, because btxld does not correctly handle input with more
than 2 PT_LOAD segments.)

Fangrui suggested to use a linker script instead, and Warner was already
attempting this in r305353, but had to revert it due to "crypto-using
boot problems" (not sure what those were :).

This review updates the stand/i386/boot.ldscript to handle more
sections, inserts some symbols like _edata and such that we use in
libsa, and also discards any .interp section.

It uses ORG which is defined on the linker command line using
--defsym ORG=value to set the start of all the sections.

Reviewed by: imp
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D23952

Remove duplicate lz4 implementations

Port illumos change: https://www.illumos.org/issues/11667

Move lz4.c out of zfs tree to opensolaris/common/lz4, adjust it to be
usable from kernel/stand/userland builds, so we can use just one single
source. Add lz4.h to declare lz4_compress() and lz4_decompress().

MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D22037

loader: support com.delphix:removing

We should support removing vdev from boot pool. Update loader zfs reader
to support com.delphix:removing.

Reviewed by: allanjude
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D18901

stand: remove CLANG_NO_IAS from zfsldr

Many components under stand/ had CLANG_NO_IAS added when Clang's
Integrated Assembler (IAS) did not handle .codeNN directives. Clang
gained support quite some time ago, and we can now build stand/ with
IAS.

Note that in some cases there are small differences in the generated
output, so CLANG_NO_IAS should be removed only after testing (or after
finding no differences in the output). For zfsldr I compared objdump
output between GNU as- and Clang IAS-built zfsldr and .text was
identical (changes were limited to the object's ELF headers and debug
info).

Sponsored by: The FreeBSD Foundation

NM and OBJCOPY are already defined for all builds. There's no need to
conditionally define them here.

Extend loader(8) geli support to all architectures and all disk-like devices.

This moves the bulk of the geli support from lib386/biosdisk.c into a new
geli/gelidev.c which implements a devsw-type device whose dv_strategy()
function handles geli decryption. Support for all arches comes from moving
the taste-and-attach code to the devopen() function in libsa.

After opening any DEVT_DISK device, devopen() calls the new function
geli_probe_and_attach(), which will "attach" the geli code to the open_file
struct by creating a geli_devdesc instance to replace the disk_devdesc
instance in the open_file. That routes all IO for the device through the
geli code.

A new public geli_add_key() function is added, to allow arch/vendor-specific
code to add keys obtained from custom hardware or other sources.

With these changes, geli support will be compiled into all variations of
loader(8) on all arches because the default is WITH_LOADER_GELI.

Relnotes: yes
Sponsored by: Microchip Technology Inc
Differential Revision: https://reviews.freebsd.org/D15743

Move ZFS files into libsa

Move the libzfs stuff into libsa. There's no need for it to be a
separate library. The separate library adds to the issues of build
ordering that we see from time to time. Move the filesystem support
into libsa, like all the other filesystem support rather than making
zfs the odd-duck out.

Discussed with: allanjude@

stand: move libgeliboot into libsa.

Reduce by 1 the number of crazy libraries we need in stand by moving
geli into libsa (where architecturally it belonged all along). This
just moves things around without any code changes.

Fix build of stand with base gcc

* Make autoboot() a static function in stand/common/boot.c, so it does
not shadow local variables in gptboot.c and zfsboot.c.
* Remove -Winline from the Makefiles for gptboot, gptzfsboot and
zfsboot, as gcc will always fail to inline some functions, and there
is nothing we can do about it.
* For gcc <= 4.2.1, silence -Wuninitialized for isoboot, as it produces
a false positive warning.
* Remove deprecated and unnecessary -mcpu=i386 flag from stand/defs.mk,
as there is already a -march=i386 flag further in the file.

Reviewed by: imp
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D15628

Hoist btx include stuff to i386/Makefile.inc

Sponsored by: Netflix

Need to include skein in the include path so we don't get this from
the "system" headers (though in buildworld, it's from the recently
built sysroot).

Sponsored by: Netflix

increase maximum size of zfsboot

Previous to the switch from sys/boot to stand/ zfsboot (used for MBR) did
not support GELI. Now that it is compiled with GELI, it is running out of
space.

zfsldr (which loads zfsboot) was modified to load 256kb in r304321

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

Sponsored by: Netflix