MFC r320252, r320686, r325769:
r320252:
In release/release.sh:
- Rename chroot_arm_armv6_build_release() to chroot_arm_build_release()
and make it hardware agnostic (such as armv6 -vs- armv7 -vs- arm64).
- Evaluate EMBEDDED_TARGET differently so release/tools/arm.subr can
be used for arm/armv6 and arm64/aarch64.
- Update comments and copyright.

In release/tools/arm.subr:
- In arm_create_disk(), change the default alignment from 63 to 512k,
fixing a boot issue on arm64 and EFI. [1]
- Update comments and copyright.

r320686:
Fix the ftp-stage target by loosening the constraints on the TARGET
and TARGET_ARCH variables.

r325769:
Update the GUMSTIX image build to use arm/arm TARGET/TARGET_ARCH.
Update the TARGET/TARGET_ARCH matching in release/release.sh and
release/Makefile.mirrors for simplification.

Note: The RPI3.conf addition from r320252 is not included, as it is
not supported on 10-STABLE. Additionally, arm64/aarch64 changes are
also excluded from this commit.

Sponsored by: The FreeBSD Foundation

MFC r323924:
Revert r323812 from release/tools/arm.subr, which has broken the
build on arm/armv6 images.

Pointyhat: gjb (myself)
MFC note: releng/10.4 has broken because of this
Sponsored by: The FreeBSD Foundation

MFC r323812:
Bootstrap etcupdate(8) and mergemaster(8) databases when creating
virtual machine images and embedded images, similar to what is
done when extracting base.txz to the target root filesystem in
a new installation.

Approved by: re (marius, insta-MFC)
Sponsored by: The FreeBSD Foundation

MFC r301101:
Turn off nfsv4acls for arm/armv6 builds, which has an impact
on performance, especially with SD cards on certain SoCs.

Sponsored by: The FreeBSD Foundation

MFC r291306:
Fix tmpfs(5) '/tmp' mount point.

Sponsored by: The FreeBSD Foundation

MFC r290550, r290573:
r290550:
Use tmpfs(5) instead of md(4) for '/tmp' mount.

r290573:
Remove noatime from tmpfs(5) fstab(5) entry.

Sponsored by: The FreeBSD Foundation

MFC r285427:
Do not mount /var/log and /var/tmp as md(4)-backed devices.

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

MFC r284004 (parital):
Use the pw(8) '-R' flag to change the relative root directory
when creating operating within the DESTDIR.

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

MFC r283896:
In arm_create_disk(), disable soft updates journaling.

Disabling soft updates journaling appears to resolve issues
with kernel panics, and may also be generally bad to have
enabled for SD cards.

Sponsored by: The FreeBSD Foundation

MFC r283894, r283895, r283913, r284004, r284010:

r283894 [1]:
Disable arm_create_user().

r283895 [1]:
Re-enable arm_create_user(), and pass the '-V DESTDIR/etc' to
pw(8) to set the correct /etc directory for the user/group
files.

r283913:
Pass the '-b' argument to pw(8) so the '/home' directory is
created in the correct place.

r284004:
Make sure /home exists within the DESTDIR before creating the
'freebsd' user account.

r284010 [2]:
Work around a potential bug in pw(8) when '-m' is specified.

[1] For recording merge history only.
[2] This commit post-dates the pw(8) '-R' addition in head/,
which is needed for conflict resolution from r284004.

Sponsored by: The FreeBSD Foundation

MFC r282500, r282693:
r282500:
Add initial support for building RPI2 images.

In release.sh, allow overriding buildenv_setup() before
the handoff to arm/release.sh.

Copy arm/RPI-B.conf -> arm/RPI2.conf, set UBOOT_PORT and
the correct KERNEL, and add the buildenv_setup() override
to install the sysutils/u-boot-rpi2 port/package.

Copy tools/arm/crochet-RPI-B.conf -> tools/arm/crochet-RPI2.conf,
and set the correct entries for the RaspberryPi2 board.

r282693:
Merge ^/projects/release-arm-redux into ^/head.

Of note:

- This commit adds native FreeBSD/arm release build support without
requiring out-of-tree utilities.

- Part of this merge removes the WANDBOARD-{SOLO,DUAL,QUAD} kernel
configuration files, for which the IMX6 kernel configuration file
should be used instead.

- The resulting images have a 'freebsd' user (password 'freebsd'),
to allow ssh(1) access when console access is not available (VGA
or serial). The default 'root' user password is set to 'root'.

- The /etc/ttys file for arm images now enable both ttyv0 and ttyu0
by default.

Note: The RPI2 kernel configuration does not yet exist in stable/10,
however the merge conflicts needed to be properly resolved.
Additionally, SRCBRANCH has been set to base/stable/10 in the updated
arm configuration files as part of this commit.

Sponsored by: The FreeBSD Foundation

MFC r285427:
Do not mount /var/log and /var/tmp as md(4)-backed devices.

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

MFC r284004 (parital):
Use the pw(8) '-R' flag to change the relative root directory
when creating operating within the DESTDIR.

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

MFC r283896:
In arm_create_disk(), disable soft updates journaling.

Disabling soft updates journaling appears to resolve issues
with kernel panics, and may also be generally bad to have
enabled for SD cards.

Sponsored by: The FreeBSD Foundation

MFC r283894, r283895, r283913, r284004, r284010:

r283894 [1]:
Disable arm_create_user().

r283895 [1]:
Re-enable arm_create_user(), and pass the '-V DESTDIR/etc' to
pw(8) to set the correct /etc directory for the user/group
files.

r283913:
Pass the '-b' argument to pw(8) so the '/home' directory is
created in the correct place.

r284004:
Make sure /home exists within the DESTDIR before creating the
'freebsd' user account.

r284010 [2]:
Work around a potential bug in pw(8) when '-m' is specified.

[1] For recording merge history only.
[2] This commit post-dates the pw(8) '-R' addition in head/,
which is needed for conflict resolution from r284004.

Sponsored by: The FreeBSD Foundation

MFC r282500, r282693:
r282500:
Add initial support for building RPI2 images.

In release.sh, allow overriding buildenv_setup() before
the handoff to arm/release.sh.

Copy arm/RPI-B.conf -> arm/RPI2.conf, set UBOOT_PORT and
the correct KERNEL, and add the buildenv_setup() override
to install the sysutils/u-boot-rpi2 port/package.

Copy tools/arm/crochet-RPI-B.conf -> tools/arm/crochet-RPI2.conf,
and set the correct entries for the RaspberryPi2 board.

r282693:
Merge ^/projects/release-arm-redux into ^/head.

Of note:

- This commit adds native FreeBSD/arm release build support without
requiring out-of-tree utilities.

- Part of this merge removes the WANDBOARD-{SOLO,DUAL,QUAD} kernel
configuration files, for which the IMX6 kernel configuration file
should be used instead.

- The resulting images have a 'freebsd' user (password 'freebsd'),
to allow ssh(1) access when console access is not available (VGA
or serial). The default 'root' user password is set to 'root'.

- The /etc/ttys file for arm images now enable both ttyv0 and ttyu0
by default.

Note: The RPI2 kernel configuration does not yet exist in stable/10,
however the merge conflicts needed to be properly resolved.
Additionally, SRCBRANCH has been set to base/stable/10 in the updated
arm configuration files as part of this commit.

Sponsored by: The FreeBSD Foundation