This one is somewhat different for readonly optical media
(where [auto]mounted disk is a nuisanse) and writable USB
Flash or even fixed disk (where it's too easy to destroy
data by missing the right letter).

...so that it's more applicable to a wider set of images
(those lacking e2k-alt-linux' specific labels just won't
get broken default boot target label name for no reason).

...otherwise a whole-disk block device would be accepted
by the script but not by the firmware's bootloader.

Optical media isn't to be checked for those of course.

alt-rescue-20210811-e2kv5.img would fail to initialize
proper videomode on an Elbrus 901-PC with Radeon R7:

[   16.742051] [drm] Loading oland Microcode
[   16.743850] [drm:si_init [radeon]] *ERROR* Failed to load firmware!

Looks like a plain omission.

Rollback from use/x11/nvidia/optimus to plain use/x11/nvidia
for now as I don't have a proper x86 stand to test it now;
feel free to revert this part if you do and bumblebee works.

There is no need to specify serial console here because it is now
specified in the use/uboot.

firefox is absent in sisyphus_riscv64

I've doubted what to base it on but settled with ve/.lxc-base
for the common prefix reason. :)

Part of mkimage-profiles' design is to make it easier
to figure out the common parts and describe these as such;
even if something's hastily implemented through copypaste,
it's worth it to have a look (amending the debugged commit
to make it pretty as well, fixing up the newcomers at the
merge time, or at least spotting crap and taking care
afterwards -- the latter having more potential for "free"
merge conflicts, doing this sort of cleanup rather earlier
than later rather pays off albeit premature optimization
can take place here either when too many "layers of
beforehand indirection" are introduced; ve/.lxc-bare
in this very commit is bordering just that, so use your
common sense and experience or ask in devel-distro@
when in doubt).

Fixes: 37e088da

xargs -r is a good habit usually.

Fixes: c7717836

- syslinux: fix broken 01-syslinux script in previous version 1.4.18
- regular-vm.mk, regular.mk: drop udev-rule-generator
- kernel: add rtw89 wifi kernel module for support Realtek RTL8852AE
  (thanks zerg@)
- install2: don't remove mmc kernel modules to allow USB 0bda:0129 cardreader
  (thanks zerg@)
- install2: do not cleanup cec and rc kernel modules (needed for amdgpu)
  (thanks zerg@)
- kernel/stage1: prevent to include nvidia to stage1 (thanks zerg@)
- drm: drop use/drm/stage2/nvidia target
- kworkstation: add latest commits from zerg@
- initrd-bootchain: add etwork interface naming udev rules
- initrd-bootchain: allow BOOTCHAIN_LOGFILE, BOOTCHAIN_LOG_VT to be reassigned
- build-vm: create initrd from a special config (/etc/initrd.mk.oem)
- kernel: add use/kernel/disable-usb-autosuspend
- mixin.mk: disable usb autosuspend for regular-x11
- kernel: add drivers/mfd drivers/clk to initrd for aarch64, armh
- grub: remove 'ip=dhcp' from netinstall.cfg
- isomd5sum: drop obsoletes feature
- build.mk: Do nothing with IMAGEDIR if $(DIRECT_TARGETS) is running
- init: Fix install /etc/os-release (thanks sem@)
- workstation: add latest commits from sem@
- slinux: add latest commits from sem@
- education: add latest commits from cas@

copy script from features.in/init/rootfs/image-scripts.d/65-os-release

As replacement for medit.

Handle /usr/lib/os-release if it exists.

It is commented out anyway, but remove it nevertheless:
they are in the mainline linux kernel >= 5.10 already.