Twelve login terminals, root only, console fixes, a faster build, a Niveus splash, and X back on evdev

- tty1-tty12 all run login; the image has only root. /dev/tty7..12 could not
  be written (cdev.c knew minors 10-16 only), which sent their jobs into a
  restart storm that took the supervisor down; fixed, and stat reports them as
  Linux's tty7..12.
- Erasing text at a prompt did nothing: erase_one sent a bare backspace, which
  only moves; it and the echo path now send back-blank-back through vt_feed.
- A white cursor block was left at the end of every line of a verbose boot:
  a line feed at the bottom scrolls the pixels, cursor included, and the
  cursor was erased after the scroll. It comes off first now. A blank cell is
  also marked dirty, which it was not.
- ldlsd died with a general protection fault on real hardware in its variadic
  log function: Linux module code calls with an 8-byte-aligned stack and an
  unset %al, and the prologue's movaps faults. LDLS guest code is built with
  -mstackrealign.
- make iso took over a minute for any change, because staging r8169 rewrote
  the same files and every mtime moved; it now replaces files only if their
  contents differ (about 10 s).
- The loader's splash is redrawn in the boot manager's style, and the boot
  manager shows its cursor whenever a pointer device exists.
- xf86-input-libinput is out of the image again: with it Xorg took both
  keyboard and pointer from libinput and, on the user's laptop, neither worked.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EVRhxi9zpdW2uDUN4FVcao

tools/posix/mkaroot.sh

@@ -358,46 +358,24 @@ chmod 1777 "$ROOT/tmp" "$ROOT/var/tmp"
 # --- accounts -------------------------------------------------------------------
 #
 # Alpine's baselayout has root and the system accounts, with root's password
-# locked. A live image needs a way in, so: root with no password, and an
-# ordinary user, `schos`, who can become root with doas and su (they are in the
-# wheel group) and uses the desktop. Both have empty passwords -- login lets
-# them in without asking -- and `passwd` sets one.
-#
-# The numbers are Alpine's: wheel 10, tty 5, video 27, input 23, audio 18.
-add_member() {   # add_member GROUP USER
-    if grep -q "^$1:[^:]*:[^:]*:$" "$ROOT/etc/group"; then
-        sed -i "s/^\($1:[^:]*:[^:]*:\)$/\1$2/" "$ROOT/etc/group"
-    else
-        sed -i "s/^\($1:[^:]*:[^:]*:.*\)$/\1,$2/" "$ROOT/etc/group"
-    fi
-}
+# locked. A live image needs a way in, so: root, with no password -- login lets
+# root in without asking, and `passwd` sets one. That is the only account; an
+# ordinary user is one `adduser` away, and the permission checks, su and doas
+# are all still there for when there is one.
 sed -i 's/^root:[^:]*:/root::/' "$ROOT/etc/shadow"
-grep -q '^schos:' "$ROOT/etc/passwd" ||
-    echo 'schos:x:1000:1000:SchOS user:/home/schos:/bin/zsh' >> "$ROOT/etc/passwd"
-grep -q '^schos:' "$ROOT/etc/group" ||
-    echo 'schos:x:1000:' >> "$ROOT/etc/group"
-grep -q '^schos:' "$ROOT/etc/shadow" ||
-    echo 'schos::0:0:::::' >> "$ROOT/etc/shadow"
-for g in wheel tty video input audio cdrom; do
-    grep -q "^$g:.*[:,]schos\(,\|\$\)" "$ROOT/etc/group" || add_member $g schos
-done
 chmod 640 "$ROOT/etc/shadow"
 
-# Who may become root with doas: the wheel group, without being asked again.
-# The file has to be root's and not writable by anyone else, or doas refuses it.
+# doas: members of wheel run anything, without being asked again. Nobody is in
+# wheel yet. The file has to be root's and not writable by anyone else.
 cat > "$ROOT/etc/doas.conf" <<'DEOF'
 # doas: see doas.conf(5). Members of wheel run anything as anyone.
 permit nopass :wheel
 DEOF
 chmod 644 "$ROOT/etc/doas.conf"
 
-# The user's home, with what startx wants there. root's are in /root.
-mkdir -p "$ROOT/home/schos"
-cp "$ROOT/root/.xinitrc" "$ROOT/root/.xserverrc" "$ROOT/home/schos/"
-chmod 755 "$ROOT/home/schos/.xserverrc"
 # zsh offers to write one on first login; /etc/zsh is where the settings are.
-: > "$ROOT/home/schos/.zshrc"
-chmod 700 "$ROOT/home/schos" "$ROOT/root"
+: > "$ROOT/root/.zshrc"
+chmod 700 "$ROOT/root"
 
 # The setuid programs. Run as an ordinary user, apk may have dropped the bit,
 # and nothing here should depend on whether it did.
@@ -406,9 +384,8 @@ for f in bin/su usr/bin/passwd usr/bin/doas; do
 done
 
 # Who owns what inside the image: everything is root's -- the build host's
-# user means nothing here -- except the user's home.
+# user means nothing here.
 cat > "$OUT/owners" <<'OEOF'
-/home/schos 1000 1000 0700
 /root 0 0 0700
 /tmp 0 0 1777
 /var/tmp 0 0 1777