Kernel 4.19 with
CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER=y
Bootloader or kernel arguments
CONFIG CMD_LINE="... init=/sbin/openrc-init quiet loglevel=3 vga=current udev.log_priority=3 ..."
apply OpenRC quiet-init.patch
mkdir -p /etc/portage/patches/sys-apps/openrc
curl -o /etc/portage/patches/sys-apps/openrc/quiet-init.patch
emerge -a1 sys-apps/openrc
suppress fsck boot message
/etc/init.d/fsck
-fsck ${fsck_args:--p} $fsck_opts "$@"
+fsck ${fsck_args:--p} $fsck_opts "$@" > /dev/null
agetty.tty1 with autologin
/etc/conf.d/agetty.tty1
agetty_options="--noclear --nohints --nonewline --skip-login --noissue --autologin USER_NAME"
suppress 'Last Login:' message
/etc/pam.d/login
-session optional pam_lastlog.so
+session optional pam_lastlog.so silent