Ripped from Fedora.
---- setserial-2.17/setserial.c
-+++ setserial-2.17/setserial.c
+--- a/setserial.c
++++ b/setserial.c
@@ -710,1 +710,1 @@
- fprintf(stderr, "\t spd_normal\tuse 38.4kb when a buad rate of 38.4kb is selected\n");
+ fprintf(stderr, "\t spd_normal\tuse 38.4kb when a baud rate of 38.4kb is selected\n");
--- /dev/null
+# Copyright 1999-2017 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=6
+
+inherit toolchain-funcs
+
+DESCRIPTION="Configure your serial ports with it"
+HOMEPAGE="http://setserial.sourceforge.net/"
+SRC_URI="
+ ftp://tsx-11.mit.edu/pub/linux/sources/sbin/${P}.tar.gz
+ ftp://ftp.sunsite.org.uk/Mirrors/tsx-11.mit.edu/pub/linux/sources/sbin/${P}.tar.gz"
+
+LICENSE="GPL-2"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~hppa ~ia64 ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86"
+
+PATCHES=(
+ "${FILESDIR}"/${P}-spelling.patch
+ "${FILESDIR}"/${P}-manpage-updates.patch
+ "${FILESDIR}"/${P}-headers.patch
+ "${FILESDIR}"/${P}-build.patch
+ "${FILESDIR}"/${P}-hayes-esp.patch
+ "${FILESDIR}"/${P}-darwin.patch
+)
+
+src_compile() {
+ tc-export CC
+ emake "${PN}"
+}
+
+src_install() {
+ doman "${PN}.8"
+ into /
+ dobin "${PN}"
+
+ insinto /etc
+ doins serial.conf
+ newinitd "${FILESDIR}"/serial-2.17-r4 serial
+
+ einstalldocs
+ docinto txt
+ dodoc Documentation/*
+}