automatically set up agetty TERM when possible

 * debvm-create will now parse a new kernel cmdline debvm.term and if
   present will pass its value to agetty as TERM.
 * debvm-run will now detect whether it is running in a terminal in
   non-graphic mode and pass its environment TERM variable as debvm.term
   to the kernel cmdline thus closing the loop.

2 files changed, 7 insertions, 1 deletions

diff --git a/bin/debvm-run b/bin/debvm-run
index c2a3f21..4f7ff44 100755
--- a/bin/debvm-run
+++ b/bin/debvm-run
@@ -250,6 +250,9 @@ if test -z "$GRAPHICAL"; then
 			KERNEL_CMDLINE="$KERNEL_CMDLINE console=ttyS0"
 		;;
 	esac
+	if test -t 0 && test -t 1 && test -n "$TERM"; then
+		KERNEL_CMDLINE="$KERNEL_CMDLINE debvm.term=$TERM"
+	fi
 fi
 
 if test -n "$SSHPORT"; then
diff --git a/share/customize-autologin.sh b/share/customize-autologin.sh
index 5592a03..d7df555 100755
--- a/share/customize-autologin.sh
+++ b/share/customize-autologin.sh
@@ -3,7 +3,8 @@
 # SPDX-License-Identifier: MIT
 #
 # This is a mmdebstrap customize hook that configures automatic root login on a
-# serial console.
+# serial console. It also parses the debvm.term kernel cmdline and passes it as
+# TERM to agetty.
 
 set -eu
 
@@ -15,6 +16,8 @@ mkdir "$TARGET/etc/systemd/system/$UNIT.d"
 
 (
 	echo '[Service]'
+	printf '%s\n' 'ExecStartPre=/bin/sed -n -e "s/.*\\(^\\| \\)debvm\\.term=\\([^ ]*\\).*/TERM=\\2/w/run/debvmterm" /proc/cmdline'
+	echo 'EnvironmentFile=-/run/debvmterm'
 	echo 'ExecStart='
 	sed -n 's,^ExecStart=-/sbin/agetty ,&-a root ,p' "$TARGET/lib/systemd/system/$UNIT"
 ) > "$TARGET/etc/systemd/system/$UNIT.d/autologin.conf"