package/ugetty: support building "proxycommand" binary for host

The "proxycommand" binary is used with SSH clients to connect to
ugetty over serial. Building it as a host package makes it easy to use
with Buildroot builds including ugetty on the target, without needing
a separate install.

Signed-off-by: Fiona Klute <fiona.klute@gmx.de>
[Peter: use install -D]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/Config.in.host

@@ -124,6 +124,7 @@ menu "Host utilities"
 	source "package/ti-cgt-pru/Config.in.host"
 	source "package/tipidee/Config.in.host"
 	source "package/uboot-tools/Config.in.host"
+	source "package/ugetty/Config.in.host"
 	source "package/util-linux/Config.in.host"
 	source "package/utp_com/Config.in.host"
 	source "package/uuu/Config.in.host"

package/ugetty/Config.in.host

@@ -0,0 +1,13 @@
+config BR2_PACKAGE_HOST_UGETTY
+	bool "host ugetty"
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_8  # std=c17
+	help
+	  A minimal getty for embedded Linux that auto-detects the
+	  client and dispatches incoming serial connections to a login
+	  prompt, a PPP session, or the local SSH server as
+	  appropriate.
+
+	  The host package builds only the "proxycommand" binary for
+	  use with SSH clients to connect to ugetty over serial.
+
+	  https://github.com/ryancdotorg/ugetty

package/ugetty/ugetty.mk

@@ -20,4 +20,14 @@ define UGETTY_INSTALL_TARGET_CMDS
 	ln -snf ugetty $(TARGET_DIR)/sbin/getty
 endef
 
+define HOST_UGETTY_BUILD_CMDS
+	$(HOST_CONFIGURE_OPTS) $(MAKE) -C $(@D) bin/proxycommand
+endef
+
+define HOST_UGETTY_INSTALL_CMDS
+	$(INSTALL) -m 0755 -D $(@D)/bin/proxycommand \
+		$(HOST_DIR)/bin/proxycommand
+endef
+
 $(eval $(generic-package))
+$(eval $(host-generic-package))