antenna-select: simple VoCore antenna control scripts

The antenna-select package is used to enable and disable the second
antenna on Morse Micro evaluation kits based on the VoCore module,
or other platforms using the MT7603 2.4 GHz Wi-Fi block.

utils/antenna-select/Makefile

@@ -0,0 +1,36 @@
+#
+# Copyright 2022 Morse Micro
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+
+PKG_NAME:=antenna-select
+PKG_RELEASE=1
+
+PKG_MAINTAINER:=Morse Micro <info@morsemicro.com>
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/antenna-select
+  SECTION:=Utilities
+  CATEGORY:=Utilities
+  TITLE:=VoCore2 Antenna Selector script (defaults 2nd antenna)
+  DEPENDS:= +kmod-mtd-rw +@BUSYBOX_CONFIG_XXD
+endef
+
+define Build/Compile
+
+endef
+
+define Package/antenna-select/install
+	$(INSTALL_DIR) $(1)/sbin
+	$(INSTALL_BIN) ./files/sbin/antenna-select $(1)/sbin/
+	$(INSTALL_DIR) $(1)/etc/init.d
+	$(INSTALL_BIN) ./files/etc/init.d/antenna-select $(1)/etc/init.d/antenna-select
+endef
+
+$(eval $(call BuildPackage,antenna-select))

utils/antenna-select/files/etc/init.d/antenna-select

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+#!/bin/sh /etc/rc.common
+#
+# Copyright (C) 2021-2022 Morse Micro Pty Ltd. All rights reserved.
+#
+
+START=01
+
+boot() {
+    /sbin/antenna-select 2
+}

utils/antenna-select/files/sbin/antenna-select

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+#!/bin/sh
+
+target_byte=52
+tempfile=/tmp/mtd2
+
+change_byte() {
+  dd if=$1 of=/tmp/cbtmpf bs=1 count=$2;
+  echo -ne "\x$3" >> /tmp/cbtmpf;
+  let "pos=$2+1";
+  dd if=$1 of=/tmp/cbtmpf bs=1 skip=$pos seek=$pos
+  mv /tmp/cbtmpf $1
+}
+
+
+cp /dev/mtd2 $tempfile
+current_value=$(xxd -p -l 1 -s $target_byte $tempfile)
+
+if [ "$1" = "1"  ]; then
+    desired_value=11
+elif [ "$1" = "2"  ]; then
+    desired_value=22
+else
+    exit 1
+fi
+
+if [ $desired_value = $current_value ]; then
+    echo "the desired antenna is already selected."
+    exit 0
+else
+    echo "switching the antenna byte from $current_value to $desired_value"
+fi
+
+change_byte $tempfile $target_byte $desired_value
+insmod mtd-rw i_want_a_brick=1
+mtd -e factory write $tempfile factory
+rmmod mtd-rw
+rm $tempfile
+wifi