mediatek: new mt7623n preloader package for Banana Pi

Download the boot preloader code from the Banana Pi github repo and make
it available for bootable SD card image creation.

Supports only Banana Pi R2 for now.

Based on work by Alexey Loukianov <lx2@lexa2.ru> and others.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

package/boot/mt7623n-preloader/Makefile

@@ -0,0 +1,61 @@
+#
+# Copyright © 2020 David Woodhouse <dwmw2@infradead.org>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=mt7623n-preloader
+PKG_VERSION:=2020-03-11
+PKG_RELEASE:=b27114e184449a33b5d875fda14198f5e6fee2bb
+
+PKG_MAINTAINER:=David Woodhouse <dwmw2@infradead.org>
+
+PKG_BUILD_DIR:=$(KERNEL_BUILD_DIR)/$(PKG_NAME)/$(PKG_NAME)-$(PKG_RELEASE)
+
+PKG_FLAGS:=nonshared
+
+include $(INCLUDE_DIR)/package.mk
+
+BPI_PRELOADER_URL:=@GITHUB/BPI-SINOVOIP/BPI-files/$(PKG_RELEASE)/SD/100MB/
+BPI_PRELOADER_PREFIX:=bpi-preloader-$(PKG_RELEASE)
+
+define Download/BPI-R2-preloader-2k.img.gz
+  FILE:=$(BPI_PRELOADER_PREFIX)-BPI-R2-preloader-DDR1600-20191024-2k.img.gz
+  URL:=$(BPI_PRELOADER_URL)
+  URL_FILE:=BPI-R2-preloader-DDR1600-20191024-2k.img.gz
+  HASH:=c731cc166c912c84846e2ed5faf727504e4dec1463754baa6328e9908c84a373
+endef
+$(eval $(call Download,BPI-R2-preloader-2k.img.gz))
+
+
+define Package/mt7623n-preloader
+  SECTION:=boot
+  CATEGORY:=Boot Loaders
+  DEPENDS:=@TARGET_mediatek_mt7623
+  TITLE:=mt7623n-preloader
+  DEFAULT:=y if TARGET_mediatek
+endef
+
+define Package/mt7623n-preloader/description
+  Preloader image for mt7623n based boards like Banana Pi R2.
+endef
+
+define Build/Prepare
+	rm -rf $(PKG_BUILD_DIR)
+	mkdir -p $(PKG_BUILD_DIR)
+	cp $(DL_DIR)/$(BPI_PRELOADER_PREFIX)-BPI-R2-preloader-DDR1600-20191024-2k.img.gz $(PKG_BUILD_DIR)/mt7623n_bpir2-preloader.bin.gz
+endef
+
+define Build/Compile
+	true
+endef
+
+define Build/InstallDev
+	mkdir -p $(STAGING_DIR_IMAGE)
+	gunzip -c $(PKG_BUILD_DIR)/mt7623n_bpir2-preloader.bin.gz > $(STAGING_DIR_IMAGE)/mt7623n_bpir2-preloader.bin
+endef
+
+$(eval $(call BuildPackage,mt7623n-preloader))