Initial commit

target/linux/mediatek/image/gen_mt7623_emmc_img.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+#
+# This script is used only to create the "legacy" image for UniElec U7623,
+# suitable for upgrading from the vendor OpenWrt or from OpenWrt 19.07.
+#
+OUTPUT_FILE=$1
+KERNEL_FILE=$2
+RECOVERY_FILE=$3
+ROOTFS_FILE=$4
+
+BS=512
+
+# These two offsets are relative to the absolute location of the kernel on the mmc
+# (0xA00), so their position in the image is -2560 blocks
+#
+# They must be kept in sync with the default command line for U7623.
+# blkdevparts=mmcblk0:3M@6M(recovery),256M@9M(root)"
+#
+# For upgrading from the vendor firmware, the total image must fit in its
+# MTD 'firmware' partition, which is typically 36MiB.
+
+# In the legacy image, the uImage starts at block 0xa00. Allow 4864 KiB (9728) blocks.
+RECOVERY_OFFSET=9728
+# The recovery image is 3MiB, or 6144 blocks.
+ROOTFS_OFFSET=15872
+
+dd bs="$BS" of="$OUTPUT_FILE" if="$KERNEL_FILE"
+dd bs="$BS" of="$OUTPUT_FILE" if="$RECOVERY_FILE" seek="$RECOVERY_OFFSET"
+dd bs="$BS" of="$OUTPUT_FILE" if="$ROOTFS_FILE" seek="$ROOTFS_OFFSET"
+dd if=/dev/zero of="$OUTPUT_FILE" bs=128k count=1 oflag=append conv=notrunc