ramips: split base-files into subtargets

While most of the target's contents are split into subtargets, the
base-files are maintained for the target as a whole.

However, OpenWrt already implements a mechanism that will use (and
even prefer) files in the subtargets' directories. This can be
exploited to make several scripts subtarget-specific and thus save
some space.

In certain cases, keeping files in parent (=target) base-files was
more convenient, and thus no splitting was performed for those.

Note that this will increase overall code lines, but reduce code
per subtarget.

base-files ipk size reduction:
master (mt7621)   60958 B
split (mt7620)    46358 B (- 14.3 kiB)
split (mt7621)    48759 B (- 11.9 kiB)
split (mt76x8)    44948 B (- 15.6 kiB)
split (rt288x)    43508 B (- 17.0 kiB)
split (rt305x)    45616 B (- 15.0 kiB)
split (rt3883)    44176 B (- 16.4 kiB)

Run-tested on:
GL.iNet GL-MT300N-V2 (mt76x8)
D-Link DWR-116 (mt7620)

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

1 files changed, 43 insertions, 0 deletions

diff --git a/target/linux/ramips/rt305x/base-files/lib/preinit/04_handle_checksumming b/target/linux/ramips/rt305x/base-files/lib/preinit/04_handle_checksumming
new file mode 100644
index 0000000000..9a2361d057
--- /dev/null
+++ b/target/linux/ramips/rt305x/base-files/lib/preinit/04_handle_checksumming
@@ -0,0 +1,43 @@
+#!/bin/sh
+
+# Netgear WNCE2001 has does a checksum check on boot and goes into recovery
+# tftp mode when the check fails.  Initializing the JFFS2 partition triggers
+# this, so we make sure to zero checksum and size to be checksummed before
+# that happens, so this needs to run very early during boot.
+
+do_checksumming_disable() {
+	. /lib/functions.sh
+
+	local board=$(board_name)
+
+	case "$board" in
+	netgear,wnce2001)
+		echo "Board is WNCE2001, updating checksum partition..."
+		local zeroes=/dev/zero
+		local tmpfile=/tmp/wnce2001_checksum
+		local partname=checksum
+		local mtd=$(find_mtd_part $partname)
+		dd if=$mtd of=$tmpfile bs=80 count=1 2>/dev/null
+		signature=$(dd if=$tmpfile bs=1 skip=24 count=20 2>/dev/null)
+		checksum=$(dd if=$tmpfile bs=1 count=4 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"')
+		if [ "$signature" != "RT3052-AP-WNCE2001-3" ]; then
+			echo "Signature of checksum partition is wrong, bailing."
+			return 0
+		fi
+		if [ "$checksum" != "00000000" ]; then
+			echo "Checksum is set, zeroing."
+			# zero out checksum
+			dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=0 count=4 2>/dev/null
+			# zero out bytecount to be checksummed
+			dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=60 count=4 2>/dev/null
+			mtd write $tmpfile $partname
+		else
+			echo "Checksum is already zero, nothing to do."
+		fi
+	;;
+	esac
+
+	return 0
+}
+
+boot_hook_add preinit_main do_checksumming_disable