gemini: make dd commands more portable

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@45039 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/gemini/image/Makefile

@@ -71,9 +71,9 @@ endif
 ifeq ($(SUBTARGET),raidsonic)
 define Image/Build
 	$(call Image/Build/$(1),$(1))
-	dd if=$(BIN_DIR)/$(IMG_PREFIX)-$(1).img of=$(BIN_DIR)/rd.gz bs=6M count=1
-#	dd if=/dev/zero of=$(BIN_DIR)/hddapp.tgz bs=6M count=1
-	dd if=$(BIN_DIR)/$(IMG_PREFIX)-$(1).img of=$(BIN_DIR)/hddapp.tgz bs=6M count=1 seek=1
+	dd if=$(BIN_DIR)/$(IMG_PREFIX)-$(1).img of=$(BIN_DIR)/rd.gz bs=6144k count=1
+#	dd if=/dev/zero of=$(BIN_DIR)/hddapp.tgz bs=6144k count=1
+	dd if=$(BIN_DIR)/$(IMG_PREFIX)-$(1).img of=$(BIN_DIR)/hddapp.tgz bs=6144k count=1 seek=1
 	cp $(BIN_DIR)/$(IMG_PREFIX)-nas4220-zImage $(BIN_DIR)/zImage
 	cp ./ImageInfo-ib4220 $(BIN_DIR)/ImageInfo
 	(cd $(BIN_DIR); tar -czf sysupgrade-ib4220.tar.gz ImageInfo zImage rd.gz hddapp.tgz)