bcm53xx: image: document arguments of various functions

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 42645

target/linux/bcm53xx/image/Makefile

@@ -13,12 +13,14 @@ define Image/Prepare
 	$(call prepare_generic_squashfs,$(KDIR)/fs_mark)
 endef
 
+# $(1): dts filename (also used for the firmware file).
 define Image/Build/initramfs/DTB
 	$(call Image/Build/DTB,zImage-initramfs,$(1))
 	$(STAGING_DIR_HOST)/bin/trx -o $(KDIR)/$(IMG_PREFIX)-initramfs-$(1).trx \
 		-f $(KDIR)/zImage-initramfs-$(1).lzma
 endef
 
+# $(1): dts filename (also used for the firmware file).
 define Image/Build/squashfs/DTB
 	$(call Image/Build/DTB,zImage,$(1))
 	$(STAGING_DIR_HOST)/bin/trx -o $(KDIR)/$(IMG_PREFIX)-squashfs-$(1).trx \
@@ -26,6 +28,8 @@ define Image/Build/squashfs/DTB
 		-a 1024 -f $(KDIR)/root.squashfs -a 0x10000 -A $(KDIR)/fs_mark
 endef
 
+# $(1): kernel (Linux) image file
+# $(2): dts filename (also used for the firmware file).
 define Image/Build/DTB
 	rm -f $(KDIR)/$(1)-$(2).lzma
 	rm -f $(KDIR)/$(1)-$(2).dts
@@ -33,6 +37,10 @@ define Image/Build/DTB
 	$(STAGING_DIR_HOST)/bin/lzma e $(KDIR)/$(1)-$(2).dts $(KDIR)/$(1)-$(2).lzma -d16
 endef
 
+# $(1): filesystem type (e.g. squashfs, initramfs).
+# $(2): dts filename (also used for the firmware file).
+# $(3): board_id (device specific magic).
+# $(4): region.
 define Image/Build/Chk
 	$(call Image/Build/$(1)/DTB,$(2))
 	$(STAGING_DIR_HOST)/bin/mkchkimg -o $(BIN_DIR)/openwrt-$(2)-$(1).chk -k $(KDIR)/$(IMG_PREFIX)-$(1)-$(2).trx -b $(3) -r $(4)