ramips: add support for Beeline SmartBox GIGA

Beeline SmartBox GIGA is a wireless WiFi 5 router manufactured by
Sercomm company.

Device specification
--------------------
SoC Type: MediaTek MT7621AT
RAM: 256 MiB, Nanya NT5CC128M16JR-EK
Flash: 128 MiB, Macronix MX30LF1G18AC
Wireless 2.4 GHz (MT7603EN): b/g/n, 2x2
Wireless 5 GHz (MT7613BE): a/n/ac, 2x2
Ethernet: 3 ports - 2xGbE (WAN, LAN1), 1xFE (LAN2)
USB ports: 1xUSB3.0
Button: 1 button (Reset/WPS)
PCB ID: DBE00B-1.6MM
LEDs: 1 RGB LED
Power: 12 VDC, 1.5 A
Connector type: barrel
Bootloader: U-Boot

Installation
-----------------
1. Downgrade stock (Beeline) firmware to v.1.0.02;
2. Give factory OpenWrt image a shorter name, e.g. 1001.img;
3. Upload and update the firmware via the original web interface.

Remark: You might need make the 3rd step twice if your running firmware
is booted from the Slot 1 (Sercomm0 bootflag). The stock firmware
reverses the bootflag (Sercomm0 / Sercomm1) on each firmware update.

Revert to stock
---------------
1. Change the bootflag to Sercomm1 in OpenWrt CLI and then reboot:
      printf 1 | dd bs=1 seek=7 count=1 of=/dev/mtdblock3
2. Optional: Update with any stock (Beeline) firmware if you want to
   overwrite OpenWrt in Slot 0 completely.

MAC Addresses
-------------
+-----+-----------+---------+
| use | address   | example |
+-----+-----------+---------+
| LAN | label     | *:16    |
| WAN | label + 1 | *:17    |
| 2g  | label + 4 | *:1a    |
| 5g  | label + 5 | *:1b    |
+-----+-----------+---------+
The label MAC address was found in Factory 0x21000

Notes
-----
1. The following scripts are required for the build:
      sercomm-crypto.py - already exists in OpenWrt
      sercomm-partition-tag.py - already exists in OpenWrt
      sercomm-payload.py - already exists in OpenWrt
      sercomm-pid.py - new, the part of this pull request
      sercomm-kernel-header.py - new, the part of this pull request
2. This device (same as other Sercomm S2,S3-based devices) requires
   special LZMA and LOADADDR settings for successful boot:
      LZMA_TEXT_START=0x82800000
      KERNEL_LOADADDR=0x81001000
      LOADADDR=0x80001000
3. This device (same as several other Sercomm-based devices - Beeline,
   Netgear, Etisalat, Rostelecom) has partition map (mtd1) containing
   real partition offsets, which may differ from device to device
   depending on the number and location of bad blocks on NAND.
   "fixed-partitions" is used if the partition map is not found or
   corrupted. This behavour (it's the same as on stock firmware) is
   provided by MTD_SERCOMM_PARTS module.

Signed-off-by: Mikhail Zhilkin <csharper2005@gmail.com>

target/linux/ramips/image/Makefile

@@ -5,7 +5,7 @@
 include $(TOPDIR)/rules.mk
 include $(INCLUDE_DIR)/image.mk
 
-DEVICE_VARS += LOADER_TYPE LOADER_FLASH_OFFS
+DEVICE_VARS += LOADER_TYPE LOADER_FLASH_OFFS LZMA_TEXT_START
 DEVICE_VARS += NETGEAR_BOARD_ID NETGEAR_HW_ID
 DEVICE_VARS += BUFFALO_TAG_PLATFORM BUFFALO_TAG_VERSION BUFFALO_TAG_MINOR
 DEVICE_VARS += SEAMA_SIGNATURE SEAMA_MTDBLOCK
@@ -22,6 +22,7 @@ ldrplatform-$(CONFIG_TARGET_ramips_mt7621) := mt7621
 ldrflashstart-y := 0x1c000000
 ldrflashstart-$(CONFIG_TARGET_ramips_mt7621) := 0x1fc00000
 
+LOADADDR := $(loadaddr-y)
 LOADER_PLATFORM := $(ldrplatform-y)
 LOADER_FLASH_START := $(ldrflashstart-y)
 
@@ -45,7 +46,8 @@ define Build/loader-common
 		PKG_BUILD_DIR="$@.src" \
 		TARGET_DIR="$(dir $@)" LOADER_NAME="$(notdir $@)" \
 		BOARD="$(BOARDNAME)" PLATFORM="$(LOADER_PLATFORM)" \
-		LZMA_TEXT_START=0x81800000 LOADADDR=$(KERNEL_LOADADDR) \
+		LZMA_TEXT_START=$(LZMA_TEXT_START) \
+		LOADADDR=$(LOADADDR) \
 		$(1) compile loader.$(LOADER_TYPE)
 	mv "$@.$(LOADER_TYPE)" "$@"
 	rm -rf $@.src
@@ -176,6 +178,7 @@ define Device/Default
   PROFILES = Default
   KERNEL := $(KERNEL_DTB) | uImage lzma
   KERNEL_LOADADDR := $(loadaddr-y)
+  LZMA_TEXT_START := 0x81800000
   SOC := $(DEFAULT_SOC)
   DEVICE_DTS_DIR := ../dts
   DEVICE_DTS = $$(SOC)_$(1)

target/linux/ramips/image/common-sercomm.mk

@@ -0,0 +1,87 @@
+DEVICE_VARS += SERCOMM_KERNEL_OFFSET SERCOMM_ROOTFS_OFFSET
+
+define Build/sercomm-crypto
+	$(TOPDIR)/scripts/sercomm-crypto.py \
+		--input-file $@ \
+		--key-file $@.key \
+		--output-file $@.ser \
+		--version $(SERCOMM_SWVER)
+	$(STAGING_DIR_HOST)/bin/openssl enc -md md5 -aes-256-cbc \
+		-in $@ \
+		-out $@.enc \
+		-K `cat $@.key` \
+		-iv 00000000000000000000000000000000
+	dd if=$@.enc >> $@.ser 2>/dev/null
+	mv $@.ser $@
+	rm -f $@.enc $@.key
+endef
+
+define Build/sercomm-kernel
+	$(TOPDIR)/scripts/sercomm-kernel-header.py \
+		--kernel-image $@ \
+		--kernel-offset $(SERCOMM_KERNEL_OFFSET) \
+		--rootfs-offset $(SERCOMM_ROOTFS_OFFSET) \
+		--output-header $@.hdr
+	dd if=$@ >> $@.hdr 2>/dev/null
+	mv $@.hdr $@
+endef
+
+define Build/sercomm-part-tag
+	$(call Build/sercomm-part-tag-common,$(word 1,$(1)) $@)
+endef
+
+define Build/sercomm-part-tag-common
+	$(eval file=$(word 2,$(1)))
+	$(TOPDIR)/scripts/sercomm-partition-tag.py \
+		--input-file $(file) \
+		--output-file $(file).tmp \
+		--part-name $(word 1,$(1)) \
+		--part-version $(SERCOMM_SWVER)
+	mv $(file).tmp $(file)
+endef
+
+define Build/sercomm-payload
+	$(TOPDIR)/scripts/sercomm-pid.py \
+		--hw-version $(SERCOMM_HWVER) \
+		--hw-id $(SERCOMM_HWID) \
+		--sw-version $(SERCOMM_SWVER) \
+		--pid-file $@.pid \
+		--extra-padding-size 0x10 \
+		--extra-padding-first-byte 0x0a
+	$(TOPDIR)/scripts/sercomm-payload.py \
+		--input-file $@ \
+		--output-file $@.tmp \
+		--pid "$$(cat $@.pid | od -t x1 -An -v | tr -d '\n')"
+	mv $@.tmp $@
+	rm $@.pid
+endef
+
+define Build/sercomm-prepend-tagged-kernel
+	$(CP) $(IMAGE_KERNEL) $(IMAGE_KERNEL).tagged
+	$(call Build/sercomm-part-tag-common,$(word 1,$(1)) \
+		$(IMAGE_KERNEL).tagged)
+	dd if=$@ >> $(IMAGE_KERNEL).tagged 2>/dev/null
+	mv $(IMAGE_KERNEL).tagged $@
+endef
+
+define Device/sercomm_dxx
+  $(Device/dsa-migration)
+  BLOCKSIZE := 128k
+  PAGESIZE := 2048
+  KERNEL_SIZE := 6144k
+  UBINIZE_OPTS := -E 5
+  LOADER_TYPE := bin
+  KERNEL_LOADADDR := 0x81001000
+  LZMA_TEXT_START := 0x82800000
+  KERNEL := kernel-bin | append-dtb | lzma | loader-kernel | lzma -a0 | \
+	uImage lzma | sercomm-kernel
+  KERNEL_INITRAMFS := kernel-bin | append-dtb | lzma | loader-kernel | \
+	lzma -a0 | uImage lzma
+  IMAGES += factory.img
+  IMAGE/sysupgrade.bin := sysupgrade-tar | append-metadata
+  IMAGE/factory.img := append-ubi | sercomm-part-tag rootfs | \
+	sercomm-prepend-tagged-kernel kernel | gzip | sercomm-payload | \
+	sercomm-crypto
+  SERCOMM_KERNEL_OFFSET := 0x400100
+  SERCOMM_ROOTFS_OFFSET := 0x1000000
+endef

target/linux/ramips/image/mt7621.mk

@@ -2,6 +2,7 @@
 # MT7621 Profiles
 #
 
+include ./common-sercomm.mk
 include ./common-tp-link.mk
 
 DEFAULT_SOC := mt7621
@@ -285,6 +286,19 @@ define Device/beeline_smartbox-flash
 endef
 TARGET_DEVICES += beeline_smartbox-flash
 
+define Device/beeline_smartbox-giga
+  $(Device/sercomm_dxx)
+  IMAGE_SIZE := 24576k
+  SERCOMM_HWID := DBE
+  SERCOMM_HWVER := 10100
+  SERCOMM_SWVER := 1001
+  DEVICE_VENDOR := Beeline
+  DEVICE_MODEL := SmartBox GIGA
+  DEVICE_PACKAGES := kmod-mt7603 kmod-mt7615e kmod-mt7663-firmware-ap \
+	kmod-usb3 uboot-envtools
+endef
+TARGET_DEVICES += beeline_smartbox-giga
+
 define Device/buffalo_wsr-1166dhp
   $(Device/dsa-migration)
   $(Device/uimage-lzma-loader)