ipq40xx: add support for ASUS RT-AC58U/RT-ACRH13

This patch adds support for ASUS RT-AC58U/RT-ACRH13.

hardware highlights:

SOC:	IPQ4018 / QCA Dakota
CPU:	Quad-Core ARMv7 Processor rev 5 (v7l) Cortex-A7
DRAM:	128 MiB DDR3L-1066 @ 537 MHz (1074?) NT5CC64M16GP-DI
NOR:	2 MiB Macronix MX25L1606E (for boot, QSEE)
NAND:   128 MiB Winbond W25NO1GVZE1G (cal + kernel + root, UBI)
ETH:    Qualcomm Atheros QCA8075 Gigabit Switch (4 x LAN, 1 x WAN)
USB:    1 x 3.0 (via Synopsys DesignWare DWC3 controller in the SoC)
WLAN1:  Qualcomm Atheros QCA4018 2.4GHz 802.11bgn 2:2x2
WLAN2:  Qualcomm Atheros QCA4018 5GHz 802.11a/n/ac 2:2x2
INPUT:	one Reset and one WPS button
LEDS:	Status, WAN, WIFI1/2, USB and LAN (one blue LED for each)
Serial:
	WARNING: The serial port needs a TTL/RS-232 3V3 level converter!
	The Serial setting is 115200-8-N-1. The board has an unpopulated
	1x4 0.1" header. The pinout (VDD, RX, GND, TX) is printed on the
	PCB right next to the connector.

U-Boot Note: The ethernet driver isn't always reliable and can sometime
time out... Don't worry, just retry.

Access via the serial console is required. As well as a working
TFTP-server setup and the initramfs image. (If not provided, it
has to be built from the OpenWrt source. Make sure to enable
LZMA as the compression for the INITRAMFS!)

To install the image permanently, you have to do the following
steps in the listed order.

1. Open up the router.
   There are four phillips screws hiding behind the four plastic
   feets on the underside.

2. Connect the serial cable (See notes above)

3. Connect your router via one of the four LAN-ports (yellow)
   to a PC which can set the IP-Address and ssh and scp from.

   If possible set your PC's IPv4 Address to 192.168.1.70
   (As this is the IP-Address the Router's bootloader expects
   for the tftp server)

4. power up the router and enter the u-boot
   choose option 1 to upload the initramfs image. And follow
   through the ipv4 setup.

Wait for your router's status LED to stop blinking rapidly and
glow just blue. (The LAN LED should also be glowing blue).

3. Connect to the OpenWrt running in RAM

   The default IPv4-Address of your router will be 192.168.1.1.

   1. Copy over the openwrt-sysupgrade.bin image to your router's
      temporary directory

   # scp openwrt-sysupgrade.bin root@192.168.1.1:/tmp

   2. ssh from your PC into your router as root.

   # ssh root@192.168.1.1

   The default OpenWrt-Image won't ask for a password. Simply hit the Enter-Key.

   Once connected...: run the following commands on your temporary installation

   3. delete the "jffs2" ubi partition to make room for your new root partition

   # ubirmvol /dev/ubi0 --name=jffs2

   4. install OpenWrt on the NAND Flash.

   # sysupgrade -v /tmp/openwrt-sysupgrade.bin

   - This will will automatically reboot the router -

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
This commit is contained in:
Christian Lamparter 2018-03-07 09:13:10 +01:00 committed by Mathias Kresin
parent 43be5087a9
commit 87c42101cf
12 changed files with 449 additions and 3 deletions

View file

@ -13,7 +13,7 @@ endef
define Build/Compile define Build/Compile
endef endef
ALLWIFIBOARDS:=avm_fritzbox-4040 glinet_gl-b1300 ALLWIFIBOARDS:=asus_rt-ac58u avm_fritzbox-4040 glinet_gl-b1300
ALLWIFIPACKAGES:=$(foreach BOARD,$(ALLWIFIBOARDS),ipq-wifi-$(BOARD)) ALLWIFIPACKAGES:=$(foreach BOARD,$(ALLWIFIBOARDS),ipq-wifi-$(BOARD))
define Package/ipq-wifi-default define Package/ipq-wifi-default
@ -47,6 +47,7 @@ Don't install it for any other device!
PREV_BOARD+=ipq-wifi-$(1) PREV_BOARD+=ipq-wifi-$(1)
endef endef
$(eval $(call generate-ipq-wifi-package,asus_rt-ac58u,board-asus_rt-ac58u.bin,ASUS RT-AC58U))
$(eval $(call generate-ipq-wifi-package,avm_fritzbox-4040,board-avm_fritzbox-4040.bin,AVM FRITZ!Box 4040)) $(eval $(call generate-ipq-wifi-package,avm_fritzbox-4040,board-avm_fritzbox-4040.bin,AVM FRITZ!Box 4040))
$(eval $(call generate-ipq-wifi-package,glinet_gl-b1300,board-glinet_gl-b1300.bin,GL.iNet GL-B1300)) $(eval $(call generate-ipq-wifi-package,glinet_gl-b1300,board-glinet_gl-b1300.bin,GL.iNet GL-B1300))

View file

@ -3,7 +3,7 @@ include $(TOPDIR)/rules.mk
ARCH:=arm ARCH:=arm
BOARD:=ipq40xx BOARD:=ipq40xx
BOARDNAME:=Qualcomm Atheros IPQ40XX BOARDNAME:=Qualcomm Atheros IPQ40XX
FEATURES:=squashfs fpu FEATURES:=squashfs fpu ramdisk nand
CPU_TYPE:=cortex-a7 CPU_TYPE:=cortex-a7
CPU_SUBTYPE:=neon-vfpv4 CPU_SUBTYPE:=neon-vfpv4
MAINTAINER:=John Crispin <john@phrozen.org> MAINTAINER:=John Crispin <john@phrozen.org>

View file

@ -11,6 +11,13 @@ board=$(board_name)
boardname="${board##*,}" boardname="${board##*,}"
case "$board" in case "$board" in
asus,rt-ac58u)
ucidef_set_led_wlan "wlan2g" "WLAN2G" "${boardname}:blue:wlan2G" "phy0tpt"
ucidef_set_led_wlan "wlan5g" "WLAN5G" "${boardname}:blue:wlan5G" "phy1tpt"
ucidef_set_led_usbport "usb" "USB" "${boardname}:blue:usb" "usb1-port1" "usb2-port1" "usb3-port1" "usb4-port1"
ucidef_set_led_netdev "wan" "WAN" "${boardname}:blue:wan" "eth1"
ucidef_set_led_switch "lan" "LAN" "${boardname}:blue:lan" "switch0" "0x1e"
;;
avm,fritzbox-4040) avm,fritzbox-4040)
ucidef_set_led_wlan "wlan" "WLAN" "fritz4040:green:wlan" "phy0tpt" "phy1tpt" ucidef_set_led_wlan "wlan" "WLAN" "fritz4040:green:wlan" "phy0tpt" "phy1tpt"
ucidef_set_led_netdev "wan" "WAN" "fritz4040:green:wan" "eth1" ucidef_set_led_netdev "wan" "WAN" "fritz4040:green:wan" "eth1"

View file

@ -12,6 +12,16 @@ board_config_update
board=$(board_name) board=$(board_name)
case "$board" in case "$board" in
asus,rt-ac58u)
CI_UBIPART=UBI_DEV
wan_mac_addr=$(mtd_get_mac_binary_ubi Factory 20486)
lan_mac_addr=$(mtd_get_mac_binary_ubi Factory 4102)
ucidef_set_interfaces_lan_wan "eth0" "eth1"
ucidef_add_switch "switch0" \
"0u@eth0" "1:lan" "2:lan" "3:lan" "4:lan"
ucidef_set_interface_macaddr "lan" "$lan_mac_addr"
ucidef_set_interface_macaddr "wan" "$wan_mac_addr"
;;
avm,fritzbox-4040) avm,fritzbox-4040)
ucidef_set_interfaces_lan_wan "eth0" "eth1" ucidef_set_interfaces_lan_wan "eth0" "eth1"
ucidef_add_switch "switch0" \ ucidef_add_switch "switch0" \

View file

@ -19,6 +19,24 @@ ath10kcal_extract() {
ath10kcal_die "failed to extract calibration data from $mtd" ath10kcal_die "failed to extract calibration data from $mtd"
} }
ath10kcal_ubi_extract() {
local part=$1
local offset=$2
local count=$3
local ubidev
local ubi
. /lib/upgrade/nand.sh
ubidev=$(nand_find_ubi $CI_UBIPART)
ubi=$(nand_find_volume $ubidev $part)
[ -n "$ubi" ] || \
ath10kcal_die "no UBI volume found for $part"
dd if=/dev/$ubi of=/lib/firmware/$FIRMWARE bs=1 skip=$offset count=$count 2>/dev/null || \
ath10kcal_die "failed to extract from $ubi"
}
[ -e /lib/firmware/$FIRMWARE ] && exit 0 [ -e /lib/firmware/$FIRMWARE ] && exit 0
. /lib/functions.sh . /lib/functions.sh
@ -30,6 +48,10 @@ board=$(board_name)
case "$FIRMWARE" in case "$FIRMWARE" in
"ath10k/pre-cal-ahb-a000000.wifi.bin") "ath10k/pre-cal-ahb-a000000.wifi.bin")
case "$board" in case "$board" in
asus,rt-ac58u)
CI_UBIPART=UBI_DEV
ath10kcal_ubi_extract "Factory" 4096 12064
;;
avm,fritzbox-4040) avm,fritzbox-4040)
/usr/bin/fritz_cal_extract -i 1 -s 0x400 -e 0x207 -l 12064 -o /lib/firmware/$FIRMWARE $(find_mtd_chardev "urlader_config") /usr/bin/fritz_cal_extract -i 1 -s 0x400 -e 0x207 -l 12064 -o /lib/firmware/$FIRMWARE $(find_mtd_chardev "urlader_config")
;; ;;
@ -44,6 +66,10 @@ case "$FIRMWARE" in
;; ;;
"ath10k/pre-cal-ahb-a800000.wifi.bin") "ath10k/pre-cal-ahb-a800000.wifi.bin")
case "$board" in case "$board" in
asus,rt-ac58u)
CI_UBIPART=UBI_DEV
ath10kcal_ubi_extract "Factory" 20480 12064
;;
avm,fritzbox-4040) avm,fritzbox-4040)
/usr/bin/fritz_cal_extract -i 1 -s 0x400 -e 0x208 -l 12064 -o /lib/firmware/$FIRMWARE $(find_mtd_chardev "urlader_config") /usr/bin/fritz_cal_extract -i 1 -s 0x400 -e 0x208 -l 12064 -o /lib/firmware/$FIRMWARE $(find_mtd_chardev "urlader_config")
;; ;;

View file

@ -5,11 +5,37 @@ RAMFS_COPY_BIN='fw_printenv fw_setenv'
RAMFS_COPY_DATA='/etc/fw_env.config /var/lock/fw_printenv.lock' RAMFS_COPY_DATA='/etc/fw_env.config /var/lock/fw_printenv.lock'
platform_check_image() { platform_check_image() {
case "$(board_name)" in
asus,rt-ac58u)
CI_UBIPART="UBI_DEV"
local ubidev=$(nand_find_ubi $CI_UBIPART)
local asus_root=$(nand_find_volume $ubidev jffs2)
[ -n "$asus_root" ] || return 0
cat << EOF
jffs2 partition is still present.
There's probably no space left
to install the filesystem.
You need to delete the jffs2 partition first:
# ubirmvol /dev/ubi0 --name=jffs2
Once this is done. Retry.
EOF
return 1
;;
esac
return 0; return 0;
} }
platform_do_upgrade() { platform_do_upgrade() {
case "$(board_name)" in case "$(board_name)" in
asus,rt-ac58u)
CI_UBIPART="UBI_DEV"
CI_KERNPART="linux"
nand_do_upgrade "$1"
;;
openmesh,a42) openmesh,a42)
PART_NAME="inactive" PART_NAME="inactive"
platform_do_upgrade_openmesh "$ARGV" platform_do_upgrade_openmesh "$ARGV"
@ -20,6 +46,15 @@ platform_do_upgrade() {
esac esac
} }
platform_nand_pre_upgrade() {
case "$(board_name)" in
asus,rt-ac58u)
CI_UBIPART="UBI_DEV"
CI_KERNPART="linux"
;;
esac
}
blink_led() { blink_led() {
. /etc/diag.sh; set_state upgrade . /etc/diag.sh; set_state upgrade
} }

View file

@ -301,6 +301,8 @@ CONFIG_MTD_M25P80=y
CONFIG_MTD_NAND=y CONFIG_MTD_NAND=y
CONFIG_MTD_NAND_ECC=y CONFIG_MTD_NAND_ECC=y
CONFIG_MTD_NAND_QCOM=y CONFIG_MTD_NAND_QCOM=y
CONFIG_MTD_SPINAND_MT29F=y
CONFIG_MTD_SPINAND_ONDIEECC=y
CONFIG_MTD_SPI_NOR=y CONFIG_MTD_SPI_NOR=y
CONFIG_MTD_SPLIT_FIRMWARE=y CONFIG_MTD_SPLIT_FIRMWARE=y
CONFIG_MTD_SPLIT_FIT_FW=y CONFIG_MTD_SPLIT_FIT_FW=y

View file

@ -0,0 +1,314 @@
/* Copyright (c) 2015, The Linux Foundation. All rights reserved.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#include "qcom-ipq4019.dtsi"
#include "qcom-ipq4019-bus.dtsi"
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/input/input.h>
#include <dt-bindings/soc/qcom,tcsr.h>
/ {
model = "ASUS RT-AC58U";
compatible = "asus,rt-ac58u", "qcom,ipq4019";
memory {
device_type = "memory";
reg = <0x80000000 0x8000000>;
};
aliases {
led-boot = &power;
led-failsafe = &power;
led-running = &power;
led-upgrade = &power;
};
reserved-memory {
#address-cells = <0x1>;
#size-cells = <0x1>;
ranges;
smem@87e00000 {
reg = <0x87e00000 0x080000>;
no-map;
};
tz@87e80000 {
reg = <0x87e80000 0x180000>;
no-map;
};
};
soc {
mdio@90000 {
status = "okay";
};
ess-psgmii@98000 {
status = "okay";
};
tcsr@1949000 {
compatible = "qcom,tcsr";
reg = <0x1949000 0x100>;
qcom,wifi_glb_cfg = <TCSR_WIFI_GLB_CFG>;
};
tcsr@194b000 {
compatible = "qcom,tcsr";
reg = <0x194b000 0x100>;
qcom,usb-hsphy-mode-select = <TCSR_USB_HSPHY_HOST_MODE>;
};
ess_tcsr@1953000 {
compatible = "qcom,tcsr";
reg = <0x1953000 0x1000>;
qcom,ess-interface-select = <TCSR_ESS_PSGMII>;
};
tcsr@1957000 {
compatible = "qcom,tcsr";
reg = <0x1957000 0x100>;
qcom,wifi_noc_memtype_m0_m2 = <TCSR_WIFI_NOC_MEMTYPE_M0_M2>;
};
usb2@60f8800 {
status = "ok";
};
serial@78af000 {
pinctrl-0 = <&serial_pins>;
pinctrl-names = "default";
status = "ok";
};
usb3@8af8800 {
status = "ok";
};
crypto@8e3a000 {
status = "ok";
};
wifi@a000000 {
status = "okay";
qcom,ath10k-calibration-variant = "ASUS-RT-AC58U";
};
wifi@a800000 {
status = "okay";
qcom,ath10k-calibration-variant = "ASUS-RT-AC58U";
};
watchdog@b017000 {
status = "ok";
};
ess-switch@c000000 {
status = "okay";
};
edma@c080000 {
status = "okay";
};
};
gpio-keys {
compatible = "gpio-keys";
reset {
label = "reset";
gpios = <&tlmm 4 GPIO_ACTIVE_LOW>;
linux,code = <KEY_RESTART>;
};
wps {
label = "wps";
gpios = <&tlmm 63 GPIO_ACTIVE_LOW>;
linux,code = <KEY_WPS_BUTTON>;
};
};
gpio-leds {
compatible = "gpio-leds";
power: status {
label = "rt-ac58u:blue:status";
gpios = <&tlmm 3 GPIO_ACTIVE_HIGH>;
};
wan {
label = "rt-ac58u:blue:wan";
gpios = <&tlmm 1 GPIO_ACTIVE_HIGH>;
};
wlan2G {
label = "rt-ac58u:blue:wlan2G";
gpios = <&tlmm 58 GPIO_ACTIVE_HIGH>;
};
wan5G {
label = "rt-ac58u:blue:wlan5G";
gpios = <&tlmm 5 GPIO_ACTIVE_HIGH>;
};
usb {
label = "rt-ac58u:blue:usb";
gpios = <&tlmm 0 GPIO_ACTIVE_HIGH>;
};
lan {
label = "rt-ac58u:blue:lan";
gpios = <&tlmm 2 GPIO_ACTIVE_HIGH>;
};
};
};
&cryptobam {
status = "ok";
};
&blsp_dma {
status = "ok";
};
&tlmm {
serial_pins: serial_pinmux {
mux {
pins = "gpio60", "gpio61";
function = "blsp_uart0";
bias-disable;
};
};
spi_0_pins: spi_0_pinmux {
mux {
function = "blsp_spi0";
pins = "gpio55", "gpio56", "gpio57";
drive-strength = <12>;
bias-disable;
};
mux_cs {
function = "gpio";
pins = "gpio54", "gpio59";
drive-strength = <2>;
bias-disable;
output-high;
};
};
};
&spi_0 { /* BLSP1 QUP1 */
pinctrl-0 = <&spi_0_pins>;
pinctrl-names = "default";
status = "ok";
cs-gpios = <&tlmm 54 0>,
<&tlmm 59 0>;
m25p80@0 {
#address-cells = <1>;
#size-cells = <0>;
/*
* U-boot looks for "n25q128a11" node,
* if we don't have it, it will spit out the following warning:
* "ipq: fdt fixup unable to find compatible node".
*/
compatible = "jedec,spi-nor";
reg = <0>;
linux,modalias = "m25p80", "mx25l1606e", "n25q128a11";
spi-max-frequency = <24000000>;
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
partition0@0 {
label = "SBL1";
reg = <0x00000000 0x00040000>;
read-only;
};
partition1@40000 {
label = "MIBIB";
reg = <0x00040000 0x00020000>;
read-only;
};
partition2@60000 {
label = "QSEE";
reg = <0x00060000 0x00060000>;
read-only;
};
partition3@c0000 {
label = "CDT";
reg = <0x000c0000 0x00010000>;
read-only;
};
partition4@d0000 {
label = "DDRPARAMS";
reg = <0x000d0000 0x00010000>;
read-only;
};
partition5@e0000 {
label = "APPSBLENV"; /* uboot env*/
reg = <0x000e0000 0x00010000>;
read-only;
};
partition5@f0000 {
label = "APPSBL"; /* uboot */
reg = <0x000f0000 0x00080000>;
read-only;
};
partition5@170000 {
label = "ART";
reg = <0x00170000 0x00010000>;
read-only;
};
/* 0x00180000 - 0x00200000 unused */
};
};
mt29f@1 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "spinand,mt29f";
reg = <1>;
spi-max-frequency = <24000000>;
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
partition0@0 {
label = "ubi";
reg = <0x00000000 0x08000000>;
};
};
};
};
&usb3_ss_phy {
status = "ok";
};
&usb3_hs_phy {
status = "ok";
};
&usb2_hs_phy {
status = "ok";
};

View file

@ -31,6 +31,27 @@ define Device/UbiFit
IMAGE/nand-sysupgrade.bin := sysupgrade-tar | append-metadata IMAGE/nand-sysupgrade.bin := sysupgrade-tar | append-metadata
endef endef
define Device/asus_rt-ac58u
$(call Device/FitImageLzma)
DEVICE_DTS := qcom-ipq4018-rt-ac58u
BLOCKSIZE := 128k
PAGESIZE := 2048
DTB_SIZE := 65536
DEVICE_TITLE := Asus RT-AC58U
IMAGE_SIZE := 20439364
FILESYSTEMS := squashfs
# Someone - in their infinite wisdom - decided to put the firmware
# version in front of the image name \03\00\00\04 => Version 3.0.0.4
# Since u-boot works with strings we either need another fixup step
# to add a version... or we are very careful not to add '\0' into that
# string and call it a day.... Yeah, we do the latter!
UIMAGE_NAME:=$(shell echo -e '\03\01\01\01RT-AC58U')
IMAGES := sysupgrade.bin
DEVICE_PACKAGES := ipq-wifi-asus_rt-ac58u kmod-usb-ledtrig-usbport
endef
TARGET_DEVICES += asus_rt-ac58u
define Device/avm_fritzbox-4040 define Device/avm_fritzbox-4040
$(call Device/FitImageLzma) $(call Device/FitImageLzma)
DEVICE_DTS := qcom-ipq4019-fritz4040 DEVICE_DTS := qcom-ipq4019-fritz4040

View file

@ -10,11 +10,12 @@ Signed-off-by: John Crispin <john@phrozen.org>
--- a/arch/arm/boot/dts/Makefile --- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile +++ b/arch/arm/boot/dts/Makefile
@@ -697,7 +697,11 @@ dtb-$(CONFIG_ARCH_QCOM) += \ @@ -697,7 +697,12 @@ dtb-$(CONFIG_ARCH_QCOM) += \
qcom-apq8074-dragonboard.dtb \ qcom-apq8074-dragonboard.dtb \
qcom-apq8084-ifc6540.dtb \ qcom-apq8084-ifc6540.dtb \
qcom-apq8084-mtp.dtb \ qcom-apq8084-mtp.dtb \
+ qcom-ipq4018-a42.dtb \ + qcom-ipq4018-a42.dtb \
+ qcom-ipq4018-rt-ac58u.dtb \
qcom-ipq4019-ap.dk01.1-c1.dtb \ qcom-ipq4019-ap.dk01.1-c1.dtb \
+ qcom-ipq4019-ap.dk04.1-c1.dtb \ + qcom-ipq4019-ap.dk04.1-c1.dtb \
+ qcom-ipq4019-fritz4040.dtb \ + qcom-ipq4019-fritz4040.dtb \

View file

@ -0,0 +1,29 @@
From b8f3a7ccbeca5bdbd1b6210b94b38d3fef2dd0bd Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@googlemail.com>
Date: Thu, 19 Jan 2017 01:57:22 +0100
Subject: [PATCH 16/38] mtd: ubi: add auto_attach HACK for the ASUS RT-AC58U
This patch adds a hack that allows UBI's autoattach feature
to work with the custom ASUS UBI_DEV partition name.
This is necessary because the vendor's u-boot doesn't leave
the bootargs / cmdline alone, so the it can't be overwritten
easily otherwise.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
---
drivers/mtd/ubi/build.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -1170,6 +1170,9 @@ static void __init ubi_auto_attach(void)
mtd = open_mtd_device("ubi");
if (IS_ERR(mtd))
mtd = open_mtd_device("data");
+ /* Hack for the Asus RT-AC58U */
+ if (IS_ERR(mtd))
+ mtd = open_mtd_device("UBI_DEV");
if (!IS_ERR(mtd)) {
size_t len;