My embedded: December 2013

Introduction

Mini USB Portable 3G/4G WiFi Hotspot IEEE 802.11b/g/n 150Mbps Wireless Router - search on ebay

This hardware seems to be exactly the same like (firmware is different ):

HAME A5 Mini
HAME A15

Upgrade with default firmware via WEB interface is not possible. Upgrade from u-boot (tftp) is not working too - because of broken ethernet configuration. Upgrade from u-boot via serial (kermit) will end with bricked router too ( verified).

Below you will find the way how to bring new working u-boot and openwrt firmware at once.

Basic device parameters:

SoC RT5350
MIPS CPU
Clock 360 MHz
4 MByte Flash (GD25Q32)
16 MByte RAM (EM639165TS-6G)
USB Host 2.0
10/100 Ethernet switch
802.11n interface
I2C
Uart
Reset button
2 LEDs
Micro usb as power source

GPIO description:

GPIO0 - Reset Button

GPIO1 - I2C_SD

GPIO2 - I2C_SCLK

GPIO7 - USB Power

GPIO12 - USB Root Hub Power

GPIO13 - Unknown, but seems to be used in bootloader

GPIO17 - Red Power LED

GPIO20 - Blue System LED

Bootloader

Default u-boot bootloader is broken - ethernet is not fully initialized, and it seems that it is protected against starting other firmware than oryginal one.
Do not try to upgrade this bootloader from bootloader menu - you will brick your device !

To load openwrt firmware new bootloader is needed - I am using - uboot128.img taken from JiapengLi

Openwrt firmware

Default firmware cannot accept openwrt images so at the beggining (after u-boot upgrade) we will load minimal openwrt firmware firmware.img .

Upgrade procedure

Verification

Check twice if it is router we are talking about:

Take a look on photos of PCB
Check MDT structure by call "cat /proc/mtd", has to be like below:

cat /proc/mtd

dev: size erasesize name

mtd2: 00010000 00010000 "Config"
mtd3: 00010000 00010000 "Factory"
mtd4: 00117a6d 00010000 "Kernel"
mtd5: 00298593 00010000 "RootFS"
mtd6: 003b0000 00010000 "Kernel_RootFS"
mtd0: 00400000 00010000 "ALL"
mtd1: 00030000 00010000 "Bootloader"

Think twice :)

First step

Reset router to default settings

Connect to router via telnet and login with default user name (admin) and password (admin)

Now you can upgrade router via FTP or USB

Upgrade via FTP

Release memory by commands:

killall udhcpd
killall dnsmasq
killall nvram_daemon
rmmod ehci_hcd
rmmod ohci_hcd
ifconfig ra0 down
rmmod rt2860v2_ap

probably you will be disconnected after last command, so login via telnet again.

Verify free memory by calling free, check if you have more than 3500 free memory

# free total used free shared buffers Mem: 12884 9180 3704 0 532 Swap: 0 0 0Total: 12884 9180 3704

Resize TMP, and start proftp server

mount -o remount,size=4M tmpfs /tmp
proftpd.sh server 192.168.100.1 192.168.100.1 21 10
proftpd

Connect to router via ftp and copy uboot128.img and firmware.img to /tmp directory on router

! Upgrade uboot - be careful, do not reset router during and after this operation !

mtd_write write /tmp/uboot128.img Bootloader

You should see on console

#Unlocking Bootloader ...
#Writing from /tmp/uboot128.img to Bootloader ... [w]

! Upgrade firmware - do not reset router during this operation!

mtd_write write /tmp/firmware.img Kernel_RootFS

You should see on console

#Unlocking Kernel_RootFS ...
#Writing from /tmp/firmware.img to Kernel_RootFS ... [w]

Reboot router :), enjoy new u-boot with working ethernet and openwrt firmware. Now you can use standard openwrt upgrade procedure.

reboot

Router will set IP address to 192.168.100.1 , you can login via telnet

Upgrade via USB

Prepare usb stick, format it with fat filesystem, and copy uboot128.img and firmware.img

Conect usb stick to router and mount it by:

mount /dev/sda1 /mnt

Wait a few seconds and verify if you see files

ls /mnt

You should see content, do not go further if you do not see files !

uboot128.img firmware.img

! Upgrade uboot - be careful, do not reset router during and after this operation !

mtd_write write /mnt/uboot128.img Bootloader

You should see on console

#Unlocking Bootloader ...
#Writing from /mnt/uboot128.img to Bootloader ... [w]

! Upgrade firmware - do not reset router during this operation!

mtd_write write /mnt/firmware.img Kernel_RootFS

You should see on console

#Unlocking Kernel_RootFS ...
#Writing from /mnt/firmware.img to Kernel_RootFS ... [w]

Reboot router :), enjoy new u-boot with working ethernet and openwrt firmware. Now you can use standard openwrt upgrade procedure.

reboot

Router will set IP address to 192.168.100.1 , you can login via telnet

Connect UART

In order to have access to bootloader (u-boot) menu and functions we have to connect serial port to the router board. Pads are quite large so soldering is relatively easy.

Serial port parameters:

Speed: 57600
Data Bits: 8
Parity: None
Stop Bits: 1

! One problem has to be fixed - when you will connect adapter to RX in router and power on system will hangs. To fix it temporary you have first power on router and next quickly connect RX cable. To fix this issue permamently you have connect router RX and adapter TX by resistor (470 ohm - 1k ohm).

Solder three thin wires to the router GND, TX, RX and connect:

Router GND to adapter GND,
Router RX via 470 ohm resistor to adapter TX,
Router TX to adapter RX.

Router pads description

To test connection:

Connect USB adapter to PC
Start terminal and connect to port with proper parameters (putty http://www.putty.org/ or TeraTerm Pro http://www.ayera.com/teraterm/ )
Power on router - you shoud see bootloader logs

USB to TTL UART converters

My recomendation is to use:

CP2102
FT232
CH340

CP2102 based adapter

and avoid if possible prolific PL2303 because of unstability ( maybe there are plenty of clones and prolific is not guilty - hard to say).

Program SPI flash

When you failed with u-boot upgrade you can program SPI flash without desoldering it.
You need to connect thin wires to MISO, MOSI, CLK, CS, VCC and GND. I recomend to desolder VCC pin and lift it little bit, you will solder it again after programming. Disconnecting VCC prevent and distrubances from SoC or other components.

SPI flash pinout

Wires connected to SPI flash,
lifted VCC pin at the right corner soldered after programming.

I have used simple programmer made of

atmega32 + serduino ported to atmega32 ( http://flashrom.org/Serprog/Arduino_flasher )
Flashroom PC software http://flashrom.org/Flashrom compiled with MinGW

But you can use any SPI programmer which supports GigaDevice GD25Q32 or flash you currently have.

Upgrade RAM

You can upgrade RAM by desoldering SDRAM chip and soldering chip with 32 MB. It is required to have 4M x 16bit x 4 (otherwise you would need to recompile bootloader) taken from old laptop memory PC133 SO-DIMM. It can be by example: