Airlink101 AR725W

This device is NOT RECOMMENDED for future use with OpenWrt due to low flash/ram.
DO NOT BUY DEVICES WITH 4MB FLASH / 32MB RAM if you intend to flash an up-to-date and secure OpenWrt version onto it! See 4/32 warning for details.

1) This device does not have sufficient resources (flash and/or RAM) to provide secure and reliable operation.
This means that even setting a password or changing simple network settings might not be possible any more, rendering the device effectively useless. See OpenWrt on 4/32 devices what you can do now.

2) OpenWrt support for this device has ended in 2022.
19.07.10 was the last official build for 4/32 devices.

Install OpenWrt (generic explanation)

FIXME Please add the installation procedure here.

The factory firmware expects a header, apparently proprietary to routers based on Gemtek boards.

/* Gemtek */
typedef struct {
        unsigned char   magic[4];       /* ASCII: GMTK */
        unsigned char   version[4];     /* x.x.x.x */
        unsigned int    pid;            /* Product ID */
        unsigned int    imagesz;        /* The length of this image file ( kernel +
                                         * romfs + this header) */
        unsigned int    checksum;       /* CRC32 */
        unsigned int    fastcksum;      /* Partial CRC32 on (First(256),
                                         * medium(256), last(512)) */
        unsigned char   build[4];
        unsigned char   language[4];
} gt_imghdr_t;

The program mkheader_gemtek, part of firmware-utils, generates this header from a uImage. The header is not written to flash.

The bootloader is uBoot.

Mapped starting at 0xbc400000:

0x000000 - 0x050000 uBoot
    0x30000 uBoot environment variables
    0x40000 RT2872 EEPROM data
    0x40004 MAC address

0x050000 - 0x130000 Linux Kernel
0x130000 - 0x390000 RootFS
0x390000 - 0x3e0000 LANGUAGE_PACK
0x3e0000 - 0x3f0000 NVRAM
0x3f0000 - 0x400000 NVRAM_FACTORY

Since the language and NVRAM partitions are only used by the factory firmware, OpenWrt uses a single partition starting at 0x50000 and running to the end of the 4MB.

The SoC's builtin Ethernet is connected to a IP175E 5-port 100mbit switch. VLAN setup is supported in OpenWrt.

The serial port is located at J6 on the board. The baud rate is 57600.

TXD 0 0 VCC 3.3V
    0 0 VCC 3.3V
    0 0 GND
RXD 0 0 GND
    0
  • Last modified: 2024/02/12 08:58
  • by 127.0.0.1