Recent Linux/OpenWrt on the IXP4xx-based Actiontec MI424-WR which includes revisions A, C and D
(Last boot 2025-06-23 with the v6.16-rc1 kernel, using OpenWRT as rootfs)

Refer to OpenWrt Actiontec MI424WR page for the bulk of device information.

Notices where I had to deviate from the OpenWrt documentation:

• The UART uses 115200n8.
• When I held down RESET for 10+ seconds and the router rebooted, the web UI offered me to change the router admin password.
• As I had a UART connected and the jungo script was failing, and I had TFTP working anyway (it is required for the install...) I just downloaded the new RedBoot image with TFTP from the host, like this:
  Wireless Broadband Router> load -u tftp://192.168.1.2/rb-mi424wr-ROM.bin -r 0
• After installing RedBoot it was apparent that only the WAN port is working for downloading kernel and rootfs, so use the WAN port only with RedBoot.
• To break into the RedBoot prompt (if you have some default boot sequence set up) just hold the RESET button pressed while powering up the device, this will drop you to the RedBoot prompt.
• I created a root partition for JFFS2/OverlayFS over the whole flash like this:
  fis create -l 0x007a0000 -f 0x50040000 -n rootfs
• Load a rootfs over TFTP:
  

        RedBoot> ip_address -l 169.254.1.2 -h 169.254.1.1
        RedBoot> load -r -v -b 0x00080000 -h 169.254.1.1 rootfs
        ...
        Raw file loaded 0x00080000-0x002fffff, assumed entry at 0x00080000
        RedBoot> fis unlock rootfs
        ... Unlocking from 0x50040000-0x507dffff: .............................................................
        RedBoot> fis write -f 0x50040000 -b 0x00080000 -l 0x00300000
        * CAUTION * about to program FLASH
              at 0x50040000..0x5033ffff from 0x00080000 - continue (y/n)? y
        ... Erase from 0x50040000-0x5033ffff: ........................
        ... Program from 0x00080000-0x00380000 to 0x50040000: ........................
        RedBoot> fis lock rootfs
        ... Locking from 0x50040000-0x507dffff: .............................................................
        RedBoot> reset
    

• Boot a raw zImage kernel over TFTP like this:
  

        RedBoot> ip_address -l 169.254.1.2 -h 169.254.1.1
        IP: 169.254.1.2/255.255.255.0, Gateway: 192.168.1.1
        Default server: 169.254.1.1
        RedBoot> load -r -v -b 0x00080000 -h 169.254.1.1 zImage
        Raw file loaded 0x00080000-0x00388831, assumed entry at 0x00080000
        RedBoot> go 0x00080000
      

Files

• rb-mi424wr-ROM.bin - RedBoot flash image for the MI424-WR A/C/D

Getting OpenWRT up on it

Installing OpenWrt currently requires UART serial console access