Linksys MX4300 LN1301 2nd partition firmware flash issue

Installing and Using OpenWrt
1

Hi,

The newest Openwrt 25.12.4 cannot be flashed into the second partition with Luci GUI. Even I forced to flash, it still didn't work. The router will get stuck on booting if I do so and after checking it won't flash it successfully.

I guess this is a Openwrt firmware issue. Not sure MX4200 MX4300 LN1301 HomeWRK all have this issue.
Please help to check and fix it if it is true or not.

(Flashing from the OEM firmware to OpenWrt works well.)
1.After you successfully upgrade the OEM firmware to OpenWRT and you want to flash the other partition to be OpenWRT, you will see your router get stuck on booting (a soft brick).

To temporarily solve this problem,
2.Unplugging and plugging the power cable for 2-3 cycles to make it swap to the "good" Openwrt partition. For the last cycle, you need to wait for 3-5 seconds to see the top LED flashing which means it is swapping.
I didn't try the power button, not sure if it works or not.

3.When you can log into the Luci, you open the SSH. Log into your router.

  1. cd /tmp

  2. wget http://downloads.openwrt.org/releases/25.12.4/targets/qualcommax/ipq807x/openwrt-25.12.4-qualcommax-ipq807x-linksys_mx4300-squashfs-factory.bin

  3. Carefully Check booted partition
    fw_printenv -n boot_part

  4. if you see 2, you use
    mtd -r -e kernel -n write openwrt-25.12.4-qualcommax-ipq807x-linksys_mx4300-squashfs-factory.bin kernel

  5. if you see 1, you use
    mtd -r -e alt_kernel -n write openwrt-25.12.4-qualcommax-ipq807x-linksys_mx4300-squashfs-factory.bin alt_kernel

(I got 2 on all routers.)

  1. Now your router should be flashing the firmware to the other partition but it won't automatically change the boot partition.

  2. Your router will automatically restart. Now, connecting the router to an Internet! Go to Software, update the list, install advanced-reboot.

11.Now you can change or reboot the partition to whatever you like.

See:

2

the wiki install steps tells you to use mtd write ?

are you actually thinking of upgrading ?

3

Not upgrading. I think users have to use mtd command to bypass this firmware issue (if it has)
With my other routers, if I have one partition installed with Openwrt, I can easily flash the second partition to be openwrt with Luci GUI by just uploading the firmware. I couldn't make it on the MX4300 model.

4

haven't read the long MX4300 thread, but does it say anywhere primary/secondary partitions are supported ?

5

No. It doesn't clearly say "primary/secondary partitions are supported" but the device works well after using the command to flash both partitions.

6

I’d double-check that the image type matches the path you are using. From OpenWrt to OpenWrt, LuCI normally wants the sysupgrade image, while the factory image is usually for flashing from vendor firmware. If you are writing the inactive kernel partition by hand, I’d treat that as a device-specific workaround and keep the wiki steps/env values handy, not as proof that normal dual-partition upgrades are supported.