Possibly set eMMC enhenced user area on MT6000?

Routers
1

Hi, i'm wondering if anyone (especially engineers at GL-iNet) has looked at ways to enable and use the enhenced user area. I'm wanting to enable some logs to be stored on the device (and persist over reboot), and I want to contain its impact on the eMMC wearing.

The plan in my mind is to set a portion of the eMMC (ideally at the end) into SLC mode to store logs, and have its wearing separated from the rest. That'd mean even if that part of the eMMC is worn out from logging, it won't affect other area and it won't brick the router.

Since partitioning is one-time writable and would destroy data, plan in my head is to get into uboot to do a full eMMC dump to USB drive, then offline manipulate the dump to resize the user/overlay partition to make room at the end, as well as identifying the ending offset of the entire eMMC data. Manipulate ECSD from uboot to create enhenced UDA after where the reduced dump would end, reset eMMC from uboot (without power cycle) to apply partition, then write this edited eMMC UDA dump back to the eMMC from uboot. (uboot runs in RAM so it doesn't rely on eMMC once jumped into, right?)

My end goal is to have an extra partition (thining in btrfs with block compression on, large block size, and long commit interval) that sits right on the enhenced UDA (SLC) portion of the eMMC.

Any idea how doable this thought is? Thanks!

2

Beware: Uboot runs from the same eMMC! It's not separated.

For me this sounds kind of doable - but bricking risk is totally high. Would not recommend it.

I would write logs simply to the normal partition, use extroot if needed or even use a syslog server.

3

I didn't want to do the extroot way due to: 1) eMMC interface should be more reliable than USB; 2) mmcblk generally have blkdiscard implemented so TRIM would work, whereas USB drives generally don't. (at least i've not yet seen an USB drive with functional unmap/blkdiscard without having jump through lots of hacks)
I would have used extroot if the MT6000 has a native (micro) SD card slot as it's much similar to eMMC in terms of the bus and discard/TRIM capability.

Setting up a syslog server at the same reliability and availability level as my main network gateway seems also like a really complicated way. Supposedly this MT6000 (as gateway) is the most available/reliable piece in my home network, as every other network device relies on it.

As for uboot, i thought uboot is loaded from eMMC to RAM (by whatever boot stage before it), but then itself runs completely in RAM and doesn't rely on eMMC after it's already running? Or was i wrong on that?

Thanks for the suggestions though.