mtkclient

mtkclient does not seem to correctly interpret the usb output of the device past some part of the early boot process. Really, any of those messages formatted by mtkclient are unfaithful to the intended meaning. So yes maybe it is "just a checksum step" or maybe something else entirely. Last year I collected some UART logs on the device during bootup in a zip here: https://github.com/bkerler/mtkclient/issues/1289

The latest Kobos use MediaTek SoCs with locked bootloaders. The Kobo Clara BW's MT8113, for example. As far as I know, one of the early bootloaders it, BL1, refuses to execute the next bootloader (BL2) unless its signature is valid. We can get the device into a mode where BL1 waits for upload of a BL2 via USB using an exploit called Kamakiri, but in public there is neither an exploit to get BL1 to boot an arbitrary BL2, nor an authorized BL2 image to upload. See here: https://github.com/bkerler/mtkclient/issues/1332 Kobo devices have root exposed but don't let users boot their own kernels (and the kernel they ship was not compiled with kexec either). I really don't know the reason so many devices these days don't have an unlock method. It seems predatory. Who knows where in the chain this happens... maybe it's Kobo, or maybe MediaTek won'

I went through a lot of trouble unlocking an old Xiaomi. mtkclient bypass methods do not work as a for all Xiaomi (or at least did not for my device). Thread: https://github.com/bkerler/mtkclient/issues/110

> Xiaomi mtkclient [0] would let you skip the whole 7/14 days thing (also: unrestricted partition dumping/flashing). Though there are chances of ending up with soft/hard brick (normally possible to revert back to working state as long as you have backups), and there may be no support for your specific chipset/device/software revision at all. 0. https://github.com/bkerler/mtkclient

"A default LineageOS installation" as in "a device which is officially supported through https://wiki.lineageos.org/devices/" is like that, indeed, and while most of the unofficial builds come with as -userdebug, no root, there's a high chance of encountering either a flaky build (permissive selinux) or having to fallback to a GSI build, some of them, and nowadays it means AndyCGYan's [0], come with optional root enabled. As for backup: stock backup facilities (adb backup/restore) aren't exactly the best thing for sure, (rip Titanium Backup, Seedvault isn't even remotely there), and TWRP is broken on most of devices with modern encryption support (specifically, on Pixels). Coincidentally, Mediatek SoC based devices are the 'best' when talking about backup (as in: you can dump and clone all partitions through a built-in service mode [1]).