Greetings, I can’t apply the u-boot patch, can I somehow check whether it worked or not, is there another way to install the patch?
Unfortunately there isn't a simple way to verify the patch has taken, it's a blind patch. The only way you can actually see the environment variables in u-boot is to solder to the jtag pads on the board and use a FTDI cable with a serial terminal utility like putty, at that point printenv lists the set environment at the prompt.
TBH, if you have a working version of libreelec installed (i.e. 7.95), and the toothpick AV boot with SD inserted, arrives at the recovery, it means it's definitely booted from the SD and the patch should have applied.
I should mention the next boot should a normal one, not another toothpick AV boot, otherwise you're just re-applying the patch.
It's really important the environment is changed, it won't effect any older version from booting, but not applying it will prevent any newer builds working. It's a massive short sight of the stock firmware that OS kernel sizes wouldn't exceed 1MB.
Little bit of detail on what is modified;
The environment variable that is changed is 'nandboot'. Basically where it loads the kernel is changed to 'nand read boot \${loadaddr} 0 800000' in it's sub-script. As you can see 0x800000 = 8MB, where as that would've been 0x100000 before the patch.
I would've added some kind of notice (text/screen) it's been applied if I could, but u-boot's capabilities are very very basic. So not possible.
To re-iterate what needs to be done to patch, unpack aml_autoscript from aml_autoscript.zip to a blank SD and toothpick AV boot with the SD inserted in the STB.
Edit: I should also note, this will only work for NAND booting, I've not messed about with the SD boot side as to be cautious not to mess that up.