drivers/video/mxc/mxc_epdc_fake_s1d13522.c has information about the video resolution. Unfortunately, changing the bVideoResolution char in the setup structure of the SD card does not set the screen to the right resolution. It *does* change the resolution - but not the way I want it.
Here's what to do on a Linux machine:
Insert the SD card of your Kobo. Let's call it /dev/sdX for now (here it is /dev/sdb, but if I use the memory card reader, it is /dev/mmcblk0). Anyway:
dd if=/dev/sdX bs=512 skip=1024 count=1 |xxd > /tmp/original-config
See below what this file means.
Anyway, now you can edit it with your favourite editor. Change, for example, the resolution from 06 to 01, like I did. This is the last byte on the third line.
Now use "xxd" again to make it a binary blob again:
xxd -r /tmp/original-config > /tmp/newconfig.blob
And use DD to put it on disk:
dd if=/tmp/newconfig.blob bs=512 seek=1024 count=1 of=/dev/sdX
Eject your disk and reboot your Kobo with it.
A config file looks like:
00000000: 4857 2043 4f4e 4649 4720 7632 2e34 0034 HW CONFIG v2.4.4
00000010: 2e0c 0000 0700 000b 0407 0200 0209 0105 ................
00000020: 0300 0002 0200 6800 e400 0005 0105 0001 ......h.........
00000030: 0b00 0100 0411 0000 0010 0000 0100 0100 ................
You can find what it all means at
https://github.com/pazos/linux-3.0.3...ntx_hwconfig.h in the tagNTXHWCFG_VAL struct.
Your screen resolution is in bDisplayResolution which is the last byte of the third line. You can see I changed it to "01", in order to look like
https://github.com/pazos/linux-3.0.3...ake_s1d13522.c suggests it to (1024x758).
As said, this does not help - i.e. it does change things, but I do not end up with a working Kobo Glo HD with downgraded screen.
I tried to change other settings, like the bDisplayPanel and even the bootup progress bar location, to no avail. I will order a proper ED060KG1. But if anyone wants to change their setup, please feel free to do so.