Since the guides on iflash.xyz itself are outdated and the main thread in this forum that covers that topic might be a little confusing to some people although OP's edit claims all issues are fixed, I decided to do this clean guide for convenience.
Disclaimer: If Windows shows any "you have to format this drive" messages in the process, always click abort and close those Explorer windows down
So here are the steps for an iPod7 using Windows, tested by myself with an iFlash Solo that holds a 512 GB SanDisk card:
- Although this step is optional I recommend it: Format the SD card with GUIformat to FAT32 with 32xxx cluster size
- Open iTunes and plug in the iPod
- After iTunes detected it, use iTunes to "restore" it
- The iPod will reboot and will be re-detected by iTunes (this might take some time)
- iTunes is trying to setup the iPod with you with a wizard -> you don't need this so close iTunes for good
- Now download the Rockbox Utility and start it
- If not autodetected, select the iPod Classic Gen6 (7 is officially Gen6 but since I tried this with a 7 I stay at it with this guide)
- In the dropdown select the development build instead of the stable release
- Make sure all checkboxes are checked and hit install
- Be careful when the message comes telling you to press and hold MENU+SELECT until it tells you to stop holding them -> you definitely have to release them as soon as the "release" message pops up -> timing is very important here
- The screen stays black but don't worry, the utility will continue -> mine stuck at 83 % for a while but then went on so be patient
- Now here's the thing -> the utility always stops at 99 % for any Gen 7 I have ever tested it with, even with the original HDD instead of iFlash -> don't worry, just proceed with the next step
- While keeping the utility open and not touching it -> get the iPod Classic dev build manually
- Find the mounted iPod SD card in your Windows explorer and copy the .rockbox folder manually from the ZIP of the previous step into the root of that SD card
- Also in the root of the SD card create a "Music" folder where you put in all your music (in fact it can be named anything and placed anywhere but I'd recommend doing it that way)
- Now click abort in the utility and close it
- Safely eject the iPod using the USB icon in the Windows taskbar next to the clock ad the bottom right
- Press and hold MENU+SELECT for 5 seconds and it should boot up Rockbox
- Enjoy
I recommend you to use the original iPod OS for transfering files from the PC. To boot into it, hold MENU+SELECT 5 seconds until the iPod reboots, then quickly lock it. If the stock OS has booted up, connect and do your file transfers. When you're finished, safely eject the iPod and reboot it once again with MENU+SELECT for 5 seconds but this time without locking it so it boots into Rockbox where you can update the database manually or wait for it to happen automatically.
I want to thank all involved devs. There's nothing better than a modded iPod with Rockbox.