Tech note: Android ROM flashing

All this information is particular for the Proximus Magic 32A particular, but it will still give you an overview of how the procedure actually works.

Searching on the web there are a lot of custom Android ROM images out there, but not a single website seems to give a highlevel overview of how the flashing procedure actually works. Understand first that flashing your ROM will void your warranty. Also, if something goes wrong in the process you might end up bricking your phone. This is just a checklist and a reminder-to-self, not a fool-proof procedure. It doesn't -for example- include backing up your settings (for which you can use Nandroid). USE WITH CAUTION!

• make sure you can talk to your phone with adb and fastboot. If you don't know what this means, you probably shouldn't be flashing your ROM. In the whole procedure, leave your phone connected to the computer by usb.
• Get a fastboot version which works with your phone. I'm not 100% sure you need the version from HTC for Magic, but I used that one anyway to be sure. Fastboot command line commands on your computer will only actually only "do" things when you're in fastboot mode (see below).
• Get a "recovery image" from web for 32A (proximus) type phone. Recovery images are images with a minimal "os" on it for you phone that let you do things like flash the rom, create and recover from backups, format the filesystem of your sdcard... those kind of things. You could call it a boot diskette. See for example this one which works very nicely with the type 32A phones.
• Now put phone in fastboot mode, you do this by switching the phone off, then start it again while holding down the "back" button (so, hit back, then hit power and hold down both). You phone should now look something like this
• On your computer command line now enter: fastboot boot recovery.img
  Obviously make sure the recovery image is in the current path. This will restart your phone with the recovery image. Your phone should now look like this
• Get the new ROM you want, I recommend the ones from gyd.be if you have a proximus branded magic
• In the recovery interface mount your sdcard, put the ROM of your choice on the card (don't unzip it, leave it as something.zip) and then "apply" it.
  If the recovery fails to read the zip (like in my case), "partition" the sdcard within the recovery image (fat32). Doing the formatting in Win7 made the card unreadable for Android in my case!