GINGERBREAD METHOD + DUMP TO GET A DIRECTLY FLASHABLE COLORED LOGO:
Rename your 480x800<100ko image (not sure maybe bigger's works,I heard that but a test with 177ko image didn't worked for me) as logo.jpg and copy it to /sdcard.
Flash a Samsung ginger rom (for me JVU).
Flash a kernel to get root (which one is up to you as long as it fits with the stock ginger firmware you just flashed,a matching CF-Root or Semaphore for instance but if semaphore don't forget to take superuser on market.
Tick usb debug in phone settings (somewhere under applications>development if i remember well) and set screen off delay to 10 minutes to be sure (adb loose connection when screen is off).
Go to download mode and flash that "empty" param.lfs .tar with Odin (or the param.lfs in it if using Heimdall):
That comes from here:http://forum.xda-developers.com/show....php?t=1065743
Device will reboot to recovery,choose reboot system.You may see download mode logo but it will boot fine.
Once device is running you plug USB (don't activate mass storage) , open command and type "adb devices" first to be sure adb see your device and then:
adb shell su -c "mount -o remount,rw /dev/block/stl6 /mnt/.lfs"
adb shell su -c "busybox cp -r /mnt/sdcard/logo.jpg /mnt/.lfs/logo.jpg"
Reboot device to check,if all went well you may see you have now two logo,the new one that appears fast followed by the samsung one...it sucks but when you'll get back to your CM10.1 or whatever aosp rom it will be ok and stay like this until you flash a stock samsung ginger rom again
If you have to use terminal emulator commands will be a little different:
mount -o remount,rw /dev/block/stl6 /mnt/.lfs
busybox cp -r /mnt/sdcard/logo.jpg /mnt/.lfs/logo.jpg
That's it you can now go back,if you came to ginger just for this, to your aosp rom but before that what about saving this new logo in a param.lfs file you'll be able to flash directly on top of aosp rom?
Open terminal emulator and type:
dd if=/dev/block/stl6 of=/sdcard/param.lfs bs=4096
You'll get a 1.25mb param.lfs file that can be flashed directly on aosp i9000 rom.
Use the param.lfs as it is if using Heimdall or .tar it for Odin (I use iZarc to get working Odin .tar on windows).
That's how it is: A param.lfs extracted from a stock Sammy ginger firmware can't be flashed on aosp (softbrick, only download mode available); but a dump of a stock ginger mnt/.lfs partition saved as param.lfs yes.
What you can get this way:
First a dump of the original i9000 logo:
Or something more shiny like this:
Download links in first post above.
Enjoy and share your products please