Custom boot image

[Stericson]

Note - You must have the modified rc30 update provided by Jesusfreke, and the unlocked bootloader from the dev g1 phone to do this! You assume any risk there may be involved in trying to do this!

Want to get rid of that t-mobile boot image?

Disconnect, over at Gotontheinter.net, has figured out how to do it using the new unlocked bootloader from the g1 dev phone. Below is a quote from the source. ( http://www.gotontheinter.net/node/9 )


"So you want to join the party and flash your own boot image, but its a weird undocumented format and you don't want to spend all year researching it in the source. Well, I'm here to help.

It is actually very simple. Start with an image you want to use, make sure it is 320x480 with 8bpp color. (In my examples, I'll use splash.png: PNG image data, 320 x 480, 8-bit/color RGBA, non-interlaced
Just make sure you have ImageMagick installed, and the utilities from the source build. (Specifically, rgb2565.)

$ convert -depth 8 splash.png rgb:splash.raw
# Make sure it is 460800 bytes long!
$ rgb2565 < splash.raw > splash.raw565
# Triple-check size before flashing! 307200 bytes
$ fastboot flash splash1 g1-splash.rle
$ fastboot reboot

Lets break it down. the convert turns it from a png (or any supported image format) into a raw 8-bits-per-color no-alpha data file. This file should be 460800 bytes - no more, no less.

Next, rgb2565 converts that file to a raw 565 16bit file (for the framebuffer on the G1.) This file is exactly 307200 bytes long - if its not, you messed up somewhere.

Finally, you use fastboot to flash the splash image and reboot. Instead of the B&W T-mobile logo, now you will see your custom splash screen. Congrats! "

Thanks to Infernix for the following extended how to:

1. find an image you like
2. edit it with your favourite editing suite and scale it to 320x480
3. after scaling it, convert the colorspace to 256 colors (8-bit)
4. Save it as a PNG without alpha channel/transparency.
5. Use the convert tool from the ImageMagick toolkit (use cygwin, or a linux box): convert -depth 8 splash.png rgb:splash.raw
6. Check that the splash.raw file is exactly 460800 bytes!
7. Compile the android tool called rgb2565 (gcc -O2 -Wall -Wno-unused-parameter -o rgb2565 to565.c)
8. Run the conversion command: rgb2565 < splash.raw > splash.raw565
9. Check that splash.raw565 is 307200 bytes. if it isn't, DO NOT FLASH IT ON YOUR PHONE. double-check your steps, something went wrong.
10. Boot your phone in SPL mode (hold camera +power).
11. After SPL shows, plug in USB connector/cord/whateva and push trackball or hit back. SPL restarts and now shows FASTBOOT.
12. If on windows, you need to install http://dl.google.com/android/android_usb_windows.zip
13. Compile android (see http://source.android.com/download) and make sure the fastboot binary (mydroid/out/host/*/bin/fastboot) is compiled (* being your OS)
14. use fastboot devices to check whether if your phone is showing up. if it isn't, try it as root (user might not have permission to access the usb device).
15. Double check that splash.raw565 is 307200 bytes. if it isn't, DO NOT FLASH IT ON YOUR PHONE.
16. Flash the splash image: fastboot flash splash1 splash.raw565
17. Reboot your phone to check: fastboot reboot

Infernix, and some others, also posted some of the files needed(located in this thread: http://forum.xda-developers.com/showthread.php?t=456071), such as fastboot, and rgb2565, for linux and mac. I posted the rgb2565 binary for Windows, however, I cannot produce fastboot for Windows because compiling the Android source on Windows is an undocumented procedure and I ran into a great deal of problems trying to compile it using cygwin. Google never intended on supporting building the Android source code from Windows anyways. So, if you don't have Linux or Mac, you are going to have a very tough time doing this.


Stericson

[Stericson]

I posted this into the wrong thread before, this is where this should have been posted, sorry.

This is what I chose for my bootscreen, instead of the default black and white T-mobile G1 screen.

[rynosaur]

I posted this into the wrong thread before, this is where this should have been posted, sorry.

This is what I chose for my bootscreen, instead of the default black and white T-mobile G1 screen.

Thanks for your efforts yet again, Stericson.

For me . . . this goes beyond light hacking. The first author to write a comprehensive program like TweakUI to incorporate all known root-level hacks will have my $10! However, at this point, it looks like a custom bootloader image can't be accomplished through Android OS b/c it involves modifying a running kernel, no?

[Stericson]

No, if you have root, the modified rc30 update installed, along with the dev bootloader installed, then you can flash a new boot image to your phone, however, it will require that you have either a mac os or a linux os in order to use fastboot and flash the file to your phone. I compiled the rgb2565 binary for windows but was unsuccesful, AKA I gave up because of how many problems I ran into, at compiling fastboot for Windows. So, there is a technical aspect of it that can get rather involved.

You don't have to modify a running kernel as you put it...That is unless I totally missed something....

Stericson

[rynosaur]

No, if you have root, the modified rc30 update installed, along with the dev bootloader installed, then you can flash a new boot image to your phone, however, it will require that you have either a mac os or a linux os in order to use fastboot and flash the file to your phone. I compiled the rgb2565 binary for windows but was unsuccesful, AKA I gave up because of how many problems I ran into, at compiling fastboot for Windows. So, there is a technical aspect of it that can get rather involved.

You don't have to modify a running kernel as you put it...That is unless I totally missed something....

Stericson

I just saw compile and I froze up. Perhaps I misread. Recompiling Ubuntu is fun for giggles, but the idea of recompiling the bootloader or kernel of my brickable G1 strikes fear into my newbie heart.

[Stericson]

Specifically you are not recompiling anything that will be flashed onto your g1. The only thing being compiled is the rgb2565, which converts your raw image file file to a raw 565 16bit file (for the framebuffer on the G1.) Then you have to compile fastboot from the android source code so that you can flash this splash file onto the g1. Nothing going to the g1 is being recompiled, or compiled.

Needless to say it does take a little time and familarity with linux or mac to do this.
If you don't have faith in yourself to do it, then you probably shouldn't. This isn't specifically pointed at you Rynosaur.

[rynosaur]

I guess the first hurdle is installing the dev bootloader. I was trying to decide between that and installing koush's auto-rotating browser first. I was a little put off by others' experiences in the install not having enough flash memory ton complete the browser mod.

*gathering courage*

Thanks

[Stericson]

I myself installed Koush's auto rotate browser and did so with no problems.

It doesn't really matter which order you install those two anyways, one over the other is fine.

Side note: Installing the dev bootloader is super easy. If you installed the mod rc30 update you can do this with no problems. And it goes really quick.

Let me know if I can be of anymore help.

[Benjorno]

Infernix, and some others, also posted some of the files needed(located in this thread: http://forum.xda-developers.com/showthread.php?t=456071), such as fastboot, and rgb2565, for linux and mac.

Can we get a copy of those files (specifically for linux) over here? I freaking lost my copy and xda is down. I have scoured the googles and can't find it...don't wanna have to compile it because you have to compile all of android for a single binary

[kaysesoze]

nice find...
this makes me wanna go out and buy the linux for dummies book.. lol...