I want to dual boot my N900 with... something. Not sure what, I want to test a few options. But I've been struggling with it and can't find my way out of the pickle.

I think I have uboot. Or do I? I am not sure. I boot with the slider open and get a white screen with a menu with two options: Boot Maemo and Power Off. Is that uboot? Probably not, because I opened the Uninstall section of the App Manager and couldn't find any uboot.

I followed the instructions for SHR, installed it on an 8GB SD card, put it in the N900 and... nothing happened. I booted with the slider open and got a white screen with a menu with two options: Boot Maemo and Power Off. No sign of SHR.

Then I followed the instructions to install Ubuntu. Boy, did that take long! 5 hours, I think! And after all that, no joy, because I can't make it boot.

So I tried to install uboot just to make sure I really had it. I found two versions: pr13 and Pali's U-boot with kernel 2.6.28-omap1. I can't install either. For pr13, an error message says it is incompatible with the Power User kernel. For Pali's, it says "!!!U-Boot with kernel 2.6.28-omap1 breaks the 3rd party package policy." Whatever that means.

Fine, I found the Power User kernel and uninstalled it. Then I rebooted.

Then I tried to install the two versions of uboot and still got the same error messages. But I uninstalled the Power User kernel! What's going on?

Then I kind of panicked a little, clicked and read a lot of things. I remember I saw somewhere that I was supposed to install 'Nokia kernel' or something like that in order to remove the Power User kernel properly. But where is that Nokia kernel? I can't find it.

I didn't use my N900 for almost a year so I forgot a lot of stuff and now I am very confused. Can someone please shed some light on this situation?

I found a 'Nokia kernel' item in the list of applications. But when I run it, it says

"Error during installation: Could not install Nokia kernel."

sigh...

Since I didn't get any help, I flashed the phone. Then I could finally install U-boot pr13.

But it still doesn't work. I followed all the instructions for SHR, and when booting, the boot sequence always defaults to the maemo OS, not the SD card.

So I press some key to interrupt the default boot sequence and 'run mmcboot' and get this error:
So I tried the Ubuntu installation, with the custom kernel. No progress, I still get the same error.

How do I make it work? And how come I don't get any replies here? Am I being punished for having failed to read some instruction somewhere that I am supposed to look again and again over and over in some corner of this forum until I finally find it and solve it by myself instead of bothering other people with my problems?

mate post the steps , install kernel power & kernel-power-bootimg
after that install cssu testing , reboot ,install latest u-boot , extract your operating system rootfs ,after that copy .item file of the kernel you want to boot in etc/bootmenu.d, after that in xterm type after you gained root : u-boot-update-bootmenu , more noobish than that I don't know how to explain

Install kernel power? But I said above, there are two versions of U-boot only, pr13 and Pali's U-boot with kernel 2.6.28-omap1. The pr13 one is incompatible with kernel power. The other one says "!!!U-Boot with kernel 2.6.28-omap1 breaks the 3rd party package policy" and won't install, even with the newly flashed phone, without kernel power.

Then you mention

I didn't see that part of the instructions in any of the tutorials. I had no way to know that was necessary. Can you please elaborate? Where is that .item file you speak of?

Thank you for the attention.