[WIP][Dev]Bootloader bypass

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No, I do not have a nook tablet so I can not offer any methods to bypass myself. This is just a thread where developers can talk about gaining the ability to flash roms and recoveries.

Developers, please use this thread to collaborate so we can have everyone working in the same space.
Users, please try to not post and if you do, don't make it a completely useless post like something that just says thanks and whatnot. Just use the button for that. The less clutter = more progress


edit: Someone is donating a nook tablet to me to try and bypass the bootloader! Here's hoping it doesn't get bricked.

I've got a Nook Tablet and would be more than happy to help with this. I'm available most evenings after 9PM EDT.

I've been reading alot about kexec and 2nd init. It looks like 2nd init is the way to go, due to the fact that it's already been used multiple times.

Ideally what I'd like to do is try to reverse engineer a current 2nd init to work for the nook.

The potential issue I see is, the kernel may not be new enough to run CM7.

Am I completely off base here?

Originally Posted by chantman

I've got a Nook Tablet and would be more than happy to help with this. I'm available most evenings after 9PM EDT.

I've been reading alot about kexec and 2nd init. It looks like 2nd init is the way to go, due to the fact that it's already been used multiple times.

Ideally what I'd like to do is try to reverse engineer a current 2nd init to work for the nook.

The potential issue I see is, the kernel may not be new enough to run CM7.

Am I completely off base here?

Kernel is good enough to run CM7 (Gingerbread), but not sufficient for CM9 (ICS). Also it is not good enough for CM8 either (although the chance we see CM8 for any device is doubtful).

We need to find a way to keep a chat between developers. Add me on g+ and ill create a huddle for every dev

Sent by breaking the sound barrier

Originally Posted by chantman

I've got a Nook Tablet and would be more than happy to help with this. I'm available most evenings after 9PM EDT.

I've been reading alot about kexec and 2nd init. It looks like 2nd init is the way to go, due to the fact that it's already been used multiple times.

Ideally what I'd like to do is try to reverse engineer a current 2nd init to work for the nook.

The potential issue I see is, the kernel may not be new enough to run CM7.

Am I completely off base here?

your pretty spot on, but i dont see cm7 being a problem, i see cm9 being a problem. with a 2nd init rom you have to build the OS around the kernel(which it is much harder than doing it the right way) and if the kernel isnt high enough or if drivers are outdated(like the nook color graphic drivers) than you can count that OS out of your list. cm7 since it is gingerbread and since gingerbread can be booted on a froyo kernel(moto droid proved that along with the droid x/2), i think it can be booted using 2nd init, ICS on the other hand needs a ICS kernel to boot and if your not using an ICS kernel than you need a custom kernel that can get ics booting properly

now i disagree with you about 2nd init being the best way to build a rom for the nook tablet, i believe kexec is the best way to go about building a rom for the nook tablet because it will allow for a custom kernel to be booted off the original kernel. from what i have read about kexec on android is that they cant get the 3g chip to get started again(but nook tablet doesnt have a 3g chip so who cares), but wifi and all the other key functions can get started up and running, so using kexec on a nook tablet seems the best logical solution to getting around the locked bootloader(but dont quote me on this cause i havent developed anything for the nook tablet yet, nor do i even own one).

---------- Post added at 11:19 PM ---------- Previous post was at 11:18 PM ----------

Originally Posted by Indirect

We need to find a way to keep a chat between developers. Add me on g+ and ill create a huddle for every dev

Sent by breaking the sound barrier

devs use irc to chat, its easier than any forum or chat program out there

Thats true but i cant always be on irc to keep up on info.

Sent by breaking the sound barrier

Also, ill look into getting kexec once i get my nook tab

Sent by breaking the sound barrier

Originally Posted by Indirect

Thats true but i cant always be on irc to keep up on info.

Sent by breaking the sound barrier

There are most likely complete logs available somewhere to review, or someone could make them available for you. I don't have the link on this pc, but there is a site that keeps up-to-date logs #nookcolor available

Originally Posted by Indirect

Also, ill look into getting kexec once i get my nook tab

Sent by breaking the sound barrier

I wouldn't spend too much time on this. Assuming that android_4430BN_defconfig from B&N's kernel sources is the defconfig used to compile the running kernel, kexec will not work as it has been disabled.

it doesn't really matter if kexec has been disabled in the kernel config. we can't really hope that they would leave a gaping hole that fricking big. honestly i'm kind of annoyed at the "omg they didn't configure their kernel specifically for us to hack the crap out of the device" posts. Seriously, even if they did this, as far as i've seen we have yet to disable OTA updates, so 3 seconds of a B&N developer time would wipe out any work depending on kexec being built into the kernel.

we can after all create modules neh? my linux kernel hacking experience is very close to non-existent, but i'll be starting by getting a module to load, followed by getting the kexec tools and a kexec module loading.

so far i'm having trouble finding any literature on kexec on ARM. it all says it's x86 only, but clearly everyone from motorola to sony communities are making use of kexec on arm. anyone know of any good points to find information on kexec for arm?

I've also seen something call splboot mentioned a few times, but am having trouble googling anything useful up. anyone familiar with that tech?