BlackBerry PlayBook (blackberry-playbook)

Research
The Blackberry PlayBook can't be unlocked through any official methods.

There has been some research into the security of the chipset:
 * http://droid-dev.mobi/wiki/Booting_chain
 * https://processors.wiki.ti.com/index.php/OMAP4_Debug_and_Trace_Tools
 * Bootrom dumps, dead links: https://forums.crackberry.com/blackberry-playbook-os-f228/playbook-bootrom-mlo-bootloader-830909/
 * Security overview from NCC Group: https://www.nccgroup.com/uk/our-research/blackberry-playbook-security-part-one/

Blackberry implemented a package-on-package configuration for the OMAP4430 and DRAM. JTAG might give more interesting information, some research was done in 2013 by QuackQuack147: https://unlockplaybook.wordpress.com/2013/08/07/progress-irc-chat/ The JTAG pins are probably buried beneath the BGA package.

Link to bootrom of the OMAP 4430 on the Motorola Milestone 3: http://droid-dev.mobi/wiki/File:Omap_4430.bin.gz

Porting kexecboot-droid4 might be interesting if there are partitions that are not verified by the bootloader: https://github.com/tmlind/droid4-kexecboot/blob/master/PARTITIONS