[Barnes & Noble Nook Tablet] digixmax:
[Caveat emptor: adopt/follow this guide at your own risk].

[

Important Note:

this process is applicable for CM11 builds that still maintains two separate partitions for /data and /media – as the case with CM10.x and stock ROMs (see http://xdaforums.com/showthread.php?p=48612997#post48612997 for more info). If/when these two partitions get merged in some future CM11 builds (as being contemplated by our NT CM developers – see http://xdaforums.com/showthread.php?t=2560827&page=28) this installation process will

not

be valid for those future builds with merged /data+media partition].

The following is the process using SD-based recovery to install CM11 internally (i.e., on emmc) on a Nook Tablet running stock ROM. [If your NT is already running CM10.x, see http://xdaforums.com/showthread.php?t=2670589 for a simpler process to update from CM10 to CM11]. This same process can also be used to install CM12.x -- see http://xdaforums.com/showpost.php?p=64624390&postcount=21 for needed corresponding versions of CM12 ROM, Android 6.0 GApps, and EMMC-based CWM recovery.

Using a disk partition tool (such as MiniTool Partition Wizard Home Edition) create on SD card a Primary FAT32 partition, and set the partition ID type for the partition to 0x0C FAT32 LBA and set its Active flag. Once this is done, the partition should appear as a (read/write accessible) drive under Windows

Obtain and copy to the SD card the following files:

first MLO, then next u-boot.bin and flashing_boot.img in succulent_boot.zip obtained from https://www.mediafire.com/folder/xjwc1a482a6ll/Nook_Tablet

TWRP (TeamWin Recovery Project) version 2.6.3.0 or later, e.g., openrecovery-twrp-2.6.3.1-acclaim-sdcard.img from http://techerrata.com/browse/twrp2/acclaim, rename it to recovery.img before copying to SD card.

the flashable_CWM_6.0.4.5_chrmhoffmann.zip zip file from https://www.mediafire.com/folder/xjwc1a482a6ll/Nook_Tablet which contains the CWM recovery v0.2 provided by Chris Hoffmann (in the first post of the XDA Official CM11 thread http://xdaforums.com/showthread.php?t=2560827).

the zip file of CM11 ROM build of your choice from http://download.cyanogenmod.org/?device=acclaim (see http://www.cyanogenmod.org/blog/cm-11-m4-post-release-items for considerations in choosing nightlies vs. snapshot/stable builds).

the zip file of the Gapps package corresponding to CM11 – e.g., from http://wiki.cyanogenmod.org/w/Google_Apps

Put the SD card into the NT, and boot from its power off by inserting a powered USB cable. Press and hold the N button as soon as CyanoBoot comes up to get the boot menu to display.

Select SDC Recovery.

[

Optional step but highly recommended

] Select Backup to backup your NT current ROM config (/boot, /recovery, /system, and /data).

Select Wipe data & factory reset.

Select install zip from SD card and install flashable CWM recovery zip file.

Select install zip from SD card and install CM11 zip file.

Select install zip from SD card and install Gapps zip file.

Remove SD card and select reboot.

Once the NT boots up, set up the wifi connectivity and your google account info. If you had previously used Google backup service on your NT your apps will be auto-downloaded (but their settings will not be auto-restored).

Notes

If the Nook fails to boot off SD -- the two most common symptoms of failed SD boot and their likely causes are:

The NT boots straight to stock -- most likely the boot partition's type and/or flag are not correctly set, or the NT cannot find the MLO in the boot partition (make sure that MLO is the very first file to be copied to the freshly made /boot partition).

The NT screen stays dark for seemingly a long time then eventually boots to stock -- most likely the MLO or u-boot.bin are corrupted. When in doubt, compare the size of the two copies of the files in bytes.

Installing CM11 ROM and Gapps will override your NT's current boot, recovery, ROM, and Apps, so make sure that you backup all this stuff using recovery backup function, for easy in reverting to previous ROM if desired. See my post at http://xdaforums.com/showthread.php?p=48612997#post48612997 for more "Info and Tips for Mitigating Risks in Rooting and Flashing Custom-ROM".

Also, I would advise against using any other functions of the recovery without first carefully researching to understand what they really do.

My thanks to all the developers who collective work created the wonderful CM11 ROM for the NT as well as the tools and info I made use of to install it.