[Nook HD, HD+ Android Development] digixmax:
Building a CM11 SD card with customized partition sizing for HD+

[Caveat emptor: adopt/follow this guide at your own risk].

FWIW, below is a digest of the process which I have used to build a CM11 SD card from scratch so as to have my own customized sizing for the 3 boot/system/data partitions.

Use a disk partition tool (such as MiniTool Partition Wizard Home Edition) to create 3 partitions: boot (Primary, FAT32), system (Primary, Ext4), and data (Primary, Ext4). Set the partition ID type for the /boot partition to 0x0C FAT32 LBA and set its Active flag (otherwise the SDcard will not be bootable). Once this is done, the boot partition should appear as a (read/write accessible) drive under Windows. (Note that you can adjust the suggested sizes of the partitions upward to fill up the entire SDcard; FWIW the sizes I use on my 8GB card for the 3 partitions are, respectively: 0.5GB/1.0GB/[remainder of SDcard]).

Download sdcard-ovation-cm11.0-v1.img linked in Bokbokan's OP http://xdaforums.com/showpost.php?p=48808658&postcount=1.

Use an archive file manager such as 7-zip to extract from sdcard-ovation-cm11.0-v1.img and copy to the boot partition of the SD card the following files:

first

MLO, then u-boot.bin, kernel, ramdisk.cwm, ramdisk.stock, uImage.

Download and copy to the /boot partition the pair of archive zip files for cm-11-yyyymmdd-UNOFFICIAL-sgt7-ovation linked in the OP and Gapps package of choice for CM11 – e.g., from http://wiki.cyanogenmod.org/w/Google_Apps.

Put the SD card into the HD+ and boot from its power off state. Press and hold the N button as soon as CyanoBoot comes up to get the boot menu to display.

Select "Boot CWM Recovery".

Select "Install zip from SD card" and install the cm-11-yyyymmdd-UNOFFICIAL-sgt7-ovation zip file.

Select "Install zip from SD card" and install the chosen gapps package zip file.

Press and hold power button to turn off the HD+.

Boot the HD+ from its power off state; the HD+ will boot into Cyanoboot which will load (CM11) boot by default, after about a couple of minutes you should see boot animation lasting for a few minutes followed by initial wifi network and google account setup process, after which your CM11 on SD is ready for use.

A few additional points worth noting:

I put together this process and used it for my HD+ (ovation), and have no means to test whether it would work for the Nook HD (hummingbird).

The two most common symptoms of failed SD boot and their likely causes are:

The HD+ boots straight to stock -- most likely the boot partition's type and/or flag are not correctly set, or the HD+ 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 (see http://xdaforums.com/showpost.php?p=46205400&postcount=96)).

If the HD+ consistently boots straight to stock in spite of a valid /boot partition and boot files, it's possible that the tablet is one of those HD+ units that have difficulty booting off SD cards, see http://xdaforums.com/showthread.php?t=2288688 for more info and potential remedies.

The HD+ screen stays dark for seemingly a long time then eventually boots to stock -- most likely the MLO or u-boot.bin are corrupted. I have had this happen to me a few times in the process of extracting them from archive zip files and also in ftp transfers between machines (need to use "binary" instead of "auto" mode). When in doubt, compare the size of the two copies of the files in bytes.

Generally the lower rating (and also cheaper) class 4 SD cards are more suitable for running a ROM than the higher classes 6 and 10 cards (since the latter are optimized for large & sequential block read/write at the expense of random read/write). So if you happen to use a class 10 or 6 card and your apps frequently crash or freeze, consider switching to a lower class SD card. See this thread http://xdaforums.com/showthread.php?t=1005633 for extensive discussion of SD card makes/models' comparative performance for use in hosting ROM.

To update the SDcard when Bokbokan posts a new CM11 build, simply repeat steps 4 through 10.

Bokbokan's ROM and Gapps zip files can be downloaded to the HD+ (in lieu of the SD card /boot partition) and selected for installation from there.

The above procedure can also be used to build from scratch a SD image of Succulent’s CM11 builds posted at http://iamafanof.wordpress.com/2013/12/20/cm11-0-kitkat-android-4-4-2-for-nook-hd-xx-20dec2013/. The set of boot files (MLO, u-boot.bin, kernel, ramdisk.cwm, uImage) can be obtained from Succulent's HD+ boot-file repo http://goo.im/devs/succulent/ovation/cyanogenmod/nook_hd+_bootfiles.zip or from one of his pre-made CM11 SDcard images posted under the heading "SDCARD IMAGE" (note that the boot files for Bokbokan's and Succulent's builds are

not

interchangeable). The archive zip files for

SD

-based versions of ROM and Gapps are posted under the heading "SDCARD ROM" and "SDCARD GAPPS".

Although flashing SD-based ROM & Gapps should not affect the stock ROM on emmc, I have run across incidents in which some part of the emmc stock ROM accidentally got corrupted and subsequently failed to boot. As such, I strongly recommend using SD-based CWM recovery to make a backup copy of the stock ROM (see http://xdaforums.com/showpost.php?p=35811322&postcount=1) for ease in restoring the stock ROM in the event of such accident. Note that if you plan to create the backup copy on SD card then make sure that the /boot partition is large enough to store the backup copy of your emmc /system and /data partitions.

HOW-TO Guides for Installing CyanogenMod on Nook HD+

Installing CM11 Internally on Nook HD+

Building a CM11 SD card with Customized Partition Sizing for HD+ (this guide)

Updating HD+ Internal EMMC to CM11 from CM10.x