[Nook HD, HD+ Q&A, Help & Troubleshooting] will4n:
I'm using the wonderfully organized files from amaces' box to image an sd card for BNVT400/hummingbird. After dd-ing the .img file, the Nook seems to try to boot from it. But, after 6 minutes of a black screen, it boots into stock normally. From the stock android I can see SD card contents -- it's mounted and has the files I expect it to.

Notably, before considering a custom ROM, I recently factory reset. Because the stock setup wizard failed with an internet connectivity issue (re: TLS<1.2), I followed B&N's instructions and updated with sideload_2.2_update.npk

Even after additional factory resets, the software version remains 2.2.1

I've read in a few places (e.g leapinlar;s tips) that SD boot isn't a sure thing. I've tried maybe 10 times across 2 days. With and without powering on via USB cable. (and via adb reboot and adb reboot bootloader). That's overkill right?

Is there something obvious I missed?

Thanks!

_________

sudo dd if=sdcard-reco-hummingbird.img of=/dev/sdd bs=1M status=progress
# 933232640 bytes (933 MB, 890 MiB) copied, 58 s, 16.1 MB/s
# 900+0 records in
# 900+0 records out
# 943718400 bytes (944 MB, 900 MiB) copied, 81.4684 s, 11.6 MB/s

SD card is formatted w/ only partition as Fat32 with boot flag, and with first file MLO

sudo fdisk -l /dev/sdd
# Disk /dev/sdd: 7.5 GiB, 8057257984 bytes, 15736832 sectors
# Disk model: MassStorageClass
# Units: sectors of 1 * 512 = 512 bytes
# Sector size (logical/physical): 512 bytes / 512 bytes
# I/O size (minimum/optimal): 512 bytes / 512 bytes
# Disklabel type: dos
# Disk identifier: 0x5387f638
#
# Device Boot Start End Sectors Size Id Type
# /dev/sdd1 * 59 1757963 1757905 858.4M c W95 FAT32 (LBA)

sudo mount /dev/sdd1 /mnt/usb -o uid=1000
stat -c "%y %n" /mnt/usb/*|sort
# 2013-06-10 15:49:44.000000000 -0400 /mnt/usb/MLO
# 2013-06-10 15:49:56.000000000 -0400 /mnt/usb/u-boot.bin
# 2014-01-19 18:22:28.000000000 -0500 /mnt/usb/ramdisk.cwm
# 2016-02-13 14:48:20.000000000 -0500 /mnt/usb/ramdisk.stock
# 2016-02-13 14:50:58.000000000 -0500 /mnt/usb/OLD
# 2016-04-03 13:35:56.000000000 -0400 /mnt/usb/kernel
# 2016-04-03 13:35:56.000000000 -0400 /mnt/usb/ramdisk
# 2016-04-03 13:35:56.000000000 -0400 /mnt/usb/uImage

# added zips to flash. but never get to use them :(
cp lnos_hummingbird-ota-NJH47F.181223.zip twrp-2.8.7.5-hummingbird.zip addonsu-14.1-arm.zip /mnt/usb/
eject /mnt/usb

As a sanity check: when the sd boot fails, I confirmed the files on the SD card are readable by the Nook. and that the Nook is in fact BNVT400/hummingbird.

aft-mtp-cli ls
# selected storage 131073 SD Card
# 155 MLO
# 156 u-boot.bin
# 157 ramdisk.stock
# 158 ramdisk
# 159 kernel
# 160 ramdisk.cwm
# 161 OLD
# 164 lnos_hummingbird-ota-NJH47F.181223.zip
# 165 twrp-2.8.7.5-hummingbird.zip
# 166 uImage
# 167 addonsu-14.1-arm.zip
# 168 B&N Downloads
# 173 My Files

adb shell cat /proc/cpuinfo
# Processor : ARMv7 Processor rev 10 (v7l)
# processor : 0
# BogoMIPS : 789.24
# processor : 1
# BogoMIPS : 792.89
# Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3
# CPU implementer : 0x41
# CPU architecture: 7
# CPU variant : 0x2
# CPU part : 0xc09
# CPU revision : 10
# Hardware : OMAP4 Hummingbird board
# Revision : 0006