[Barnes & Noble Nook Tablet] DeanGibson:
Patitioning details

The firmware is in partition mmcblk0p7.

Here is a dump of the EFI-partition table (see http://en.wikipedia.org/wiki/GUID_Partition_Table for formatting ):

dd bs=512 if=/dev/block/mmcblk0 count=34 | hexdump -C
00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff |................|
000001c0 ff ff ee ff ff ff 01 00 00 00 ff ef d1 01 00 00 |................|
000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 |EFI PART....\...|
00000210 e9 a9 dc dd 00 00 00 00 01 00 00 00 00 00 00 00 |................|
00000220 ff ef d1 01 00 00 00 00 22 00 00 00 00 00 00 00 |........".......|
00000230 fe ef d1 01 00 00 00 00 8c 38 21 ce 27 b9 5c 4a |.........8!.'.\J|
00000240 91 ce db d1 de 4a b3 bc 02 00 00 00 00 00 00 00 |.....J..........|
00000250 80 00 00 00 80 00 00 00 30 06 da 82 00 00 00 00 |........0.......|
00000260 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000400 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000410 00 40 4c cc a1 26 5c 47 ae cd 95 94 b7 6e 02 47 |.@L..&\G.....n.G|
00000420 00 01 00 00 00 00 00 00 ff 01 00 00 00 00 00 00 |................|
00000430 00 00 00 00 00 00 00 00 78 00 6c 00 6f 00 61 00 |........x.l.o.a.|
00000440 64 00 65 00 72 00 00 00 00 00 00 00 00 00 00 00 |d.e.r...........|
00000450 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000480 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000490 01 8a 9f c5 ea c7 e8 48 81 d0 7c 1f 7b 42 36 a5 |.......H..|.{B6.|
000004a0 00 02 00 00 00 00 00 00 ff 03 00 00 00 00 00 00 |................|
000004b0 00 00 00 00 00 00 00 00 62 00 6f 00 6f 00 74 00 |........b.o.o.t.|
000004c0 6c 00 6f 00 61 00 64 00 65 00 72 00 00 00 00 00 |l.o.a.d.e.r.....|
000004d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000500 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000510 02 40 f9 0b 5c 86 e7 43 aa ec a2 67 34 c5 4b b8 |.@..\..C...g4.K.|
00000520 00 04 00 00 00 00 00 00 ff 7b 00 00 00 00 00 00 |.........{......|
00000530 00 00 00 00 00 00 00 00 72 00 65 00 63 00 6f 00 |........r.e.c.o.|
00000540 76 00 65 00 72 00 79 00 00 00 00 00 00 00 00 00 |v.e.r.y.........|
00000550 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000580 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000590 03 b6 40 6a 37 7a 9f 47 91 ea f5 95 67 21 e1 ca |..@j7z.G....g!..|
000005a0 00 80 00 00 00 00 00 00 ff ff 00 00 00 00 00 00 |................|
000005b0 00 00 00 00 00 00 00 00 62 00 6f 00 6f 00 74 00 |........b.o.o.t.|
000005c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000600 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000610 04 7c 8f d5 fc 3f 50 45 97 1c 05 4b 8f 91 85 6b |.|...?PE...K...k|
00000620 00 00 01 00 00 00 00 00 ff 7f 02 00 00 00 00 00 |................|
00000630 00 00 00 00 00 00 00 00 72 00 6f 00 6d 00 00 00 |........r.o.m...|
00000640 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000680 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000690 05 d7 81 d9 0b fc 31 43 b1 b2 75 3f 6c f6 c0 ca |......1C..u?l...|
000006a0 00 80 02 00 00 00 00 00 ff ff 03 00 00 00 00 00 |................|
000006b0 00 00 00 00 00 00 00 00 62 00 6f 00 6f 00 74 00 |........b.o.o.t.|
000006c0 64 00 61 00 74 00 61 00 00 00 00 00 00 00 00 00 |d.a.t.a.........|
000006d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000700 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000710 06 e2 2e 46 e6 7f 5d 4c aa 16 1b 5e 9c 7b 4e 80 |...F..]L...^.{N.|
00000720 00 00 04 00 00 00 00 00 ff 8f 0f 00 00 00 00 00 |................|
00000730 00 00 00 00 00 00 00 00 66 00 61 00 63 00 74 00 |........f.a.c.t.|
00000740 6f 00 72 00 79 00 00 00 00 00 00 00 00 00 00 00 |o.r.y...........|
00000750 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000780 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000790 07 31 30 d2 3b 13 78 42 ab 09 a3 36 82 9e bc e4 |.10.;.xB...6....|
000007a0 00 90 0f 00 00 00 00 00 ff af 22 00 00 00 00 00 |..........".....|
000007b0 00 00 00 00 00 00 00 00 73 00 79 00 73 00 74 00 |........s.y.s.t.|
000007c0 65 00 6d 00 00 00 00 00 00 00 00 00 00 00 00 00 |e.m.............|
000007d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000800 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000810 08 10 e6 87 c7 b8 63 45 9e 3e 7d 09 6d 66 d5 e5 |......cE.>}.mf..|
00000820 00 b0 22 00 00 00 00 00 ff ff 2f 00 00 00 00 00 |.."......./.....|
00000830 00 00 00 00 00 00 00 00 63 00 61 00 63 00 68 00 |........c.a.c.h.|
00000840 65 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |e...............|
00000850 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000880 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000890 09 28 48 e1 68 cb f7 45 b0 07 a9 49 f2 e0 d8 62 |.(H.h..E...I...b|
000008a0 00 00 30 00 00 00 00 00 ff ff 4f 00 00 00 00 00 |..0.......O.....|
000008b0 00 00 00 00 00 00 00 00 6d 00 65 00 64 00 69 00 |........m.e.d.i.|
000008c0 61 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |a...............|
000008d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000900 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.|
00000910 0a 12 e4 66 a3 54 28 43 86 92 47 91 e0 80 37 37 |...f.T(C..G...77|
00000920 00 00 50 00 00 00 00 00 d7 ef d1 01 00 00 00 00 |..P.............|
00000930 00 00 00 00 00 00 00 00 75 00 73 00 65 00 72 00 |........u.s.e.r.|
00000940 64 00 61 00 74 00 61 00 00 00 00 00 00 00 00 00 |d.a.t.a.........|
00000950 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00004400
34+0 records in
34+0 records out
17408 bytes transferred in 0.016 secs (1088000 bytes/sec)

The "8 interrupted boots" will cause both the /system and /data ("userdata" above) to be reloaded from the recovery partition. Historically (eg, on the Nook Color), even a firmware upgrade (OTA or sideloaded) did not touch the recovery partition, which meant that a complete factory reset reverted the device to the firmware that was installed at the time of manufacture. Presumably you could install a different factory.zip to partition 0p7, and then future complete factory resets would install that, but who knows if there is some sort of legitimacy test.

Note that I have done a complete copy (dd if=/dev/block/mmcblk0 of=/dev/block/mmcblk1) of the internal memory to an SDcard, and then attempted to reboot with the SDcard still installed. My theory was that even if the SDcard started to boot (which it does), that subsequent references to partitions (whether on mmcblk0 or mmcblk1) would get identical contents, and that therefore the device should boot. Instead, the boot hangs. So, my theory is wrong :o