[Asus Transformer TF700] utx:
I spent some time in analyzing of flash layout. The comprehensive description below attempts to map each byte of the flash and describes way to extract it.

I would be glad if somebody could provide more detailed info about bootloader, signatures, DRM etc.

Patches are welcome.

mmcblk0 layout
All dumps were done on Asus Eee Pad Transformer Infinity TF700T, 64GB version, firmware 9.4.5.26, locked

mmcblk0 off-partition section
Offset: 0 (0x0)
Size: 38273024 (0x2480000)
Read command: busybox dd if=/dev/block/mmcblk0 of=/mnt/sdcard/mmcblk0pre1.img bs=524288 count=73

Offset: 0 (0x0)
Size: 3670016 (0x380000)
Contains: Zeroes
Purpose: Unknown
Extract command: dd if=mmcblk0pre1.img of=mmcblk0pre1s1.img bs=3670016 count=1
Process command: tr -d '\0' <mmcblk0pre1s1.img >mmcblk0pre1s1nz.img # mmcblk0pre1s1nz.img must be empty file

Offset: 3670016 (0x380000)
Contains: Recovery kernel image followed by zeroes
Size: 8388608 (0x800000)
Extract command: dd if=mmcblk0pre1.img of=mmcblk0pre1s2.img bs=524288 skip=7 count=16
Process commands:
perl split_bootimg.pl mmcblk0pre1s2.img
mkdir mmcblk0pre1s2.img-ramdisk
cd mmcblk0pre1s2.img-ramdisk
zcat ../mmcblk0pre1s2.img-ramdisk.gz | cpio -i
cd ..
# end Process commands

Offset: 12058624 (0xb80000)
Contains: Regular boot kernel image followed by zeroes
Size: 8388608 (0x800000)
Extract command: dd if=mmcblk0pre1.img of=mmcblk0pre1s3.img bs=524288 skip=23 count=16
Process commands:
perl split_bootimg.pl mmcblk0pre1s3.img
mkdir mmcblk0pre1s3.img-ramdisk
cd mmcblk0pre1s3.img-ramdisk
zcat ../mmcblk0pre1s3.img-ramdisk.gz | cpio -i
cd ..
# end Process commands

Offset: 20447232 (0x1380000)
Contains: Block of 16 bytes followed by 0x2de0 hexadecimal numbers followed by FF
Size: 12288 (0x3000)
Extract command: dd if=mmcblk0pre1.img of=mmcblk0pre1s4.img bs=524288 skip=39
Vital data:
Extract command: dd if=mmcblk0pre1s4.img of=mmcblk0pre1s4ss2.img bs=4096 skip=3
Binary part of vital data:
Extract command: dd if=mmcblk0pre1s4ss1.img of=mmcblk0pre1s4ss1ch1.img bs=16 count=1
Hexadecimal part of vital data:
Extract command: dd if=mmcblk0pre1s4ss1.img of=mmcblk0pre1s4ss1ch2.img bs=16 count=734 skip=1
Process command: unhex <mmcblk0pre1s4ss1ch2.img >mmcblk0pre1s4ss1ch2bin.img
FF part of vital data:
Extract command: dd if=mmcblk0pre1s4ss1.img of=mmcblk0pre1s4ss1ch3.img bs=16 skip=735
Process command: tr -d '\377' <mmcblk0pre1s4ss1ch3.img >mmcblk0pre1s4ss1ch3nff.img # mmcblk0pre1s4ss1ch3nff.img must be empty file
Zeroes:
Extract command: dd if=mmcblk0pre1s4.img of=mmcblk0pre1s4ss1.img bs=4096 count=3
Process command: tr -d '\0' <mmcblk0pre1s4ss2.img >mmcblk0pre1s4ss2nz.img # mmcblk0pre1s4ss2nz.img must be empty file
Purpose: Probably encrypted bootloader

mmcblk0p1
Offset: 38273024 (0x2480000)
Size: 805306368 (0x30000000)
File system size: 196608 * 4096 = 805306368 (fully occupies partition)
Format: Linux ext4 filesystem
Mounted at: /system
Mount options: read only, extended attributes, ACL
Permissions: only root can manipulate
Contains: Base system and embedded applications
Purpose: Base system

mmcblk0p2
Offset: 843579392 (0x32480000)
Size: 448790528 (0x1ac00000)
File system size: 109568 * 4096 = 448790528 (fully occupies partition)
Format: Linux ext4 filesystem
Mounted at: /cache
Mount options: read/write, no SUID, no device nodes, no atime
Permissions: only root can manipulate, UID system and GID cache can read and write
Contains: Cache
Purpose: Application cache
Note: The volume has the same UUID as mmcblk0p1

mmcblk0p3
Offset: 1292369920 (0x4d080000)
Size: 2097152 (0x200000)
File system size: 512 * 4096 = 2097152 (fully occupies partition)
Linux rev 1.0 ext3 filesystem
Not mounted
Permissions: GID system can manipulate
Contains: Empty file system
Purpose: Recovery /misc
Referenced by: /system/lib/libandroid_runtime.so recovery ramdisk: /etc/recovery.fstab
Note: File system is referenced in recovery as emmc, not ext3!

mmcblk0p4
Offset: 1294467072 (0x4d280000)
Size: 855638016 (0x33000000)
File system size: 208896 * 4096 = 855638016
Linux rev 1.0 ext3 filesystem
Not mounted
Permissions: GID system can manipulate
Contains: Empty file system
Purpose: Recovery /staging
Referenced by: recovery ramdisk: init.rc /etc/recovery.fstab

mmcblk0p5
Offset: 2150105088 (0x80280000)
Size: 5242880 (0x500000)
File system size: 5092 * 1024 = 5147488
Format: FAT32 file system, no partition table, MS-DOS "Non-system disk" boot block
Not mounted
Permissions: only root can manipulate
Contains: File system with files:
Serial numbers (ISN, PPID, SSN, UUID)
Calibration data (AL3010 light sensor, AMI304 magnetic sensor, KXTF9 motion sensor)
Purpose: Device specific unique system data, mounted as /btmac during Android boot
Referenced by: /system/bin/wifimacwriter /system/bin/brcm_patchram_plus /system/bin/sensors-config /system/bin/sixpair ramdisk: /init recovery ramdisk: /etc/recovery.fstab /init

mmcblk0p5 off file-system area
Offset in section: 5147488 (0x4e8b60)
Size: 28672 (0x7000)
Read command: busybox dd if=/dev/block/mmcblk0p5 of=/mnt/sdcard/mmcblk0p5s2.img bs=1024 skip=5092
Process command: tr -d '\0' <mmcblk0p5s2.img >mmcblk0p5s2nz.img # mmcblk0p5s2nz.img must be empty file

mmcblk0p6
Offset: 2155347968 (0x80780000)
Size: 524288 (0x80000)
Format: binary data
Permissions: UID drm can manipulate
Contains: 208 bytes of binary data, the rest are zeroes
Purpose: DRM, probably contains encrypted DRM key
Referenced by: /system/bin/wvdrmserver /system/vendor/lib/drm/libdrmwvmplugin.so

mmcblk0p7
Offset: 2155872256 (0x80800000)
Size: 5242880 (0x500000)
Format: empty
Contains: Zeroes
Purpose: Unknown

mmcblk0p8
Offset: 2161115136 (0x80d00000)
Size: 61415620608 (0xe4ca80000)
File system size: 14994040 * 4096 = 61415587840
Format: Linux ext4 filesystem
Mounted at: /data
Mount options: read/write, no SUID, no device nodes, no atime
Permissions: only root can manipulate, read and write are directory specific
Contains: User applications, user data, and virtual internal SD card
Note: /data/media is mounted via UID/GID stripping FUSE as /mnt/sdcard

mmcblk0p8 off file-system area
Offset in section: 61415587840 (0xe4ca78000)
Size: 32768 (0x8000)
Read command: busybox dd if=/dev/block/mmcblk0p8 of=/mnt/sdcard/mmcblk0p8s2.img bs=4096 skip=14994040

mmcblk0 off-partition section
Offset: 63576735744 (0xecd780000)
Size: 524288 (0x80000)
Read command: busybox dd if=/dev/block/mmcblk0 of=/mnt/sdcard/mmcblk0post8.img bs=524288 skip=121263
Process command: tr -d '\0' <mmcblk0p8s2.img >mmcblk0p8s2nz.img # mmcblk0p8s2nz.img must be empty file

Offset: 63576735744 (0xecd780000)
Offset in section: 0 (0x0)
Size: 507392 (0x7be00)
Contains: Zeroes
Purpose: Unknown
Extract command: dd if=mmcblk0post8.img of=mmcblk0post8s1.img bs=507392 count=1
Process command: tr -d '\0' <mmcblk0post8s1.img >mmcblk0post8s1nz.img # mmcblk0post8s1nz.img must be empty file

Offset: 63577243136 (0xecd7fbe00)
Offset in section: 507392 (0x7be00)
Size: 16896 (0x4200)
Contains: EFI Partition table (partition names: APP, CAC, MSC, USP, PER, YTU, CRA, UDA)
Extract command: dd if=mmcblk0post8.img of=mmcblk0post8s2.img bs=512 skip=991
Purpose: Partition table

Total size of mmcblk0: 63577260032 (0xecd800000)

Notes:
can manipulate = can read, write partition vital data, only root can mount
can read, write = can read, write partition file system contents
Read commands are ran on the Transformer
Extract and process commands are run anywhere, with pre-read image file in the current directory.
You need dd with large files support. Vanilla dd on TF700T does not support large files. Busybox dd does.

Dropbox link to Asus_Transformer_Infinity_TF700T/flash_layout.txt