[Nokia Lumia 800] biktor_gj:
Well, I first did a DD of the entire disk just in case, and then a DD of all the partitions except partition 5 which is the Extended partition container...

Key combination which work for me:

Hold Power for more than 5 Seconds: Soft reset

Hold Camera+Power: Seems like what you guys call "Nokia DLOAD". I get a picture of a phone and a laptop on screen for some seconds, then it reboots to Windows Mobile. My linux box detects it as a Microsoft HID device:

generic-usb 0003:045E:041E.0007: hiddev0,hidraw2: USB HID v1.10 Device [Microsoft Windows Phone] on usb-0000:00:06.1-2/input0

Hold Volume UP + Power: I also get the mass storage device mode:

[ 655.912077] usb 2-2: new high speed USB device number 9 using ehci_hcd
[ 661.797096] usb 2-2: USB disconnect, device number 9
[ 765.836050] usb 2-2: new high speed USB device number 10 using ehci_hcd
[ 765.968707] usb 2-2: config 1 has an invalid interface number: 20 but max is 1
[ 765.968713] usb 2-2: config 1 has no interface number 1
[ 766.869700] usbcore: registered new interface driver uas
[ 766.905673] Initializing USB Mass Storage driver...
[ 766.905816] scsi2 : usb-storage 2-2:1.20
[ 766.906108] usbcore: registered new interface driver usb-storage
[ 766.906110] USB Mass Storage support registered.
[ 767.906264] scsi 2:0:0:0: Direct-Access Qualcomm MMC Storage 2.31 PQ: 0 ANSI: 2
[ 767.964504] sd 2:0:0:0: Attached scsi generic sg2 type 0
[ 767.968542] sd 2:0:0:0: [sdb] 31047680 512-byte logical blocks: (15.8 GB/14.8 GiB)
[ 767.969066] sd 2:0:0:0: [sdb] Write Protect is off
[ 767.969069] sd 2:0:0:0: [sdb] Mode Sense: 0f 0e 00 00
[ 767.970061] sd 2:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 767.977005] sdb: sdb1 sdb2 sdb3 sdb4 < sdb5 sdb6 sdb7 sdb8 sdb9 >
[ 767.977264] sdb: p9 size 30632075 extends beyond EOD, enabling native capacity
[ 767.983196] sdb: sdb1 sdb2 sdb3 sdb4 < sdb5 sdb6 sdb7 sdb8 sdb9 >
[ 767.983463] sdb: p9 size 30632075 extends beyond EOD, truncated
[ 767.988075] sd 2:0:0:0: [sdb] Attached SCSI removable disk

Hold Volume UP+Volume DOWN + Power: The same as above...

EDIT: Shame on you you made me boot to Windows 7 :P

About the Camera+Power key combo, if I plug it to the usb port, then press and hold camera+power, and then release power when I see the picture with the phone and a laptop (attached a photo), Windows 7 actually downloads a driver and puts the phone in something like a MTP device. Cannot access it on anyway, but when it doesn't have any driver it just says Windows Phone, when it installs the driver from Windows Update it calls itself 'SEARAY' (the mainboard codename)

EDIT2: Dump Tool is doing something guys! after 15 minutes my Mac Mini is starting to get a little hot...

sdb9_redump.payload:
Extracting XIP...Ok

KERNEL : WP7

dllFirst : 0x4001EF8A (User Lo=0x40010000; Kernel Lo=0xEF8A0000)
dllLast : 0x4002F000
physFirst : 0x80500000
physLast : 0x80956780
modules : 77
RAMStart : 0x80957000
RAMFree : 0x809EF000
RAMEnd : 0x83B00000
CopyEntries : 3
CopyOffset : 0x80583FC0
ProfileLength : 0x00000000
ProfileOffset : 0x00000000
files : 46
KernelFlags : 0x00000002
FSRamPercent : 0x00000004
DrivglobStart : 0x00000000
DrivglobLength : 0x00000000
CPUType : 0x01C2 (ARMV4I)
MiscFlags : 0x0002
pExtensions : 0x8050103C
TrackingStart : 0x00000000
TrackingLength : 0x00000000

XIP (memory spaces bounds):
User space low bound : 0x40010000 (ceddk.dll 0x40010000)
Kernel space low bound : 0xEF8A0000 (rpc_server.dll 0xEF8A0000)

XIP (cecompr.dll):
XPR: is not supported
LZX: is not supported
XPH: is supported

XIP (packages):
2b9faa51-bf35-4e40-84d1-8a10aede910b.dsm QC_7x30_NK 1600.2475.11414.7720
02e1d1b8-8c53-4c34-9b5d-9228c54e7ba3.dsm OEM_7x30_NK 1600.2475.11414.7720
b5332311-48f1-4b76-ad70-8efa5db8fa3a.dsm MSXIPKERNEL 7.10.68.7720
f124a3e7-1321-4c02-8a77-73f625ebdc59.dsm QC_7x30_NK_EMMC 1600.2475.11414.7720
9ff7ec5f-f708-4d83-927c-c85689559e96.dsm QC_7x30_NK_EMMC_LOCK 1600.2475.11414.7720
8057be06-5624-4cc3-ac20-3e983d4703ec.dsm NOKIA_RM801_214_BrandingNK 1600.2475.11414.7720
e9f18a05-77ee-4579-a4f3-22d62c594c42.dsm NOKIA_RM801_BrandingNK 1600.2475.1.7720
e8126878-1bd6-4aaf-ac1d-b315d7126607.dsm NOKIA_RM801_214_PhoneMetadata 1600.2475.11414.7720
068e3145-5fbb-489d-ab5a-d6e8b9157d99.dsm NOKIA_RM801_SPAIN_PhoneMetadata 1600.2475.1.7720
eebbabb2-0689-4692-9e80-5eb9a62126d1.dsm BaseDrivers_NK 7.10.68.7720
daf41ca7-392b-496f-ac29-9a88c3f07994.dsm NOKIA_RM801_PhoneMetadata 1600.2475.1.7720
4f1c798e-206d-41c8-93c5-36781aeeb771.dsm OEM_7X30_EMMCWP 1600.2475.11414.7720
ed14fc29-d898-4b33-8d5b-f1d55291fb23.dsm OEM_7x30_NK_DIP 1600.2475.11414.7720
4c09c376-dc94-4033-9277-b6732fe19069.dsm Watson_Core 7.10.68.7720
7da1c1a8-1fd2-4a18-a081-84e4825266b1.dsm WinCENLS 7.10.68.7720
75604d75-c716-4137-86a2-9e3521eeac49.dsm GFX_NK 7.10.68.7720
1a4c638a-ecb1-48ad-9efa-92d6859ac1bf.dsm CCFGSVC 7.10.68.7720
42d1aab7-6dfa-4c03-9797-d66f7620883d.dsm MSXIPKERNELLTK 7.10.68.7720
8ba03a79-81f0-40ff-ae5a-112b35421ff0.dsm KFPCRT 7.10.68.7720

Reading IMGFS:
Reading packages.sof...Ok
Reading dsm...Ok

OS:	7.10.68.7720
NetCF:	7.10.68.7720

1600.2475.11414.7720 SYS\AKM_8975
7.10.68.7720 SYS\AppChecker
7.10.68.7720 SYS\APPCHECKER_Lang_0404
... too long to fit it in a post...
7.10.68.7720 SYS\WindowsLiveIDUI_Lang_0809
7.10.68.7720 SYS\WindowsLiveIDUI_Lang_0816
7.10.68.7720 SYS\WindowsLiveIDUI_Lang_0C0A
7.10.68.7720 SYS\XmlLite
7.10.68.7720 SYS\XNA

Certificates:
CN=Microsoft Windows Mobile PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
CN=Microsoft Windows Mobile PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
CN=Microsoft Windows Mobile PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
CN=Nokia Online Certification Authority II, O=Nokia

Certificates in DefaultCerts.dat:
CN=Microsoft Windows Mobile Firmware Installation PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
CN=Microsoft Windows Mobile Firmware Installation PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
CN=Microsoft Windows Mobile Firmware CA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
CN=Nokia Windows Phone Firmware Signing Authority, O=Nokia
CN=Microsoft Mobile Device Unprivileged PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US

What did you say you needed for InteropUnlock? :)

Dumping all the contents of the flash right now... Let's hope I can build them back!

Any instructions I could follow to recompile the imgfs into something flashable with InteropUnlock enabled?

EDIT3: Attached logs of everything...

EDIT4: This is what Dump Tool said after some minutes when I clicked 'Create Packages'

Creating template...Arithmetic operation resulted in an overflow.

But Advanced Dump Tool shows Packages, the tree structure etc. Don't know where to move forward...

I'm uploading copies of partitions and the structured flash dump to MediaFire so you can take a look to whatever you want... If you don't see it there, it means it's still uploading!

http://www.mediafire.com/?kknt4lnc3tn7w