[Q] Recover data with Heimdall. "boot-loop" issue, no USB debugging enabled - Galaxy S II Q&A, Help & Troubleshooting

On a I9100 Galaxy S2: Device freeze/loops during boot process at the Samsung logo step. I need to recover the data (eventually) and get the phone "back to work". I recently experienced some (may be unrelated issues):
System clock was regularly resetting time to default (1 jan 2000)
Phone reboot unexpectingly
The device is a "Original" SG2: No root access, no custom ROM, no custom recovery, no new app installed before "current issue"....
Device has been regularly updated with Samsung Kies Official builds. USB debugging is disabled (I can't boot the device, so no way to enabled it).
System start is stuck somewhere at the boot process where the screen show the Samsung logo
I can boot the device in "Recovery mode" using (Volume UP + Power + Home hardkeys combination)
I can boot the device in "Download mode" (Volume DOWN + Power + Home hardkeys combination)
Wiping the cache partition in Recovery Mode(2) doesn't resolve the issue (1). SO I installed Heimdall on Ubuntu 14.04, plug the USB cable between the I9100 device, detect the device
Code:
sudo heimdall detect
, print the partition table
Code:
$ sudo heimdall print-pit
.
Heimdall seem to detect partitions, I get 15 entries: --- Entry #0 --- to --- Entry #14 ---. Filtering partitions information, I get the following partition names
Code:
$ sudo heimdall print-pit | grep 'Partition Name'
(...)
Partition Name: GANG
Partition Name: BOOT
Partition Name: EFS
Partition Name: SBL1
Partition Name: SBL2
Partition Name: PARAM
Partition Name: KERNEL
Partition Name: RECOVERY
Partition Name: CACHE
Partition Name: MODEM
Partition Name: FACTORYFS
Partition Name: DATAFS
Partition Name: UMS
Partition Name: HIDDEN
Partition Name:
Right after issuing the command, the device reboot automatically and come back to the "stuck boot" with Samsung Logo.
I wonder if this mean that I could install a custom recovery in order to backup/image the whole system in order to get data back. The second question is: How to back up the data?
Help would be appreciated
Note: Find below the complete output for the RECOVERY partition. I wonder why there is no indication about filesystem (EXT, FAT, ...).
Code:
--- Entry #6 ---
Binary Type: 0 (AP)
Device Type: 2 (MMC)
Identifier: 6
Attributes: 0 (Read-Only)
Update Attributes: 0
Partition Block Size/Offset: 73728
Partition Block Count: 16384
File Offset (Obsolete): 0
File Size (Obsolete): 0
Partition Name: KERNEL
Flash Filename: zImage
FOTA Filename:
--- Entry #7 ---
Binary Type: 0 (AP)
Device Type: 2 (MMC)
Identifier: 7
Attributes: 0 (Read-Only)
Update Attributes: 0
Partition Block Size/Offset: 90112
Partition Block Count: 16384
File Offset (Obsolete): 0
File Size (Obsolete): 0
Partition Name: RECOVERY
Flash Filename:
FOTA Filename:
(...)
Thanks

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I'm sorry, but you won't be able to save your data. You can try going to download mode and flashing a stock firmware.