connexion serie readynas 104

Hello
There is a 3.3V serial connexion behind  the readynas 104, where you can log in and use in case you have problems with your nas.
attached is a picture of the pins
top left : RX
top right: Tx

bottom left : ground

bottom right : 3.3V

hope this helps.

also some details:

CPU: ARMv7 Processor [561f5811] revision 1 (ARMv7), cr=10c5387d
Kernel command line: console=ttyS0,115200 reason=normal bdtype=rn104

some elements of the serial console at boot

BootROM 1.08
Booting from NAND flash

General initialization - Version: 1.0.0

High speed PHY - Version: 2.1.4 (COM-PHY-V20)
Update PEX Device ID 0x6710
High speed PHY - Ended Successfully
0000
DDR3 Training Sequence - Ver 5.7.1
DDR3 Training Sequence - Run without PBS.
DDR3 Training Sequence - Ended Successfully
BootROM: Image checksum verification PASSED

U-Boot 2011.12-gec25d27-dirty (Oct 26 2015 - 16:56:14) Marvell version: v2011.12 2014_T2.0p1
06/23/2015 ReadyNAS-104 V2.0

Board: DB-88F6710-BP
SoC: MV6710 A1
CPU: Marvell PJ4B v7 UP (Rev 1) LE
CPU @ 1200 [MHz]
L2 @ 600 [MHz]
TClock @ 200 [MHz]
DDR @ 600 [MHz]
DDR 16Bit Width, FastPath Memory Access
DRAM: 512 MiB

Map: Code: 0x1feef000:0x1ff9f514
BSS: 0x1ffef8a0
Stack: 0x1f9eeef8
Heap: 0x1f9ef000:0x1feef000

NAND: (ID 0xf1ad) 128 MiB
MMC: MRVL_MMC: 0
Bad block table found at page 65472, version 0x01
Bad block table found at page 65408, version 0x01
nand_read_bbt: Bad block at 0x000003500000
nand_read_bbt: Bad block at 0x000005d20000

Initialize and scan all PCI interfaces
PEX unit.port(active IF[-first bus]):
------------------------------------------
PEX 0: Root Complex Interface, Detected Link X1, GEN 2.0
PEX 1: Root Complex Interface, Detected Link X1, GEN 2.0
FPU not initialized
USB 0: Host Mode
USB 1: Host Mode
Shutting down unused interfaces:
SDIO
AUDIO
TDM
Modules/Interfaces Detected:
RGMII0 Phy
RGMII1 Phy
PEX0 (Lane 0)
PEX1 (Lane 1)
SATA0 (Lane 2)
SATA1 (Lane 3)
Net: egiga0, egiga1 [PRIME]
Power On!

FDT loaded successfully
Delay 7s then power on another group of HDDs 1
Hit any key to stop autoboot: 0

NAND read: device 0 offset 0x200000, size 0x400000
4194304 bytes read: OK

NAND read: device 0 offset 0x800000, size 0x400000
4194304 bytes read: OK
## Booting kernel from Legacy Image at 02000000 ...
Image Name: Linux-4.4.218.armada.1
Created: 2023-06-28 22:22:10 UTC
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 3477992 Bytes = 3.3 MiB
Load Address: 00008000
Entry Point: 00008000
Verifying Checksum ... OK
## Loading init Ramdisk from Legacy Image at 03000000 ...
Image Name: initramfs
Created: 2024-01-10 5:26:30 UTC
Image Type: ARM Linux RAMDisk Image (lzma compressed)
Data Size: 3427797 Bytes = 3.3 MiB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
## Flattened Device Tree blob at 01000000
Booting using the fdt blob at 0x01000000
Loading Kernel Image ... OK
Using Ramdisk in place at 03000040, end 03344e15
Using Device Tree in place at 01000000, end 010068e5
Updating device tree successful

Starting kernel ...

Starting the boot process...
Detected system type: RN104
Loading kernel modules...done
Boot mode: Normal
UBI device number 0, total 918 LEBs (116563968 bytes, 111.2 MiB), available 9 LEBs (1142784 bytes, 1.1 MiB), LEB size 126976 bytes (124.0 KiB)
Bringing up network...eth0.done
Bringing up RAID arrays...done
e2fsck 1.42.13 (17-May-2015)
0e358bfe_root: clean, 52912/1048576 files, 618968/1047552 blocks
Switching root to RAID device.

Welcome to ReadyNASOS 6.10.10!

[ OK ] Listening on /dev/initctl Compatibility Named Pipe.
[ OK ] Started Dispatch Password Requests to Console Directory Watch.
[ OK ] Listening on udev Control Socket.
[ OK ] Created slice System Slice.
[ OK ] Listening on udev Kernel Socket.
[ OK ] Created slice system-openvpn.slice.
[ OK ] Created slice system-getty.slice.
[ OK ] Listening on Journal Socket.
Starting Load Kernel Modules...