Netgear GS308E v4, adding support for RTL8370N based switches

For Developers
1

Hi,
I would like to add support for this type of SoC from Realtek, so far I have dumped the original firmware of my Netgear GS308E v4. By loading up the dumped firmware I can only find references of RTL8367N within the dump itself and it's quite confusing.

For anyone I have uploaded on my GitHub repository here the dumped firmware of the switch.

I also already messed around with the UART interface (56k Baud, 8 Bits, 1 Stop Bit, CR ending) that is available on the device but nothing really interesting is logged there, other than this boot menu:

image
image1280×750 68.3 KB

I would like if anyone else is interested on porting OpenWRT on these devices since they are quite decent switches and also really cheap (around 30euros on Amazon).

2

I hope not, with a firmware image size of ~1MB, it's bound to fail.

image
image761×110 7.1 KB

3

Hm… yes, I have noticed the size of the update on their website is around 1MB… altho the winbond chip onboard is a WS25Q32 which is a 32M-bit flash which is pretty much 4MBs. I am aware that the Realtek chip contains an intel 8051 microcontroller inside but I haven’t been able to get it’s firmware from the flash.

4

still a dead en, openwrt requires > 8MB flash for new devices.
you might get away with 8MB for a switch, but you only got 4MB.

5

That's quite interesting to know... my bad for not checking the minimal required specs to run OpenWRT.

(I could mod a +8MBs Flash on there but I guess it's pretty much a waste of time and nobody would perform such mod)

Do you have any idea on something that could run on this Realtek chipset?

It would be fun to even write something bare-metal but sadly I haven't found any toolchain or pretty much any datasheet describing how the SoC actually works.

6

It could be nice as a hobby project, but it looks more like a timesink. For now it looks like you'd be bringing up this target from scratch, by yourself (unless you find someone to partner with with the same hardware and a sufficient skillset), and the question is if and how much code you would be able to share with rtl838x (the weakest supported switch target in OpenWrt).

7

Yeah, the issue is that this chipset has little to no documentation. I have searched pretty much everywhere but there's nothing really interesting around that can be used to actually understand how the device works and also the firmware inside the flash is quite compressed and obfuscated.

8

Based on the fact the firmware is ~1MB, it might not even run Linux, hence the lack of info on internet.

1 Like
9

It surely isn't running linux at all by default ; )

10

Another reason for not touching it, as @Borromini pointed out.

11

Does it run some sort of API on the UART after bootup? Could It maybe be used to add a (DSA)-switch to another Openwrt host, that has not enough LAN ports?
Do DSA-switches have to be internal? Because, in theory, DSA is supposed to be daisy-chainable.

12

That’s what I was thinking of too but sadly there’s no API on the UART at all… I could send some pictures of the pcb too later but there’s nothing really interesting: /