Need help in Accessing the bootloader on DLink DES-1210 28

Hello everyone, I am trying to get bootloader access, using serial connection for DLink DES-1210 28.
But unfortunately the OS loads automatically, and didn't do anything on pressing escape key.
I am trying to flash DLink GPL bootloader but I can't find a good resource. Any kind of help is greatly appreciated. Moreover as far as I can see, I don't find openwrt support for DLink DES 1210, so if any developer can integrate this model than it would be too good.

check if it's RTL838X/9X based, you should be able to see it in the boot log.
Replacing the boot loader might not be needed.

Thanks, @frollic I opened my switch, I found it has RTL8208L. So I guess DGS-1210 has RTL838X but my query is regarding DES-1210. Please correct me if I am wrong !!!

Ah, didn't see the one char difference :frowning:

But it's the only switch chipset supported, afaik.
If it's not RTL838X, you're out of luck, from an openwrt point of view.

Thanks, @frollic for the quick response. By any chance do you know how to access its bootloader, it's not responding to my "esc key"(as with most common of the D-link switches including DGS-1210-28).

Some devices, have the boot loader (is it uboot?) write protected.

You can read the output, but not interact with it.

In some cases, it's just a parameter, but you need OS access to change the value.

OS is completely restricted, they have given very few USER EXEC commands, yes the bootloader is U-Boot but it automatically loads firmware on start, I am not getting how to interrupt the normal boot. Anyways thanks @frollic for your quick responses.

Try to gather as much information about the hardware and how it is set up as you can, also read the GPL tarball if available. I wouldn't be too optimistic though.

Edit: E.g. flash/ RAM sizes, is it using linux as firmware - and as much as you can about the (older) SOC.

Sure I will, thanks @slh

If the uboot is restricted by a parameter, replacing it might not change anything, since the parameter
is (perhaps, could also be hardcoded) read from the uboot env partition, which won't change by
replacing uboot.

To get around it, you'd need to either hack the uboot source, to ignore the parameter value,
try to change it from the OS, or manage to extract the uboot env partition, hex edit it, and write it back.

Just an image to show, what serial console logs while booting

the 2.6.19 kernel appears to be 15 years old ... yuck.

I am relatively sure that the DGS-1210 28 image should work on this device, at least to get it booted.
You will need to interrupt u-boot though, to run with an initramfs image initially. There is basically always some key that interrupts booting. I have seen ctrl-d ctrl-c
If this does not work, the last resort is to read out the flash using a soic-clamp, change the bootdelay setting to prevent automatic boot and write this back onto the flash.

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Which version of the DES-1210-28 do you have? I have a Rev A1 version that actually has a Marvell Prestera SOC/Switch with 16MB Flash and 64MB RAM. U-Boot was easily interrupted just by pressing a key on boot. Based on your boot log you have a later revision that likely uses a Realtek RTL8332M. The RTL8208L you mentioned above is the Ethernet Phy chip not the processor.

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Sorry, I thought RTL8208L was the controller, Anyways I am using the Rev C1 version of DES-1210-28

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