Recovery, accessing eMMC

Installing and Using OpenWrt
1

Hi,

My device, a NanoPi R5S with OpenWrt 24.10.5, recently became inaccessible over the network due to a VPN misconfiguration.

I don’t appear to be able to see the console, either via the HDMI port or using UART (well I can see garbage in picocom (115200, 8n1, TxRx swapped)), so I’m now booting vanilla OpenWrt from an SD card to try and access the eMMC where OpenWrt is installed so I can edit ‘/etc/config/network’.

I have installed usb-utils, mmc-utils, kmod-fs-ext4, e2fsprogs and a couple of others that I forget now.

‘dmesg | grep mmc’ shows amongst other things, ‘mmc1: error -84 whilst initialising MMC card’

The SD card I’m booting from is in /dev as mmcblk0 and is the only mmc entry.

I’m guessing that there is a missing driver or kernel module which is preventing the eMMC from being configured.

Can anyone tell me how I can make the eMMC available so I can mount the filesystem and correct the config error?

TIA

2

Installation procedure tells that you just need to use dd. Default image should see the eMMC.

3

Hi,

Thanks for the reply.
Forgive my ignorance, but dd is for writing an image isn’t it? That isn’t what I want to do.

I have already written 24.10.5 to an SD card and am using mask to make the R5S boot from the SD card. What I’m trying to do is mount a broken OpenWrt that is installed on the eMMC so I can fix its config

4

It just occured to me to try failsafe mode, but it seems the NanoPi R5S’ ‘mask’ button doesn’t work for that :frowning:

5

The idea is to rewrite the whole eMMC rather than trying to mount/repair it. Once done just restore the right settings (assuming you saved them). It's more convinient to use straight forward procedures.

6

Well that may be, but I’d like to learn :slight_smile:

I’m flashing Debian to the SD card now and will try that for recovery

7

Gave up.

FriendlyElec’s Trixie image is kernel 6.1.141 and also didn’t configure the eMMC and as I didn’t have aworking internet connection, I couldn’t update the kernel and see if that would help.

The RKDevTool also doesn’t appear to be able to extract or otherwise backup the eMMC using USB-to-USB and I couldn’t get UART to work with my (shady)PL2303; which I’ve used in the past to flash BT HH5a routers.

I puzzles me, because OpenWrt is clearly able to boot from the eMMC, but can’t configure it as a storage device if booting from SD card?

Could anyone tell me how to enable the video console for OpenWrt? At least if I do that now, if I have a problem in the future, I can plug in a monitor and keyboard

8

Indeed, this is a case where you can learn :sweat_smile:

You may have partitions corruption. Hence you can't boot neither mount as storage. So obvious solution is ... dd :slight_smile:

9

Yes, it got the big stick :slight_smile:

Even if the partitions were corrupt, it wasn’t even initialising the device, so it didn’t even show up in /dev. I would expect it to be there and I could use parted to remove any corrupted partitions.

Unfortunately, Google doesn’t have ANY information for a -84 error with regards to initialising MMC, so we’re on our own :D. All clues pointed to a missing driver which is why I wanted to try a later kernel. It’s a PITA trying to problem solve when you don’t have an internet connection. Even Debian doesn’t come with pppoeconf, so you can’t even try and configure PPPoE.

If I had more time, I would have hooked up the ISPs router and tried a bit harder, but in the end it was quicker to nuke it from orbit.

I’m also guessing OpenWrt doesn’t have support for HDMI on this device? FriendlyWRT does apparently. I briefly flashed FriendlyWRT and it looked pretty decent TBF, but I always prefer vanilla.
I seem to remember reading in the release notes for the 25 RC that there’s better support for video?

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