Support for Xiaomi Mi 3C

minax007 · May 24, 2021, 11:30am

Dear @eduardo010174
looking on BREED bootloader I see that the file size is only 89 kB.
https://breed.hackpascal.net/breed-mt7688-reset38.bin

Therefore the available address range of uboot should not get exceeded - and therefore other partitions should not be overwritten with BREED.

Moving partitions would only be needed if those would get overwritten when flashing BREED.

But I am not sure if I understood you correctly.

Could you please check the file linked above and see if partitions are overwritten?

Thanks!

minax007 · May 24, 2021, 12:57pm

It is correct. The mt0 "ALL" block is being used to create a dump of the complete flash image.

This can be done with following command:

cat /dev/mtd0 > /tmp/full_flash.bin

The file full_flash.bin is 16.8 MB in size for the Mi-3C.

It resembles all partitions in one file.

This is the complete partitioning for the stock ROM of the Mi-3C I had recorded, before my router got bricked:

dev:    size   erasesize  name
mtd0: 01000000 00010000 "ALL"
mtd1: 00030000 00010000 "Bootloader"
mtd2: 00010000 00010000 "Config"
mtd3: 00010000 00010000 "Bdata"
mtd4: 00010000 00010000 "Factory"
mtd5: 00010000 00010000 "crash"
mtd6: 00010000 00010000 "cfg_bak"
mtd7: 000c0000 00010000 "overlay"
mtd8: 00760000 00010000 "OS1"
mtd9: 00600000 00010000 "rootfs"
mtd10: 00760000 00010000 "OS2"

With regards to BREED the following partition is relevant:

mtd1: 00030000 00010000 "Bootloader"

This one has a size of 00030000.

Looking on the image size of BREED (link see above) I can see that it only has 00016428.

Therefore BREED should fit into the "Bootloader" partition without overwriting the following partitions:

mtd2: 00010000 00010000 "Config"
mtd3: 00010000 00010000 "Bdata"
mtd4: 00010000 00010000 "Factory"
...

@eduardo010174: What do you think?

minax007 · May 25, 2021, 3:25pm

Dear @eduardo010174

do you know which partitions are saved as "EEPROM" in BREED?
As far as I know the "EEPROM" includes the MAC adresses and router specific WiFi configuration parameters.
Is there more in EEPROM?
And do you know why it is called EEPROM?
Thanks in advance!

eduardo010174 · May 25, 2021, 4:36pm

I only write how to install openwrt from stock.

Before all is need backup using /dev/mtd0
Move factory partition data for new position for match with breed.(copy)
Install breed.
erase os1
erase os2

@minax what is next steps your use for install openwrt sysupgarde?

I write for prepare draft for request official support.

eduardo010174 · May 25, 2021, 4:43pm

EEPROM is error name. https://en.wikipedia.org/wiki/EEPROM

Correcte name is Factory or in other builds is art partition.
Into the breed eeprom is only factory partition.

minax007 · May 25, 2021, 7:29pm

Dear @eduardo010174

I had provided you already a full dump for the MI-3C stock firmware.
Actually I am not able to support you as I do not have a new flash chip. This could take some time.

In the meanwhile I would appreciate if @earth08 could support you with testing.

Dear @earth08

would this be possible for you?

earth08 · May 26, 2021, 1:42pm

I can, I would surely,
My problem is I am not techy like you both,
If angering go writing my device will die.
Even than I am ready to help,
Again I am not techie guy

minax007 · May 26, 2021, 1:49pm

Dear @earth08
thanks you very much!
And don't worry, as long as you have BREED installed on your router the router will not die.
I had removed BREED and flashed stock firmware ... and then I did things in addition which I shouldn't have done ... e.g. locking the flash. This led to a full brick.

Nevertheless the Mi-3C should not be your primary router in case you want to participate in development.

So as long as you have BREED installed - you can always recover the firmware.
And in case you need help never hesitate to ask.

minax007 · May 30, 2021, 5:38pm

Dear @eduardo010174
actually I am waiting to get the flash chip to be able to support you together with @earth08 on the development.
I had ordered the chip from China ... so it will take some weeks until I get it.

Two days ago I have set up my other Xiaomi routers (AC2100 and Mi-4) in MESH mode to extend the WiFi signal in my home.
And it works great!

I have also updated the Github repository for the Mi-3C (based on Mi-Nano) with MESH support, because I want to use the Mi-3C in future for improving the network quality further.

In case anyone wants to try out the OpenWrt MESH functionality, please install the "MESH" version found under releases in this repository:

I have followed following description found on YouTube:

Good thing is that you do not need to use 5 GHz for the mesh point (router to router) communication.
I had tried 5 GHz on my other routers and compared it to 2.4 GHz and see that 2.4 GHz has better coverage.

Therefore the Mi-3C is well equipped for being a suitable mesh point

minax007 · June 10, 2021, 12:36pm

Dear @eduardo010174
good news:
Today I have received the flash chip.
I have flashed it and soldered it into the router.
Now it is up and running and I can support you again.

eduardo010174 · June 10, 2021, 12:52pm

In my country today is not day for work. Is completely free. Only have one work for delivering and finish in university.

A quinta, 10/06/2021, 13:46, Minax007 via OpenWrt Forum <mail@forum.openwrt.org> escreveu:

eduardo010174 · June 10, 2021, 1:16pm

I watch video is only need add wpad package into builds.

minax007 · June 10, 2021, 1:36pm

Yes, that is correct.
I have added the following packages:
luci
luci-theme-material
luci-app-nlbwmon
luci-app-sqm
wpad-mesh-wolfssl
mtr

And I have deleted the following:
wpad-basic-wolfssl

eduardo010174 · June 10, 2021, 1:37pm

If you install package wpad is package contais all factures enable including mesh.

minax007 · June 10, 2021, 1:40pm

But I have done intensive testing the last weeks with the Xiaomi Mi AC2100 and Xiaomi Mi 4 routers and see that Mesh-Networking is not very stable - but I couldn't figure out why.
Maybe because of the snapshot-builds I was using.
Sometimes it was fine and sometimes really bad.
Today I have changed back on my main router (AC2100) to Padavan and see that WiFi signal strenght is much better in 2.4 GHz - because I need this one for working from home office.
But I still like OpenWrt more because it is more flexible.
So I will try further.

minax007 · June 10, 2021, 1:41pm

That is correct. I had also tried wpad with openssl.

eduardo010174 · June 10, 2021, 1:50pm

I don't think why ...

eduardo010174 · June 10, 2021, 1:53pm

I start write all setup for install.

minax007 · June 10, 2021, 2:11pm

By the way - a couple of posts ago I had explained you why I think that BREED is not a problem to be used on this device as the partition size of the bootloader is smaller than the BREED image.
Of course it also works without BREED. But BREED makes flashing much safer - as you have always the possiblity to recover the firmware when something goes wrong (like in my case recently ).

eduardo010174 · June 10, 2021, 2:30pm

openwrt-invasion
create backup of all fash.
backup /dev/mtd0 to your computer.
Is needed because after install openwrt is not possible recovery for stock bootloader.
/dev/mtd0 is block that contains all partitions
```
scp root@<ip>:/dev/mtd0 .
```
backup /dev/mtd4 to your computer. This partition contains eeprom info. This file is needed for replace in breed because in breed sector of eeprom is different from stock.
install breed
in breed page replace eeprom with /dev/mtd4. It's needed because sector for breed is in different position of stock firmware.
install openwrt image from breed

@minax007 agree?
I change image finally for use all 16mb of flash.
I need check macs on stock firmware and on openwrt is set correctly.