RCP firmware

When using Silicon Labs hardware, developers have 2 options to build the RCP firmware

Either from the OpenThread repository
Directly within Simplicity Studio

This second method will not be covered in this guide

Important Note:

For developpers wishing to evaluate Matter ecosystem implementations at the time of writing (November 29th 2021)

Since Matter is still in its alpha stage, we recommend to use the 1st option with a checkout to a specific commit hash (mentioned below)

We will do our best keeping this page up to date

Downloading and flashing a Bootloader to the MCU

In order to get our RCP firmware to boot, we will need to flash a bootloader on it

Such bootloader can be built using Simplicity Studio : see UG266

For convenience, we hosted a pre built Internal Storage Bootloader for BRD4166 (Built using GSDK 3.2.4)

Download the Thunderboard Sense 2 bootloader

wget https://www.dropbox.com/s/qqh45vmflw3w8le/bootloader-storage-internal-single-combined-BRD4166A.s37
  

Flash the Bootloader image If you installed JLink utilities in our prerequisites then you already know how to launch the JLinkExe tool :

JLinkExe -device EFR32MG12P432F1024GL125 -speed 4000 -if SWD -autoconnect 1
  

Note: If you have several kits connected to your Rpi or computer you will need to pass its JLink serial no otherwise this will fail

Flash the RCP using loadfile ./bootloader-storage-internal-single-combined-BRD4166A.s37 in the newly opened prompt:

J-Link>loadfile ./bootloader-storage-internal-single-combined-BRD4166A.s37
Downloading file [./bootloader-storage-internal-single-combined-BRD4166A.s37]...
Unable to load library icui18n "Cannot load library icui18n: (icui18n: cannot open shared object file: No such file or directory)"
JLinkGUIServerExe: cannot connect to X server
J-Link: Flash download: Bank 3 @ 0x0FE10000: 1 range affected (14336 bytes)
J-Link: Flash download: Total: 0.523s (Prepare: 0.190s, Compare: 0.005s, Erase: 0.000s, Program & Verify: 0.270s, Restore: 0.055s)
J-Link: Flash download: Program & Verify speed: 52 KB/s
O.K.
J-Link>
  

Then reset the device and quit

J-Link>r
Reset delay: 0 ms
Reset type NORMAL: Resets core & peripherals via SYSRESETREQ & VECTRESET bit.
Reset: Halt core after reset via DEMCR.VC_CORERESET.
Reset: Reset device via AIRCR.SYSRESETREQ.
J-Link>q
  

Building the RCP dongle firmware from github

If you followed the instructions from the home page of this guide, your shell should be in /home/pi/border_router_dev, and have git installed

First we need to clone the Openthread repository for EFR32
```
git clone https://github.com/openthread/ot-efr32.git
```
Browse into it
```
cd ot-efr32/
```
At this point you should be in /home/pi/border_router_dev/ot-efr32
Init submodules and run the bootstrap so all needed tools and dependencies for build are installed on your dev environment

As of November 10th, this commit needs to be used to build an OpenThread RCP compliant with Matter
```
git checkout ec69725
```
Start by cloning all submodules (this will download the actual Openthread repository) :
```
git submodule update --init
```
And run the bootstrap script
```
sudo ./script/bootstrap
```
Please be patient, both last steps can take some (a lot of) time
Now we will build the OpenThread RCP firmware for the Thunderboard Sense 2

If you would like to use another platform, please follow these steps

Start the build process for Thunderboard Sense 2
```
./script/build efr32mg12 -DBOARD=brd4166a
```
A this stage, the build should be successful

Verify that you have all binaries built in ot-efr32/build/efr32mg12/bin using ls

$ ls build/efr32mg12/bin
ot-cli-ftd      ot-cli-mtd      ot-ncp-ftd      ot-ncp-mtd      ot-rcp      sleepy-demo-ftd      sleepy-demo-mtd
ot-cli-ftd.s37  ot-cli-mtd.s37  ot-ncp-ftd.s37  ot-ncp-mtd.s37  ot-rcp.s37  sleepy-demo-ftd.s37  sleepy-demo-mtd.s37
  

Flashing the RCP dongle firmware on our Thunderboard Sense 2

If you installed JLink utilities in our prerequisites then you already know how to launch the JLinkExe tool :

JLinkExe -device EFR32MG12P432F1024GL125 -speed 4000 -if SWD -autoconnect 1
  

Note 1: If you have several kits connected to your Rpi or computer you will need to pass its JLink serial no

Note 2: Do not erase memory before flash, doing so will erase the bootloader section. Redo bootloader flash if necessary (cf above)

This time we will flash the RCP using loadfile ./build/efr32mg12/bin/ot-rcp.s37 in the newly opened prompt:

J-Link>loadfile ./build/efr32mg12/bin/ot-rcp.s37
Downloading file [./build/efr32mg12/bin/ot-rcp.s37]...
Unable to load library icui18n "Cannot load library icui18n: (icui18n: cannot open shared object file: No such file or directory)"
JLinkGUIServerExe: cannot connect to X server
J-Link: Flash download: Bank 0 @ 0x00000000: 1 range affected (88064 bytes)
J-Link: Flash download: Total: 1.821s (Prepare: 0.242s, Compare: 0.017s, Erase: 0.000s, Program & Verify: 1.455s, Restore: 0.104s)
J-Link: Flash download: Program & Verify speed: 59 KB/s
O.K.
J-Link>
  

Now just reset the device and quit the JLinkExe prompt by using r then q:

J-Link>r
Reset delay: 0 ms
Reset type NORMAL: Resets core & peripherals via SYSRESETREQ & VECTRESET bit.
Reset: Halt core after reset via DEMCR.VC_CORERESET.
Reset: Reset device via AIRCR.SYSRESETREQ.
J-Link>q
  

You can now proceed to the Border Router Core Installation

Troubleshoot

If you precisely follow all of the previous sections (including git checkouts and prerequisites), you should have built and flashed the RCP firmware as well as a bootloader onto the Thunderboard

Still, if you run into some of these issues:

Bootstrap fails because of permissions Make sure you ran the script as sudo
Build fails because of permissions Make sure you ran the script as sudo
Build fails because of unidentified BOARD_ID of device family : Make sure to run the build script specifying it: ./script/build efr32mg12 -DBOARD=brd4166a

You can list available boards and fanilies using the shell commands below :
```
source ./script/efr32-definitions
efr32_get_platforms
efr32mg1 efr32mg12 efr32mg13 efr32mg21
  
efr32_get_boards efr32mg12
brd4161a
brd4166a
brd4170a
brd4304a
```
JLinkExe throws errors :

If the errors are :
```
Unable to load library icui18n "Cannot load library icui18n: (icui18n: cannot open shared object file: No such file or directory)"
JLinkGUIServerExe: cannot connect to X server
```
-> You do not need to worry about it

However if you face any other error related to device connection :
1. Be sure that you have connected your Thunderboard to your Raspberry Pi
2. Check that you have one and only one Thunderboard connected to your Raspberry Pi