RP2350

Introduction

RP2350 features a dual-core Arm Cortex-M33 processor with 520 kiB on-chip SRAM, support for up to 16MB of off-chip flash and a wide range of flexible I/O option including I2C, SPI, and - uniquely - Programmable I/O (PIO). With its security features RP2350 offers significant enhancements over RP2040.

This platform port supports TF-M regression tests (Secure and Non-secure) with Isolation Level 1 and 2.

Note

Only GNU toolchain is supported.

Note

Only “profile_medium” predefined profile is supported.

Building TF-M

Follow the instructions in Building instructions.

Build instructions with platform name: rpi/rp2350

-DTFM_PLATFORM=rpi/rp2350

Note

This platform port relies on Raspberry Pi Pico SDK. Make sure it is either cloned locally or available to download during build. SDK version used for testing: SDK 2.1.1 release.

To use a different version of the SDK than the one your version of TF-M uses by default, you can pass -DPICO_SDK_PATH=/path/to/pico-sdk to CMake. You may also need to patch this SDK to work with the TF-M build system. If required, the patch is available in the platform/ext/target/rpi/rp2350/pico-sdk.patch file from a TF-M version that uses the SDK version you want to use, and it can be applied with git apply <TF-M source dir>/platform/ext/target/rpi/rp2350/pico-sdk.patch.

For example, to use SDK version 2.1.1, you can take the pico-sdk.patch file from TF-M version 2.1.2 and apply it to the SDK version 2.1.1.

Note

Building the default platform configuration requires the board to be provisioned. For this the provision bundle needs to be built and run on the board with -DPLATFORM_DEFAULT_PROVISIONING=OFF. The binary must be placed in flash at the address defined by PROVISIONING_BUNDLE_START. One way to do this is to generate a .uf2 file containing the bundle at the start address and copy it to the board. There is an example in the provided pico_uf2.sh script and in the description below.

If -DPLATFORM_DEFAULT_PROVISIONING=OFF and -DTFM_DUMMY_PROVISIONING=ON then the keys in the <TF-M source dir>/platform/ext/common/provisioning_bundle/provisioning_config.cmake and the default MCUBoot signing keys will be used for provisioning.

If -DPLATFORM_DEFAULT_PROVISIONING=OFF and -DTFM_DUMMY_PROVISIONING=OFF are set then unique values can be used for provisioning. The keys and seeds can be changed by passing the new values to the build command, or by setting the -DPROVISIONING_KEYS_CONFIG flag to a .cmake file that contains the keys. An example config cmake file can be seen at <TF-M source dir>/platform/ext/common/provisioning_bundle/provisioning_config.cmake. Otherwise new random values are going to be generated and used. For the image signing the ${MCUBOOT_KEY_S} and ${MCUBOOT_KEY_NS} will be used. These variables should point to .pem files that contain the code signing private keys. The public keys are going to be generated from these private keys and will be used for provisioning. The hash of the public key is going to be written into the provisioning_data.c automatically.

If -DMCUBOOT_GENERATE_SIGNING_KEYPAIR=ON is set then a new mcuboot signing public and private keypair is going to be generated and it’s going to be used to sign the S and NS binaries.

The new generated keypair can be found in the <build dir>/bin folder or in the <install directory>/image_signing/keys after installation. The generated provisioning_data.c file can be found at <build dir>/platform/target/provisioning/provisioning_data.c

Note

The provisioning bundle generation depends on pyelftools that needs to be installed via:

pip3 install pyelftools

Example of build instructions for regression tests with dummy keys:

Building Secure side with provisioning bundle:

Note

Add optionally:

-DTFM_MULTI_CORE_TOPOLOGY=ON for multicore support
-DPICO_SDK_PATH=<abs-path-to-pico-sdk> for a pre-fetched Pico SDK

cmake -S <TF-M-tests source dir>/tests_reg/spe \
-B <TF-M-tests source dir>/tests_reg/spe/build_rpi_single \
-DTFM_PLATFORM=rpi/rp2350 \
-DTFM_TOOLCHAIN_FILE=<TF-M source dir>/toolchain_GNUARM.cmake \
-DCONFIG_TFM_SOURCE_PATH=<TF-M source dir> \
-DTFM_PROFILE=profile_medium \
-DPLATFORM_DEFAULT_PROVISIONING=OFF \
-DTEST_S=ON \
-DTEST_NS=ON

cmake --build <TF-M-tests source dir>/tests_reg/spe/build_rpi_single \
-- -j8 install

Building Non-Secure side:

cmake -S <TF-M-tests source dir>/tests_reg \
-B <TF-M-tests source dir>/tests_reg/build_rpi_single \
-DCONFIG_SPE_PATH=<TF-M tests source dir>/tests_reg/spe/build_rpi_single/api_ns \
-DTFM_TOOLCHAIN_FILE=<TF-M-tests source dir>/tests_reg/spe/build_rpi_single/api_ns/cmake/toolchain_ns_GNUARM.cmake

cmake --build <TF-M-tests source dir>/tests_reg/build_rpi_single -- -j8

Binaries need to be converted with a small script pico_uf2.sh. It requires uf2conv.py from here: https://github.com/microsoft/uf2/blob/master/utils/uf2conv.py. It depends on: https://github.com/microsoft/uf2/blob/master/utils/uf2families.json. Both the above files need to be copied into the same place where pico_uf2.sh runs. Also, you may need to give executable permissions to both pico_uf2.sh and uf2conv.py. The tool takes the combined and signed S and NS images in .bin format, and generates the corresponding .uf2 file. It also generates the .uf2 for the bootloader (bl2.uf2) and the provisioning bundle one.

pico_uf2.sh <TF-M-tests source dir> build_rpi_single

Then just copy (drag-and-drop) the bl2.uf2 and tfm_s_ns_signed.uf2 files into the board, one at time. It will run the BL2, S and NS tests and print the results to the UART (Baudrate 115200). If the board needs provisioning, the .uf2 file containing the provisioning bundle needs to be copied before tfm_s_ns_signed.uf2. It only needs to be done once.

Note

If a different application was copied to the board before, erasing the flash might be necessary.

Erasing the flash:

Generating flash sized image of zeros can be done with the truncate command, then it can be converted to the uf2 format with the uf2conv.py utility. The resulting uf2 file then needs to be copied to the board. Current platform flash size is 2MB, please adjust size based on your board specs ( PICO_FLASH_SIZE_BYTES ):

truncate -s 2M nullbytes2M.bin
uf2conv.py nullbytes2M.bin --base 0x10000000 --convert --output nullbytes2M.uf2 --family 0xe48bff59

SPDX-License-Identifier: BSD-3-Clause SPDX-FileCopyrightText: Copyright The TrustedFirmware-M Contributors