boards: add initial code for Raspberry Pi Pico 2

This commit adds the code for the RP2350 MCU and
the RP2350 board that uses that MCU.
At the moment, the board supports the following:
- UART Console;
- Timers;
- GPIO with interrupts.
It also changes `tock_kernel_layout.ld` because of an apparent
bug with arm-none-eabi-objcopy.

Author: JADarius

Cargo.toml

@@ -6,9 +6,11 @@
 members = [
     "arch/cortex-m",
     "arch/cortex-v7m",
+    "arch/cortex-v8m",
     "arch/cortex-m0",
     "arch/cortex-m0p",
     "arch/cortex-m3",
+    "arch/cortex-m33",
     "arch/cortex-m4",
     "arch/cortex-m7",
     "arch/riscv",
@@ -41,6 +43,7 @@ members = [
     "boards/particle_boron",
     "boards/pico_explorer_base",
     "boards/raspberry_pi_pico",
+    "boards/raspberry_pi_pico_2",
     "boards/apollo3/redboard_artemis_atp",
     "boards/apollo3/redboard_artemis_nano",
     "boards/apollo3/lora_things_plus",
@@ -92,6 +95,7 @@ members = [
     "chips/qemu_rv32_virt_chip",
     "chips/psoc62xa",
     "chips/rp2040",
+    "chips/rp2350",
     "chips/sam4l",
     "chips/segger",
     "chips/sifive",

arch/cortex-m/src/mpu.rs

@@ -156,15 +156,6 @@ impl<const NUM_REGIONS: usize, const MIN_REGION_SIZE: usize> MPU<NUM_REGIONS, MI
         }
     }
 
-    // Function for boards that have TrustZone.
-    pub const unsafe fn new_ns() -> Self {
-        Self {
-            registers: MPU_NS_BASE_ADDRESS,
-            config_count: Cell::new(NonZeroUsize::MIN),
-            hardware_is_configured_for: OptionalCell::empty(),
-        }
-    }
-
     // Function useful for boards where the bootloader sets up some
     // MPU configuration that conflicts with Tock's configuration:
     pub unsafe fn clear_mpu(&self) {

arch/cortex-m33/src/lib.rs

@@ -4,14 +4,20 @@
 
 //! Shared implementations for ARM Cortex-M33 MCUs.
 
-#![crate_name = "cortexm33"]
-#![crate_type = "rlib"]
 #![no_std]
 
 use core::fmt::Write;
 
 pub mod mpu {
-    pub type MPU = cortexm::mpu::MPU<16, 32>; // Cortex-M7 MPU has 16 regions
+    use kernel::utilities::StaticRef;
+    pub type MPU = cortexm::mpu::MPU<16, 32>;
+
+    const MPU_BASE_ADDRESS: StaticRef<cortexm::mpu::MpuRegisters> =
+        unsafe { StaticRef::new(0xE002ED90 as *const cortexm::mpu::MpuRegisters) };
+
+    pub unsafe fn new() -> MPU {
+        MPU::new(MPU_BASE_ADDRESS)
+    }
 }
 
 pub use cortexm::initialize_ram_jump_to_main;

arch/cortex-v8m/src/lib.rs

@@ -4,8 +4,6 @@
 
 //! Generic support for all Cortex-M platforms.
 
-#![crate_name = "cortexv8m"]
-#![crate_type = "rlib"]
 #![no_std]
 
 // These constants are defined in the linker script.

boards/README.md

@@ -97,6 +97,7 @@ but the approximate definitions:
 | [Digilent Arty A-7 100T](arty_e21/README.md)                      | RISC-V RV32IMAC  | SiFive E21     | openocd    | tockloader                  | No            |
 | [MSP432 Evaluation kit MSP432P401R](msp_exp432p401r/README.md)    | ARM Cortex-M4    | MSP432P401R    | openocd    | custom                      | No            |
 | [CY8CPROTO-062-4343W](cy8cproto_62_4343_w/README.md)              | ARM Cortex-M0+   | PSoC62         | openocd    | custom                      | No            |
+| [Raspberry Pi Pico 2](raspberry_pi_pico_2/README.md)              | ARM Cortex-M33   | RP2350         | openocd    | openocd                     | No            |
 
 
 ### Other

boards/raspberry_pi_pico_2/.cargo/config.toml

@@ -0,0 +1,14 @@
+# Licensed under the Apache License, Version 2.0 or the MIT License.
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+# Copyright Tock Contributors 2024.
+
+include = [
+  "../../cargo/tock_flags.toml",
+  "../../cargo/unstable_flags.toml",
+]
+
+[build]
+target = "thumbv8m.main-none-eabi"
+
+[unstable]
+config-include = true

boards/raspberry_pi_pico_2/Cargo.toml

@@ -0,0 +1,27 @@
+# Licensed under the Apache License, Version 2.0 or the MIT License.
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+# Copyright OxidOS Automotive 2025.
+
+[package]
+name = "raspberry_pi_pico_2"
+version.workspace = true
+authors.workspace = true
+build = "../build.rs"
+edition.workspace = true
+
+[dependencies]
+cortexm33 = { path = "../../arch/cortex-m33" }
+kernel = { path = "../../kernel" }
+rp2350 = { path = "../../chips/rp2350" }
+components = { path = "../components" }
+enum_primitive = { path = "../../libraries/enum_primitive" }
+
+capsules-core = { path = "../../capsules/core" }
+capsules-extra = { path = "../../capsules/extra" }
+capsules-system = { path = "../../capsules/system" }
+
+[build-dependencies]
+tock_build_scripts = { path = "../build_scripts" }
+
+[lints]
+workspace = true

boards/raspberry_pi_pico_2/Makefile

@@ -0,0 +1,40 @@
+# Licensed under the Apache License, Version 2.0 or the MIT License.
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+# Copyright OxidOS Automotive 2025.
+
+# Makefile for building the tock kernel for the Raspberry Pi Pico 2 board.
+
+include ../Makefile.common
+
+OPENOCD=openocd
+OPENOCD_INTERFACE=picoprobe
+OPENOCD_OPTIONS=-f openocd-$(OPENOCD_INTERFACE).cfg
+
+BOOTSEL_FOLDER?=/run/media/$(USER)/RP2350
+
+KERNEL=$(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM).elf
+KERNEL_WITH_APP=$(TOCK_ROOT_DIRECTORY)/target/$(TARGET)/release/$(PLATFORM)-app.elf
+
+
+# Default target for installing the kernel.
+.PHONY: install
+install: flash
+
+.PHONY: flash-openocd
+flash-openocd: $(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM).elf
+	$(OPENOCD) $(OPENOCD_OPTIONS) -c "adapter speed 5000" -c "program $<; verify_image $<;  reset; shutdown;"
+
+.PHONY: flash
+flash: $(KERNEL)
+	picotool uf2 convert $< $(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM).uf2
+	@if [ -d $(BOOTSEL_FOLDER) ]; then cp $(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM).uf2 "$(BOOTSEL_FOLDER)"; else echo; echo Please edit the BOOTSEL_FOLDER variable to point to you Raspberry Pi Pico 2 Flash Drive Folder; echo You can download and flash $(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM).uf2; fi
+
+.PHONY: program
+program: $(KERNEL)
+ifeq ($(APP),)
+	$(error Please define the APP variable with the TBF file to flash an application)
+endif
+	arm-none-eabi-objcopy --set-section-flags .apps=LOAD,ALLOC $(KERNEL) $(KERNEL_WITH_APP)
+	arm-none-eabi-objcopy --update-section .apps=$(APP) $(KERNEL_WITH_APP)
+	picotool uf2 convert $(KERNEL_WITH_APP) $(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM)-app.uf2
+	@if [ -d $(BOOTSEL_FOLDER) ]; then cp $(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM)-app.uf2 "$(BOOTSEL_FOLDER)"; else echo; echo Please edit the BOOTSEL_FOLDER variable to point to you Raspberry Pi Pico 2 Flash Drive Folder; echo You can download and flash $(TOCK_ROOT_DIRECTORY)target/$(TARGET)/release/$(PLATFORM)-app.uf2; fi

boards/raspberry_pi_pico_2/README.md

@@ -0,0 +1,156 @@
+Raspberry Pi Pico 2 - RP2350
+============================
+
+<img src="https://www.raspberrypi.com/documentation/microcontrollers/images/pico-2.png?hash=c4b2ccf2504c98fdd111405dd95346b5" width="80%">
+
+The [Raspberry Pi Pico 2](https://www.raspberrypi.com/products/raspberry-pi-pico-2/) is a
+board developed by the Raspberry Pi Foundation and is based on the RP2350 chip.
+
+## Getting Started
+
+First, follow the [Tock Getting Started guide](../../doc/Getting_Started.md)
+
+## Installing picotool
+
+The RP2350 uses UF2 files for flashing. Tock compiles to an ELF file.
+The `picotool` utility is needed to transform the Tock ELF file into an UF2 file.
+
+To install `picotool`, check the instructions from their GitHub [page](https://github.com/raspberrypi/picotool).
+
+
+## Flashing the kernel
+
+The Raspberry Pi Pico 2 RP2350 Connect can be programmed using its bootloader, which requires an UF2 file.
+
+### Enter BOOTSEL mode
+
+To flash the Pico RP2350, it needs to be put into BOOTSEL mode. This will mount
+a flash drive that allows one to copy a UF2 file. To enter BOOTSEL mode, press the BOOTSEL button and hold it while you connect the other end of the micro USB cable to your computer.
+
+Then `cd` into `boards/raspberry_pi_pico_2` directory and run:
+
+```bash
+$ make flash
+
+(or)
+
+$ make flash-debug
+```
+
+> Note: The Makefile provides the BOOTSEL_FOLDER variable that points towards the mount point of
+> the Pico 2 RP2350 flash drive. By default, this is located in `/media/$(USER)/RP2350`. This might
+> be different on several systems, make sure to adjust it.
+
+## Flashing app
+
+Enter BOOTSEL mode.
+
+Apps are built out-of-tree. Once an app is built, you can add the path to it in the Makefile (APP variable), then run:
+```bash
+$ APP="<path to app's tbf file>" make flash-app
+```
+
+## Debugging
+
+The Raspberry Pi Pico can also be programmed via an SWD connection, which requires the Pico to be connected to a regular Raspberry Pi device that exposes the necessary pins OR using another Raspberry Pi Pico set up in “Picoprobe” mode. The kernel is transferred to the Raspberry Pi Pico using a [custom version of OpenOCD](https://github.com/raspberrypi/openocd).
+
+### Flashing Setup
+
+#### From a regular Raspberry Pi (option 1)
+
+To install OpenOCD on the Raspberry Pi run the following commands on the Pi:
+```bash
+$ sudo apt update
+$ sudo apt install automake autoconf build-essential texinfo libtool libftdi-dev libusb-1.0-0-dev git
+$ git clone https://github.com/raspberrypi/openocd.git --recursive --branch sdk-2.0.0 --depth=1
+$ cd openocd
+$ ./bootstrap
+$ ./configure --enable-ftdi --enable-sysfsgpio --enable-bcm2835gpio
+$ make -j4
+$ sudo make install
+```
+
+Enable SSH on the Raspberry Pi by following the [instructions on the Raspberry Pi website](https://www.raspberrypi.org/documentation/remote-access/ssh/).
+
+Next, connect the SWD pins of the Pico 2 (the tree lower wires) to GND, GPIO 24, and GPIO 25 of the Raspberry Pi. You can follow the schematic in the [official documentation](https://datasheets.raspberrypi.org/pico/getting-started-with-pico.pdf#%5B%7B%22num%22%3A22%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C115%2C431.757%2Cnull%5D) and connect the blue, black, and purple wires.
+
+Also connect the other three wires as shown in the schematic, which will connect the Pico UART to the Raspberry Pi. This will enable the serial communication between the two devices.
+
+#### From a Linux Host using a Picoprobe (option 2)
+
+To install OpenOCD on Debian/Ubuntu run the following commands:
+```bash
+$ sudo apt update
+$ sudo apt install automake autoconf build-essential texinfo libtool libftdi-dev libusb-1.0-0-dev git
+$ git clone https://github.com/raspberrypi/openocd.git --recursive --branch sdk-2.0.0 --depth=1
+$ cd openocd
+$ ./bootstrap
+$ ./configure --enable-picoprobe
+$ make -j4
+$ sudo make install
+```
+
+Download the Picoprobe UF2 file onto the USB mass storage device presented by the Pico that is going to act as Picoprobe device after plugging it into some USB port: https://datasheets.raspberrypi.com/soft/picoprobe.uf2 (the device should automatically restart after the file has been written).
+
+Next, connect the SWD pins of the Pico 2 target (the tree lower wires, left-to-right) to GP2, GND, and GP3 of the Pico that will act as Picoprobe. You can follow the schematic in the [official documentation](https://datasheets.raspberrypi.com/pico/getting-started-with-pico.pdf#%5B%7B%22num%22%3A64%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C115%2C696.992%2Cnull%5D) and connect the blue, black, and purple wires.
+
+Also connect the other four wires as shown in the schematic, which will connect the Pico UART and power to the Picoprobe. This will enable the serial communication between the two devices.
+
+### Flashing the tock kernel
+
+#### Building and Deploying from the same System
+`cd` into `boards/raspberry_pi_pico` directory and run:
+
+```bash
+$ make flash OPENOCD_INTERFACE=[swd|picoprobe]
+```
+
+The *OPENOCD_INTERFACE* parameter selects which mode to flash the target Pico device in: `swd` flashes directly via SWD over GPIO (default, needs to be run a regular Raspberry Pi), `picoprobe` flashes indirectly via another Raspberry Pi Pico device.
+
+You can also open a serial console on to view debug messages:
+```bash
+$ sudo apt install picocom
+$ picocom /dev/ttyACM0 -b 115200 -l
+```
+
+#### Building on a Desktop/Laptop then Flashing via regular Raspberry Pi
+
+`cd` into `boards/raspberry_pi_pico_2` directory and run:
+
+```bash
+$ make
+
+(or)
+
+$ make debug
+```
+
+Connect via ssh to the Raspberry Pi and forward port 3333. Then start OpenOCD on the Pi.
+```bash
+$ ssh pi@<pi_IP> -L 3333:localhost:3333
+
+(wait to connect)
+
+$ openocd -f interface/raspberrypi-swd.cfg -f target/rp2350.cfg
+```
+You can also open a serial console on the Raspberry Pi for debug messages.
+```bash
+$ sudo apt install minicom
+$ minicom -b 115200 -o -D /dev/serial0
+```
+
+On the local computer use gdb-multiarch on Linux or arm-none-eabi-gdb on MacOS to deploy tock.
+```bash
+$ arm-none-eabi-gdb tock/target/thumbv8m.main-none-eabi/release/raspberry_pi_pico_2.elf
+(gdb) target remote :3333
+(gdb) load
+(gdb) continue
+```
+## Flashing app
+
+Apps are built out-of-tree. Once an app is built, you can add the path to it in the Makefile (APP variable), then run:
+```bash
+$ make program
+```
+
+This will generate a new ELF file that can be deployed on the Raspberry Pi Pico 2 via gdb and OpenOCD as described in the [section above](#flash-the-tock-kernel).

boards/raspberry_pi_pico_2/layout.ld

@@ -0,0 +1,41 @@
+/* Licensed under the Apache License, Version 2.0 or the MIT License. */
+/* SPDX-License-Identifier: Apache-2.0 OR MIT                         */
+/* Copyright OxidOS Automotive 2025.                                  */
+
+MEMORY
+{
+  /* uncomment this to boot from RAM */
+  /* reset (rx)  : ORIGIN = 0x20000000, LENGTH = 16K
+  rom (rx)  : ORIGIN = 0x20000100, LENGTH = 256K
+  prog (rx) : ORIGIN = 0x20040000, LENGTH = 1K
+  ram (rwx) : ORIGIN = 0x20004000, LENGTH = 240K */
+
+  /* boot from Flash */
+  bootloader (rx) : ORIGIN = 0x10000000, LENGTH = 1024
+  rom (rx)  : ORIGIN = 0x10000400, LENGTH = 255K
+  prog (rx) : ORIGIN = 0x10040000, LENGTH = 256K
+  ram (rwx) : ORIGIN = 0x20000000, LENGTH = 264K
+}
+
+PAGE_SIZE = 4K;
+
+ENTRY(jump_to_bootloader)
+
+SECTIONS {
+  .bootloader  : ALIGN(4)
+    {
+        KEEP (*(.metadata_block));
+        KEEP (*(.flash_bootloader));
+        . = ALIGN (256);
+    } > bootloader
+
+    /*
+     * This padding has been added because arm-none-eabi-objcopy
+     * wrongly aligns the .stack section.
+     */
+   .padding (NOLOAD) : {
+        BYTE(0xFF)
+    } > ram
+}
+
+INCLUDE tock_kernel_layout.ld