# pi-pico2-linux

**Repository Path**: embeddedboys/pi-pico2-linux

## Basic Information

- **Project Name**: pi-pico2-linux
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-11-08
- **Last Updated**: 2025-11-08

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Raspberry Pi Pico 2 Buildroot

How to build:

```bash
git clone https://github.com/Mr-Bossman/pi-pico2-linux

cd pi-pico2-linux

git submodule update --init

# cd buildroot
# make BR2_EXTERNAL=$PWD/../ raspberrypi-pico2_defconfig
make -C buildroot BR2_EXTERNAL=$PWD/ raspberrypi-pico2_defconfig

make -C buildroot

make -C psram-bootloader flash-kernel
```

## Designed to work with [SparkFun Pro Micro - RP2350](https://www.sparkfun.com/products/24870)

![Image of boot](images/booting.png)

#### NOTES on SDK
This project uses the sdk and tools installed to `~/.pico-sdk/`.
To use the tools and sdk installed to another location see [this issue](https://github.com/raspberrypi/pico-sdk/pull/1820#issuecomment-2291611448)
or the following.

```bash
export PICO_SDK_PATH=~/example_sdk/sdk/2.0.0/
export PICO_TOOLCHAIN_PATH=~/example_sdk/toolchain/13_2_Rel1
export pioasm_DIR=~/example_sdk/tools/2.0.0/pioasm
export picotool_DIR=~/example_sdk/picotool/2.0.0/picotool

make flash-kernel
```

#### NOTES on Atomics
On page 307 of the RP2350 Datasheet MCAUSE register CODE 7 says:
> Store/AMO access fault. A store/AMO failed a PMP check, or
encountered a downstream bus error. Also set if an AMO is attempted on a
region that does not support atomics (on RP2350, anything but SRAM).

Atomics will only work in SRAM, the kernel is located PSRAM, not SRAM.
The `lr` and `sr` atomic load and store will always return error in this region causing most code using them to behave incorrectly.
Most implementations assume `lr` and `sr` will eventually succeed.

### Use on other boards

This only works on the RP2350 RISC-V cores.

If you want to run this on other boards, please change the `PICO_BOARD` variable in `CMakeLists.txt`.
`set(PICO_BOARD sparkfun_promicro_rp2350 CACHE STRING "Board type")`

You will also need to set the psram CS pin with the `SFE_RP2350_XIP_CSI_PIN` macro in `bootloader.c`.
As of now the only psram chip tested is the `APS6404L` and any others may not work.