================== Espressif ESP32-H2 ================== The ESP32-H2 is an ultra-low-power and highly integrated SoC with a RISC-V core and supports 2.4 GHz transceiver, Bluetooth 5 (LE) and the 802.15.4 protocol. * Address Space - 452 KB of internal memory address space accessed from the instruction bus - 452 KB of internal memory address space accessed from the data bus - 832 KB of peripheral address space - 16 MB of external memory virtual address space accessed from the instruction bus - 16 MB of external memory virtual address space accessed from the data bus - 260 KB of internal DMA address space * Internal Memory - 128 KB ROM - 320 KB SRAM (16 KB can be configured as Cache) - 4 KB of SRAM in RTC * External Memory - Up to 16 MB of external flash * Peripherals - Multiple peripherals * GDMA - 7 modules are capable of DMA operations. ESP32-H2 Toolchain ================== A generic RISC-V toolchain can be used to build ESP32-H2 projects. It's recommended to use the same toolchain used by NuttX CI. Please refer to the Docker `container `_ and check for the current compiler version being used. For instance: .. code-block:: ############################################################################### # Build image for tool required by RISCV builds ############################################################################### FROM nuttx-toolchain-base AS nuttx-toolchain-riscv # Download the latest RISCV GCC toolchain prebuilt by xPack RUN mkdir riscv-none-elf-gcc && \ curl -s -L "https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v13.2.0-2/xpack-riscv-none-elf-gcc-13.2.0-2-linux-x64.tar.gz" \ | tar -C riscv-none-elf-gcc --strip-components 1 -xz It uses the xPack's prebuilt toolchain based on GCC 13.2.0-2. Installing ---------- First, create a directory to hold the toolchain: .. code-block:: console $ mkdir -p /path/to/your/toolchain/riscv-none-elf-gcc Download and extract toolchain: .. code-block:: console $ curl -s -L "https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v13.2.0-2/xpack-riscv-none-elf-gcc-13.2.0-2-linux-x64.tar.gz" \ | tar -C /path/to/your/toolchain/riscv-none-elf-gcc --strip-components 1 -xz Add the toolchain to your `PATH`: .. code-block:: console $ echo "export PATH=/path/to/your/toolchain/riscv-none-elf-gcc/bin:$PATH" >> ~/.bashrc You can edit your shell's rc files if you don't use bash. Building and flashing NuttX =========================== Installing esptool ------------------ First, make sure that ``esptool.py`` is installed and up-to-date. This tool is used to convert the ELF to a compatible ESP32-H2 image and to flash the image into the board. It can be installed with: ``pip install esptool>=4.8.1``. .. warning:: Installing ``esptool.py`` may required a Python virtual environment on newer systems. This will be the case if the ``pip install`` command throws an error such as: ``error: externally-managed-environment``. If you are not familiar with virtual environments, refer to `Managing esptool on virtual environment`_ for instructions on how to install ``esptool.py``. Bootloader and partitions ------------------------- NuttX can boot the ESP32-H2 directly using the so-called "Simple Boot". An externally-built 2nd stage bootloader is not required in this case as all functions required to boot the device are built within NuttX. Simple boot does not require any specific configuration (it is selectable by default if no other 2nd stage bootloader is used). For compatibility among other SoCs and future options of 2nd stage bootloaders, the commands ``make bootloader`` and the ``ESPTOOL_BINDIR`` option (for the ``make flash``) are kept (and ignored if Simple Boot is used). If features like `Flash Encryption`_ are required, an externally-built 2nd stage bootloader is needed. The MCUBoot bootloader is built using the ``make bootloader`` command. This command generates the firmware in the ``nuttx`` folder. The ``ESPTOOL_BINDIR`` is used in the ``make flash`` command to specify the path to the bootloader. For compatibility among other SoCs and future options of 2nd stage bootloaders, the commands ``make bootloader`` and the ``ESPTOOL_BINDIR`` option (for the ``make flash``) can be used even if no externally-built 2nd stage bootloader is being built (they will be ignored if Simple Boot is used, for instance):: $ make bootloader .. note:: It is recommended that if this is the first time you are using the board with NuttX to perform a complete SPI FLASH erase. .. code-block:: console $ esptool.py erase_flash Building and flashing --------------------- This is a two-step process where the first step converts the ELF file into an ESP32-H2 compatible binary and the second step flashes it to the board. These steps are included in the build system and it is possible to build and flash the NuttX firmware simply by running:: $ make flash ESPTOOL_PORT= ESPTOOL_BINDIR=./ where: * ``ESPTOOL_PORT`` is typically ``/dev/ttyUSB0`` or similar. * ``ESPTOOL_BINDIR=./`` is the path of the externally-built 2nd stage bootloader and the partition table (if applicable): when built using the ``make bootloader``, these files are placed into ``nuttx`` folder. * ``ESPTOOL_BAUD`` is able to change the flash baud rate if desired. Flashing NSH Example -------------------- This example shows how to build and flash the ``nsh`` defconfig for the ESP32-H2-DevKitM-1 board:: $ cd nuttx $ make distclean $ ./tools/configure.sh esp32h2-devkitc:nsh $ make -j$(nproc) When the build is complete, the firmware can be flashed to the board using the command:: $ make -j$(nproc) flash ESPTOOL_PORT= ESPTOOL_BINDIR=./ where ```` is the serial port where the board is connected:: $ make flash ESPTOOL_PORT=/dev/ttyUSB0 ESPTOOL_BINDIR=./ CP: nuttx.hex MKIMAGE: NuttX binary esptool.py -c esp32h2 elf2image --ram-only-header -fs 4MB -fm dio -ff 48m -o nuttx.bin nuttx esptool.py v4.8.1 Creating esp32h2 image... Image has only RAM segments visible. ROM segments are hidden and SHA256 digest is not appended. Merged 1 ELF section Successfully created esp32h2 image. Generated: nuttx.bin esptool.py -c esp32h2 -p /dev/ttyUSB0 -b 921600 --no-stub write_flash -fs 4MB -fm dio -ff 48m 0x0000 nuttx.bin esptool.py v4.8.1 Serial port /dev/ttyUSB0 Connecting.... Chip is ESP32-H2 (revision v0.0) [...] Flash will be erased from 0x00000000 to 0x0003cfff... Erasing flash... Took 0.27s to erase flash block Wrote 249856 bytes at 0x00000000 in 5.0 seconds (401.4 kbit/s)... Hash of data verified. Leaving... Hard resetting via RTS pin... Now opening the serial port with a terminal emulator should show the NuttX console:: $ picocom -b 115200 /dev/ttyUSB0 NuttShell (NSH) NuttX-12.8.0 nsh> uname -a NuttX 12.8.0 759d37b97c-dirty Mar 5 2025 20:16:34 risc-v esp32h2-devkit Debugging ========= This section describes debugging techniques for the ESP32-H2. Debugging with ``openocd`` and ``gdb`` -------------------------------------- Espressif uses a specific version of OpenOCD to support ESP32-H2: `openocd-esp32 `_. Please check `Building OpenOCD from Sources `_ for more information on how to build OpenOCD for ESP32-H2. You do not need an external JTAG to debug, the ESP32-H2 integrates a USB-to-JTAG adapter. .. note:: One must configure the USB drivers to enable JTAG communication. Please check `Configure USB Drivers `_ for more information. OpenOCD can then be used:: openocd -s -c 'set ESP_RTOS hwthread' -f board/esp32c3-builtin.cfg -c 'init; reset halt; esp appimage_offset 0x0' .. note:: - ``appimage_offset`` should be set to ``0x0`` when ``Simple Boot`` is used. For MCUboot, this value should be set to ``CONFIG_ESPRESSIF_OTA_PRIMARY_SLOT_OFFSET`` value (``0x10000`` by default). - ``-s `` defines the path to the OpenOCD scripts. Usually set to `tcl` if running openocd from its source directory. It can be omitted if `openocd-esp32` were installed in the system with `sudo make install`. If you want to debug with an external JTAG adapter it can be connected as follows: ============ =========== ESP32-H2 Pin JTAG Signal ============ =========== GPIO2 TMS GPIO5 TDI GPIO4 TCK GPIO3 TDO ============ =========== Furthermore, an efuse needs to be burnt to be able to debug:: espefuse.py -p burn_efuse DIS_USB_JTAG .. warning:: Burning eFuses is an irreversible operation, so please consider the above option before starting the process. OpenOCD can then be used:: openocd -c 'set ESP_RTOS hwthread; set ESP_FLASH_SIZE 0' -f board/esp32h2-ftdi.cfg Once OpenOCD is running, you can use GDB to connect to it and debug your application:: riscv-none-elf-gdb -x gdbinit nuttx whereas the content of the ``gdbinit`` file is:: target remote :3333 set remote hardware-watchpoint-limit 2 mon reset halt flushregs monitor reset halt thb nsh_main c .. note:: ``nuttx`` is the ELF file generated by the build process. Please note that ``CONFIG_DEBUG_SYMBOLS`` must be enabled in the ``menuconfig``. Please refer to :doc:`/quickstart/debugging` for more information about debugging techniques. Stack Dump and Backtrace Dump ----------------------------- NuttX has a feature to dump the stack of a task and to dump the backtrace of it (and of all the other tasks). This feature is useful to debug the system when it is not behaving as expected, especially when it is crashing. In order to enable this feature, the following options must be enabled in the NuttX configuration: ``CONFIG_SCHED_BACKTRACE``, ``CONFIG_DEBUG_SYMBOLS`` and, optionally, ``CONFIG_ALLSYMS``. .. note:: The first two options enable the backtrace dump. The third option enables the backtrace dump with the associated symbols, but increases the size of the generated NuttX binary. Espressif also provides a tool to translate the backtrace dump into a human-readable format. This tool is called ``btdecode.sh`` and is available at ``tools/espressif/btdecode.sh`` of NuttX repository. .. note:: This tool is not necessary if ``CONFIG_ALLSYMS`` is enabled. In this case, the backtrace dump contains the function names. Example - Crash Dump ^^^^^^^^^^^^^^^^^^^^ A typical crash dump, caused by an illegal load with ``CONFIG_SCHED_BACKTRACE`` and ``CONFIG_DEBUG_SYMBOLS`` enabled, is shown below:: riscv_exception: EXCEPTION: Store/AMO access fault. MCAUSE: 00000007, EPC: 42012df0, MT0 riscv_exception: PANIC!!! Exception = 00000007 _assert: Current Version: NuttX 10.4.0 2ae3246e40-dirty Sep 19 2024 14:53:33 risc-v _assert: Assertion failed panic: at file: :0 task: backtrace process: backtrace 0x42012daa up_dump_register: EPC: 42012df0 up_dump_register: A0: 0000005a A1: 408095e4 A2: 00000001 A3: 00000088 up_dump_register: A4: 00007fff A5: 00000001 A6: 00000000 A7: 00000000 up_dump_register: T0: 00000000 T1: 00000000 T2: ffffffff T3: 00000000 up_dump_register: T4: 00000000 T5: 00000000 T6: 00000000 up_dump_register: S0: 408086ae S1: 40808698 S2: 00000000 S3: 00000000 up_dump_register: S4: 00000000 S5: 00000000 S6: 00000000 S7: 00000000 up_dump_register: S8: 00000000 S9: 00000000 S10: 00000000 S11: 00000000 up_dump_register: SP: 40809640 FP: 408086ae TP: 00000000 RA: 42012df0 dump_stack: User Stack: dump_stack: base: 0x408086b8 dump_stack: size: 00004040 dump_stack: sp: 0x40809640 stack_dump: 0x40809620: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00001880 stack_dump: 0x40809640: 00000000 408082b0 42012daa 42006e1e 00000000 00000000 40808698 00000002 stack_dump: 0x40809660: 00000000 00000000 00000000 42004d8a 00000000 00000000 00000000 00000000 stack_dump: 0x40809680: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 sched_dumpstack: backtrace| 2: 0x42012df0 dump_tasks: PID GROUP PRI POLICY TYPE NPX STATE EVENT SIGMASK STACKBASE STACKSIZE COMMAND dump_tasks: ---- --- --- -------- ------- --- ------- ---------- ---------------- 0x40805120 2048 irq dump_task: 0 0 0 FIFO Kthread - Ready 0000000000000000 0x408068b0 2032 Idle_Task dump_task: 1 1 100 RR Task - Waiting Semaphore 0000000000000000 0x408077c8 1992 nsh_main dump_task: 2 2 255 RR Task - Running 0000000000000000 0x408086b8 4040 backtrace task sched_dumpstack: backtrace| 0: 0x42008420 sched_dumpstack: backtrace| 1: 0x420089a2 sched_dumpstack: backtrace| 2: 0x42012df0 The lines starting with ``sched_dumpstack`` show the backtrace of the tasks. By checking it, it is possible to track the root cause of the crash. Saving this output to a file and using the ``btdecode.sh``:: ./tools/btdecode.sh esp32h2 /tmp/backtrace.txt Backtrace for task 2: 0x42012df0: assert_on_task at backtrace_main.c:158 (inlined by) backtrace_main at backtrace_main.c:194 Backtrace dump for all tasks: Backtrace for task 2: 0x42012df0: assert_on_task at backtrace_main.c:158 (inlined by) backtrace_main at backtrace_main.c:194 Backtrace for task 1: 0x420089a2: sys_call2 at syscall.h:227 (inlined by) up_switch_context at riscv_switchcontext.c:95 Backtrace for task 0: 0x42008420: up_idle at esp_idle.c:74 Peripheral Support ================== The following list indicates the state of peripherals' support in NuttX: ============== ======= ==================== Peripheral Support NOTES ============== ======= ==================== ADC Yes Oneshot and internal temperature sensor AES No Bluetooth No CAN/TWAI Yes DMA Yes DS No ECC No eFuse Yes GPIO Yes Dedicated GPIO supported HMAC No I2C Yes Master and Slave mode supported I2S Yes LED/PWM Yes MCPWM No Pulse Counter Yes RMT Yes RNG Yes RSA No RTC Yes SHA Yes SPI Yes SPIFLASH Yes SPIRAM No Timers Yes UART Yes USB Serial Yes Watchdog Yes Wifi No XTS No ============== ======= ==================== Analog-to-digital converter (ADC) --------------------------------- One ADC unit is available for the ESP32-H2, with 5 channels. During bringup, GPIOs for selected channels are configured automatically to be used as ADC inputs. If available, ADC calibration is automatically applied (see `this page `__ for more details). Otherwise, a simple conversion is applied based on the attenuation and resolution. The ADC unit is accessible using the ADC character driver, which returns data for the enabled channels. The ADC unit can be enabled in the menu :menuselection:`System Type --> Peripheral Support --> Analog-to-digital converter (ADC)`. Then, it can be customized in the menu :menuselection:`System Type --> ADC Configuration`, which includes operating mode, gain and channels. ========== =========== Channel ADC1 GPIO ========== =========== 0 1 1 2 2 3 3 4 4 5 ========== =========== .. _MCUBoot H2: MCUBoot ======= The ESP32-H2 supports MCUBoot. Read more about the MCUBoot for Espressif devices `here `__. Flash Encryption ---------------- Flash encryption is intended for encrypting the contents of the ESP32-H2's off-chip flash memory. Once this feature is enabled, firmware is flashed as plaintext, and then the data is encrypted in place on the first boot. As a result, physical readout of flash will not be sufficient to recover most flash contents. The current state of flash encryption for ESP32-H2 allows the use of Virtual E-Fuses and development mode, which permit users to evaluate and test the firmware before making definitive changes such as burning E-Fuses. Flash encryption supports the following features: .. list-table:: :header-rows: 1 * - Feature - Description * - **Flash Encryption with Virtual E-Fuses** - Use flash encryption without burning E-Fuses. Default selection when flash encryption is enabled. * - **Flash Encryption in Development mode** - Allows reflashing an encrypted device by appending the ``--encrypt`` argument to the ``esptool.py write_flash`` command. This is done automatically if ``ESPRESSIF_SECURE_FLASH_ENC_FLASH_DEVICE_ENCRYPTED`` is set. * - **Flash Encryption in Release mode** - Does not allow reflashing the device. This is a permanent setting. * - **Flash Encryption key** - A user-generated key is required by default. Alternatively, a device-generated key is possible, but it will not be recoverable by the user (not recommended). See ``ESPRESSIF_SECURE_FLASH_ENC_USE_HOST_KEY``. * - **Encrypted MTD Partition** - If SPI Flash is enabled, an empty user MTD partition will be automatically encrypted on first flash. .. note:: It is **strongly suggested** to read the following before working on flash encryption: - `MCUBoot Flash Encryption `_ - `General E-Fuse documentation `_ - `Flash Encryption Relevant E-Fuses `_ Flash Encryption Requirements ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Flash encryption requires burning E-Fuses to enable it on chip. This is not a reversible operation and should be done with caution. There is, however, a way to test the flash encryption by simulating them on flash. Both paths are described below. Build System Features ''''''''''''''''''''' The build system contains some safeguards to avoid accidentally burning E-Fuses and automations for convenience. Those are summarized below: 1. A yellow warning will show up during build alerting that flash encryption is enabled (same for Virtual E-Fuses). 2. If ``ESPRESSIF_SECURE_FLASH_ENC_USE_HOST_KEY`` is set, build will fail if the flash encryption key is not found. 3. If SPI Flash is enabled, the user MTD partition is automatically encrypted with the provided encryption key. 4. ``make flash`` command will prompt the user for confirmation before burning the E-Fuse, if Virtual E-Fuses are disabled. Simulating Flash Encryption with Virtual E-Fuses ''''''''''''''''''''''''''''''''''''''''''''''''' It is highly recommended to use this method for testing the flash encryption before actually burning the E-Fuses. The E-Fuses are stored in flash and persist between reboots. No real E-Fuses are changed. To enable virtual E-Fuses for flash encryption testing, open ``menuconfig`` and: 1. Enable flash encryption on boot on: :menuselection:`System Type --> Bootloader and Image Configuration` 2. Verify Virtual E-Fuses are enabled (this is done by default): :menuselection:`System Type --> Peripheral Support --> E-Fuse support` Now build the bootloader and the firmware. Flashing the device (or opening on QEMU) will trigger the following: 1. On the first boot, the bootloader will encrypt the flash:: ... [esp32h2] [WRN] eFuse virtual mode is enabled. If Secure boot or Flash encryption is enabled then it does not provide any security. FOR TESTING ONLY! [esp32h2] [WRN] [efuse] [Virtual] try loading efuses from flash: 0x10000 (offset) ... [esp32h2] [INF] [flash_encrypt] Encrypting bootloader... [esp32h2] [INF] [flash_encrypt] Bootloader encrypted successfully [esp32h2] [INF] [flash_encrypt] Encrypting primary slot... [esp32h2] [INF] [flash_encrypt] Encrypting remaining flash... [esp32h2] [INF] [flash_encrypt] Flash encryption completed ... [esp32h2] [INF] Resetting with flash encryption enabled... 2. Device will reset and it should be now operating similar to an actual encrypted device:: ... [esp32h2] [INF] Checking flash encryption... [esp32h2] [INF] [flash_encrypt] flash encryption is enabled (1 plaintext flashes left) [esp32h2] [INF] Disabling RNG early entropy source... [esp32h2] [INF] br_image_off = 0x20000 [esp32h2] [INF] ih_hdr_size = 0x20 [esp32h2] [INF] Loading image 0 - slot 0 from flash, area id: 1 ... NuttShell (NSH) NuttX-12.8.0 nsh> Actual encryption and burning E-Fuses ''''''''''''''''''''''''''''''''''''' E-Fuses are burned by esptool and the bootloader on the first boot after flashing with encryption enabled. This process is automated on NuttX build system. .. warning:: Burning E-Fuses is NOT a reversible operation and should be done with caution. To build a firmware with E-Fuse support and flash encryption enabled, open ``menuconfig`` and: 1. Enable flash encryption on boot on: :menuselection:`System Type --> Bootloader and Image Configuration` 2. Disable Virtual E-Fuses :menuselection:`System Type --> Peripheral Support --> E-Fuse support` 3. Check usage mode is Development (this allows reflashing, while Release mode does not). .. note:: If using development mode of flash encryption (see menuconfig and documentation above), it is still possible to re-flash the device with esptool by setting ``ESPRESSIF_SECURE_FLASH_ENC_FLASH_DEVICE_ENCRYPTED`` which adds ``--encrypt`` argument to the ``esptool.py write_flash`` command. This will apply the burned encryption key to the image while flashing. Flash Allocation for MCUBoot ---------------------------- When MCUBoot is enabled on ESP32-H2, the flash memory is organized as follows based on the default KConfig values: .. note:: Even though OTA is not available on ESP32-H2 (no Wi-Fi), firmware binaries can still be uploaded to flash using other means, such as an SD card. **Flash Layout (MCUBoot Enabled)** .. list-table:: :header-rows: 1 :widths: 40 20 20 :align: left * - Region - Offset - Size * - Bootloader - 0x000000 - 64KB * - E-Fuse Virtual (see Note) - 0x010000 - 64KB * - Primary Application Slot (/dev/ota0) - 0x020000 - 1MB * - Secondary Application Slot (/dev/ota1) - 0x120000 - 1MB * - Scratch Partition (/dev/otascratch) - 0x220000 - 256KB * - Storage MTD (optional) - 0x260000 - 1MB * - Available Flash - 0x360000+ - Remaining .. raw:: html
**Note**: The E-Fuse Virtual region is optional and only used when ``ESPRESSIF_EFUSE_VIRTUAL_KEEP_IN_FLASH`` is enabled. However, this 64KB location is always allocated in the memory layout to prevent accidental erasure during board flashing operations, ensuring data preservation if virtual E-Fuses are later enabled. .. code-block:: text Memory Map (Addresses in hex): 0x000000 ┌─────────────────────────────┐ │ │ │ MCUBoot Bootloader │ │ (64KB) │ │ │ 0x010000 ├─────────────────────────────┤ │ E-Fuse Virtual │ │ (64KB) │ 0x020000 ├─────────────────────────────┤ │ │ │ Primary App Slot │ │ (1MB) │ │ /dev/ota0 │ │ │ 0x120000 ├─────────────────────────────┤ │ │ │ Secondary App Slot │ │ (1MB) │ │ /dev/ota1 │ │ │ 0x220000 ├─────────────────────────────┤ │ │ │ Scratch Partition │ │ (256KB) │ │ /dev/otascratch │ │ │ 0x260000 ├─────────────────────────────┤ │ │ │ Storage MTD (optional) │ │ (1MB) │ │ │ 0x360000 ├─────────────────────────────┤ │ │ │ Available Flash │ │ (Remaining) │ │ │ └─────────────────────────────┘ The key KConfig options that control this layout: - ``ESPRESSIF_OTA_PRIMARY_SLOT_OFFSET`` (default: 0x20000) - ``ESPRESSIF_OTA_SECONDARY_SLOT_OFFSET`` (default: 0x120000) - ``ESPRESSIF_OTA_SLOT_SIZE`` (default: 0x100000) - ``ESPRESSIF_OTA_SCRATCH_OFFSET`` (default: 0x220000) - ``ESPRESSIF_OTA_SCRATCH_SIZE`` (default: 0x40000) - ``ESPRESSIF_STORAGE_MTD_OFFSET`` (default: 0x260000 when MCUBoot enabled) - ``ESPRESSIF_STORAGE_MTD_SIZE`` (default: 0x100000) For MCUBoot operation: - The **Primary Slot** contains the currently running application - The **Secondary Slot** receives OTA updates - The **Scratch Partition** is used by MCUBoot for image swapping during updates - MCUBoot manages image validation, confirmation, and rollback functionality _`Managing esptool on virtual environment` ========================================== This section describes how to install ``esptool``, ``imgtool`` or any other Python packages in a proper environment. Normally, a Linux-based OS would already have Python 3 installed by default. Up to a few years ago, you could simply call ``pip install`` to install packages globally. However, this is no longer recommended as it can lead to conflicts between packages and versions. The recommended way to install Python packages is to use a virtual environment. A virtual environment is a self-contained directory that contains a Python installation for a particular version of Python, plus a number of additional packages. You can create a virtual environment for each project you are working on, and install the required packages in that environment. Two alternatives are explained below, you can select any one of those. Using pipx (recommended) ------------------------ ``pipx`` is a tool that makes it easy to install Python packages in a virtual environment. To install ``pipx``, you can run the following command (using apt as example):: $ apt install pipx Once you have installed ``pipx``, you can use it to install Python packages in a virtual environment. For example, to install the ``esptool`` package, you can run the following command:: $ pipx install esptool This will create a new virtual environment in the ``~/.local/pipx/venvs`` directory, which contains the ``esptool`` package. You can now use the ``esptool`` command as normal, and so will the build system. Make sure to run ``pipx ensurepath`` to add the ``~/.local/bin`` directory to your ``PATH``. This will allow you to run the ``esptool`` command from any directory. Using venv (alternative) ------------------------ To create a virtual environment, you can use the ``venv`` module, which is included in the Python standard library. To create a virtual environment, you can run the following command:: $ python3 -m venv myenv This will create a new directory called ``myenv`` in the current directory, which contains a Python installation and a copy of the Python standard library. To activate the virtual environment, you can run the following command:: $ source myenv/bin/activate This will change your shell prompt to indicate that you are now working in the virtual environment. You can now install packages using ``pip``. For example, to install the ``esptool`` package, you can run the following command:: $ pip install esptool This will install the ``esptool`` package in the virtual environment. You can now use the ``esptool`` command as normal. When you are finished working in the virtual environment, you can deactivate it by running the following command:: $ deactivate This will return your shell prompt to its normal state. You can reactivate the virtual environment at any time by running the ``source myenv/bin/activate`` command again. You can also delete the virtual environment by deleting the directory that contains it. Supported Boards ================ .. toctree:: :glob: :maxdepth: 1 boards/*/*