wolfssl/IDE/Espressif

wolfSSL Espressif IDE

This directory contains documentation and examples for the Espressif SoC devices.

Although wolfSSL should work on any Espressif device, there's explicit support for these:

• esp32
• esp32c2
• esp32c3
• esp32c6
• esp32s2
• esp32s3
• esp32h2

Getting Started

If you are new to wolfSSL on the Espressif ESP32, this video can help to get started:

Additional ESP-IDF specifics can be found in Espressif/ESP-IDF. The wolfSSL Manual is also a useful resource.

Requirements

The wolfSSL Espressif code requires the ESP-IDF to be installed for Windows or Linux / MacOS.

See the Espressif Getting Started Guide.

Any editor can be used. The wolfSSL examples all include a ./VisualGDB directory with SoC-specific configurations to help get started quickly.

Although not required, a JTAG Adapter can be helpful for development. When not using a built-in JTAG from Espressif, the examples typically use the open source Tigard board.

Examples:

There are a variety of examples to help get started:

• ESP-IDF Examples

Managed Component

The wolfSSL library can be installed as a managed component:

• Espressif Managed Component Registry

Notes:

WSL environment:

Contents of /etc/wsl.conf:

[automount]
options = "metadata"

To ignore changes in file attributes, see https://github.com/microsoft/WSL/issues/936#issuecomment-1751469229

git config core.filemode false

Quick start

WORKSPACE=/mnt/c/workspace
WRK_IDF_PATH=/mnt/c/SysGCC/esp32/esp-idf/v5.1
WRK_WOLFSSL_PATH=${WORKSPACE}/wolfssl-$USER
WRK_PROJECT_DIR=${WRK_WOLFSSL_PATH}/IDE/Espressif/ESP-IDF/examples/wolfssl_test

echo "Run export.sh from ${WRK_IDF_PATH}"
. ${WRK_IDF_PATH}/export.sh

echo "Build and flash project in ${WRK_PROJECT_DIR}"
cd ${WRK_PROJECT_DIR}
idf.py build flash -p /dev/ttyS9 -b 115200 monitor

Bad chip version:

ESP-ROM:esp32c3-20200918
Build:Sep 18 2020
rst:0x3 (RTC_SW_SYS_RST),boot:0xc (SPI_FAST_FLASH_BOOT)
Saved PC:0x403d151e
SPIWP:0xee
mode:DIO, clock div:2
load:0x3fcd6100,len:0x16c8
load:0x403ce000,len:0x930
load:0x403d0000,len:0x2d28
entry 0x403ce000
I (34) boot: ESP-IDF v4.4.2-1-g0aba20e63d-dirty 2nd stage bootloader
I (35) boot: compile time 08:29:06
I (35) boot: chip revision: 2
E (38) boot_comm: This chip is revision 2 but the application is configured for minimum revision 3. Can't run.

If you've encountered a chip version earlier than that confirmed to be working at wolfSSL, try adjusting the settings in menuconfig.

A fatal error occurred: This chip is esp[X] not esp[Y]

A fatal error occurred: This chip is ESP32-S3 not ESP32-C3. Wrong --chip argument?
CMake Error at run_serial_tool.cmake:56 (message):
  /home/gojimmypi/.espressif/python_env/idf4.4_py3.8_env/bin/python
  /mnt/c/SysGCC/esp32/esp-idf/v4.4.2/components/esptool_py/esptool/esptool.py
  --chip esp32c3 failed

Delete the ./build and rename/delete your sdkconfig file, then run idf.py set-target, in this example setting to esp32c3:

idf.py set-target esp32c3

Cmake Cache Warning

Executing action: clean
Project sdkconfig was generated for target 'esp32s3', but CMakeCache.txt contains 'esp32c3'. To keep the setting in sdkconfig (esp32s3) and re-generate CMakeCache.txt, run 'idf.py fullclean'. To re-generate sdkconfig for 'esp32c3' target, run 'idf.py set-target esp32c3'.

As indicated, run idf.py set-target and/or delete the ./build directory.

Connecting, but fails to connect.

Some devices, particularly 3rd party, non-Espressif dev boards may not have implemented the reset-program hardware properly, causing devices to not be programmed with the idf.py flash command:

Connecting......................................

A fatal error occurred: Failed to connect to ESP32: Wrong boot mode detected (0x13)! The chip needs to be in download mode.
CMake Error at run_serial_tool.cmake:56 (message):
  /home/gojimmypi/.espressif/python_env/idf4.4_py3.8_env/bin/python
  /mnt/c/SysGCC/esp32/esp-idf/v4.4.2/components/esptool_py/esptool/esptool.py
  --chip esp32 failed

Solution:

Press and hold EN button, press and release IO0 button, then release EN button.

Unknown CMake command "esptool_py_flash_project_args".

This unintuitive error was observed when including an unneeded set(COMPONENTS in the project-level CMakeLists.txt and attempting to build with an older toolchain, such as the RTOS SDK 3.4 for the ESP8266.

PermissionError: [Errno 13] Permission denied could not open port {}

This error, other than the obvious permissions, also occurs when the port is in use by another application:

Traceback (most recent call last):
  File "/home/gojimmypi/.espressif/python_env/rtos3.4_py3.10_env/lib/python3.10/site-packages/serial/serialposix.py", line 322, in open
    self.fd = os.open(self.portstr, os.O_RDWR | os.O_NOCTTY | os.O_NONBLOCK)
PermissionError: [Errno 13] Permission denied: '/dev/ttyS55'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
    [... snip ...]
raise SerialException(msg.errno, "could not open port {}: {}".format(self._port, msg))
serial.serialutil.SerialException: [Errno 13] could not open port /dev/ttyS55: [Errno 13] Permission denied: '/dev/ttyS55'

Panic Task watchdog got triggered.

Long-running code may trip the watchdog timer.

Task watchdog got triggered.

Guru Meditation Error: Core  0 panic'ed (unknown). Exception was unhandled.

The watchdog needs to be fed on a regular basis with void esp_task_wdt_reset(void) from esp8266/include/esp_task_wdt.h.

Try turning off the WDT in menuconfig, or for Makefiles:

EXTRA_CFLAGS += -DNO_WATCHDOG

Other Solutions

See also Espressif esp-faq-en-master.pdf