From Free Pascal wiki
Revision as of 09:48, 19 April 2020 by FPK (talk | contribs)

Warning: The ESP32 support is highly experimental and prone to be broken. This description is work in progress.

Building FPC


So far Linux and Mac hosts only


Native stable FPC must be installed and working on the system.

Install esp-idf based on the instructions given here:

Get Started (for Stable Release)

Follow the instructions to a least step 8 where you build the hello_word demo project.

copy all the freshly compiled .a files from the current project directory to a directory of your choice:

 mkdir ~/esp/xtensa-esp32-elf-libs
 find ~/esp/ -name "*.a" -exec cp {} ~/esp/xtensa-esp32-elf-libs \; 


  • One should not copy libraries from the project/build/bootloader directory, since these libraries do not contain full functionality.
  • Some of the required libraries are located in the esp-idf/components folder. Important to also copy the libraries in the ~/esp/esp-idf/component directory if the demo project was copied to outside the esp-idf directory.

Now you are ready to compile fpc and rtl.


export IDF_PATH=~/esp/esp-idf
source ~/esp/esp-idf/export.sh

to get the path and environment set (namely tools path and $IDF_PATH are needed)

Change into the fpc directory and run

 make FPC=fpc CPU_TARGET=xtensa OS_TARGET=freertos "CROSSOPT=-Cplx6 -XPxtensa-esp32-elf- -Cfhard" all -j

Create a hello world program in the fpc dir and compile it with

 compiler/ppcrossxtensa -Furtl/units/xtensa-freertos/ -Tfreertos -XPxtensa-esp32-elf- -O3 -Wpesp32 -Fl~/esp/xtensa-esp32-elf-libs  -Fl~/.espressif/tools/xtensa-esp32-elf/esp-2019r2-8.2.0/xtensa-esp32-elf/xtensa-esp32-elf/lib/ hello

Get partition-table.bin and bootloader.bin from the hello_world example compiled above and copy them into the same dir as the compiled hello.bin

Flash with

 esptool.py -p /dev/ttyUSB0 -b 460800 --before default_reset --after hard_reset --chip esp32  write_flash --flash_mode dio --flash_size detect --flash_freq 40m 0x1000 bootloader.bin 0x8000 partition-table.bin 0x10000 hello.bin

Monitor the output with:

 idf_monitor.py  --port /dev/ttyUSB0 hello.elf


  • Once the bootloader and partition table has been flashed once one could also just flash the application only:
 esptool.py -p /dev/ttyUSB0 -b 460800 --before default_reset --after hard_reset --chip esp32  write_flash --flash_mode dio --flash_size detect --flash_freq 40m 0x10000 hello.bin