v0.7.0-alpha.0 release

This is an alpha release, the first pre-release on the road to v0.7.0. It represents over two year of development and introduces several groundbreaking features. While we have taken care to test thoroughly, APIs may still evolve before the stable release. If you need maximum stability for production deployments, we recommend staying on v0.6.x. That said, we encourage you to try v0.7.0-alpha.0 and report any issues you encounter, your feedback is invaluable in shaping the stable release.

OTP-28 and OTP-29 are now supported. This is a major improvement over v0.6.6 which did not include OTP-28 support. On macOS, Homebrew and MacPorts default to OTP-28 or later, so this release works out of the box with default system installations. You can use asdf or mise to manage multiple Erlang/OTP versions if needed.

Please read the getting started guide for flashing instructions.

Highlights

Distributed Erlang

AtomVM now supports the Erlang distribution protocol, allowing AtomVM nodes running on microcontrollers to connect to standard BEAM nodes or other AtomVM instances via message passing. This release includes:

• A pure Erlang erl_epmd client implementation
• Support for external pids, ports, and refs in external terms
• Remote shell support (with the necessary io and io_lib functions)
• Cookie-based authentication
• The distribution protocol supports alternative transport carriers beyond TCP/IP, opening up communication paths specific to embedded systems

This enables powerful use cases: debugging an MCU directly from a standard OTP shell, coordinating multiple microcontrollers via message passing, and building mixed clusters of BEAM and AtomVM nodes. TLS distribution is not yet available.

JIT Compilation and Multiple Execution Modes

AtomVM now supports four execution strategies:

• Emulated - interprets BEAM bytecode (default, small and portable)
• JIT - runtime compilation to native code
• Native (AoT) - pre-compiled native code deployment
• Hybrid - native code with bytecode fallback for unsupported opcodes

The JIT compiler is itself written in Erlang. Supported JIT architectures include RISC-V32, ARM v6-M (Cortex-M0+), x86_64, and aarch64.

Big Integer Support

AtomVM now supports integers up to 256-bit (sign + 256-bit magnitude). All arithmetic operations (+, -, *, div, rem, abs, etc.) and all bitwise operations (band, bor, bxor, bnot, bsl, bsr) work with big integers. Serialization via binary_to_term/1 and term_to_binary/1,2 is also supported.

Cryptographic Operations

A comprehensive crypto module has been added:

• Key generation and exchange (crypto:generate_key/2, crypto:compute_key/4)
• Digital signatures (crypto:sign/4, crypto:verify/5)
• Streaming hashes and MACs (crypto:hash_init/update/final, crypto:mac_init/update/final)
• AEAD encryption (crypto:crypto_one_time_aead)
• PBKDF2 key derivation (crypto:pbkdf2_hmac/5)
• Ed25519 support via optional libsodium integration (AVM_USE_LIBSODIUM=ON)

ETS

A limited but functional implementation of the OTP ets interface is now available, including support for set, bag, and duplicate_bag table types with operations such as insert, lookup, delete, member, update_counter, update_element, and more.

Expanded Hardware Support

• ESP32C5 and ESP32C61: initial support for these new Espressif chips
• ESP32P4 WiFi: WiFi connectivity via esp-wifi-external (requires ESP-IDF v5.4+)
• 10 new STM32 families: enabled by switching to the official ST HAL/LL SDK
• ESP-IDF v5.5: release images are now built with ESP-IDF v5.5

Elixir Improvements

• Native GenServer and Supervisor support
• Added Function.ex and Protocol.ex for improved Elixir 1.18 support
• Process.link/1 and Process.unlink/1
• Base64 encode/decode functions in the Base module
• ESP32 builds can now enable Elixir support with a simple cmake flag: -DATOMVM_ELIXIR_SUPPORT=on

WebAssembly

AtomVM's Emscripten/WASM port continues to improve. Pre-built binaries are available for both Node.js and browser environments. This release powers projects like Popcorn, which runs Elixir directly in the browser, including the Elixir Language Tour.

POSIX File and Directory Operations

New POSIX functions for file I/O (seek, pread, pwrite, fsync, ftruncate, rename, stat, fstat) and directory operations (mkdir, rmdir) are now available on supported platforms.

Upgrade Notes

If upgrading from v0.6.x, please review the UPDATING.md file. Key changes:

• Entry point change: init:boot/1 is now used as the entry point if it exists. It automatically starts the kernel application and calls start/0 from the identified startup module. Users who were manually starting the kernel application (typically for distribution) must stop doing so. Starting net_kernel is still required.
• Ports replace pids for native processes: Port drivers should now return ports instead of pids. Socket matching code may need to change from is_pid/1 to is_port/1.
• bsl overflow checking: Bitshift left now checks for overflows. Mask values before shifting: e.g. (Value band 0xF) bsl 252.
• binary_to_integer/list_to_integer: No longer raise overflow: they raise badarg when the result exceeds 256 bits.
• ESP32 Elixir builds: Can now be configured with idf.py -DATOMVM_ELIXIR_SUPPORT=on set-target ${CHIP} instead of copying partition files.
• C API: The externalterm module has been renamed to external_term with a completely new API.
• Removed: The deprecated network_fsm module has been removed.

Pre-built Binaries

Pre-built binaries are available for download from this release page:

• ESP32: flashable images for esp32, esp32c2, esp32c3, esp32c5, esp32c6, esp32c61, esp32s2, esp32s3, esp32h2, and esp32p4 (standard and Elixir flavors)
• Raspberry Pi Pico: UF2 firmware for pico, pico_w, pico2, and pico2_w (including RP2350 RISC-V variants)
• WebAssembly: JS+WASM bundles for Node.js and browser environments

All binaries include SHA256 checksums for verification.

Added

• Added a limited implementation of the OTP ets interface
• Added code:all_loaded/0 and code:all_available/0
• Added erlang:loaded/0
• Added erlang:split_binary/2
• Added inet:getaddr/2
• Added support for external pids and encoded pids in external terms
• Added support for external refs and encoded refs in external terms
• Introduce ports to represent native processes and added support for external ports and encoded ports in external terms
• Added atomvm:get_creation/0, equivalent to erts_internal:get_creation/0
• Added menuconfig option for enabling USE_USB_SERIAL, eg. serial over USB for certain ESP32-S2 boards etc.
• Partial support for erlang:fun_info/2 and erlang:fun_info/1
• Added support for registered_name in erlang:process_info/2 and Process.info/2
• Added net:gethostname/0 on platforms with gethostname(3).
• Added socket:getopt/2
• Added supervisor:terminate_child/2, supervisor:restart_child/2 and supervisor:delete_child/2
• Added support for 'erlang:--/2'.
• Added esp:partition_read/3, and documentation for esp:partition_erase_range/2/3 and esp:partition_write/3
• Added support for list insertion in 'ets:insert/2'.
• Support to OTP-28
• Added atomvm:subprocess/4 to perform pipe/fork/execve on POSIX platforms
• Added erl_epmd client implementation to epmd using socket module
• Added support for socket asynchronous API for recv, recvfrom and accept.
• Added support for UDP multicast with socket API.
• Added support for ets:update_counter/3 and ets:update_counter/4.
• Added erlang:+/1
• Added lists:append/1 and lists:append/2
• Added erlang:spawn_monitor/1, erlang:spawn_monitor/3
• Added lists:dropwhile/2.
• Support for float/1 BIF.
• Added erlang:get/0 and erlang:erase/0.
• Added erlang:unique_integer/0 and erlang:unique_integer/1
• Added support for 'ets:delete/1'.
• Added lists:flatmap/2
• Added io:fwrite/1,2,3 and io:format/3 as well as few io functions required by remote shell
• Added code:is_loaded/1 and code:which/1
• Added several io_lib functions including io_lib:fwrite/2 and io_lib:write_atom/1
• Added init:get_argument/1, init:get_plain_arguments/0 and init:notify_when_started/1
• Added application:get_env/2
• Added CodeQL analysis to esp32, stm32, pico, and wasm workflows
• Added Function.ex and Protocol.ex improving Elixir 1.18 support
• Added WiFi support for ESP32P4 via esp-wifi-external for build with ESP-IDF v5.4 and later
• Added Process.link/1 and unlink/1 to Elixir Process.ex
• Added erlang:module_loaded/1
• Added binary:longest_common_prefix/1
• Added binary:replace/3, binary:replace/4
• Added binary:match/2 and binary:match/3
• Added supervisor:which_children/1 and supervisor:count_children/1
• Added monitored_by in process_info/2
• Added mock implementation for current_stacktrace in process_info
• Added erlang:list_to_bitstring
• Reimplemented lists:keyfind, lists:keymember and lists:member as NIFs
• Added AVM_PRINT_PROCESS_CRASH_DUMPS option
• Added lists:ukeysort/2
• Added support for big integers up to 256-bit (sign + 256-bit magnitude)
• Added support for big integers in binary_to_term/1 and term_to_binary/1,2
• Added proc_lib
• Added gen_server support for timeout tuples in callback return actions introduced in OTP-28.
• Added sys
• Added esp:timer_get_time/0
• Added esp_dac module, exposing DAC oneshot mode on ESPs that support it
• Added support for resource managed binaries (enif_make_resource_binary)
• Added initial support for ESP32C5 and ESP32C61
• Added Range:size/1
• Added missing ledc functions for esp32 platform
• Added support for Elixir GenServer and Supervisor.
• Added support for 10 new STM32 families by switching to STM32 official SDK
• Added network:sta_connect/0,1 and network:sta_disconnect/0 to ESP32 network driver.
• Added option to set a custom callback for esp32 network driver disconnected events
• Added network:sta_status/0 to get the current connection state of the sta interface.
• Added ESP32 -DATOMVM_ELIXIR_SUPPORT=on configuration option
• Added support for ESP32 development builds to include NVS partition data at build time
• Added missing inet functions: ntoa/1, parse_address/1, parse_ipv4_address/1, parse_ipv4strict_address/1
• Added support for new is_integer/3 BIF, introduced with OTP-29
• Support for OTP-29
• Added base64:encode/2 and base64:decode/2 functions, that take in addition also a map with encoding/decoding options, also Elixir (url_)encode64/(url_)decode64 have been added to Base.
• Added nanosecond and native time unit support to erlang:system_time/1, erlang:monotonic_time/1, and calendar:system_time_to_universal_time/2
• Added erlang:system_time/0, erlang:monotonic_time/0, and os:system_time/0,1 NIFs
• Added filename:join/1 and filename:split/1
• Added crypto:generate_key/2, crypto:compute_key/4, crypto:sign/4 and crypto:verify/5
• Added crypto:hash_init/1, crypto:hash_update/2 and crypto:hash_final/1
• Added crypto:crypto_init/3, crypto:crypto_init/4, crypto:crypto_update/2 and crypto:crypto_final/1
• Added crypto:crypto_one_time_aead/6 and crypto:crypto_one_time_aead/7
• Added crypto:pbkdf2_hmac/5 and crypto:hash_equals/2
• Added crypto:mac/4, crypto:mac_init/3, crypto:mac_update/2, crypto:mac_final/1 and crypto:mac_finalN/2
• Added crypto:info_lib/0
• Added erlang:crc32/1, erlang:crc32/2 and erlang:crc32_combine/3
• Added support for Ed25519 curve when libsodium support is enabled at build time (AVM_USE_LIBSODIUM=ON)
• Added support for bag and duplicate_bag table types in ets
• Added ets:insert_new/2, ets:member/2, ets:lookup_element/4, ets:delete_object/2, ets:take/2, ets:update_element/3 and ets:update_element/4
• Added POSIX file functions: atomvm:posix_seek/3, atomvm:posix_pread/3, atomvm:posix_pwrite/3, atomvm:posix_fsync/1, atomvm:posix_ftruncate/2, atomvm:posix_rename/2, atomvm:posix_stat/1, atomvm:posix_fstat/1
• Added POSIX directory functions: atomvm:posix_mkdir/1, atomvm:posix_rmdir/1

Changed

• Release images for ESP32 chips are built with ESP-IDF v5.5
• Only support ESP32P4 on ESP-IDF v5.5.2, v5.4.4 and later.
• ESP32: SPI peripheral defaults to "spi2" instead of deprecated hspi
• Added zlib:compress/1
• Entry point now is init:boot/1 if it exists. It starts the kernel application and calls start/0 from the identified startup module. Users who started kernel application (typically for distribution) must no longer do it. Starting net_kernel is still required.
• All arithmetic operations (+, -, *, div, rem, abs, etc.) now support integers up to 256-bit
• All bitwise operations (band, bor, bxor, bnot, bsl, bsr) now support integers up to 256-bit
• Float conversion functions now support converting to/from big integers
• bsl now properly checks for overflow
• binary_to_integer/1 no longer accepts binaries such as <<"0xFF">> or <<" 123">>
• binary_to_integer and list_to_integer do not raise anymore overflow error, they raise instead badarg.
• Resources are now references instead of empty binaries.
• Badarg error return from calling crypto:crypto_one_time with invalid arguments now matches OTP24+.
• When function head doesn't match, function arguments are now in stacktrace
• Function arguments are added to stacktrace also for some NIFs, when one of the arguments is badarg
• Using a custom callback for STA disconnected events in esp32 network driver will stop automatic re-connect, allowing applications to use scan results or other means to decide when and where to connect.
• ESP32 cmake build options are now also exposed in idf.py menuconfig.
• ESP32 Elixir support is determined automatically from the offset of boot.avm in the partition table.
• ESP32 ports now flash a complete working image using the idf.py flash task.
• ESP32 platform now uses reproducible builds.
• C API: externalterm module was renamed to external_term and it has a completely new API

Fixed

• ESP32: improved sntp sync speed from a cold boot.
• Fixed gen_server internal messages to match OTP so it works across erlang distribution
• Utilize reserved phy_init partition on ESP32 to store wifi calibration for faster connections.
• Support for zero count in lists:duplicate/2.
• packbeam: fix memory leak preventing building with address sanitizer
• Fixed a bug where empty atom could not be created on some platforms, thus breaking receiving a message for a registered process from an OTP node.
• Fix a memory leak in distribution when a BEAM node would monitor a process by name.
• Fix list_to_integer, it was likely buggy with integers close to INT64_MAX
• Added missing support for supervisor one_for_all strategy.
• Supervisor now honors period and intensity options.
• Fix supervisor crash if a one_for_one child fails to restart.
• Fix collision in references created with make_ref/0 on 32 bits platforms.
• Fixed a bug in OP_BS_CREATE_BIN
• Fix re-raise behavior by implementing erlang:raise/3 3rd argument support

Removed

• Removed deprecated network_fsm