RIOT-2025.04 "MakeSpringClean" - Release Notes

RIOT is a multi-threading operating system which enables soft real-time capabilities and comes with support for a range of devices that are typically found in the Internet of Things: 8-bit and 16-bit microcontrollers as well as light-weight 32-bit processors.

RIOT is based on the following design principles: energy-efficiency, soft real-time capabilities, small memory footprint, modularity, and uniform API access, independent of the underlying hardware (with partial POSIX compliance).

RIOT is developed by an international open-source community which is independent of specific vendors (e.g. similarly to the Linux community) and is licensed with a non-viral copyleft license (LGPLv2.1), which allows indirect business models around the free open-source software platform provided by RIOT.

About this release

The 2025.04 release includes some spring cleaning activity in the build system and documentation, as well as the following highlights:

RIOT provides native as a board that can be used for fast development cycles on the development machine without the need for external microcontroller hardware. Starting with this release, native will default to a 64-bit executable on 64-bit hosts (#21242). If you prefer to cross-compile 32-bit executables, please now use native32 instead.

This new board alias mechanism also paves the way towards more consistent board names in RIOT. As a first step, the two Adafruit Feather nRF52840 boards have been renamed, while maintaining the old board names as aliases (#21349).

The examples contained in the RIOT source repository have been restructured as a first step towards easing the experience for RIOT newcomers (#21135, #21221). Stay tuned for more!

This release includes support for three new boards from the Seeed Studio XIAO family, notably the nRF52840 (#20980), nRF52840 Sense (#21332), and the ESP32C3 variant (#21267). RIOT now also boots on SAM4S Xplained Pro evaluation kits (#21201).

The default terminal program for RIOT (pyterm) now requires the psutil Python module. On Ubuntu/Debian, it can be installed with python3-psutil (#21399). RIOT started the transition from header guards to #pragma once in its source code. New code contributions should follow this style from now on (#21367, #21369).

175 pull requests, composed of 357 commits, have been merged since the last release, and 12 issues have been solved. 35 people contributed with code in 82 days. 1963 files have been touched with 49418 (+) insertions and 37661 deletions (-).

Notations used below

+ means new feature/item
* means modified feature/item
- means removed feature/item

New features and changes

Core

core/cib: Add a prominent warning about thread safety (#21401)

core/debug: extend doc about DEBUG() / LOG_DEBUG() (#21276)
core/thread: error in thread.c corrected (#21253)

System Libraries

sys/bcd: add bcd_buf_from_u32() (#21308)
sys/event: add event_deferred_callback_post() helper (#21219)
sys/event: add event_loop_debug pseudo-module (#20849)
sys/fmt: add {fmt,scn}_time_tm_iso8601 (#21391)
sys/psa_crypto: Adding hmac hashing on psa_import_key and fix max hmac key size (#21297)
sys/ztimer: add hint for setting static sleep adjustment (#21376)

drivers/mtd_default: remove deprecated mtd_default_get_dev() (#21386)
sys/fido2: update tests (#20876)
psa_crypto: fold some long lines (#21303)
rust: Simplify Makefiles (#21239)
sys/chunked_ringbuffer: let crb_end_chunk() return size of the chunk (#20942)
sys/isrpipe: unit tests, doc, and fix init (#21344)
sys/malloc_tracing: remove deprecated module (#21384)
sys/psa_crypto: drop no-op Doxygen statements (#21393)
sys/psa_crypto: usa auto_init module for initialization (#21322)
sys/vfs: remove deprecated vfs_iterate_mounts() (#21387)
sys/ztimer: fix small typo in doc (#21208)
treewide: update riot-wrappers and riot-sys (#21383)

Networking

sys/net/nanocoap: Implement Observe (Server-Side) (#21147)

drivers/include: fixing order of doxygen tags and header guards (#21325)
ieee802154/submac: calculate symbol time on demand (#19668)
lwip: bump to v2.2.1 (#21196)
nanocoap: avoid non static buffers of configurable size (#21270)
nanocoap_sock: implement observe (Client-Side) (#21160)
net_sock_async_event: cancel async event on sock_*_close() (#21180)
sys/net/gcoap: remove deprecated gcoap_req_send_tl() (#21385)
sys/net/ipv6: use markdown links in doc (#21356)

Packages

Pkg/ccn-lite: use latest ccn-lite commit (#21279)
pkg/driver_cryptocell_310: allow data to be in ROM on hash update (#21214)
pkg/driver_cryptocell_310: check for input data to be in RAM (#21138)
pkg/esp32_sdk: Fix broken rtc_io.h declaration and prevent sys/uio.h inclusion outside RIOT (#21408)

Boards

boards/seeedstudio-xiao-esp32c3: Add support for Seeed Studio ESP32C3 Xiao (#21267)
boards/feather-nrf52840*: add external flash configuration (#21324)
boards/nucleo-f722ze: add ADC support (#21233)
boards/nucleo-wl55jc: add ADC configuration (#21235)
boards/nucleo64: Add Compile Warning about LED0 when using SPI (#21338)
boards/seeedstudio-xiao-nrf52840-sense: Add Initial Support (#21332)
boards: introduce stdio_default (#21294)
boards: introduce board alias and make native default to host target (#21242)
Buildsystem: Introduce Global Makefiles for boards Directory (#21327)
cpu/sam4s: add initial support with SAM4S-XPRO board (#21201)

boards/common: Make Adafruit nRF52 Bootloader shared (#21281)
boards/feather-nrf52840*: rename to adafruit-feather-nrf52840-* (#21349)
boards/nrf6310: Remove nRF6310 board from RIOT (#20966)
boards/seeedstudio-xiao-nrf52840: initial board support (#20980)

CPU

core: add stdio.h to replace stdout functions with stdio_null (#20872)

cpu/native: Gardening/QoL (#21283)
cpu/nrf5*: mark and resolve radio conflict (#21250)
cpu/nrf52/radio/nrf802154: fix beacon acceptance (#20982)
cpu/sam0_common/flashpage: disable interrupts while writing (#21326)
cpu/sam0_eth: fix hang with broken PHY (#21172)
cpu/sam3: fix hwrng peripheral register access (#21177)
cpu/sam3: optimize gpio ISR processing (#21179)
cpu/samd5x: improve can-initialization (#21173)
cpu/stm32{f0,g0,c0}: fix ADC initialization sequence (#21230)
dist/tools/esptools: Upgrade the ESP32 toolchain to GCC v14.2, GDB v14.2 and OpenOCD v0.12 (#21144)
{cpu/sam0_common/sam0_sdhc,drivers/mtd}: do not allocate work_area twice (#21169)

Device Drivers

drivers/periph_timer: add timer_get_closest_freq() (#20581)
drivers/sen5x: Add device driver for SEN5x (#19955)
drivers/tm1637: add driver and tests for tm1637 7-segment display (#21112)

driver/sen5x: Small Fixups (#21392)
drivers/at: at_readline_stop_at_str fix remaining buffer length (#21195)
drivers/sdmmc/sdmmc_sdhc: remove DMA check (#21260)
drivers/{mtd_sdmmc,sdmmc}: reinit card (#21305)

Documentation

add *.doc.md to doxygen sources (#21319)
boards/nrf52840{dk,dongle}: add MCU table, move to doc.md (#21271)
boards/nucleo-f413zh: add MCU table, move to doc.md (#21264)
dist/tools: Add Doxygen as a Tool for CI (#21300)
doc, buildsystem: Add a Version Check for Doxygen, Fix doc* Target Execution (#21277)
doc/managing-a-release: add looking out for release tests to preps (#21368)
doc: add psutil requirement to Getting Started (#21399)

boards/arduino-due: update doc.txt (#21207)
boards/nucleo-144: rename doc.txt to doc.md (#21318)
boards/nucleo-f746zg: board doc update (#21310)
boards/rpi-pico*: Update and fix documentation and image (#21218)
build-system: Drop -Wno-error=documentation (#21377)
doc/porting-boards: Change example doc.txt to doc.md (#21257)
doc: doc.txt -> doc.md (#21255)
doc: hack to hide doc.md files until doxygen gets fixed (#21273)
doc: remove and replace deprecated mailing lists (#21285)
doc: Use the correct Doxygen Logo File Type in the Footer (#21274)
docs/rust: Install c2rust with --locked (#21236)
docs: Switch out pkg reference link (#21229)
sys/cord/doc.txt: Update additional references to RFC 9176 (#21159)
sys/malloc_monitor: Fix documentation (#21225)
sys/psa_crypto/doc: correctly end code block (#21380)
treewide: fix double the in doc and comments (#21224)
treewide: fix example references in docs (#21212)
CODING_CONVENTION.md: migrate to #pragma once (#21369)

Build System / Tooling

buildsystem: Enable -Wdocumentation for LLVM (#21358)
dist/tools: add #pragma once to headerguard check (#21367)

buildsystem: Remove buildtest Goal & Fix info-buildsizes-diff (#21359)
dist/tools/bmp: additional improvements to auto-detection (#21128)
dist: tools: avoid hanging tapsetup in the absence of a DHCP server (#20411)
Makefile.include: perform checks for all relevant targets (#21199)
makefiles: bump riotdocker (#21258)
makefiles: colorize board alias warning (#21352)
makefiles: fix output of info-applications (#21213)
tools: Use RIOT maintained cosy (#21070)

Examples

examples: restructure examples folder (#21135)
examples: shorten subfolders' names (#21221)
Configure default DNS resolver in 6lbr example (#21117)
examples/nanocoap_server: enable LWIP IPv4 (#21333)
examples: migrate to XFA SHELL_COMMAND (#21171)
examples: update dtls-echo source (#21247)
examples/gnrc_border_router: Request temporary address (IA_NA) for the 6lbr example (#21118)

Testing

tests/bench/runtime_coreapis: add clist_sort() benchmark (#21403)
tests/pkg/relic: add Paillier encryption tests (#21301)

.github/labeler: recognize boards/common/native as native (#21351)
test/pkg/relic: increase stacksize for paillier encryption (#21306)
tests/adc: always test all resolutions (#21223)
tests/drivers/candev: minor cleanup (#21175)
tests/nanocoap_cli: allow to build with lwIP (#21314)
tests/sys/suit_manifest: remove unnecessary custom native board (#21248)
tests/test-rtc: test retrieval of unix-time (#20031)
tests/unittests: test parsing of out-of-bounds CoAP opt (#21167)

API Changes

can: add CAN FD support to STM32G4 and native architecture (#20428)
cpu/samd5x: add enable pin to CAN configuration (#21287)

drivers/periph_uart: document acquire/release semantic (#20624)

And 22 minor changes.

Deprecations

Deprecations (1)

gnrc/ipv6/nib: make CONFIG_GNRC_IPV6_STATIC_LLADDR_IS_FIXED the default & deprecate it (#21157)

Bug fixes (28)

LOSTANDFOUND.md: add missing URL, fix Markdown typo (#21154)
boards/feather-m0*: Update Default Bootloader to UF2 (#21280)
buildsystem: Fix boards/Makefile.features Inclusion (#21334)
buildsystem: Fix Supported Board List in info-build (#21361)
buildsystem: Set term Goal to NOTPARALLEL (#21354)
cpu/esp32: fix bus_width in periph_sdmmc (#21259)
cpu/esp32: Fixes of compile problems with GCC 14.2 (#21245)
cpu/esp_common: create partitions.csv more robustly (#21185)
cpu/native: use async read for stdio_read() (#19002)
cpu/sam3: fix PMC enable/disable peripheral clock access (#21168)
cpu/samd5x/periph_can: fix RX (#21181)
cpu/stm32: Make ADC Resolution Definition uniform (#20971)
cpu/stm32{f3,l4,wb,wl}: Replace ztimer with busy_wait, fix VBat sampling time and {wl only} fix initialization sequence (#21238)
doc: fix image references for ESP32x boards (#21204)
drivers/periph_{i2c,spi}: fix doc on initialization (#21188)
examples/default: fix dependency modeling (#21191)
examples/suit_update: fix compilation for native [backport 2025.04] (#21427)
gnrc_sock/udp: zero-init sock struct on create (#21363)
pkg/nimble: Fix compilation with USEMODULE += nimble_svc_bas (#21200)
pyterm: send SIGINT to the subprocess' child (#21309)
socket_zep: properly implement the radio HAL (#19213)
sys/can: fix compilation issues under native (#21388)
sys/net/nanocoap: align request handling with spec (#21163)
sys/net/nanocoap: drop typedef hack [v2] (#21193)
sys/net/nanocoap: fix API inconsistency (#21241)
sys/net/nanocoap: fix dereferencing a null pointer (#21227)
tree wide: various doc fixes (#21357)
tree-wide: mixed back of documentation fixes (#21371)

Known issues

Network related issues (55)

6lo: RIOT does not receive packets from Linux when short_addr is set (#11033)
Address registration handling inappropriate (#15867)
app/netdev: application stops working after receiving frames with assertion or completely without error (#8271)
at86rf2xx: Dead lock when sending while receiving (#8242)
cpu/esp8266: Tracking open problems of esp_wifi netdev driver (#10861)
DHCPv6 client: Handling of NotOnLink incorrect (#20349)
dist/tools/sliptty/start_network.sh: IPv6 connectivity is broken on PC (#14689)
driver/mrf24j40: blocks shell input with auto_init_gnrc_netif (#12943)
drivers/at86rf215: Incorrect channel number set for subGHz (#15906)
DTLS examples cannot send message to localhost (#14315)
Emcute cannot create a double-byte name (#12642)
ethernet: Missing multicast addr assignment (#13493)
ethos: fails to respond to first message. (#11988)
ethos: Unable to handle fragmented IPv6 packets from Linux kernel (#12264)
example/gnrc_border_router cannot answer after some time (#19578)
examples/cord_ep: Dead lock when (re-)registering in callback function (#12884)
examples/gnrc_border_router: esp_wifi crashes on disconnect (#14679)
Forwarding a packet back to its link layer source should not be allowed (#5051)
gcoap example request on tap I/F fails with NIB issue (#8199)
gcoap: Suspected crosstalk between requests (possible NULL call) (#14390)
Global IPv6 addresses remain deprecated after receiving RA (#19846)
gnrc ipv6: multicast packets are not dispatched to the upper layers (#5230)
gnrc/ipv6: "invalid payload length" - corrupted IPv6 header when ENABLE_DEBUG=1 in mbox.c (#20390)
gnrc_border_router stops routing after a while (#16398)
gnrc_border_router: Kconfig and C disagree about number of addresses per interface (#19947)
gnrc_icmpv6_echo: flood-pinging another node leads to leaks in own packet buffer (#12565)
gnrc_ipv6: Multicast is not forwarded if routing node listens to the address (#4527)
gnrc_netif_pktq leaks memory (#17924)
gnrc_rpl: missing bounds checks in _parse_options (#16085)
gnrc_rpl: nib route not updated when topology / DODAG changes (#17327)
gnrc_rpl: old routes are not deleted (#19423)
gnrc_rpl: takes unusually long time to start routing packets (#19147)
gnrc_sock_udp: Possible Race condition on copy in application buffer (#10389)
gnrc_tcp: gnrc_tcp_recv() never generates -ECONNABORTED (#17896)
gomach: Resetting netif with cli doesn't return (#10370)
ieee802154_submac: IPv6 fragmentation broken (#16998)
LoRaWan node ISR stack overflowed (#14962)
LWIP TCP Communication Error (#19676)
lwip_sock_tcp / sock_async: received events before calling sock_accept() are lost due to race condition. (#16303)
Missing drop implementations in netdev_driver_t::recv (#10410)
Neighbor Discovery not working after router reboot when using SLAAC (#11038)
netdev_ieee802154: Mismatch between radio ll address and in memory address (#10380)
nrf52: Not able to add global or ULA address to interface (#13280)
nrfmin: communication not possible after multicast ping with no interval (#11405)
ping6 is failing when testing with cc2538dk (#13997)
pkg/tinydtls: auxiliary data API does not work for async sockets (#16054)
pkg/tinydtls: DTLS handshake does not work (#19595)
Removing a TNT global address then adding a new one does not work (#20318)
samr30 xpro doesn't seem to use its radio ok (#12761)
scan-build errors found during 2019.07 testing (#11852)
stale border router does not get replaced (#12210)
test/lwip: enabling both, IPv4 and IPv6, results in unexpected behavior (#18097)
tests/lwip: does not compile for IPv4 on 6LoWPAN-based boards. (#17162)
two nodes livelock sending neighbor solicitations back and forth between each other (#16670)
xbee: setting PAN ID sometimes fails (#10338)

Timer related issues (6)

misc issues with tests/trickle (#9052)
periph/timer: timer_set() underflow safety check (tracking issue) (#13072)
periph_timer: systematic proportional error in timer_set (#10545)
saml21 system time vs rtc (#10523)
stm32_common/periph/rtc: current implementation broken/poor accuracy (#8746)
sys/newlib: gettimeofday() returns time since boot, not current wall time. (#9187)

Drivers related issues (11)

at86rf2xx: Simultaneous use of different transceiver types is not supported (#4876)
cpu/msp430: GPIO driver doesn't work properly (#9419)
examples/dtls-wolfssl not working on pba-d-01-kw2x (#13527)
fail to send data to can bus (#12371)
mdt_erase success, but vfs_format resets board (esp32-heltec- lora32-v2) (#14506)
periph/spi: Switching between CPOL=0,1 problems on Kinetis with software CS (#6567)
periph: GPIO drivers are not thread safe (#4866)
PWM: Single-phase initialization creates flicker (#15121)
STM32: SPI clock not returning to idle state and generating additional clock cycles (#11104)
TCP client cannot send read only data (#16541)
tests/periph_flashpage: unexpected behavior on nucleo-l4r5zi (#17599)

Native related issues (4)

examples/micropython: floating point exception while testing on native (#15870)
native not float safe (#495)
native: tlsf: early malloc will lead to a crash (#5796)
ztimer doesn't wake up on native if the pm_layered module is used (#21083)

Other platforms related issues (13)

Failing tests on FE310 (Hifive1b) (#13086)
[TRACKING] Fixes for automatic tests of ESP32 boards. (#12763)
boards/hifive1: flashing issue (#13104)
cpu/sam0: flashpage write / read cycle produces different results depending on code layout in flash (#14929)
esp32-wroom-32: tests/netstats_l2 failing sometimes (#14237)
examples/gnrc_border_router: esp_wifi_init failed with return value 257 on ESP32-C3 with nimble_rpble (#19319)
gcoap/esp8266: Stack overflow with gcoap example (#13606)
Interrupt callback function is instantly called on samd51 after setting it from within interrupt callback function (#19861)
MPU doesn't work on cortex-m0+ (#14822)
newlib-nano: Printf formatting does not work properly for some numeric types (#1891)
periph_timer: Test coverage & broken on STM32F767ZI (#15072)
riscv: ISR stack is too small for ENABLE_DEBUG in core files (#16395)
stm32f7: Large performance difference between stm32f746 and stm32f767 (#14728)

Build system related issues (5)

Build dependencies - processing order issues (#9913)
dist/tools/cppcheck/cppchck.sh: errors when running with Cppcheck 1.89 (#12771)
EXTERNAL_MODULE_DIRS silently ignores non-existent entries (#17696)
make: ccache leads to differing binaries (#14264)
make: use of immediate value of variables before they have their final value (#8913)

Other issues (70)

2023.04 release bug tracking (#19469)
[tracking] Bugs found by the peripheral selftest (#20071)
[Tracking] Fix failures of test-on-iotlab (#20791)
[TRACKING] sys/shell refactoring. (#12105)
[tracking] unnecessary use of floating point arithmetic (#19614)
_NVIC_SystemReset stuck in infinite loop when calling pm_reboot through shell after flashing with J-Link (#13044)
make term no longer works with JLinkExe v6.94 (#16022)
at86rf215 stops receiving until sending a packet (#19653)
b-l072z-lrwan1: tests/ztimer_overhead: test failure (#19224)
backport_pr: Only works for when fork is in user (not in organization) (#18486)
benchmark_udp: hammering with low interval causes issues (#16808)
boards/esp32-wroom-32: tests/mtd_raw flakey (#16130)
Builds fail when different execstack options are around in objects (#18522)
Can't build relic with benchmarks or tests (#12897)
CC2538-CC2592EM has a very weak transmit power (#17543)
CC2538DK board docs: broken links (#12889)
cpp: Exception handling undefined (#17523)
cpu/stm32: some tests are failing on CM33 (l5, u5) (#17439)
doc/boards: information concerning access to RIOT shell (#17453)
doxygen: CSS hack to hide doc breaks on older browsers (#21312)
edbg: long lines flooded over serial become garbled (#14548)
examples / tests: LoRa tests fail on platforms that don't support LoRa (#14520)
examples/gcoap: client broken (#19379)
flashing issue on frdm-k64f (#15903)
frdm-k22f failing tests/periph_flashpage (#17057)
frdm-k22f fails tests/periph_timer (#19543)
Freeze into semtech_loramac_send call (pkg/semtech-loramac) (#18790)
gcoap: gcoap_req_send and related should return negative for errors (#19393)
gnrc_ipv6_nib: Neighbor Solicitation ping-pong (#18164)
I2C Crashes Kernel on Raspberry Pi Pico (#21187)
I2C not working under RIOT with U8G2 pkg (#16381)
ieee802154_security: Nonce is reused after reboot (#16844)
kconfiglib.py choice override of menuconfig bug (#19069)
lwip: drivers/at86rf2xx/at86rf2xx_netdev.c invalid state during TCP disconnect (#17209)
lwip: invalid state transition on ieee802154_submac users (#17208)
Making the newlib thread-safe (#4488)
mcuboot: flashes but no output (#17524)
MTD is confusing (#17663)
nanocoap: incomplete response to /.well-known/core request (#10731)
Order of auto_init functions (#13541)
periph_rtt: rtt_set_alarm() blocks IRQ for 80 plus usec on STM32 (#19520)
pkg/tinydtls: Multiple issues (#16108)
Potential race condition in compile_and_test_for_board.py (#12621)
RIOT is saw-toothing in energy consumption (even when idling) (#5009)
riotboot: ECC faults (eg. in STM32L5 or STM32WB) not handled gracefully (#17874)
rust-gcoap example is incompatible with littlefs2 (#17817)
Samr30/gpio: Erasing then write mux can generate spurious IRQ (#19993)
samr34-xpro: some tests failing (#19223)
sock_dtls: unable to send big messages (#17996)
spurious IRQs in periph_timer (#18976)
stdio_ethos: infinite shell loop (#17972)
stdio_tinyusb_cdc_acm hangs with picolibc (#19277)
STM32 Nucleo boards improperly clocked (#19778)
STM32F4-discovery + mrf24j40 not working (#19711)
sys/riotboot: documentation issues (#11243)
sys/usb/usbus/cdc/ecm: interface thread blocked when connected host interface is down (#21098)
tests/lwip target board for python test is hardcoded to native (#6533)
tests/periph_flashpage: failing on stm32l475ve (#17280)
tests/pkg/lvgl: compilation error for BOARD=samr21-xpro (#21446)
tests/pkg/relic is failing on samr21-xpro when built using llvm (#19903)
tests/pkg_libhydrogen: test fails on master for the samr21-xpro with LLVM (#15066)
tests/pkg_libschc: Failing test_reassemble_success_ack_always (#19445)
tests/test_tools: test fails while testing on samr21-xpro/iotlab-m3 (#15888)
tests: broken with stdio_rtt if auto_init is disabled (#13120)
tests: some tests don't work with newlib lock functions. (#12732)
Types in byteorder.h need a cleanup (#14737)
USB identifiers with funny characters create mojibake (#17776)
usbus/msc: wrong error handling and behavior after usb reset (#19478)
Use of multiple CAN bus on compatible boards (#14801)
ztimer is incompatible with real-time requirements (#18883)

There are 164 known issues in this release

Fixed Issues since the last release (2025.01)

buildsystem: make distclean does not clean dist/... (#21409)
native: Exiting pyterm does not terminate the native process any more (#21307)
Buildsystem: Makefile of Common Board Directories never called without adding DIRS (#21298)
Build System: make -C path/path doc fails in Base Folder (#21278)
dist/tools/uf2: Flashing a board with RIOT seems to prevent flashing other UF2 files afterwards (#21205)
build system: race condition when building and running an app for native (#20948)
feather-m0: make flash reports "device unsupported" (#17722)
doc/LOSTANDFOUND: not rendered as expected (#17063)
native getchar is blocking RIOT (#16834)
border_router: significant packet loss when sending out packets using USB cdc-ecm on nrf52 (#16411)
buildtest uses wrong build directory (#9742)
MSP430: periph_timer clock config wrong (#8251)

12 fixed issues since last release (2025.01)

Acknowledgements

We would like to thank all companies that provided us with hardware for porting and testing RIOT. Further thanks go to companies and institutions that directly sponsored development time. And finally, big thanks to all of you contributing in so many different ways to make RIOT worthwhile!

More information

http://www.riot-os.org

Matrix and Forum

Join the RIOT Matrix room at: #riot-os:matrix.org
Join the RIOT Forum at: forum.riot-os.org

License

The code developed by the RIOT community is licensed under the GNU Lesser General Public License (LGPL) version 2.1 as published by the Free Software Foundation.
Some external sources and packages are published under a separate license.

All code files contain licensing information.

RIOT-2025.04 "MakeSpringClean" - Release Notes

About this release

The 2025.04 release includes some spring cleaning activity in the build system and documentation, as well as the following highlights:

The examples contained in the RIOT source repository have been restructured as a first step towards easing the experience for RIOT newcomers (#21135, #21221). Stay tuned for more!

Notations used below

+ means new feature/item
* means modified feature/item
- means removed feature/item

New features and changes

Core

core/cib: Add a prominent warning about thread safety (#21401)

core/debug: extend doc about DEBUG() / LOG_DEBUG() (#21276)
core/thread: error in thread.c corrected (#21253)

System Libraries

sys/bcd: add bcd_buf_from_u32() (#21308)
sys/event: add event_deferred_callback_post() helper (#21219)
sys/event: add event_loop_debug pseudo-module (#20849)
sys/fmt: add {fmt,scn}_time_tm_iso8601 (#21391)
sys/psa_crypto: Adding hmac hashing on psa_import_key and fix max hmac key size (#21297)
sys/ztimer: add hint for setting static sleep adjustment (#21376)

drivers/mtd_default: remove deprecated mtd_default_get_dev() (#21386)
sys/fido2: update tests (#20876)
psa_crypto: fold some long lines (#21303)
rust: Simplify Makefiles (#21239)
sys/chunked_ringbuffer: let crb_end_chunk() return size of the chunk (#20942)
sys/isrpipe: unit tests, doc, and fix init (#21344)
sys/malloc_tracing: remove deprecated module (#21384)
sys/psa_crypto: drop no-op Doxygen statements (#21393)
sys/psa_crypto: usa auto_init module for initialization (#21322)
sys/vfs: remove deprecated vfs_iterate_mounts() (#21387)
sys/ztimer: fix small typo in doc (#21208)
treewide: update riot-wrappers and riot-sys (#21383)

Networking

sys/net/nanocoap: Implement Observe (Server-Side) (#21147)

drivers/include: fixing order of doxygen tags and header guards (#21325)
ieee802154/submac: calculate symbol time on demand (#19668)
lwip: bump to v2.2.1 (#21196)
nanocoap: avoid non static buffers of configurable size (#21270)
nanocoap_sock: implement observe (Client-Side) (#21160)
net_sock_async_event: cancel async event on sock_*_close() (#21180)
sys/net/gcoap: remove deprecated gcoap_req_send_tl() (#21385)
sys/net/ipv6: use markdown links in doc (#21356)

Packages

Pkg/ccn-lite: use latest ccn-lite commit (#21279)
pkg/driver_cryptocell_310: allow data to be in ROM on hash update (#21214)
pkg/driver_cryptocell_310: check for input data to be in RAM (#21138)
pkg/esp32_sdk: Fix broken rtc_io.h declaration and prevent sys/uio.h inclusion outside RIOT (#21408)

Boards

boards/seeedstudio-xiao-esp32c3: Add support for Seeed Studio ESP32C3 Xiao (#21267)
boards/feather-nrf52840*: add external flash configuration (#21324)
boards/nucleo-f722ze: add ADC support (#21233)
boards/nucleo-wl55jc: add ADC configuration (#21235)
boards/nucleo64: Add Compile Warning about LED0 when using SPI (#21338)
boards/seeedstudio-xiao-nrf52840-sense: Add Initial Support (#21332)
boards: introduce stdio_default (#21294)
boards: introduce board alias and make native default to host target (#21242)
Buildsystem: Introduce Global Makefiles for boards Directory (#21327)
cpu/sam4s: add initial support with SAM4S-XPRO board (#21201)

boards/common: Make Adafruit nRF52 Bootloader shared (#21281)
boards/feather-nrf52840*: rename to adafruit-feather-nrf52840-* (#21349)
boards/nrf6310: Remove nRF6310 board from RIOT (#20966)
boards/seeedstudio-xiao-nrf52840: initial board support (#20980)

CPU

core: add stdio.h to replace stdout functions with stdio_null (#20872)

cpu/native: Gardening/QoL (#21283)
cpu/nrf5*: mark and resolve radio conflict (#21250)
cpu/nrf52/radio/nrf802154: fix beacon acceptance (#20982)
cpu/sam0_common/flashpage: disable interrupts while writing (#21326)
cpu/sam0_eth: fix hang with broken PHY (#21172)
cpu/sam3: fix hwrng peripheral register access (#21177)
cpu/sam3: optimize gpio ISR processing (#21179)
cpu/samd5x: improve can-initialization (#21173)
cpu/stm32{f0,g0,c0}: fix ADC initialization sequence (#21230)
dist/tools/esptools: Upgrade the ESP32 toolchain to GCC v14.2, GDB v14.2 and OpenOCD v0.12 (#21144)
{cpu/sam0_common/sam0_sdhc,drivers/mtd}: do not allocate work_area twice (#21169)

Device Drivers

drivers/periph_timer: add timer_get_closest_freq() (#20581)
drivers/sen5x: Add device driver for SEN5x (#19955)
drivers/tm1637: add driver and tests for tm1637 7-segment display (#21112)

driver/sen5x: Small Fixups (#21392)
drivers/at: at_readline_stop_at_str fix remaining buffer length (#21195)
drivers/sdmmc/sdmmc_sdhc: remove DMA check (#21260)
drivers/{mtd_sdmmc,sdmmc}: reinit card (#21305)

Documentation

add *.doc.md to doxygen sources (#21319)
boards/nrf52840{dk,dongle}: add MCU table, move to doc.md (#21271)
boards/nucleo-f413zh: add MCU table, move to doc.md (#21264)
dist/tools: Add Doxygen as a Tool for CI (#21300)
doc, buildsystem: Add a Version Check for Doxygen, Fix doc* Target Execution (#21277)
doc/managing-a-release: add looking out for release tests to preps (#21368)
doc: add psutil requirement to Getting Started (#21399)

boards/arduino-due: update doc.txt (#21207)
boards/nucleo-144: rename doc.txt to doc.md (#21318)
boards/nucleo-f746zg: board doc update (#21310)
boards/rpi-pico*: Update and fix documentation and image (#21218)
build-system: Drop -Wno-error=documentation (#21377)
doc/porting-boards: Change example doc.txt to doc.md (#21257)
doc: doc.txt -> doc.md (#21255)
doc: hack to hide doc.md files until doxygen gets fixed (#21273)
doc: remove and replace deprecated mailing lists (#21285)
doc: Use the correct Doxygen Logo File Type in the Footer (#21274)
docs/rust: Install c2rust with --locked (#21236)
docs: Switch out pkg reference link (#21229)
sys/cord/doc.txt: Update additional references to RFC 9176 (#21159)
sys/malloc_monitor: Fix documentation (#21225)
sys/psa_crypto/doc: correctly end code block (#21380)
treewide: fix double the in doc and comments (#21224)
treewide: fix example references in docs (#21212)
CODING_CONVENTION.md: migrate to #pragma once (#21369)

Build System / Tooling

buildsystem: Enable -Wdocumentation for LLVM (#21358)
dist/tools: add #pragma once to headerguard check (#21367)

buildsystem: Remove buildtest Goal & Fix info-buildsizes-diff (#21359)
dist/tools/bmp: additional improvements to auto-detection (#21128)
dist: tools: avoid hanging tapsetup in the absence of a DHCP server (#20411)
Makefile.include: perform checks for all relevant targets (#21199)
makefiles: bump riotdocker (#21258)
makefiles: colorize board alias warning (#21352)
makefiles: fix output of info-applications (#21213)
tools: Use RIOT maintained cosy (#21070)

Examples

examples: restructure examples folder (#21135)
examples: shorten subfolders' names (#21221)
Configure default DNS resolver in 6lbr example (#21117)
examples/nanocoap_server: enable LWIP IPv4 (#21333)
examples: migrate to XFA SHELL_COMMAND (#21171)
examples: update dtls-echo source (#21247)
examples/gnrc_border_router: Request temporary address (IA_NA) for the 6lbr example (#21118)

Testing

tests/bench/runtime_coreapis: add clist_sort() benchmark (#21403)
tests/pkg/relic: add Paillier encryption tests (#21301)

.github/labeler: recognize boards/common/native as native (#21351)
test/pkg/relic: increase stacksize for paillier encryption (#21306)
tests/adc: always test all resolutions (#21223)
tests/drivers/candev: minor cleanup (#21175)
tests/nanocoap_cli: allow to build with lwIP (#21314)
tests/sys/suit_manifest: remove unnecessary custom native board (#21248)
tests/test-rtc: test retrieval of unix-time (#20031)
tests/unittests: test parsing of out-of-bounds CoAP opt (#21167)

API Changes

can: add CAN FD support to STM32G4 and native architecture (#20428)
cpu/samd5x: add enable pin to CAN configuration (#21287)

drivers/periph_uart: document acquire/release semantic (#20624)

And 22 minor changes.

Deprecations

Deprecations (1)

gnrc/ipv6/nib: make CONFIG_GNRC_IPV6_STATIC_LLADDR_IS_FIXED the default & deprecate it (#21157)

Bug fixes (28)

LOSTANDFOUND.md: add missing URL, fix Markdown typo (#21154)
boards/feather-m0*: Update Default Bootloader to UF2 (#21280)
buildsystem: Fix boards/Makefile.features Inclusion (#21334)
buildsystem: Fix Supported Board List in info-build (#21361)
buildsystem: Set term Goal to NOTPARALLEL (#21354)
cpu/esp32: fix bus_width in periph_sdmmc (#21259)
cpu/esp32: Fixes of compile problems with GCC 14.2 (#21245)
cpu/esp_common: create partitions.csv more robustly (#21185)
cpu/native: use async read for stdio_read() (#19002)
cpu/sam3: fix PMC enable/disable peripheral clock access (#21168)
cpu/samd5x/periph_can: fix RX (#21181)
cpu/stm32: Make ADC Resolution Definition uniform (#20971)
cpu/stm32{f3,l4,wb,wl}: Replace ztimer with busy_wait, fix VBat sampling time and {wl only} fix initialization sequence (#21238)
doc: fix image references for ESP32x boards (#21204)
drivers/periph_{i2c,spi}: fix doc on initialization (#21188)
examples/default: fix dependency modeling (#21191)
examples/suit_update: fix compilation for native [backport 2025.04] (#21427)
gnrc_sock/udp: zero-init sock struct on create (#21363)
pkg/nimble: Fix compilation with USEMODULE += nimble_svc_bas (#21200)
pyterm: send SIGINT to the subprocess' child (#21309)
socket_zep: properly implement the radio HAL (#19213)
sys/can: fix compilation issues under native (#21388)
sys/net/nanocoap: align request handling with spec (#21163)
sys/net/nanocoap: drop typedef hack [v2] (#21193)
sys/net/nanocoap: fix API inconsistency (#21241)
sys/net/nanocoap: fix dereferencing a null pointer (#21227)
tree wide: various doc fixes (#21357)
tree-wide: mixed back of documentation fixes (#21371)

Known issues

Network related issues (55)

6lo: RIOT does not receive packets from Linux when short_addr is set (#11033)
Address registration handling inappropriate (#15867)
app/netdev: application stops working after receiving frames with assertion or completely without error (#8271)
at86rf2xx: Dead lock when sending while receiving (#8242)
cpu/esp8266: Tracking open problems of esp_wifi netdev driver (#10861)
DHCPv6 client: Handling of NotOnLink incorrect (#20349)
dist/tools/sliptty/start_network.sh: IPv6 connectivity is broken on PC (#14689)
driver/mrf24j40: blocks shell input with auto_init_gnrc_netif (#12943)
drivers/at86rf215: Incorrect channel number set for subGHz (#15906)
DTLS examples cannot send message to localhost (#14315)
Emcute cannot create a double-byte name (#12642)
ethernet: Missing multicast addr assignment (#13493)
ethos: fails to respond to first message. (#11988)
ethos: Unable to handle fragmented IPv6 packets from Linux kernel (#12264)
example/gnrc_border_router cannot answer after some time (#19578)
examples/cord_ep: Dead lock when (re-)registering in callback function (#12884)
examples/gnrc_border_router: esp_wifi crashes on disconnect (#14679)
Forwarding a packet back to its link layer source should not be allowed (#5051)
gcoap example request on tap I/F fails with NIB issue (#8199)
gcoap: Suspected crosstalk between requests (possible NULL call) (#14390)
Global IPv6 addresses remain deprecated after receiving RA (#19846)
gnrc ipv6: multicast packets are not dispatched to the upper layers (#5230)
gnrc/ipv6: "invalid payload length" - corrupted IPv6 header when ENABLE_DEBUG=1 in mbox.c (#20390)
gnrc_border_router stops routing after a while (#16398)
gnrc_border_router: Kconfig and C disagree about number of addresses per interface (#19947)
gnrc_icmpv6_echo: flood-pinging another node leads to leaks in own packet buffer (#12565)
gnrc_ipv6: Multicast is not forwarded if routing node listens to the address (#4527)
gnrc_netif_pktq leaks memory (#17924)
gnrc_rpl: missing bounds checks in _parse_options (#16085)
gnrc_rpl: nib route not updated when topology / DODAG changes (#17327)
gnrc_rpl: old routes are not deleted (#19423)
gnrc_rpl: takes unusually long time to start routing packets (#19147)
gnrc_sock_udp: Possible Race condition on copy in application buffer (#10389)
gnrc_tcp: gnrc_tcp_recv() never generates -ECONNABORTED (#17896)
gomach: Resetting netif with cli doesn't return (#10370)
ieee802154_submac: IPv6 fragmentation broken (#16998)
LoRaWan node ISR stack overflowed (#14962)
LWIP TCP Communication Error (#19676)
lwip_sock_tcp / sock_async: received events before calling sock_accept() are lost due to race condition. (#16303)
Missing drop implementations in netdev_driver_t::recv (#10410)
Neighbor Discovery not working after router reboot when using SLAAC (#11038)
netdev_ieee802154: Mismatch between radio ll address and in memory address (#10380)
nrf52: Not able to add global or ULA address to interface (#13280)
nrfmin: communication not possible after multicast ping with no interval (#11405)
ping6 is failing when testing with cc2538dk (#13997)
pkg/tinydtls: auxiliary data API does not work for async sockets (#16054)
pkg/tinydtls: DTLS handshake does not work (#19595)
Removing a TNT global address then adding a new one does not work (#20318)
samr30 xpro doesn't seem to use its radio ok (#12761)
scan-build errors found during 2019.07 testing (#11852)
stale border router does not get replaced (#12210)
test/lwip: enabling both, IPv4 and IPv6, results in unexpected behavior (#18097)
tests/lwip: does not compile for IPv4 on 6LoWPAN-based boards. (#17162)
two nodes livelock sending neighbor solicitations back and forth between each other (#16670)
xbee: setting PAN ID sometimes fails (#10338)

Timer related issues (6)

misc issues with tests/trickle (#9052)
periph/timer: timer_set() underflow safety check (tracking issue) (#13072)
periph_timer: systematic proportional error in timer_set (#10545)
saml21 system time vs rtc (#10523)
stm32_common/periph/rtc: current implementation broken/poor accuracy (#8746)
sys/newlib: gettimeofday() returns time since boot, not current wall time. (#9187)

Drivers related issues (11)

at86rf2xx: Simultaneous use of different transceiver types is not supported (#4876)
cpu/msp430: GPIO driver doesn't work properly (#9419)
examples/dtls-wolfssl not working on pba-d-01-kw2x (#13527)
fail to send data to can bus (#12371)
mdt_erase success, but vfs_format resets board (esp32-heltec- lora32-v2) (#14506)
periph/spi: Switching between CPOL=0,1 problems on Kinetis with software CS (#6567)
periph: GPIO drivers are not thread safe (#4866)
PWM: Single-phase initialization creates flicker (#15121)
STM32: SPI clock not returning to idle state and generating additional clock cycles (#11104)
TCP client cannot send read only data (#16541)
tests/periph_flashpage: unexpected behavior on nucleo-l4r5zi (#17599)

Native related issues (4)

examples/micropython: floating point exception while testing on native (#15870)
native not float safe (#495)
native: tlsf: early malloc will lead to a crash (#5796)
ztimer doesn't wake up on native if the pm_layered module is used (#21083)

Other platforms related issues (13)

Failing tests on FE310 (Hifive1b) (#13086)
[TRACKING] Fixes for automatic tests of ESP32 boards. (#12763)
boards/hifive1: flashing issue (#13104)
cpu/sam0: flashpage write / read cycle produces different results depending on code layout in flash (#14929)
esp32-wroom-32: tests/netstats_l2 failing sometimes (#14237)
examples/gnrc_border_router: esp_wifi_init failed with return value 257 on ESP32-C3 with nimble_rpble (#19319)
gcoap/esp8266: Stack overflow with gcoap example (#13606)
Interrupt callback function is instantly called on samd51 after setting it from within interrupt callback function (#19861)
MPU doesn't work on cortex-m0+ (#14822)
newlib-nano: Printf formatting does not work properly for some numeric types (#1891)
periph_timer: Test coverage & broken on STM32F767ZI (#15072)
riscv: ISR stack is too small for ENABLE_DEBUG in core files (#16395)
stm32f7: Large performance difference between stm32f746 and stm32f767 (#14728)

Build system related issues (5)

Build dependencies - processing order issues (#9913)
dist/tools/cppcheck/cppchck.sh: errors when running with Cppcheck 1.89 (#12771)
EXTERNAL_MODULE_DIRS silently ignores non-existent entries (#17696)
make: ccache leads to differing binaries (#14264)
make: use of immediate value of variables before they have their final value (#8913)

Other issues (70)

2023.04 release bug tracking (#19469)
[tracking] Bugs found by the peripheral selftest (#20071)
[Tracking] Fix failures of test-on-iotlab (#20791)
[TRACKING] sys/shell refactoring. (#12105)
[tracking] unnecessary use of floating point arithmetic (#19614)
_NVIC_SystemReset stuck in infinite loop when calling pm_reboot through shell after flashing with J-Link (#13044)
make term no longer works with JLinkExe v6.94 (#16022)
at86rf215 stops receiving until sending a packet (#19653)
b-l072z-lrwan1: tests/ztimer_overhead: test failure (#19224)
backport_pr: Only works for when fork is in user (not in organization) (#18486)
benchmark_udp: hammering with low interval causes issues (#16808)
boards/esp32-wroom-32: tests/mtd_raw flakey (#16130)
Builds fail when different execstack options are around in objects (#18522)
Can't build relic with benchmarks or tests (#12897)
CC2538-CC2592EM has a very weak transmit power (#17543)
CC2538DK board docs: broken links (#12889)
cpp: Exception handling undefined (#17523)
cpu/stm32: some tests are failing on CM33 (l5, u5) (#17439)
doc/boards: information concerning access to RIOT shell (#17453)
doxygen: CSS hack to hide doc breaks on older browsers (#21312)
edbg: long lines flooded over serial become garbled (#14548)
examples / tests: LoRa tests fail on platforms that don't support LoRa (#14520)
examples/gcoap: client broken (#19379)
flashing issue on frdm-k64f (#15903)
frdm-k22f failing tests/periph_flashpage (#17057)
frdm-k22f fails tests/periph_timer (#19543)
Freeze into semtech_loramac_send call (pkg/semtech-loramac) (#18790)
gcoap: gcoap_req_send and related should return negative for errors (#19393)
gnrc_ipv6_nib: Neighbor Solicitation ping-pong (#18164)
I2C Crashes Kernel on Raspberry Pi Pico (#21187)
I2C not working under RIOT with U8G2 pkg (#16381)
ieee802154_security: Nonce is reused after reboot (#16844)
kconfiglib.py choice override of menuconfig bug (#19069)
lwip: drivers/at86rf2xx/at86rf2xx_netdev.c invalid state during TCP disconnect (#17209)
lwip: invalid state transition on ieee802154_submac users (#17208)
Making the newlib thread-safe (#4488)
mcuboot: flashes but no output (#17524)
MTD is confusing (#17663)
nanocoap: incomplete response to /.well-known/core request (#10731)
Order of auto_init functions (#13541)
periph_rtt: rtt_set_alarm() blocks IRQ for 80 plus usec on STM32 (#19520)
pkg/tinydtls: Multiple issues (#16108)
Potential race condition in compile_and_test_for_board.py (#12621)
RIOT is saw-toothing in energy consumption (even when idling) (#5009)
riotboot: ECC faults (eg. in STM32L5 or STM32WB) not handled gracefully (#17874)
rust-gcoap example is incompatible with littlefs2 (#17817)
Samr30/gpio: Erasing then write mux can generate spurious IRQ (#19993)
samr34-xpro: some tests failing (#19223)
sock_dtls: unable to send big messages (#17996)
spurious IRQs in periph_timer (#18976)
stdio_ethos: infinite shell loop (#17972)
stdio_tinyusb_cdc_acm hangs with picolibc (#19277)
STM32 Nucleo boards improperly clocked (#19778)
STM32F4-discovery + mrf24j40 not working (#19711)
sys/riotboot: documentation issues (#11243)
sys/usb/usbus/cdc/ecm: interface thread blocked when connected host interface is down (#21098)
tests/lwip target board for python test is hardcoded to native (#6533)
tests/periph_flashpage: failing on stm32l475ve (#17280)
tests/pkg/lvgl: compilation error for BOARD=samr21-xpro (#21446)
tests/pkg/relic is failing on samr21-xpro when built using llvm (#19903)
tests/pkg_libhydrogen: test fails on master for the samr21-xpro with LLVM (#15066)
tests/pkg_libschc: Failing test_reassemble_success_ack_always (#19445)
tests/test_tools: test fails while testing on samr21-xpro/iotlab-m3 (#15888)
tests: broken with stdio_rtt if auto_init is disabled (#13120)
tests: some tests don't work with newlib lock functions. (#12732)
Types in byteorder.h need a cleanup (#14737)
USB identifiers with funny characters create mojibake (#17776)
usbus/msc: wrong error handling and behavior after usb reset (#19478)
Use of multiple CAN bus on compatible boards (#14801)
ztimer is incompatible with real-time requirements (#18883)

There are 164 known issues in this release

Fixed Issues since the last release (2025.01)

buildsystem: make distclean does not clean dist/... (#21409)
native: Exiting pyterm does not terminate the native process any more (#21307)
Buildsystem: Makefile of Common Board Directories never called without adding DIRS (#21298)
Build System: make -C path/path doc fails in Base Folder (#21278)
dist/tools/uf2: Flashing a board with RIOT seems to prevent flashing other UF2 files afterwards (#21205)
build system: race condition when building and running an app for native (#20948)
feather-m0: make flash reports "device unsupported" (#17722)
doc/LOSTANDFOUND: not rendered as expected (#17063)
native getchar is blocking RIOT (#16834)
border_router: significant packet loss when sending out packets using USB cdc-ecm on nrf52 (#16411)
buildtest uses wrong build directory (#9742)
MSP430: periph_timer clock config wrong (#8251)

12 fixed issues since last release (2025.01)

Acknowledgements

More information

http://www.riot-os.org

Matrix and Forum

Join the RIOT Matrix room at: #riot-os:matrix.org
Join the RIOT Forum at: forum.riot-os.org

License

The code developed by the RIOT community is licensed under the GNU Lesser General Public License (LGPL) version 2.1 as published by the Free Software Foundation.
Some external sources and packages are published under a separate license.

All code files contain licensing information.

RIOT-2025.04 "MakeSpringClean" - Release Notes

About this release

Notations used below

New features and changes

Core

System Libraries

Networking

Packages

Boards

CPU

Device Drivers

Documentation

Build System / Tooling

Examples

Testing

API Changes

Deprecations

Deprecations (1)

Bug fixes (28)

Known issues

Network related issues (55)

Timer related issues (6)

Drivers related issues (11)

Native related issues (4)

Other platforms related issues (13)

Build system related issues (5)

Other issues (70)

Fixed Issues since the last release (2025.01)

Acknowledgements

More information

Matrix and Forum

License

More C Projects

scrcpy

netdata

redis

RIOT-2025.04 "MakeSpringClean" - Release Notes

About this release

Notations used below

New features and changes

Core

System Libraries

Networking

Packages

Boards

CPU

Device Drivers

Documentation

Build System / Tooling

Examples

Testing

API Changes

Deprecations

Deprecations (1)

Bug fixes (28)

Known issues

Network related issues (55)

Timer related issues (6)

Drivers related issues (11)

Native related issues (4)

Other platforms related issues (13)

Build system related issues (5)

Other issues (70)

Fixed Issues since the last release (2025.01)

Acknowledgements

More information

Matrix and Forum

License

More C Projects

scrcpy

netdata

redis

curl