RIOT-2020.07 - 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 2020.07 release puts a focus on the improvement of automated testing. In that vein, various new CI integrations such as CircleCI for documentation building and online presentation, and Github Actions to check the tooling of RIOT when merged. The riotctrl_shell python module allows to abstract shell commands as python methods for testing using the newly created riotctrl python package 1. Kconfig migration reached phase 2 with various board features being exposed to Kconfig. New network protocols were ported for RIOT such as MQTT (in form of the paho-mqtt package) and the lookup client component for CoRE RD cord_lc. The OpenWSN network stack with 6TiSCH support was reintegrated into RIOT. Support for several new boards and new sensors was added. Additionally, this release contains a number of bug fixes and test improvements.

546 pull requests, composed of 10452 commits, have been merged since the last release, and 84 issues have been solved. 64 people contributed with code in 106 days. 2371 files have been touched with 822149 (+) insertions and 700313 deletions (-).

Notations used below:

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

New features and changes

Core

• core: make idle thread optional

• macros/units: add unit conversion helper macros
• msg: add message bus

• panic: launch USB bootloader on crash for easy recovery

System libraries

• auto_init: automatically determine auto_init_*.c
• base64: Clean up / improve implementation

• hashes: add sha224 and reuse sha256 code
• luid: provide luid_get_lb()
• phydat: added phydat to JSON converter
• posix: initial import of select() function (only support sockets for now)

• ps: show free stack space in addition to used and total
• shell:
  • add optional hooks for shell commands
  • native: stop RIOT when the shell reads EOF
  • refactor readline function
  • refactor tokenizer code

• shell_commands:
  • alias ping=ping6
  • provide command to reboot to bootloader
• stdio_semihosting: Initial include of Semihosting-based STDIO
• touch_dev: add generic API for touch device
• trace: add trace module
• pm: Add pm_get_blocker()

• random:
  • add option to use HWRNG as source of randomness
  • optimize sha1prng
• usb:
  • allow for boards to define default custom VID/PID
  • warn on test-ID usage in a unified location

• xtimer: xtimer_rmutex_lock_timeout

• ztimer:
  • add power management for ztimer clocks
  • expose ZTIMER_MSEC/USEC_BASE

Networking

• cord: add CoRE RD lookup client implementation
• gcoap: add CoAP ping request

• gnrc:
  • gnrc_ipv6_ext_opt: initial import of hop-by-hop and destination option handling
  • gnrc_netif:
    • add IPv6 event bus
    • add option for non-std 6lo MTU
    • add support for internal event loop
    • use gnrc_netif-submodules to pull in upper-layer struct members
  • gnrc_nettype: indirect NETTYPE definition via pseudo-modules
  • gnrc_pktdump: fix dependencies
  • gnrc_tcp:
    • add retransmission timer
    • rewrite API internal messaging
    • rewrite recv buffer allocation/returning
  • use exponent to configure message queue sizes
• nanocoap: allow coap_opt_add_string() for non-zero-terminated strings

• netif: add functions to get and get by identifier
• sock_dtls: provide getter function for UDP sock

• sock_util: add interface descriptor parsing to str2ep

Packages

• pkg: rework checkout process
  • avoid copying Makefiles in package source when possible
  • store packages sources in a global package directory
• pkg: cleanup build system integration for
  • cryptoauthlib, openthread, semtech-loramac, tinydtls, wakaama, u8g2, ucglib, wolfssl
• pkg: tools: ensure cmake based packages/tools are built out-of-source

• cryptoauthlib: wake pulse implementation for CPUs supporting periph_i2c_reconfigure
• emlearn: add support to RIOT

• gecko_sdk: update to v2.7.6
• lwip:
  • add IPv4 support for netdev_tap
  • add support for nrf802154
  • enable IPv4/IPv6 dual stack mode
  • lwip_sock: provide implementation for sock_*_recv_buf()

• lua: remove unnecessary patch

• paho-mqtt: add package and example

• nimble:
  • add static connection manager statconn
  • netif:
    • set host thread prio to 1
    • simplify mbuf pool initialization
  • update NimBLE ver (cd7d7aa286) + timing param cleanup

• openwsn: re-integrate the network stack as a package

• tinydtls:
  • add sock_async support for sock_dtls
  • use latest development version (eda63f000c)
• ucglib: refactoring and fixes

Boards

• cc1352p-launchpad: add support

• common/blxxxpill:
  • provide periph_rtt
  • improve adc

• dwm1001: add support to Decawave DWM1001 dev board
• mcb2388: misc enhancements
• nrf52840-dongle: add support
• nrf52840dk: Add MTD configuration
• nucleo-g474re: add support

• pic32-clicker: rename to 6lowpan-clicker

• samr30-xpro: add SPI dev for ext pin header
• samr3x-xpro: add riotboot feature
• serpente: add support
• sltb001a: enable CCS811 sensor
• sodaq-sff: add support for SODAQ SFF
• stm32f429i-disco: add support
• weact-f411ce: add support
• wemos-zero: add support

CPU

• arm7_common: Update to inlineable IRQ API
• atmega_common: Update to inlineable IRQ API
• cortexm:
  • allow to define reserved fields in CortexM vector table
  • "free" SVC
• cc26x2_cc13x2:
  • add oscillator switching functions
  • add periph_i2c implementation
  • trim device registers on cpu_init
• esp32:
  • support of multiple heaps for newlib malloc
  • replace RTC implementation by RTT implementation
• fe310: migrate to inlined IRQ API

• kinetis: implement power modes for pm_layered

• lpc2387:
  • pm: enable SLEEP & POWERDOWN mode
  • timer: use lpc2387_pclk_scale()

• mips_pic32_common: Implement GPIO IRQ
• native:
  • add periph_eeprom driver implementation
  • rename trace -> backtrace
• nrf52:
  • add black magic probe config
  • add missing vendor files
  • implement EasyDMA-based SPI peripheral implementation
• nrf52811: initial support

• nrf5x_common:
  • add configurable RTT_FREQUENCY
  • enable bias correction in hwrng
• sam0_common:
  • add DMA peripheral driver
  • add PWM support for saml21, samd5x
  • implement periph/dac
  • make SPI peripheral DMA compatible
  • move PWM to common code
  • spi: move clk pin muxing into spi_acquire / spi_release
  • UART: implement inverted RX & TX
• samd21: PWM don't hard-code number of channels to 3
• samd5x: allow to use XOSC as clock source
• saml1x: pm: set deep flag

• stm32:
  • add QDEC support for CPU_FAM_STM32F1
  • add non-blocking UART
  • decrease latency in SPI DMA path
  • implement reset to bootloader
  • filter availability of RNG by CPU not by board
  • stm32_common: make RTT_FREQUENCY configurable
  • stm32f4: Add DMA config for SPI
  • stm32g4: add support

Device Drivers

• atwinc15x0: add WiFi netdev driver
• at: Add at_urc_isr module to process URCs upon arrival
• at24cxxx: MTD wrapper for at24cxxx
• at86rf215:
  • implement MR-O-QPSK
  • implement MR-OFDM
• at86rf2xx: add support for high data rates
• dfplayer: New driver for the DFPlayer Mini MP3 player

• ethos: use luid_get_eui48()

• edbg_eui: add driver to get MAC address from Atmel EDBG
• mhz19: initial support
• mrf24j40: add Turbo Mode
• mtd_spi_eeprom: add MTD wrapper for AT25XXX EEPROMs
• pca9633: add new driver
• periph/timer: add timer_set_periodic()
• periph/i2c: add periph_i2c_reconfigure feature & implementation for sam0
• periph/rtt: introduce RTT_MIN_OFFSET
• periph/spi: add periph_spi_reconfigure feature & implementation for sam0

• pulse_counter: Use C11 atomics & bugfix

• sdp3x : Add driver for sdp3x sensor

Build System / Tooling

• make:
  • add code generator targets
  • add JLink support for stm32
  • docker.inc.mk: add and use generic docker_run_make
  • allow multiple external board dirs
  • info-global.inc.mk: add info-boards-features-blacklisted
  • resolve dependencies before Makefile.include
• riotctrl_shell:
  • initial import of shell interaction spawn
  • provide ipv6_nib interactions and parsers
  • provide netif interactions and parsers
• tools:
  • add script to run radvd on a tun interface
  • provide tool to parse pktbuf output
  • kconfiglib:
    • add riot_kconfig to override default behaviours
    • kconfiglib: bump to v14.1.0

Testing

• fuzzing framework:
  • add AFL-based fuzzing setup for network modules
  • add fuzzing application for gcoap
• ci: setup github actions
• sys/test_utils/dummy_thread: initial commit
• tests/irq_disable_restore: Add test for irq_disable() / irq_restore()
• tests/periph_spi: add benchmark for acquire / release
• tests/periph_spi_dma: Add test for SPI with DMA
• uncrustify: add auto uncrustify with blacklist

Kconfig migration

• armv7_m/cortexm: declare CPU_ARCH and CPU_CORE
• boards: Model features in Kconfig
  • arduino-leonardo, arduino-mega2560, atmega128x-based, atmega256rfr2-based, atmega328p-based, cc2538-based, cc26xx_cc13xx-based, efm32-based, esp-based, fe310-based, kinetis-based, msp430-based, samr21-xpro, slwstk6220a

• kconfig: Declare common feature symbols

• drivers: Expose Configurations to Kconfig
  • ads101x, at, at86rf215, bmx055, cc110x, dose.h, fxos8700, hdc1000, isl29020, l3g4200d, lpsxxx, mag3110, mma8x5x, motor_driver, mtd_sdcard, opt3001, pn532, rn2xx3, slipdev, sps30, tcs37727, tmp00x
• networking: Expose configurations to Kconfig
  • asymcute, coap, csma
  • gnrc:
    • gomach, lwmac, mac, pktdump, pktbuf, rpl, tcp
• usbus/cdc/ecm: Expose configurations to Kconfig

API Changes

• cpu/sam0_common: drop prescaler from timer config
• cpu/sam0_common: PWM config now requires GCLK source
• drivers/mtd: Change API to return 0 on success
• drivers/mtd_mapper: count offset in sectors
• net/sock_dtls: provide getter function for UDP sock
• net/sock_dtls: add timeout to sock_dtls_send and add sock_dtls_session_init

  diff --git a/sys/include/net/sock/dtls.h b/sys/include/net/sock/dtls.h
  index 96569723fc..6e66048bd4 100644
  --- a/sys/include/net/sock/dtls.h
  +++ b/sys/include/net/sock/dtls.h
  @@ -476,6 +485,13 @@
   extern "C" {
   #endif
  
  +#ifndef DTLS_HANDSHAKE_BUFSIZE
  +#define DTLS_HANDSHAKE_BUFSIZE  (256)   /**< Size buffer used in handshake to
  +                                             hold credentials */
  +#endif
  +
  +#define SOCK_DTLS_HANDSHAKE     (EXDEV) /**< Return value for a successful
  +                                             handshake */
  +
   /**
    * @brief DTLS version number
  @@ -546,26 +564,26 @@ void sock_dtls_init(void);
   int sock_dtls_create(sock_dtls_t *sock, sock_udp_t *udp_sock,
                        credman_tag_t tag, unsigned version, unsigned role);
  
  +
   /**
  - * @brief Creates a new DTLS session
  + * @brief Initialize session handshake.
    *
  - * Initializes handshake process with a DTLS server  at @p ep.
  - *
  - * @param[in]  sock     DLTS sock to use
  - * @param[in]  ep       Remote endpoint of the session
  - * @param[out] remote   The created session, cannot be NULL
  + * Sends a ClientHello message to initialize the handshake. Call
  + * @ref sock_dtls_recv() to finish the handshake.
    *
  - * @return  0 on success
  - * @return  -EAGAIN, if DTLS_HANDSHAKE_TIMEOUT is `0` and no data is available.
  - * @return  -EADDRNOTAVAIL, if the local endpoint of @p sock is not set.
  - * @return  -EINVAL, if @p remote is invalid or @p sock is not properly
  - *          initialized (or closed while sock_udp_recv() blocks).
  - * @return  -ENOBUFS, if buffer space is not large enough to store received
  - *          credentials.
  - * @return  -ETIMEDOUT, if timed out when trying to create session.
  + * @param[in] sock      DTLS sock to use
  + * @param[in] ep        Remote endpoint to start a handshake with
  + * @param[out] remote   Resulting session
  + *
  + * @return 1, if new handshake is started
  + * @return 0, if there is an existing session
  + * @return -ENOMEM, not enough memory to allocate for new peer
  + * @return -EADDRNOTAVAIL, if the local endpoint of @p sock is not set.
  + * @return -EINVAL, if @p remote is invalid or @p sock is not properly
  + *         initialized (or closed while sock_udp_recv() blocks).
    */
  -int sock_dtls_session_create(sock_dtls_t *sock, const sock_udp_ep_t *ep,
  -                             sock_dtls_session_t *remote);
  +int sock_dtls_session_init(sock_dtls_t *sock, const sock_udp_ep_t *ep,
  +                           sock_dtls_session_t *remote);
  
   /**
    * @brief Destroys an existing DTLS session
  @@ -578,7 +596,7 @@ int sock_dtls_session_create(sock_dtls_t *sock, const sock_udp_ep_t *ep,
   void sock_dtls_session_destroy(sock_dtls_t *sock, sock_dtls_session_t *remote);
  
   /**
  - * @brief Decrypts and reads a message from a remote peer.
  + * @brief Receive handshake messages and application data from remote peer.
    *
    * @param[in] sock      DTLS sock to use.
    * @param[out] remote   Remote DTLS session of the received data.
  @@ -593,7 +611,8 @@ void sock_dtls_session_destroy(sock_dtls_t *sock, sock_dtls_session_t *remote);
    *
    * @note Function may block if data is not available and @p timeout != 0
    *
  - * @return The number of bytes received on success
  + * @return  The number of bytes received on success
  + * @return  -SOCK_DTLS_HANDSHAKE when new handshake is completed
    * @return  -EADDRNOTAVAIL, if the local endpoint of @p sock is not set.
    * @return  -EAGAIN, if @p timeout is `0` and no data is available.
    * @return  -EINVAL, if @p remote is invalid or @p sock is not properly
  @@ -657,28 +676,32 @@ ssize_t sock_dtls_recv_buf(sock_dtls_t *sock, sock_dtls_session_t *remote,
    *                      if no session exist between client and server.
    * @param[in] data      Pointer where the data to be send are stored
    * @param[in] len       Length of @p data to be send
  + * @param[in] timeout   Handshake timeout in microseconds.
  + *                      If `timeout > 0`, will start a new handshake if no
  + *                      session exists yet. The function will block until
  + *                      handshake completed or timed out.
  + *                      May be SOCK_NO_TIMEOUT to block indefinitely until
  + *                      handshake complete.
    *
  - * @note Function may block until a session is created if there is no
  - *       existing session with @p remote.
  - *
  - * @note Initiating a session through this function will require
  - * @ref sock_dtls_recv() called from another thread to receive the handshake
  - * messages.
  + * @note    When blocking, we will need an extra thread to call
  + *          @ref sock_dtls_recv() function to handle the incoming handshake
  + *          messages.
    *
    * @return The number of bytes sent on success
  + * @return  -ENOTCONN, if `timeout == 0` and no existing session exists with
  + *          @p remote
    * @return  -EADDRINUSE, if sock_dtls_t::udp_sock has no local end-point.
    * @return  -EAFNOSUPPORT, if `remote->ep != NULL` and
    *          sock_dtls_session_t::ep::family of @p remote is != AF_UNSPEC and
    *          not supported.
  - * @return  -EHOSTUNREACH, if sock_dtls_session_t::ep of @p remote is not
  - *          reachable.
    * @return  -EINVAL, if sock_udp_ep_t::addr of @p remote->ep is an
    *          invalid address.
    * @return  -EINVAL, if sock_udp_ep_t::port of @p remote->ep is 0.
    * @return  -ENOMEM, if no memory was available to send @p data.
  + * @return  -ETIMEDOUT, `0 < timeout < SOCK_NO_TIMEOUT` and timed out.
    */
   ssize_t sock_dtls_send(sock_dtls_t *sock, sock_dtls_session_t *remote,
  -                       const void *data, size_t len);
  +                       const void *data, size_t len, uint32_t timeout);
  
   /**
    * @brief Closes a DTLS sock
  @@ -694,6 +717,47 @@ ssize_t sock_dtls_send(sock_dtls_t *sock, sock_dtls_session_t *remote,
    */
   void sock_dtls_close(sock_dtls_t *sock);
  
  +/**
  + * @brief Creates a new DTLS session
  + *
  + *  Initiates a handshake with a DTLS server at @p ep and wait until it
  + * completes or timed out.
  + *
  + * @deprecated Will not be available after the 2020.10 release.
  + *             Please use @ref sock_dtls_session_init() and
  + *             @ref sock_dtls_recv() instead.
  + *
  + * @param[in]  sock     DLTS sock to use
  + * @param[in]  ep       Remote endpoint of the session
  + * @param[out] remote   The created session, cannot be NULL
  + * @param[in]  timeout  Timeout to wait for handshake to finish.
  + *                      Returns immediately if 0.
  + *                      May be SOCK_NO_TIMEOUT to wait indefinitely until
  + *                      handshake complete.
  + *
  + * @return  0 on success
  + * @return  -ENOMEM, if no memory to allocate for new peer
  + * @return  -EADDRNOTAVAIL, if the local endpoint of @p sock is not set.
  + * @return  -EINVAL, if @p remote is invalid or @p sock is not properly
  + *          initialized (or closed while sock_udp_recv() blocks).
  + */
  +static inline int sock_dtls_session_create(sock_dtls_t *sock, const sock_udp_ep_t *ep,
  +                                    sock_dtls_session_t *remote, unsigned timeout)
  +{
  +    int res;
  +    uint8_t buf[DTLS_HANDSHAKE_BUFSIZE];
  +
  +    assert(sock);
  +    assert(remote);
  +
  +    res = sock_dtls_session_init(sock, ep, remote);
  +    if (res <= 0) {
  +        return res;
  +    }
  +
  +    return sock_dtls_recv(sock, remote, buf, sizeof(buf), timeout);
  +}
  +
   #include "sock_dtls_types.h"
  
   #ifdef __cplusplus
  

Deprecations

Warnings

• GNRC_MAC_ENABLE_DUTYCYCLE_RECORD: Will be removed after 2021.01 release. Use inverse CONFIG_GNRC_MAC_DISABLE_DUTYCYCLE_RECORD instead.
• saul_reg_rm(): will be removed at a future date
• sock_dtls_session_create(): will be removed after 2020.10 release. Please use sock_dtls_session_init() and sock_dtls_recv() instead
• pkg/nordic_softdevice_ble: will be removed after the 2020.10 release

Removals

• netdev: remove NETOPT_IPV6_IID support for network devices

Known issues

Networking related issues (44)

#13997: ping6 is failing when testing with cc2538dk #13745: ethos: Unable to choose global source address. #13496: cpu/stm32/eth, board/nucleo-f767z1: ethernet buffering issue (ping >1s) after debug break #13493: ethernet: Missing multicast addr assignment #13490: cpu/stm32/eth, board/nucleo-f767z1: ethernet initialisation fails sometimes #13280: nrf52: Not able to add global or ULA address to interface #13088: Riot-os freezes with lwip + enc28j60 + stm32L4 #12943: driver/mrf24j40: blocks shell input with auto_init_gnrc_netif #12884: examples/cord_ep: Dead lock when (re-)registering in callback function #12857: examples/gnrc_networking_mac broken on ATmega #12761: samr30 xpro doesn't seem to use its radio ok #12642: Emcute cannot create a double-byte name #12565: gnrc_icmpv6_echo: flood-pinging another node leads to leaks in own packet buffer #12264: ethos: Unable to handle fragmented IPv6 packets from Linux kernel #12210: stale border router does not get replaced #11988: ethos: fails to respond to first message. #11860: send data with UDP at 10HZ, the program die #11852: scan-build errors found during 2019.07 testing #11405: nrfmin: communication not possible after multicast ping with no interval #11033: 6lo: RIOT does not receive packets from Linux when short_addr is set #10969: net: netdev_driver_t::send() doc unclear #10861: cpu/esp8266: Tracking open problems of esp_wifi netdev driver #10809: openthread: does not build on current Arch #10410: Missing drop implementations in netdev_driver_t::recv #10389: gnrc_sock_udp: Possible Race condition on copy in application buffer #10380: netdev_ieee802154: Mismatch between radio ll address and in memory address #10370: gomach: Resetting netif with cli doesn't return #10338: xbee: setting PAN ID sometimes fails #9709: examples: failed assertion in dtls-echo example #9656: gnrc/netif: various problems after resetting interface a second time #8779: CC2538 RF overlapping PIN usage #8752: mrf24j40: does not link for examples/default #8271: app/netdev: application stops working after receiving frames with assertion or completely without error #8242: at86rf2xx: Dead lock when sending while receiving #8199: gcoap example request on tap I/F fails with NIB issue #7737: pkg: libcoap is partially broken and outdated #7474: 6lo gnrc fragmentation expects driver to block on TX #7304: General 802.15.4/CC2538 RF driver dislikes fast ACKs #6018: nRF52: gnrc_6lowpan_ble: memory leak with nordic_softdevice_ble #5863: OSX + SAMR21-xpro: shell cannot handle command inputs larger than 64 chars #5486: at86rf2xx: lost interrupts #5230: gnrc ipv6: multicast packets are not dispatched to the upper layers #5051: Forwarding a packet back to its link layer source should not be allowed #4527: gnrc_ipv6: Multicast is not forwarded if routing node listens to the address

Timer related issues (17)

#14217: tests/periph_timer_periodic is failing #13321: Sleep mode for Arduino #13204: xtimer problem with nucleo32 boards #13072: periph/timer: timer_set() underflow safety check (tracking issue) #10545: periph_timer: systematic proportional error in timer_set #10523: saml21 system time vs rtc #10510: xtimer_set_msg: crash when using same message for 2 timers #10073: xtimer_usleep wrong delay time #9187: sys/newlib: gettimeofday() returns time since boot, not current wall time. #9052: misc issues with tests/trickle #9049: xtimer mis-scaling with long sleep times #8746: stm32_common/periph/rtc: current implementation broken/poor accuracy #8251: MSP430: periph_timer clock config wrong #7347: xtimer_usleep stuck for small values #7114: xtimer: add's items to the wrong list if the timer overflows between _xtimer_now() and irq_disable() #6442: cpu/native: timer interrupt issue #6052: tests: xtimer_drift gets stuck on native

Drivers related issues (13)

#14506: mdt_erase success, but vfs_format resets board (esp32-heltec-lora32-v2) #14439: (almost solved) SPI SD-Card driver: SPI initialisation freeze until timeout #14424: adc is not a ADC-Driver but a analog pin abstraction #13527: examples/dtls-wolfssl not working on pba-d-01-kw2x #13444: Potential security and safety race conditions on attached devices #13079: drivers/srf04: incorrect values on ATmega based platforms #12445: driver/hts221: Temperature and Humidity readings incorrect #12371: fail to send data to can bus #12057: ESP32 + DHT + SAUL reading two endpoints causes freeze. #12045: floats and doubles being used all over the place. #11104: STM32: SPI clock not returning to idle state and generating additional clock cycles #9419: cpu/msp430: GPIO driver doesn't work properly #4876: at86rf2xx: Simultaneous use of different transceiver types is not supported

Native related issues (3)

#13501: SDL2 does not work due to missing getpid #5796: native: tlsf: early malloc will lead to a crash #495: native not float safe

Other platforms related issues (19)

#14572: tests/mpu_noexec_ram: fails on i-nucleo-lrwan1 #14410: MIPS: toolchain objcopy doesn't work and no .bin can be generated #14237: esp32-wroom-32: tests/netstats_l2 failing sometimes #14015: stm32152re: hardfault when DBGMCU_CR_DBG* bits are set and branch after __WFI() #13606: gcoap/esp8266: Stack overflow with gcoap example #13390: Cannot use LLVM with Cortex-M boards #13267: Failing tests on MSP430 (z1) #13104: boards/hifive1: flashing issue #13086: Failing tests on FE310 (Hifive1b) #12763: [TRACKING] Fixes for automatic tests of ESP32 boards. #12651: Failing tests on AVR (tested with atmega256rfr2-xpro) #12168: pkg/libb2: blake2s doesn't work on AVR #11885: arm7: printf() with float/double not working #10258: Incorrect default $PORT building for esp32-wroom-32 on macOS #10122: Indeterministic hard fault in _mutex_lock(), with nRF52 SoftDevice #10076: cpu/cortexm_common: irq_enable returns the current state of interrupts (not previous) #8408: pkg/fatfs: linker error when build tests/pkg_fatfs_vfs for msb430 based boards #6567: periph/spi: Switching between CPOL=0,1 problems on Kinetis with software CS #4954: chronos: compiling with -O0 breaks

Build system related issues (13)

#14504: BUILD_IN_DOCKER ignores USEMODULE #14288: pkg/ccn-lite: unable to make -j -C examples/ccn-lite-relay #14264: make: ccache leads to differing binaries #13492: make -j flash broken on esp* (will always flash the previous binary) #12771: dist/tools/cppcheck/cppchck.sh: errors when running with Cppcheck 1.89 #10850: Tracking: remove harmful use of export in make and immediate evaluation #9913: Build dependencies - processing order issues #9742: buildtest uses wrong build directory #9645: Different build behavior between murdock and riot/riotbuild:latest image #8913: make: use of immediate value of variables before they have their final value #8122: doxygen: riot.css modified by 'make doc' #6120: Windows AVR Mega development makefile Error #4053: macros: RIOT_FILE_RELATIVE printing wrong file name for headers

Other issues (41)

#14578: tests/cpp11_%: failing on i-nucleo-lrwan1 #14576: riotboot/nrf52840dk: flashing slot1 with JLINK fails #14568: tests/pkg_libfixmath_unittests: failing on multiple platforms #14548: edbg: long lines flooded over serial become garbled #14520: examples / tests: LoRa tests fail on platforms that don't support LoRa #14514: Uncrustify enforces deviation of coding convention #14466: Linking C++ #14390: gcoap: Suspected crosstalk between requests (possible NULL call) #14315: DTLS examples cannot send message to localhost #14169: Gcoap does not handle separate responses #14167: Gcoap drops long packages instead of gracefully erring out #13918: cpu/stm32f1: CPU hangs after wake-up from STOP power mode #13541: Order of auto_init functions #13345: sys/xtimer: segmentation fault: in function xtimer_msg_received_timeout #13285: Bug: openocd 0.10.0-6 Ubuntu dies while debugging with -rtos auto #13277: Y2038 tracking issue / strategy #13133: tests/pkg_tensorflow-lite: tests randomly failing on nrf52dk and esp32-wroom-32 #13120: tests: broken with stdio_rtt if auto_init is disabled #13044: _NVIC_SystemReset stuck in infinite loop when calling pm_reboot through shell after flashing with J-Link #12897: Can't build relic with benchmarks or tests #12889: CC2538DK board docs: broken links #12732: tests: some tests don't work with newlib lock functions. #12621: Potential race condition in compile_and_test_for_board.py #12108: make term output is inconsistent between boards, ethos and native #12105: [TRACKING] sys/shell refactoring. #11243: sys/riotboot: documentation issues #10751: Possible memset optimized out in crypto code #10731: nanocoap: incomplete response to /.well-known/core request #10639: sys/stdio_uart: dropped data when received at once #10121: RIOT cannot compile with the latest version of macOS (10.14) and Xcode 10 #9882: sys/tsrb is not thread safe #9518: periph/i2c: tracking bugs and untested acks #9371: assert: c99 static_assert macro doesn't function for multiple static_asserts in the same scope #7365: scheduler: priority inversion problem #7220: sys/fmt: Missing tests for fmt_float, fmt_lpad #6533: tests/lwip target board for python test is hardcoded to native #5009: RIOT is saw-toothing in energy consumption (even when idling) #4866: periph: GPIO drivers are not thread safe #4488: Making the newlib thread-safe #3256: make: Setting constants on compile time doesn't really set them everywhere #2346: Tracker: Reduce scope on unintended COMMON variables

There are 150 known issues in this release

Fixed Issues since the last release (2020.04)

#14521: tests/test_tools: fails on iotlab-m3 due to core/cpu regression #14415: Flashing nrf52dk with bmp breaks board #14409: doc/search: hitting return while searching on api.riot-os.org reloads current page #14407: gnrc/RPL: instance ID not updated on reconnect #14399: cord_ep example timed out when registering to a resource directory #14380: dist/tools/flatc: cloning of the tool sporadically fails on the CI #14361: Bug : bad assertion in cpu/stm32/periph/pwm.c #14330: Improve driver implementation documentation #14328: sam0_common: make debug broken for boards using EDBG #14184: Part of puts/printf output is skipped #14164: Failed assertion when using netdev_ieee802154_mr_fsk #14158: kconfig is broken on case-insensitive file systems #14074: Memory read beyond input buffer boundaries in nanocoap packet parser #14035: I can't use w5100 to work on Release-2020.04 by using RIOT/examples/emcute_mqttsn/. #14034: gcoap server breaks or becomes very unresponsive (sock_async related?) #13984: tests/pkg_ubasic: failing on esp32-wroom-32 #13920: stm32: ztimer RTT backend overflow #13838: Global Address remains in state TNT[3] forever #13834: DHCPv6 client ends up in busy loop after a while #13419: Can't use nimble as prefix for modules #13209: examples/gnrc_border_router is crashing after some time #12909: Bug: Unexpected behavior with xtimer_periodic_wakeup() for large periods on Nucleo-f401re #12858: KW2XRF: Broken network communication without netstats-l2 #12205: core: atomic: Unable to compile starting with gcc 9.1.0 #11859: examples: dtls-echo fails silently when DTLS_ECC flag enabled #11795: gnrc_tftp: string functions on non-null terminated input #11523: xtimer_periodic_wakeup crashing at high frequencies on frdm-kw41z #11472: Warnings from objcopy and size (binutils 2.32) #11388: SD card initialization: timeouts effectively blocking #11212: POSIX sockets + lwIP: bad file descriptor #11149: xtimer: hang on xtimer_spin_until (corner case) #10367: sam0.inc.mk: Did not find a device with serial ATML21xxxxxxxx #8589: Why using -F in avrdude? #8436: Kinetis PhyNode: failed to flash binary > 256K #8172: gnrc_netif, gnrc_uhcpc: Replacing prefix on border router results in no configured prefix #8086: gnrc_rpl_p2p: port to nib and fix compile errors #8045: stm32/periph/uart: extra byte transmitted on first transmission #7753: pic32-wifire: race-condition when linking in concurrent build #5775: cpu: cortex-m: compiling vectors.c with LTO triggers compiler bug #5774: cpu: cortexm_common: context switching code breaks when compiling with LTO #5769: Possible problem in scheduler #5748: gnrc: nodes crashing with too small packet buffer

42 fixed issues since last release (2020.04)

Acknowledgements

We would like to thank all companies that provided us with hardware for porting and testing RIOT-OS. 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

Mailing lists

• RIOT OS kernel developers list devel@riot-os.org (http://lists.riot-os.org/mailman/listinfo/devel)
• RIOT OS users list users@riot-os.org (http://lists.riot-os.org/mailman/listinfo/users)
• RIOT commits commits@riot-os.org (http://lists.riot-os.org/mailman/listinfo/commits)
• Github notifications notifications@riot-os.org (http://lists.riot-os.org/mailman/listinfo/notifications)

IRC

• Join the RIOT IRC channel at: irc.freenode.net, #riot-os

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.