Release-2023.04

RIOT-2023.04 - 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 2023.04 release includes:

• Mass Storage Class Support in USBUS
• Initial support for libSCHC
• FlashDB support
• BLE downlink in GNRC Border Router
• DTLS support for nanoCoAP in client mode
• Congestion control for 6LoWPAN Selective Fragment Recovery
• avr/flash_utils: strings (and other const data) no longer needs to be copied
  to RAM
• New boards:
  • esp32c3-wemos-mini
  • esp32s2-lilygo-ttgo-t8
  • esp32s2-wemos-mini
  • esp32s3-pros3
  • rpi-pico-w
  • sipeed-longan-nano
• New device drivers:
  • Black/white e-Paper/e-Ink display
  • RFID reader (MFRC522)
  • ST VL53L1X Time-of-Flight sensor

280 pull requests, composed of 595 commits, have been merged since the
last release, and 3 issues have been solved. 27 people contributed with
code in 83 days. 1246 files have been touched with 177090 (+) insertions and
36429 deletions (-).

Notations used below

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

New features and changes

Core

• core/compiler_hints: add likely() / unlikely() hints (#19156)

• core/xfa: disable asan on llvm (#19271)
• pkg/libfixmath: bump version (#19182)

System Libraries

• drivers/wdt: add periph_wdt_auto_start for early watchdog (#18257)
• fuzzing: Add uri_parser setup (#19057)
• Revert "sys/pm_layered: pm_(un)block add attribute optimize(3)" (#19155)
• sys/coding: add XOR based coding module (#17045)
• sys/event: add event sources (#18758)
• sys/irq: Add C++ wrapper using RAII (#17066)
• sys/phydat: add functions for Unix time conversion to phydat (#19080)
• sys/trickle: cleanup deps (#19404)
• sys/vfs: add force option to vfs_umount() (#19320)
• usbus/msc: add CONFIG_USBUS_MSC_AUTO_MTD option to create LUNs on
  init (#19356)
• usbus/msc: add initial Mass Storage Class support (#19242)
• USBUS: Add URB support (#17091)
• ztimer: add ztimer_stopwatch convenience functions (#19343)

• bootloaders: fix bootloader button logic (#19365)
• makefiles/suit: make it possible to accept multiple SUIT keys (#18459)
• sys/bitfield: don't touch unrelated bits in bf_{set, clear}_all() (#19400)
• sys/cpp11-compat: Remove xtimer deps (#19369)
• sys/fmt: optimize scn_u32_dec scn_u32_hex (#19027)
• sys/fmt: use fflush(); stdio_write() instead of fwrite() (#19250)
• sys/shell_lock: do not call strlen, less jumpy (#19157)
• sys/tiny_strerror: make use of flash_utils.h (#19332)
• test_utils/print_stack_usage: use thread.h API (#19226)
• usbus/dfu: do not create alt interface if NUM_SLOTS=1 (#19386)

Networking

• gcoap/fileserver: add event callbacks (#18414)
• gnrc_sixlowpan_frag_sfr_congure: optional congestion control support
  (#16171, #16159, #16170, #16158)
• gnrc_static: add static network configuration (#18477)
• nanocoap_link_format: add helper function to parse Link Format (#18134)
• pkg/tinyusb: add tinyUSB netdev driver (#18903)

• cord: bump reference from draft to rfc (#19367)
• cord: convert to ztimer (#19391)
• gnrc_ipv6_nib: clean up _resolve_addr() (#18939)
• nanocoap_sock: ensure response address is the same as request address (#19361)
• nanocoap_sock: implement DTLS socket (#18724)
• nanocoap_sock: implement nanocoap_sock_delete() (#18738)
• nanocoap_sock: store message ID in nanocoap_sock_t (#19178)
• pkg/tinydtls: Reduce default verbosity, increase default sizes when CoAP is
  used (#19331)
• shell/cmds: GNRC: replace puts() with printf() (#19327)
• shell/gnrc_icmpv6_echo: separate ICMPv6 echo sending / parsing from
  shell command (#18934)
• sock_dtls: move common code into sock_dtls_establish_session() (#19142)
• sys/net/gnrc/netif: fixing no global address wait (#19402)
• sys/net/grnc/netreg: avoid creating an infinite loop (#19238)

Packages

• libschc: initial import as package (#18515)
• pkg/arduino_adafruit_sensor: add Adafruit Unified Sensor Driver as
  package (#17460)
• pkg/wolfssl: Update wolfSSL to 5.5.4 and add DTLS 1.3 support (#19302)
• pkg: add FlashDB (#17612)

• pkg/fatfs: bump to r0.15 (#19347)
• pkg/lz4: bump version to 1.9.4 (#19180)
• pkg/minmea: bump version (#19183)
• pkg/nanopb: bump version to 0.4.7 (#19179)
• pkg/tinydtls: bump version (#19184)
• pkg/tinydtls: drop libc_gettimeofday dependency (#19247)
• pkg/tinyusb: bump to 0.15 (#19276)
• pkg/u8g2: bump version (#19285)
• pkg/wolfssl: Fix memory leaks in wolfSSL sock_tls (#19190)
• tests/pkg_nanors: use static allocation (#19382)

• pkg/tinyusb: add GD32VF103 support (#19256)
• pkg/lwext4: add lightweight implementation of the ext2/3/4 filesystem (#18682)

Boards

• boards/esp32c3-wemos-mini: add support for Wemos ESP32-C3 mini (#19417)
• boards/esp32s2-mini: add definition for ESP32 S2 Mini (#18863)
• boards/nucleo64: Add pinout diagrams from UM1724 (#19406)
• boards/seeedstudio-gd32: add mtd_sdcard_default (#19293)
• boards/seeedstudio-gd32: complete and improve board definition (#19166)
• boards/sipeed-longan-nano: add BOOT as user button (#19419)
• boards/sipeed-longan-nano: add definition for the Sipeed Longan Nano
  GD32VF103 board (#19170)
• boards: add esp32s3-pros3 support (#19088)
• boards: support for the LILYGO TTGO T8 ESP32-S2 board (#19284)
• cpu/native: implement periph_rtc_ms (#19340)
• drivers/mrf24j40: add support for IEEE 802.15.4 Radio HAL (#18472)
• drivers/mtd_sdcard: add mtd_sdcard_default module (#19216)
• makefiles/tools/serial.inc.mk: Allow detection of debug adapter (#19119)

• boards/adafruit-itsybitsy-m4: turn off APA102 LED on startup (#19357)
• boards/esp*: complete SD Card MTD config (#19255)
• boards/esp32: enable RGB LED support (#19408)
• boards/gd32v: improve board definitions (#19249)
• boards/rpi-pico-w: fix too large board image (#19159)
• boards/rpi-pico-w: initial support for rpi pico W board (#19071)
• boards/sipeed-longan-nano: default to flashing via DFU (#19204)
• boards/stm32f4discovery: default to stdio via CDC ACM (#19259)
• boards: common: stdio_cdc_acm: let tests wait a bit for serial port (#19128)
• cpu/rpx0xx/cmsis: Update vendor header files (#19416)

CPU

• bootloaders/riotboot: add tinyUSB DFU support (#19010)
• core/init: add early_init() (#19082)
• cpu/esp32: add periph_flashpage support (#19079)
• cpu/gd32v: add periph_adc support (#19188)
• cpu/gd32v: add periph_dac support (#19248)
• cpu/gd32v: add periph_gpio_irq support (#19185)
• cpu/gd32v: add periph_gpio_ll and periph_gpio_ll_irq support (#19243)
• cpu/gd32v: add periph_i2c support (#19201)
• cpu/gd32v: add periph_pwm support (#19209)
• cpu/gd32v: add periph_rtc support (#19186)
• cpu/gd32v: add periph_rtc_mem support (#19254)
• cpu/gd32v: add periph_rtt support (#19202)
• cpu/gd32v: add periph_spi support (#19214)
• cpu/gd32v: add pm_layered support in periph_pm (#19187)
• cpu/stm32/periph: Add GPIO LL IRQ support for STM32F1 (#19412)
• cpu/stm32/periph: Implement GPIO LL for STM32F1 without IRQ support
  (yet) (#19407)
• picolibc: add support for picolibc >= 1.8 (#19341)
• sys/stdio_udp: add stdio over UDP (#19081)

• cpu/esp32: cleanup of ESP-IDF interface API (module esp_idf_api) (#19426)
• cpu/esp_common: use generic WIFI_SSID/WIFI_PASS defines (#19286)
• cpu/gd32v/periph_i2c: interrupt based driver (#19269)
• cpu/native: Switch to ztimer for gettimeofday (#19349)
• cpu/riscv_common: convert to uword_t usage (#19345)
• cpu/sam0_common: adc: implement 16 bit mode by oversampling (#19165)
• cpu/stm32/periph/i2c: export PERIPH_I2C_MAX_BYTES_PER_FRAME (#19279)
• cpu/stm32/periph/timer: don't stop counter (#19263)
• cpu/stm32/periph/timer: fix clobered IRQ flag (#19385)
• cpu/stm32/usbdev_fs: fix ep registration and EP_REG assignments
  [backport 2023.04] (#19462)
• drivers/at24cxxx: implement _mtd_at24cxxx_read_page (#19270)
• Fix stm32 timer periodic (#19363)
• sam0/usbdev: partial revert of #17086 (#19384)
• sys/usbus: check for the number of required and provided EPs in
  static configurations (#19371)

Device Drivers

• black/white e-Paper/e-Ink display driver (#12509)
• drivers/mfrc522: add new driver (#16782)
• drivers/servo: reimplement with high level interface (#18392)
• drivers/usbdev_synopsys_dwc2: add ESP32x power management (#19399)
• drivers: add driver for ST VL6180X ranging and ambient light sensor (#10462)

• drivers/at24cxxx: merge mtd driver with at24cxxx.c (#19281)
• drivers/periph_common/flashpage: fix silent error (#19175)
• drivers/slipdev: implement sleep states (#17810)
• drivers/ws281x: improve timing for ESP32x (#19422)

• drivers/ws281x: add RMT hardware support for ESP32x SoCs (#19424)

Documentation

• doc: Add out of tree RIOT app documentation (#19324)

• blobs: include documentation in doxygen (#19200)
• doc/porting-boards.md: fix code snippets in md view (#19206)
• Doc: document generate-makefile.ci (#19239)
• doccheck: avoid generating dot or html (#19228)

Build System / Tooling

• tools/compile_like_murdock: Add features (#19351)
• tools/doccheck: add simple exclude to doccheck (#19240)
• tools/renode: add support for target reset (#19375)

• build system: Fix linker feature test with newlib 4.3.0 (#19232)
• ci/print_versions: print all ESP32 toolchains (#19309)
• dist/tools/doccheck: Fix grep warning (#19220)
• dist/tools/insufficient_memory: Improve and clean up script (#19291)
• esptools/install.sh: Fix shellcheck issues (#19325)
• Fix compile_like_murdock.py when board is empty (#19370)
• make: pass make jobserver to cargo (#19203)
• Makefile.dep: pull in FEATURES_REQUIRED for periph (#19234)
• toolchain/gnu.inc.mk: don't check version if CC is not installed (#19137)

Kconfig

• drivers/sx126x: make MODULE_SX126X_RF_SWITCH hidden in kconfig (#19194)
• Fix SX126X-STM32WL module in Kconfig (#19191)

Examples

• examples/gnrc_border_router: add BLE as downlink option (#19321)

Testing

• bors.yaml: re-activate labels check + add block_labels (#19161)
• CI: re-add "synchronize" event to check-labels (#19136)
• gh-actions: report release-tests result to Matrix (#19102)

• CI: .murdock: fix bors fast build (#19241)
• CI: .murdock: use build checkout for ccache tmp (#19274)
• CI: separate check-labels and check-commits workflows (#19120)
• CI: update check-labels-action (#19101)
• test/periph_rtc: reset struct tm time between tests (#19344)
• tests/gnrc_rpl: Disable CI test for native (#19171)
• tests/periph_flashpage_unittest: enable periph_flashpage (#19215)

API Changes

• usbdev: Add dedicated stall functions (#17086)

• drivers/mtd_flashpage: implement pagewise API, don't use raw
  addresses (#19258)
• gcoap: Finish the gcoap_get_resource_list_tl ->
  gcoap_get_resource_list renaming (#19295)

• drivers/servo: reimplement with high level interface (#18392)

• cpu/esp_common: use generic WIFI_SSID/WIFI_PASS defines (#19286)

• sys/vfs: add force option to vfs_umount() (#19320)

Uncategorized

• MAINTAINING.md: add some notes on Bors (#19329)
• RDM: The 802.15.4 Radio HAL (#13943)

• SECURITY: Describe that declassification is an option (#19149)
• SUBSYSTEMS.md: migrate subsystem list from wiki (#19060)

And 57 minor changes.

Bug fixes (53)

• boards/common: add common timer config for GD32VF103 boards (#19205)
• cpu/esp_common: Add missing disconnect reasons (#19381)
• Make: Add generate-Makefile.ci (#19244)
• usbus: Add support for full speed with high speed phy (#19438)
• boards/common/cc26xx cc13xx: clean up and fix flash configs (#19050)
• boards/esp32s2-lilygo-ttgo-t8: fix STDIO selection in Kconfig (#19287)
• boards/remote-*: drop custom led_init() (#19348)
• boards/seeedstudio-gd32: fix HXTAL clock in Kconfig (#19129)
• boards/stm32f4discovery: use default port to access stdio via cdc acm (#19376)
• boards: fix USB configuration for stm32f429i-disco (#19437)
• cord: include gcoap_req_send returning 0 in error (#19383)
• cpu/esp32: fix and improve UART initialization (#19146)
• cpu/esp32: fix stdio_usb_serial_jtag for ESP32-C3 (#19415)
• cpu/esp32: fixes for boot issues and crashes on ESP32 (#19192)
• cpu/esp32: use ets_printf instead of puts in startup (#19420)
• cpu/gd32v: fix gpio_read in periph_gpio (#19418)
• cpu/gd32v: move board dependent RTT configs to board config (#19211)
• cpu/stm32: Fix periph_spi operation in non-DMA mode (#19431)
• dist/tools/esptools/export.sh: fixes IDF_TOOLS_PATH default setting (#19125)
• dist/tools/openocd: fix problems with riotboot caused by _flash_addr
  function for OpenOCD v0.12 (#19409)
• driver/usbdev_synopsys_dwc2: use correct number of EPs (#19380)
• drivers/at86rf2xx: fix default page being ignored [backport 2023.04] (#19473)
• drivers/usbdev_synopsys_dwc2: disable DMA mode (#19388)
• drivers/usbdev_synopsys_dwc2: fix and re-enable DMA mode (#19397)
• drivers/usbus_synopsys_dwc2: fix interrupt handling in DMA mode
  [backport 2023.04] (#19472)
• efm32/dac: Shift instead of masking (#19318)
• gcoap: Do not send responses from multicast addresses (#19272)
• gh-actions: check-labels: move to upstream fix (#19160)
• gnrc_netif: set lower bound for IEEE802154_STACKSIZE_DEFAULT (#19339)
• gnrc_static: don't parse address as prefix (#19313)
• makefiles/boards/stm32: fix DFU_USB_ID handling (#19374)
• makefiles/tools/serial.inc.mk: Handle new miniterm versions [backport
  2023.04] (#19489)
• matrix keypad: Fix memcpy bug in initialization (#19162)
• nanocoap_sock: don't include token in empty ACK response (#19366)
• native/stdio: Explicitly provide getchar (#19330)
• pkg/esp8266_sdk: fix version string generation (#19123)
• pkg/nimble/autoadv: fix flag comparisons (#19235)
• pkg/tinyusb: fix default VID/PID configuration (#19377)
• release-tests: fix PASSED chat message (#19145)
• security fixes [backport 2023.04] (#19497)
• shell/gnrc_icmpv6_echo: acquire ZTIMER_USEC clock for time
  measurement (#19055)
• socket_zep: only report size of single datagram (#19121)
• sys/clif: Fixing out of bounds read under certain conditions (#18746)
• sys/net/dhcpv6: include IA Prefix Option in SOLICIT (#19225)
• sys/phydat: Fix unit confusion (#19292)
• sys/shell: don't include suit command by default (#19294)
• sys/suit: Ensure previous thread is stopped before reusing its stack (#19199)
• sys/usbus/cdc/ecm: fix High-Speed mode (#19358)
• sys/usbus: handle exceeding number of endpoints (#19362)
• sys/ztimer: ztimer_mock: guard ztimer_ondemand static functions (#19118)
• tests/driver_dac_dds: fix output of sine and saw functions (#19251)
• tests/{sys_fido2_ctap/usbus_board_reset}: fix stdio_usb_serial_jtag
  dependency (#19261)
• usbus/msc: fixes for synopsys dwc2 [backport 2023.04] (#19456)

Known issues

Network related issues (52)

• 6lo: RIOT does not receive packets from Linux when short_addr is set (#11033)
• [gcoap-dtls] Posting a message yields a stack overflow on the
  samr21-xpro with ECC (#18292)
• 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)
• CC2538 RF overlapping PIN usage (#8779)
• cpu/esp8266: Tracking open problems of esp_wifi netdev driver (#10861)
• 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 choose global source address. (#13745)
• ethos: Unable to handle fragmented IPv6 packets from Linux kernel (#12264)
• 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)
• gnrc ipv6: multicast packets are not dispatched to the upper layers (#5230)
• gnrc_border_router stops routing after a while (#16398)
• 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: 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_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)
• Possible memory leak in RIOT/build/pkg/ndn-riot/app.c (#15638)
• Riot-os freezes with lwip + enc28j60 + stm32L4 (#13088)
• samr30 xpro doesn't seem to use its radio ok (#12761)
• scan-build errors found during 2019.07 testing (#11852)
• send data with UDP at 10HZ, the program die (#11860)
• 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 (9)

• cpu/native: timer interrupt issue (#6442)
• misc issues with tests/trickle (#9052)
• MSP430: periph_timer clock config wrong (#8251)
• 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)
• Sleep mode for Arduino (#13321)
• 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 (16)

• adc is not a ADC-Driver but a analog pin abstraction (#14424)
• at86rf2xx: Simultaneous use of different transceiver types is not
  supported (#4876)
• cpu/msp430: GPIO driver doesn't work properly (#9419)
• driver/hts221: Temperature and Humidity readings incorrect (#12445)
• examples/dtls-wolfssl not working on pba-d-01-kw2x (#13527)
• fail to send data to can bus (#12371)
• floats and doubles being used all over the place. (#12045)
• 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)
• Potential security and safety race conditions on attached devices (#13444)
• 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)
• Two bugs may lead to NULL dereference. (#15006)

Native related issues (4)

• examples/micropython: floating point exception while testing on
  native (#15870)
• native getchar is blocking RIOT (#16834)
• native not float safe (#495)
• native: tlsf: early malloc will lead to a crash (#5796)

Other platforms related issues (16)

• Failing tests on FE310 (Hifive1b) (#13086)
• [TRACKING] Fixes for automatic tests of ESP32 boards. (#12763)
• boards/hifive1: flashing issue (#13104)
• Cannot use LLVM with Cortex-M boards (#13390)
• cpu/sam0: flashpage write / read cycle produces different results
  depending on code layout in flash (#14929)
• cpu/stm32f1: CPU hangs after wake-up from STOP power mode (#13918)
• 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)
• 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)
• stm32152re: hardfault when DBGMCU_CR_DBG* bits are set and branch
  after __WFI() (#14015)
• stm32f7: Large performance difference between stm32f746 and stm32f767 (#14728)
• sys/riotboot/flashwrite: unaligned write when skipping
  RIOTBOOT_MAGIC on stm32wb (#15917)

Build system related issues (11)

• buildtest uses wrong build directory (#9742)
• make -j flash fails due to missing make dependencies or make flash-only rebuilds the .elf (#16385)
• Build dependencies - processing order issues (#9913)
• build: info-build doesn't work with boards without port set (#15185)
• BUILD_IN_DOCKER ignores USEMODULE (#14504)
• dist/tools/cppcheck/cppchck.sh: errors when running with Cppcheck
  1.89 (#12771)
• doxygen: riot.css modified by 'make doc' (#8122)
• macros: RIOT_FILE_RELATIVE printing wrong file name for headers (#4053)
• make: ccache leads to differing binaries (#14264)
• make: use of immediate value of variables before they have their
  final value (#8913)
• Tracking: remove harmful use of export in make and immediate
  evaluation (#10850)

Other issues (48)

• 2023.04 release bug tracking (#19469)
• [TRACKING] sys/shell refactoring. (#12105)
• _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)
• Basic test for periph/rtt introduced in #15431 is incorrect (#15940)
• boards/esp32-wroom-32: tests/mtd_raw flakey (#16130)
• Bug: openocd 0.10.0-6 Ubuntu dies while debugging with -rtos auto (#13285)
• Can't build relic with benchmarks or tests (#12897)
• CC2538DK board docs: broken links (#12889)
• cpu/stm32/periph/rtc overflow error (#16574)
• cpu/stm32: some tests are failing on CM33 (l5, u5) (#17439)
• doc/LOSTANDFOUND: not rendered as expected (#17063)
• edbg: long lines flooded over serial become garbled (#14548)
• examples / tests: LoRa tests fail on platforms that don't support
  LoRa (#14520)
• feather-m0: make flash reports "device unsupported" (#17722)
• flashing issue on frdm-k64f (#15903)
• frdm-k22f failing tests/periph_flashpage (#17057)
• I2C not working under RIOT with U8G2 pkg (#16381)
• ieee802154_security: Nonce is reused after reboot (#16844)
• 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)
• nanocoap: incomplete response to /.well-known/core request (#10731)
• newlib-nano: Printf formatting does not work properly with "PRIu8" (#17083)
• Order of auto_init functions (#13541)
• pkg/tinydtls: Multiple issues (#16108)
• pkg_libhydrogen tests fail / update libhydrogen (#18508)
• Potential race condition in compile_and_test_for_board.py (#12621)
• RIOT is saw-toothing in energy consumption (even when idling) (#5009)
• riotboot/nrf52840dk: flashing slot1 with JLINK fails (#14576)
• riotboot: ECC faults (eg. in STM32L5 or STM32WB) not handled
  gracefully (#17874)
• rust-gcoap example is incompatible with littlefs2 (#17817)
• SPI access in LoRa-e5 and im880b? (#19025)
• stdio_ethos: infinite shell loop (#17972)
• stdio_tinyusb_cdc_acm hangs with picolibc (#19277)
• sys/riotboot: documentation issues (#11243)
• sys/stdio_uart: dropped data when received at once (#10639)
• tests/cpp11_*: failing on i-nucleo-lrwan1 (#14578)
• tests/lwip target board for python test is hardcoded to native (#6533)
• tests/periph_flashpage: failing on stm32l475ve (#17280)
• 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)
• usbus/msc: wrong error handling and behavior after usb reset (#19478)
• Use of multiple CAN bus on compatible boards (#14801)

There are 156 known issues in this release

Fixed Issues since the last release (2023.01)

• bootloader: BTN_BOOTLOADER_INVERTED doesn't work as expected. (#19364)
• Race condition in SUIT around threads terminating (#19195)
• socket_zep: fragmentation broken if destination is multicast /
  ACK_REQ not set (#19117)

3 fixed issues since last release (2023.01)

Boards tested during this release

• esp32-wroom-32 PASS
• nrf52840dk PASS
• nucleo-f429zi PASS
• samr21-xpro PASS
• arduino-mega2560 FAIL
• b-l072z-lrwan1 FAIL
• b-l475e-iot01a FAIL
• dwm1001 FAIL
• frdm-kw41z FAIL
• iotlab-m3 FAIL
• nrf52dk FAIL
• nucleo-l452re FAIL
• nucleo-wl55jc FAIL
• remote-revb FAIL
• saml10-xpro FAIL
• samr34-xpro FAIL

See the release tracking issue (#19469) for more details.

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

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.