Zephyr building blocks
Zephyr RTOS building blocks :: Device Tree Source :: Kconfig :: cmake :: `west` manifest files
Contents
^ OVERVIEW
Local NN wiki page to hold notes on Zephyr RTOS explorations and Zephyr building blocks. These "building blocks" are worth mentioning here in overview, but this page and several related ones Ted needs to review and condense. They're not well organized yet. This disorganization is more obvious now with a greater though not complete understanding of Zephyr RTOS' architecture and chosen hardware and software paradigms. Building blocks of Zephyr worth note:
- `west` and cmake
- Device Tree Source (DTS)
- Kconfig
- Zephyr Device Drivers API
- Zephyr modules
A further post few weeks into Zephyr development, this blog post references a prior post in which setting up Zephyr build environment and project for first time is covered:
'uart_poll_in()' Zephyr peripheral library routine:
^ Zephyr In-Tree Drivers
Starting notes here with a commonly used bus peripheral and protocol driver, Zephyr's in-tree I2C driver. First link is to a specific routine for burst writes:
Note above link is Zephyr 'latest' version, a moving target, following link is version 2.6.0:
^ Zephyr Modules
Zephyr RTOS provides an interactive shell code module. This represents an advanced CLI which can be used via UART and some other physical bus interfaces:
QUESTION: how using Zephyr's sensor driver API may we read back more than a sensor_value e.g. two integers worth of data with a call to [device_name]_channel_get() API? Could this following link to device specific API extensions hold an answer?
Mention of run time mutable parts in this Zephyr documentation page:
Sensor API and sensor_value data structure in Zephyr project (release 2.6.0):
Timing Facilities
Timing and Zephyr kernel clocks, this first page however may be for a very old version of Zephyr. The 2.6.0 page is current for 2021 Q4:
- https://docs.zephyrproject.org/2.6.0/reference/timing_functions/index.html?highlight=kernel%20timing
STMicro IIS2DH sensor and SPI interface
- https://docs.zephyrproject.org/2.6.0/reference/peripherals/spi.html?highlight=spi
- https://docs.zephyrproject.org/2.6.0/reference/devicetree/bindings/sensor/st,iis2dh-spi.html?highlight=spi
^ USART references
"Hello world" example build command:
west build -b circuitdojo_feather_nrf9160ns samples/hello_world -p
Programming command:
newtmgr -c serial image upload build/zephyr/app_update.bin
In given example code directory, enable MCU bootloading with last line of following prj.conf file:
CONFIG_GPIO=y ## 2021-08-02 adding stanza per https://learn.sparkfun.com/tutorials/nrf9160-thing-plus-hookup-guide#example---blinky: CONFIG_BOOTLOADER_MCUBOOT=y
2021-10-05 Tuesday work to enable alternate USART for simple CLI:
^ LIS2DH example project build errors
Build errors when attempting to compile LIS2DH sensor example with circuitdojo board as target board:
[192/197] Linking C executable zephyr/zephyr_prebuilt.elf
Memory region Used Size Region Size %age Used
FLASH: 32 KB 48 KB 66.67%
SRAM: 5520 B 64 KB 8.42%
IDT_LIST: 40 B 2 KB 1.95%
[197/197] Linking C executable zephyr/zephyr.elf
[24/159] Building C object CMakeFiles/app.dir/src/main.c.obj
FAILED: CMakeFiles/app.dir/src/main.c.obj
ccache /opt/zephyr-sdk-0.12.4/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc -DBUILD_VERSION=v2.4.0-ncs2 -DEXT_API_MAGIC=0x281ee6de,0xb845acea,23298 -DFIRMWARE_INFO_MAGIC=0x281ee6de,0x8fcebb4c,23298 -DKERNEL -DNRF9160_XXAA -DNRF_TRUSTZONE_NONSECURE -DUSE_PARTITION_MANAGER=1 -D_FORTIFY_SOURCE=2 -D__PROGRAM_START -D__ZEPHYR__=1 -I/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include -Izephyr/include/generated -I/home/ted/projects/embedded/ncs/v1.4.1/zephyr/soc/arm/nordic_nrf/nrf91 -I/home/ted/projects/embedded/ncs/v1.4.1/nrf/include -I/home/ted/projects/embedded/ncs/v1.4.1/modules/hal/cmsis/CMSIS/Core/Include -I/home/ted/projects/embedded/ncs/v1.4.1/modules/hal/nordic/nrfx -I/home/ted/projects/embedded/ncs/v1.4.1/modules/hal/nordic/nrfx/drivers/include -I/home/ted/projects/embedded/ncs/v1.4.1/modules/hal/nordic/nrfx/mdk -I/home/ted/projects/embedded/ncs/v1.4.1/modules/hal/nordic/. -isystem /home/ted/projects/embedded/ncs/v1.4.1/zephyr/lib/libc/minimal/include -isystem /opt/zephyr-sdk-0.12.4/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/10.2.0/include -isystem /opt/zephyr-sdk-0.12.4/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/10.2.0/include-fixed -Os -imacros /home/ted/projects/embedded/ncs/v1.4.1/build/zephyr/include/generated/autoconf.h -ffreestanding -fno-common -g -mcpu=cortex-m33 -mthumb -mabi=aapcs -imacros /home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/toolchain/zephyr_stdint.h -Wall -Wformat -Wformat-security -Wno-format-zero-length -Wno-main -Wno-pointer-sign -Wpointer-arith -Wno-address-of-packed-member -Wno-unused-but-set-variable -Werror=implicit-int -fno-asynchronous-unwind-tables -fno-pie -fno-pic -fno-strict-overflow -fno-reorder-functions -fno-defer-pop -fmacro-prefix-map=/home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh=CMAKE_SOURCE_DIR -fmacro-prefix-map=/home/ted/projects/embedded/ncs/v1.4.1/zephyr=ZEPHYR_BASE -fmacro-prefix-map=/home/ted/projects/embedded/ncs/v1.4.1=WEST_TOPDIR -ffunction-sections -fdata-sections -std=c99 -nostdinc -MD -MT CMakeFiles/app.dir/src/main.c.obj -MF CMakeFiles/app.dir/src/main.c.obj.d -o CMakeFiles/app.dir/src/main.c.obj -c /home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh/src/main.c
In file included from /home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/arch/arm/aarch32/arch.h:20,
from /home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/arch/cpu.h:19,
from /home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/kernel_includes.h:38,
from /home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/kernel.h:17,
from /home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/zephyr.h:18,
from /home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh/src/main.c:8:
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh/src/main.c: In function 'main':
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:297:40: error: 'DT_N_INST_0_st_lis2dh_P_label' undeclared (first use in this function)
297 | #define DT_INST(inst, compat) UTIL_CAT(DT_N_INST, DT_DASH(inst, compat))
| ^~~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:1911:38: note: in definition of macro 'DT_CAT'
1911 | #define DT_CAT(node_id, prop_suffix) node_id##prop_suffix
| ^~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:496:27: note: in expansion of macro 'DT_PROP'
496 | #define DT_LABEL(node_id) DT_PROP(node_id, label)
| ^~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh/src/main.c:53:51: note: in expansion of macro 'DT_LABEL'
53 | const struct device *sensor = device_get_binding(DT_LABEL(DT_INST(0, st_lis2dh)));
| ^~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/sys/util_internal.h:105:26: note: in expansion of macro 'UTIL_PRIMITIVE_CAT'
105 | #define UTIL_CAT(a, ...) UTIL_PRIMITIVE_CAT(a, __VA_ARGS__)
| ^~~~~~~~~~~~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:297:31: note: in expansion of macro 'UTIL_CAT'
297 | #define DT_INST(inst, compat) UTIL_CAT(DT_N_INST, DT_DASH(inst, compat))
| ^~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh/src/main.c:53:60: note: in expansion of macro 'DT_INST'
53 | const struct device *sensor = device_get_binding(DT_LABEL(DT_INST(0, st_lis2dh)));
| ^~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:297:40: note: each undeclared identifier is reported only once for each function it appears in
297 | #define DT_INST(inst, compat) UTIL_CAT(DT_N_INST, DT_DASH(inst, compat))
| ^~~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:1911:38: note: in definition of macro 'DT_CAT'
1911 | #define DT_CAT(node_id, prop_suffix) node_id##prop_suffix
| ^~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:496:27: note: in expansion of macro 'DT_PROP'
496 | #define DT_LABEL(node_id) DT_PROP(node_id, label)
| ^~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh/src/main.c:53:51: note: in expansion of macro 'DT_LABEL'
53 | const struct device *sensor = device_get_binding(DT_LABEL(DT_INST(0, st_lis2dh)));
| ^~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/sys/util_internal.h:105:26: note: in expansion of macro 'UTIL_PRIMITIVE_CAT'
105 | #define UTIL_CAT(a, ...) UTIL_PRIMITIVE_CAT(a, __VA_ARGS__)
| ^~~~~~~~~~~~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/include/devicetree.h:297:31: note: in expansion of macro 'UTIL_CAT'
297 | #define DT_INST(inst, compat) UTIL_CAT(DT_N_INST, DT_DASH(inst, compat))
| ^~~~~~~~
/home/ted/projects/embedded/ncs/v1.4.1/zephyr/samples/sensor/lis2dh/src/main.c:53:60: note: in expansion of macro 'DT_INST'
53 | const struct device *sensor = device_get_binding(DT_LABEL(DT_INST(0, st_lis2dh)));
| ^~~~~~~
[29/159] Building C object zephyr/CMakeFiles/zephyr.dir/lib/os/onoff.c.obj
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: /usr/bin/cmake --build /home/ted/projects/embedded/ncs/v1.4.1/build
ted@localhost:~/projects/embedded/ncs/v1.4.1$
Search for DT_N_INST:
ted@indulkana:~/projects/embedded/ncs/v1.4.1$ grep -nr 'DT_N_INST[^_]' ./* ./zephyr/include/devicetree.h:297:#define DT_INST(inst, compat) UTIL_CAT(DT_N_INST, DT_DASH(inst, compat)) ./zephyr/include/devicetree.h:1245: UTIL_CAT(DT_N_INST, DT_DASH(compat, NUM_OKAY)))
^ LIS2DH example code
ted@localhost:~/projects/embedded/ncs/v1.4.1$ grep -nr st_lis2dh ./* ./zephyr/drivers/sensor/lis2dh/lis2dh_spi.c:11:#define DT_DRV_COMPAT st_lis2dh ./zephyr/drivers/sensor/lis2dh/lis2dh_i2c.c:11:#define DT_DRV_COMPAT st_lis2dh ./zephyr/drivers/sensor/lis2dh/lis2dh_trigger.c:7:#define DT_DRV_COMPAT st_lis2dh ./zephyr/drivers/sensor/lis2dh/lis2dh.c:7:#define DT_DRV_COMPAT st_lis2dh ./zephyr/samples/shields/x_nucleo_iks01a2/src/main.c:22: const struct device *lsm303agr_a = device_get_binding(DT_LABEL(DT_INST(0, st_lis2dh))); ./zephyr/samples/sensor/lsm303dlhc/src/main.c:42: DT_LABEL(DT_INST(0, st_lis2dh))); ./zephyr/samples/sensor/lsm303dlhc/src/main.c:48: DT_LABEL(DT_INST(0, st_lis2dh))); Binary file ./zephyr/samples/sensor/lis2dh/src/.main.c.swp matches ./zephyr/samples/sensor/lis2dh/src/main.c:53: const struct device *sensor = device_get_binding(DT_LABEL(DT_INST(0, st_lis2dh))); ./zephyr/samples/sensor/lis2dh/src/main.c:57: DT_LABEL(DT_INST(0, st_lis2dh)));
^ Setting Up Revisit
This link from Zephyr's documentation home page / home site a good and detailed overview of the Zephyr RTOS project:
Detailed steps to install Zephyr's needed build tools and Zephyr SDK:
Board support for CircuitDojo nRF9160 Thing Plus is not available in either Nordic's ncs v1.4.1 SDK nor Zephyr's SDK which comes as part of Zephyr 2.6.0. Steps to locating an SDK which include board support and files for the Thing Plus include navigating the following URLs:
-
(1) https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/boards/index.html#boards
(2) https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/boards/arm/sparkfun_thing_plus_nrf9160/doc/index.html
(3) https://docs.jaredwolff.com/nrf9160-getting-started.html
(4) https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/guides/tools/nordic_segger.html#nordic-segger
(5) https://github.com/nrfconnect/sdk-zephyr/blob/master/boards/arm/sparkfun_thing_plus_nrf9160/sparkfun_thing_plus_nrf9160_common.dts
Link (3) Jared Wolff does not spell out nor provide a direct link to an SDK supporting the nRF9160 Thing Plus.
Findings: Ok, Zephyr project's SDK, largely the firmware projects under the 'samples' directory contains support for CircuitDojo nRF9160 Thing Plus. This SDK however lacks the mcuboot option firmware build step and piece, so none of the Zephyr SDKs will build in a manner in which utility newtmgr can be used to program given target board.
^ References
A useful C language facet tutorial, "Complex C Declarations" and untangling complex C declarations by one Brian Barto. This link present elsewhere on Neela Nurseries wiki given that this tutorial is so helpful:
./zephyr/doc/guides/dts/howtos.rst:710: #define I2C_DEV_INST DT_INST(0, vnd_i2c_device) ./zephyr/doc/guides/dts/howtos.rst:735: #define SPI_DEV_INST DT_INST(0, vnd_spi_device) # nRF91 Series > nRF9160 > Production Programming > Updating the modem # https://developer.arm.com/ip-products/processors/cortex-m/cortex-m33
Rohm Kionix header files:
