D officially supported on Apache NuttX RTOS

Jun 07

Matheus Catarino

Jun 09

Sergey

Jun 09

Matheus Catarino

Jun 10

Denis Feklushkin

Jun 10

Matheus Catarino

$ qemu-system-arm -cpu cortex-a7 -nographic -M virt,virtualization=off,gic-version=2 -net none -chardev stdio,id=con,mux=on -serial chardev:con -mon chardev=con,mode=readline -kernel nuttx psci_detect: Detected PSCI v1.1 nx_start: Entry uart_register: Registering /dev/console uart_register: Registering /dev/ttyS1 work_start_highpri: Starting high-priority kernel worker thread(s) nxtask_activate: hpwork pid=1,TCB=0x4013b2d8 nx_start_application: Starting init thread task_spawn: name=nsh_main entry=0x4010b18c file_actions=0 attr=0x4013afbc argv=0x4013afb8 nxtask_activate: nsh_main pid=2,TCB=0x4013c690 lib_cxx_initialize: _sinit: 0x4012c000 _einit: 0x4012c000 NuttShell (NSH) NuttX-12.5.1 nsh> nx_start: CPU0: Beginning Idle Loop nsh> hello_d task_spawn: name=hello_d entry=0x4011e824 file_actions=0x4013d8e4 attr=0x4013d8ec argv=0x4013d980 spawn_execattrs: Setting policy=2 priority=100 for pid=3 nxtask_activate: hello_d pid=3,TCB=0x4013dd80 Hello World, [cortex-a7]! hello_d_main: Saying hello from the dynamically constructed instance DHelloWorld.HelloWorld: CONSTRUCTION FAILED! hello_d_main: Saying hello from the instance constructed on the stack DHelloWorld.HelloWorld: Hello, World!! nxtask_exit: hello_d pid=3,TCB=0x4013dd80

June 09

Re: D officially supported on Apache NuttX RTOS

Posted by Matheus Catarino
in reply to Sergey

Permalink

Matheus Catarino

Posted in reply to Sergey

Permalink

On Sunday, 9 June 2024 at 11:43:30 UTC, Sergey wrote:

D
For those who far away from embedding maybe you can add a couple of words about this system, and which applications it allows to create with D?
I suppose only betterC mode is supported, so there is no Phobos on those tiny machines?

NuttX (RTOS) is POSIX compliant. Unlike the popular FreeRTOS (task scheduler), NuttX is a more robust system, ideal for seeking a top-down view (Linux/MacOS/BSD dev).

NuttX has not only (now) integrated support for one of the D compilers into the settings (Kconfig). However, it will serve as one of the already integrated alternatives like Zig/Nim/C++/Rust.

The idea is to be able to interactive applications (CLI) from your host system (Unix-like) to NuttX without completely rewriting. It is also possible to develop GUI interfaces using LVGL or anything similar (e.g. slint-rs).

About betterC, it will not be an imposition of exclusivity. In other words, only the available example uses betterC as an initial solution.

Note that the D.defs configuration does not have a betterC flag (intentional decision).
https://github.com/apache/nuttx/blob/ce0c98f0fd24422af4f9acef1318eca9ac56efd7/tools/D.defs#L23

Hello D - Makefile
https://github.com/apache/nuttx-apps/blob/6db9d5e58235640a5419669e82bdb8c426954506/examples/hello_d/Makefile#L29

Why? Is it possible to use DRT and phobos2?

To support phobos it is necessary to adapt the DRT, especially when it involves dynamic allocation.

After Adam Ruppe's experiments to running miniDRT in Webassembly, another user choose to port an old Sega video-game Dreamcast (arch: SH4) using tinyDRT.

So, I take the opportunity to carry out some tests with the architectures available through NuttX (stm32/esp32/riscv/arm, etc...)

Note: NuttX also runs on WebAssembly!! Need tinyEMU (riscv64)

Apache NuttX RTOS in a Web Browser? Adventures with TinyEMU and VirtIO

The selling point of D that applied in the NuttX community is FFI with C and C++ (w/TMP). Less painful than trying to use cxx-rs or doing extern"C" at all!!

What prevents from porting ETLcpp (static containers) to Dlang or making an alternative solution?

For those who already develop in C++ (embedded), they constantly hear about avoiding using STL.

And for those interested in learning about NuttX, there is mentoring support for GSOC (Google Summer of Code), this year Rust was chosen (previously).

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