www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.announce - Update to Bare Metal STM32F4 (ARM Cortex-M4) LCD Demo Proof of Concept

reply Mike <none none.com> writes:
A few years ago I created a bare metal demo on an ARM Cortex-M4 
microcontroller entirely in D.  It was just a demonstration that 
one could do bare metal programming for microcontrollers in D 
without any dependencies on C or assembly.  It was also a proof 
of some ideas I had about leveraging compile-time features of D 
to generate highly-optimized code (both small and fast) for these 
resource constrained systems.  I hit a wall, however, with Issue 
14758[0], and ultimately abandoned D for other alternatives.

Well, that issue was recently fixed in GDC [1].  In addition, he 
GDC developers did some work to reduce the number of phony stubs 
one had to add to the runtime to get a build [2], removed the 
"shared is volatile" hack, and implemented the 
`volatileLoad/Store` intrinsics so I no longer need to do 
volatile access in assembly.  So, I decided to give it another 
try, and updated that demo. You can see the results at 
https://github.com/JinShil/stm32f42_discovery_demo

A few observations:
* It is a better experience than it was a few years ago.  Fewer 
dirty hacks are required, and the resulting binary is small and 
fast.
* Everything is in D (inline assembly is D).  There's no need for 
any C or assembly startup code, and no need for silly things like 
-betterC (i.e. -worseD).  If you don't want the overhead from a 
feature of D, don't use it.
* Compile times are quite slow (about 1 minute to get a 3kB 
binary).  Some discussion about that is taking place on the GDC 
forum [4].
* -O2 and -O3 give me a broken binary, but -O0, -O1, and -Os work 
well.

I'm not sure where I'll go from here.  I'm interested in helping 
an amputee play the drums again, and building my own mechanical 
keyboard, so I probably won't be spending much more time on this 
LCD demo, except maybe to help compiler devs debug some issues.  
However, I might spend some more time with D in the near future, 
and see how far I can take this.  I'm still not as excited as I 
once was, but it's nice to see these improvements.

Anyway, Well done, GDC!

Mike

[0] - TypeInfo causes excessive binary bloat - 
https://issues.dlang.org/show_bug.cgi?id=14758
[1] - Put the TypeInfo name field into a static var - 
https://github.com/D-Programming-GDC/GDC/pull/505
[2] - Refactor and reformat typeinfo.cc - 
https://github.com/D-Programming-GDC/GDC/pull/456
[3] - Slow compile-time discussion at GDC forum - 
http://forum.dlang.org/post/iqryqssxooypdnszmzmg forum.dlang.org
Jul 20
next sibling parent reply Mr.D <4d.eniz.zz gmail.com> writes:
Thanks for your work with bare metal MCUs! I am dreaming that 
someday I can program smart house IoT automation on D.
Jul 20
parent reply Mike <none none.com> writes:
On Thursday, 20 July 2017 at 17:09:40 UTC, Mr.D wrote:
 Thanks for your work with bare metal MCUs! I am dreaming that 
 someday I can program smart house IoT automation on D.
You already can; it just may not be the most professional experience. If you have the hardware and the time, do it! Mike
Jul 20
next sibling parent Andrey <avraliov gmail.com> writes:
On Friday, 21 July 2017 at 00:27:09 UTC, Mike wrote:
 On Thursday, 20 July 2017 at 17:09:40 UTC, Mr.D wrote:
 Thanks for your work with bare metal MCUs! I am dreaming that 
 someday I can program smart house IoT automation on D.
You already can; it just may not be the most professional experience. If you have the hardware and the time, do it! Mike
Thanks for your work!!!!
Jul 20
prev sibling parent Mr.D <4d.eniz.zz gmail.com> writes:
On Friday, 21 July 2017 at 00:27:09 UTC, Mike wrote:
 On Thursday, 20 July 2017 at 17:09:40 UTC, Mr.D wrote:
 Thanks for your work with bare metal MCUs! I am dreaming that 
 someday I can program smart house IoT automation on D.
You already can; it just may not be the most professional experience. If you have the hardware and the time, do it! Mike
I am stopped by the lack of a system library for work with GPIO, PWM etc specific MCU things.
Jul 21
prev sibling next sibling parent reply Andrea Fontana <nospam example.com> writes:
On Thursday, 20 July 2017 at 12:23:31 UTC, Mike wrote:
 A few years ago I created a bare metal demo on an ARM Cortex-M4 
 microcontroller entirely in D.  It was just a demonstration 
 that one could do bare metal programming for microcontrollers 
 in D without any dependencies on C or assembly.  It was also a 
 proof of some ideas I had about leveraging compile-time 
 features of D to generate highly-optimized code (both small and 
 fast) for these resource constrained systems.  I hit a wall, 
 however, with Issue 14758[0], and ultimately abandoned D for 
 other alternatives.
It has a lot of potential. I always hope that someone will start a 3d Printer firmware written in D for a 32bit microcontroller.
Jul 21
next sibling parent aberba <karabutaworld gmail.com> writes:
On Friday, 21 July 2017 at 07:40:20 UTC, Andrea Fontana wrote:
 On Thursday, 20 July 2017 at 12:23:31 UTC, Mike wrote:
 A few years ago I created a bare metal demo on an ARM 
 Cortex-M4 microcontroller entirely in D.  It was just a 
 demonstration that one could do bare metal programming for 
 microcontrollers in D without any dependencies on C or 
 assembly.  It was also a proof of some ideas I had about 
 leveraging compile-time features of D to generate 
 highly-optimized code (both small and fast) for these resource 
 constrained systems.  I hit a wall, however, with Issue 
 14758[0], and ultimately abandoned D for other alternatives.
It has a lot of potential. I always hope that someone will start a 3d Printer firmware written in D for a 32bit microcontroller.
Can't wait to see that day
Jul 21
prev sibling parent reply =?UTF-8?Q?S=c3=b6nke_Ludwig?= <sludwig+d outerproduct.org> writes:
Am 21.07.2017 um 09:40 schrieb Andrea Fontana:
 It has a lot of potential. I always hope that someone will start a 3d
 Printer firmware written in D for a 32bit microcontroller.
I've actually started to implement a GCode processor in D a while ago, because I was unsatisfied with the open source firmwares that exist. It's more tailored towards CNC routers, but since those are pretty similar that shouldn't be a big problem. The bad news is that I don't have time to work on it anymore and it was still at a relatively early stage.
Jul 22
parent Andrea Fontana <nospam example.com> writes:
On Saturday, 22 July 2017 at 18:51:34 UTC, Sönke Ludwig wrote:
 Am 21.07.2017 um 09:40 schrieb Andrea Fontana:
 It has a lot of potential. I always hope that someone will 
 start a 3d
 Printer firmware written in D for a 32bit microcontroller.
I've actually started to implement a GCode processor in D a while ago, because I was unsatisfied with the open source firmwares that exist. It's more tailored towards CNC routers, but since those are pretty similar that shouldn't be a big problem. The bad news is that I don't have time to work on it anymore and it was still at a relatively early stage.
D for programming + Vibe for web/mobile interface + Mir for math would be a win for a 3d printer firmware. Using templates and component programming should fit perfectly a generic-composable firmware for printers. (check delta vs cartesian vs corexy + different stepper drivers + different motors + different boards + ...)
Jul 27
prev sibling next sibling parent Mike <none none.com> writes:
On Thursday, 20 July 2017 at 12:23:31 UTC, Mike wrote:

 * -O2 and -O3 give me a broken binary, but -O0, -O1, and -Os 
 work well.
Turned out to be a problem in my code, not with the compiler. All optimiziation options work well. Mike
Jul 22
prev sibling parent Laeeth Isharc <laeeth nospam.kaleidic.io> writes:
On Thursday, 20 July 2017 at 12:23:31 UTC, Mike wrote:
 A few years ago I created a bare metal demo on an ARM Cortex-M4 
 microcontroller entirely in D.  It was just a demonstration 
 that one could do bare metal programming for microcontrollers 
 in D without any dependencies on C or assembly.  It was also a 
 proof of some ideas I had about leveraging compile-time 
 features of D to generate highly-optimized code (both small and 
 fast) for these resource constrained systems.  I hit a wall, 
 however, with Issue 14758[0], and ultimately abandoned D for 
 other alternatives.

 Well, that issue was recently fixed in GDC [1].  In addition, 
 he GDC developers did some work to reduce the number of phony 
 stubs one had to add to the runtime to get a build [2], removed 
 the "shared is volatile" hack, and implemented the 
 `volatileLoad/Store` intrinsics so I no longer need to do 
 volatile access in assembly.  So, I decided to give it another 
 try, and updated that demo. You can see the results at 
 https://github.com/JinShil/stm32f42_discovery_demo
Congratulations, Mike. https://www.reddit.com/r/programming/comments/6pn31c/d_on_bare_metal_stm32f4_redux/ Could someone post to Hacker News? I don't have enough rep for it to propagate.
Jul 26