digitalmars.D - Severin Teona - SAOC Milestone 1 Update 2 - Druntime for
- Severin Teona (64/64) Sep 30 2020 Hi all,
Hi all, This post represents the second weekly update for the first milestone for #SAoC2020. After the first week, my plan for this week was: - to build the runtime for the target architecture (ARM Cortex-M4 based MCUs), in order to have a working environment for the runtime. First, I tried compiling the runtime using the ‘ldc-build-runtime’ tool but I was using it wrong. This week: - thanks to kinke’s advice([1]) I managed to build the runtime for cortex-m4, but that came with a few questions. 1. During the installation, because I was using ‘arm-none-eabi-gcc’, I got the following messages: — The C compiler identification is GNU 9.3.1 — Detecting C compiler ABI info — Detecting C compiler ABI info - failed — Detecting C compile features — Detecting C compile features - done — The ASM compiler identification is GNU — Found assembler: /home/teona/gcc-arm-none-eabi-9-2020-q2-update/bin/arm-none-eabi-gcc — Looking for sys/types.h — Looking for sys/types.h - not found — Looking for stdint.h — Looking for stdint.h - not found — Looking for stddef.h — Looking for stddef.h - not found — Check size of void* — Check size of void* - failed — Looking for unistd.h — Looking for unistd.h - not found — Configuring done — Generating done Both the build and the linking parts were succesful, but I wanted to ask you if I should care about those messages, or if they appear because I wasn’t using ‘gcc’. 2. Also, I tried building the runtime without ‘BUILD_SHARED_LIBS=OFF’ and it failed, as it was looking for some dynamic libraries (-lpthread, -ldl, -lrt, and so on). My question here is, does abynody here know if there exists a set of dynamic libraries, compiled for this architecture? With TockOS, I’ve been using newlib([2]) as C standard library, but newlib is a static library. Would it make a big difference if I used a dynamic library? My plan for next week is: - to try to emulate a Cortex-M4 device using qemu - the biggest issue I have here is that there are just 2 Cortex-M4 based devices that can be emulated, and the resources(64KB of RAM and 256KB of flash) are way smaller than what I need (>2.5MB flash - the current size of the compiled runtime). - to try to compile and run using qemu a basic `int main() { return 0;}` application in C, in D (using -betterC), in D (linked with the compiled druntime) and finally, a bigger application that uses GC from the compiled druntime (such as using a class or string concatenation) - lastly, I will try to move and run all my work on a docker. There is a strong possibility I won’t be able to test the druntime using qemu. Do you have any advice about what should I do next? (the board I am using has only 2MB of flash). Thank you so much! [1]: https://forum.dlang.org/post/vgnlauzerzezwfrgnrkv forum.dlang.org [2]: https://sourceware.org/newlib/
Sep 30 2020
kinke <noone nowhere.com> On Wednesday, 30 September 2020 at 16:35:05 UTC, Severin Teona wrote:1. During the installation, because I was using ‘arm-none-eabi-gcc’, I got the following messages: — The C compiler identification is GNU 9.3.1 — Detecting C compiler ABI info — Detecting C compiler ABI info - failed — Detecting C compile features — Detecting C compile features - done — The ASM compiler identification is GNU — Found assembler: /home/teona/gcc-arm-none-eabi-9-2020-q2-update/bin/arm-none-eabi-gcc — Looking for sys/types.h — Looking for sys/types.h - not found — Looking for stdint.h — Looking for stdint.h - not found — Looking for stddef.h — Looking for stddef.h - not found — Check size of void* — Check size of void* - failed — Looking for unistd.h — Looking for unistd.h - not found — Configuring done — Generating done Both the build and the linking parts were succesful, but I wanted to ask you if I should care about those messages, or if they appear because I wasn’t using ‘gcc’.Seems okay for the moment, although the failing `size of void*` test certainly isn't ideal (IIRC, we make use of it in the CMake script). But no need to worry for now if things seem to be working.2. Also, I tried building the runtime without ‘BUILD_SHARED_LIBS=OFF’ and it failed, as it was looking for some dynamic libraries (-lpthread, -ldl, -lrt, and so on). My question here is, does abynody here know if there exists a set of dynamic libraries, compiled for this architecture? With TockOS, I’ve been using newlib([2]) as C standard library, but newlib is a static library. Would it make a big difference if I used a dynamic library?I strongly suggest not caring about the shared druntime/Phobos libs for now, those introduce lots of complexity, especially wrt. TLS, so focus on the static libs first (or even exclusively).My plan for next week is: - to try to emulate a Cortex-M4 device using qemu - the biggest issue I have here is that there are just 2 Cortex-M4 based devices that can be emulated, and the resources(64KB of RAM and 256KB of flash) are way smaller than what I need (>2.5MB flash - the current size of the compiled runtime).I'm definitely no qemu expert, but are you sure you can't use the generic `virt` machine via something like `-M virt -m 1024 -cpu cortex-m4`? For reference, here's what I use for emulating AArch64 (on a Windows host), giving it 3 cores and 6 GB of RAM: "C:\Program Files\qemu\qemu-system-aarch64" -M virt -m 6144 -cpu cortex-a57 -smp 3 -kernel vmlinuz -initrd initrd.img -append "root=/dev/vda1" -drive if=none,file=disk.raw,format=raw,id=hd -device virtio-blk-device,drive=hd -netdev user,id=mynet,hostfwd=tcp::2222-:22 -device virtio-net-device,netdev=mynet
Sep 30 2020
On Wednesday, 30 September 2020 at 16:35:05 UTC, Severin Teona wrote:2. Also, I tried building the runtime without ‘BUILD_SHARED_LIBS=OFF’ and it failed, as it was looking for some dynamic libraries (-lpthread, -ldl, -lrt, and so on). My question here is, does abynody here know if there exists a set of dynamic libraries, compiled for this architecture? With TockOS, I’ve been using newlib([2]) as C standard library, but newlib is a static library. Would it make a big difference if I used a dynamic library?Dynamic libraries and microcontrollers usually don't make any sense. Microcontrollers often don't have an MMU which means you don't win anything by having shared libraries. I would just skip druntime and phobos and try to use the OS API directly from D.
Sep 30 2020