[FR] Raspberry Pi support

[maxcpaladin]

[READ] For Firebase Unity SDK question, please report to Firebase Unity Sample

Once you've read this section and determined that your issue is appropriate for this repository, please delete this section.

[REQUIRED] Please fill in the following fields:

• Pre-built SDK from the website or open-source from this repo: _____
• Firebase C++ SDK version: main
• Main Firebase Components in concern: Database (Auth, Database, etc.)
• Other Firebase Components in use: _____ (Auth, Database, etc.)
• Platform you are using the C++ SDK on: Arm Linux (raspberry Pi) (Mac, Windows, or Linux)
• Platform you are targeting: raspberry Pi (iOS, Android, and/or desktop)

[REQUIRED] Please describe the question here:

Hi, I am trying to access database from raspberry pi running Linux (Armv7l). Can some one provide guide what changes need to be made for the c++ api to work on that?

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[maxcpaladin]

And to further describe my encounter question: when running the test_linux.sh on the raspberry pi, I encounter the following error:

/usr/bin/ld: CMakeFiles/firebase_app_scheduler_test.dir/scheduler_test.cc.o: in function `firebase::compat::Atomic<unsigned long long>::fetch_sub(unsigned long long)':
scheduler_test.cc:(.text._ZN8firebase6compat6AtomicIyE9fetch_subEy[_ZN8firebase6compat6AtomicIyE9fetch_subEy]+0x40): undefined reference to `__atomic_fetch_sub_8'
/usr/bin/ld: ../libfirebase_app.a(scheduler.cc.o): in function `firebase::compat::Atomic<unsigned long long>::fetch_add(unsigned long long)':
scheduler.cc:(.text._ZN8firebase6compat6AtomicIyE9fetch_addEy[_ZN8firebase6compat6AtomicIyE9fetch_addEy]+0x40): undefined reference to `__atomic_fetch_add_8'
/usr/bin/ld: ../libfirebase_app.a(scheduler.cc.o): in function `firebase::compat::Atomic<unsigned long long>::store(unsigned long long)':
scheduler.cc:(.text._ZN8firebase6compat6AtomicIyE5storeEy[_ZN8firebase6compat6AtomicIyE5storeEy]+0x50): undefined reference to `__atomic_store_8'
collect2: error: ld returned 1 exit status
gmake[2]: *** [app/tests/CMakeFiles/firebase_app_scheduler_test.dir/build.make:109: app/tests/firebase_app_scheduler_test] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:8684: app/tests/CMakeFiles/firebase_app_scheduler_test.dir/all] Error 2
gmake[1]: *** Waiting for unfinished jobs....

Seems to be an issue with lib atomic. Any suggestions on how to fix this?

[AlmostMatt]

I think this may be an issue that current build configurations for linux only support x86 and x64 architectures. It is theoretically possible, but it is not clear what would be needed to support linux arm architectures.

[MMlodzinski]

I wonder if anyone has managed this problem already?