Tagging subscribers to this area:@agocke,@MichalStrehovsky,@jkotas
See info inarea-owners.md if you want to be subscribed.

Rough status of the linux-arm bring up:

• Some of the assembler code is not position independent. It's relatively easy fix, keeping it for next round. Current workaround: Compile withPositionIndependentExecutable=false
• FEATURE_64BIT_ALIGNMENT seems not to be defined for the GC and it sometimes triggers asserts. Current workaround: Define it in the CMakeLists.txt
• Exception unwinding doesn't work. Current workaround: Enable DWARF unwinderhere. Ideally, we would emit EHABI exception data but it's not necessary for now. Bothlld andlldb know how to work with DWARF so linking and debugging works.
• Exception handler address is misinterpreted somewhere (off by few bytes), so instructions at wrong address are executed. Exception handler return address is misinterpreted somewhere, so the app crashes after executing catch handler.Turns out the issue is that an address of a method is loaded with MOVW/MOVT instruction pair with a relocation and it's missing the thumb bit; later RhpCallCatchFunclet calls it withbx r4 and switches the processor to wrong mode.
• Some assembly helpers are missing.
• GC asserts onexecutionAborted

• Turns out the issue is that an address of a method is loaded with MOVW/MOVT instruction pair with a relocation and it's missing the thumb bit; later RhpCallCatchFunclet calls it withbx r4 and switches the processor to wrong mode.

I have a fix/workaround that I will submit in subsequent PR. There's a bug in the LLD linker in the way how it resolvesR_ARM_THM_MOVW_PREL_NC relocations. Instead of((S + A) | T) – P it's resolved as(((S | T) + A)) – P (S | T is already in the symbol table, so that's not an explicit expression in the LLD code). RyuJIT generates the thumb bit in the embedded addend which is quite unusual but not prohibited.

license/cla bot is stuck...