I have tried to get FPC running on Windows for ARM64. And I must say: everything was there already ! Good work FPC devs !! However, all binaries did crash on exit. After a lot of debugging, I found two issues that seem to solve this. 1: `TTlsDirectory={packed} record <--- do not pack on ARM64` 2: ``` procedure SysInitThreadvar(var offset : dword;size : dword); begin offset:=threadvarblocksize; {$ifdef CPUAARCH64} // Specific to ARM64 size := (size + 7) and not dword(7); <---- align 8 on ARM64 {$else ifdef CPUARM} // ARM32 size := (size + 3) and not dword(3); {$endif} inc(threadvarblocksize,size); end; ``` For me, these changes create working binaries on ARM64 !