__tls_get_addr symbol

[Marius Cristian Baciu via Digitalmars-d-learn]

Hi,
I'm currently working on porting the D runtime on Unikraft[1] and 
I am having some trouble locating a symbol referenced in 
rt/sections_elf_shared.d (__tls_get_addr).
Could someone tell me where does the runtime expect to retrieve 
its implementation from and what's its purpose?

Thanks,
Cristi

[1]:http://www.unikraft.org/