For a main thread a thread object is created by the CRT0 before _main gets
called so that _main can already run in a generic environment that, e.g.,
catches stack overflows as a page-fault instead of corrupting the BSS.
Additionally dynamic programs have only one CRT0 - the one of the LDSO -
which does the initialization for both LDSO and program.
ref #989
- use the generic 'crt0.s' for Linux
- move the read-only '__dso_handle' definition into the '.text' section
- move the '__initial_sp' definition into the '.bss' section
- remove the '_main_utcb' definition
Part of #766.
Martin Stein
Alexander Boettcher
Christian Prochaska
Norman Feske
Genode Labs