Instead of mapping all physical memory 1:1 into core/kernel's address space,
this commit limits the 1:1 mapping to the binary image, and I/O memory
regions used by the kernel only. All subsequent memory accesses of core
are done by mapping the corresponding memory on demand, and not necessarily
1:1.
This commit has several side effects:
The page table code had to be revisited completely. The kernel inserts no
longer anything into the page tables, apart from the initial translations
to have the core/kernel image available when enabling the MMU. The page
tables and higher level translation tables are no longer named Tlb, but
Translation_table instead. There is no indirection class required to define
the translation tables of a concrete SoC, the appropriated ARM specifier
is sufficient.
The ability to map core's memory the same way like it's done for all other
protection domains, makes a special treatment of core's threads (no context
area) obsolete.
Ref #567 (partly solves it)
Fix#723Fix#1068
Instead of using a special bitfield use a compound of boolean
values for the generic page attributes. To reduce copy overhead,
change the corresponding functions, where Page_flags are used as
arguments, to use references.
Enable routing of thread events to signal contexts via
Kernel::route_thread_event.
Replace Kernel::set_pager by Kernel::route_thread_event.
In base-hw a pager object is a signal context and a pager activation
is a signal receiver. If a thread wants to start communicating its page
faults via a pager object, the thread calls Kernel::route_thread_event with
its thread ID, event ID "FAULT", and the signal context ID of the pager object.
If a pager activation wants to start handling page faults of a pager object,
the pager activation assigns the corresponding signal context to its signal
receiver. If a pager activation wants to stop handling page faults of a pager
object, the pager activation dissolves the corresponding signal context from
its signal receiver. If a thread wants to start communicating its page faults
via a pager object, the thread calls Kernel::route_thread_event with its
thread ID, event ID "FAULT", and the invalid signal context ID.
Remove Kernel::resume_faulter.
Move all page fault related code from generic kernel sources to CPU
specific cpu_support.h and cpu_support.cc.
fix#935
