This patch replaces the former prominent use of pointers by references
wherever feasible. This has the following benefits:
* The contract between caller and callee becomes more obvious. When
passing a reference, the contract says that the argument cannot be
a null pointer. The caller is responsible to ensure that. Therefore,
the use of reference eliminates the need to add defensive null-pointer
checks at the callee site, which sometimes merely exist to be on the
safe side. The bottom line is that the code becomes easier to follow.
* Reference members must be initialized via an object initializer,
which promotes a programming style that avoids intermediate object-
construction states. Within core, there are still a few pointers
as member variables left though. E.g., caused by the late association
of 'Platform_thread' objects with their 'Platform_pd' objects.
* If no pointers are present as member variables, we don't need to
manually provide declarations of a private copy constructor and
an assignment operator to avoid -Weffc++ errors "class ... has
pointer data members [-Werror=effc++]".
This patch also changes a few system bindings on NOVA and Fiasco.OC,
e.g., the return value of the global 'cap_map' accessor has become a
reference. Hence, the patch touches a few places outside of core.
Fixes#3135
This patch replaces the 'Parent::Quota_exceeded',
'Service::Quota_exceeded', and 'Root::Quota_exceeded' exceptions
by the single 'Insufficient_ram_quota' exception type.
Furthermore, the 'Parent' interface distinguished now between
'Out_of_ram' (the child's RAM is exhausted) from
'Insufficient_ram_quota' (the child's RAM donation does not suffice to
establish the session).
This eliminates ambiguities and removes the need to convert exception
types along the path of the session creation.
Issue #2398
Instead of organizing page tables within slab blocks and allocating such
blocks dynamically on demand, replace the page table allocator with a
simple, static alternative. The new page table allocator is dimensioned
at compile-time. When a PD runs out of page-tables, we simply flush its
current mappings, and re-use the freed tables. The only exception is
core/kernel that should not produce any page faults. Thereby it has to
be ensured that core has enough page tables to populate it's virtual
memory.
A positive side-effect of this static approach is that the accounting
of memory used for page-tables is now possible again. In the dynamic case
there was no protocol existent that solved the problem of donating memory
to core during a page fault.
Fix#1588
Instead of handing over object ids to the kernel, which has to find them
in object pools then, core can simply use object pointers to reference
kernel objects.
Ref #1443
The verb "bin" in the context of destroying kernel objects seems pretty
unusual in contrast to "delete". When reading "bin" in the context of
systems software an association to something like "binary" is more likely.
Ref #1443
* enables world-switch using ARM virtualization extensions
* split TrustZone and virtualization extensions hardly from platforms,
where it is not used
* extend 'Vm_session' interface to enable configuration of guest-physical memory
* introduce VM destruction syscall
* add virtual machine monitor for hw_arndale that emulates a simplified version
of ARM's Versatile Express Cortex A15 board for a Linux guest OS
Fixes#1405
