This patch introduces principal support for extending session interfaces
with specialized functionality in a clean way. For example, an 'Uart'
interface may implement the 'Terminal' interface but also offers
additional functions for setting the baud rate. A service that
implements the 'Uart' service will then automatically announce both the
'Uart' and 'Terminal' services.
For 64-bit registers we cannot compute MASK and SHIFT values via enums
because enum values are always of type int. But we can use static member
functions instead. Furthermore, the patch fixes the type trait for
64-bit registers. (apparently, this access width was never used so far)
Introduce a new Noncopyable class, one can derive from to mark a class of
objects to be uncopyable. This way the compiler can check for any violations
for you.
Replace 'Reg_array' in 'Genode::Mmio' by 'Register_array' and 'Subreg'
in 'Genode::Register', 'Genode::Mmio::Register'and
'Genode::Mmio::Register_array' by 'Bitfield'.
Update and beautify comments in the according headers and test programs.
'Reg_array' contains items whose width can be the width of the register
storage type at a max. Nethertheless they can be smaller and iterate all
subregs that are covered by the item width. The array uses as much
successive instances of its storage type as needed.
The test 'run/util_mmio' also tests these new features heavily.
The run script 'run/util_mmio.run' runs a test over basic
functionalities of 'Mmio::Register' and 'Mmio::Register::Subreg'. The
test covers the functions 'read' and 'bits', 'set', 'clear' and 'get'.
Inline function in 'Mmio::Register::Subreg' whose definition otherwise
looks ugly.
To accommodate CPU registers, which have a structured layout but don't
depend on a region base address, this patch introduces the generic
'Genode::Register' and 'Genode::Subreg' to 'register.h'.
'Mmio::Register' and 'Mmio::Subreg' inherit from them.
The MMIO access framework consists of an abstraction for a contiguous
MMIO area with a base address set dynamically. Within this class 'Mmio'
are declarations for 'Register' and 'Subreg'. These two can be
parameterized statically via template parameters to create arbitrary
MMIO structures.
Whereas 'Register' relies to a POD like subregion of 'Mmio', 'Subreg'
relies to a MMIO region within a specific 'Register' and therefore is
smaller or equal then the storage type of its superior 'Register'.
Furthermore with 'Reg_array' and 'Subreg_array', there exists the
possibility to handle arrays of uniform contiguous registers or subregs
by index. 'Subreg_array' therefore abstracts from the width boundary of
its superior 'Register' and handles a steady distance between its
members in addition. Both also check array size limits.
Related to issue #69.
Until now, the RPC framework did not support const RPC functions. Rather
than being a limitation inherent to the concept, const RPC functions
plainly did not exist. So supporting them was not deemed too important.
However, there are uses of RPC interfaces that would benefit from a way
to declare an RPC function as const. Candidates are functions like
'Framebuffer::Session::mode()' and 'Input::Session::is_pending()'.
This patch clears the way towards declaring such functions as const.
Even though the patch is simple enough, the thorough support for
const-qualified RPC functions would double the number of overloads for
the 'call_member' function template (in 'base/include/util/meta.h'). For
this reason, the patch does support const getter functions with no
arguments only. This appears to be the most common use of such
functions.
