This patch introduces support for ROM sessions that update their
provided data during the lifetime of the session. The 'Rom_session'
interface had been extended with the new 'release()' and 'sigh()'
functions, which are needed to support the new protocol. All ROM
services have been updated to the new interface.
Furthermore, the patch changes the child policy of init
with regard to the handling of configuration files. The 'Init::Child'
used to always provide the ROM dataspace with the child's config file
via a locally implemented ROM service. However, for dynamic ROM
sessions, we need to establish a session to the real supplier of the ROM
data. This is achieved by using a new 'Child_policy_redirect_rom_file'
policy to handle the 'configfile' rather than handling the 'configfile'
case entirely within 'Child_config'.
To see the new facility in action, the new 'os/run/dynamic_config.run'
script provides a simple scenario. The config file of the test program
is provided by a service, which generates and updates the config data
at regular intervals.
In addition, new support has been added to let slaves use dynamic
reconfiguration. By using the new 'Child_policy_dynamic_rom_file', the
configuration of a slave can be changed dynamically at runtime via the
new 'configure()' function.
The config is provided as plain null-terminated string (instead of a
dataspace capability) because we need to buffer the config data anyway.
So there is no benefit of using a dataspace. For buffering configuration
data, a 'Ram_session' must be supplied. If no 'Ram_session' is specified
at construction time of a 'Slave_policy', no config is supplied to the
slave (which is still a common case).
An example for dynamically reconfiguring a slave is provided by
'os/run/dynamic_config_slave.run'.
The old variant provided 8K capability slots to all processes on core,
which increased binaries by 180 KB for the static allocator. I reduced it
to 4K capabilities stay under 100 KB overhead for the allocator.
Anyway, pci_drv and pl11x_drv need more RAM quota now: 2M for pl11x_drv
and 1M for pci_drv.
This patch makes use of the recently added support for const RPC
functions by turning 'Framebuffer::Session::mode()' and
'Input::Session::is_pending()' into const functions.
The new d3m component is the designated device-driver manager for the
upcoming live CD. It addresses the auto probing of USB storage and ATAPI
boot devices (issue #94) and the aggregation of user input coming from
USB HID and PS/2.
As a preliminary step for working on issue #11, this patch revisits the
'Framebuffer::info' RPC call. Instead of using C-style out paramters,
the new 'mode()' RPC call returns the mode information as an object of
type 'Mode'. Consequently, mode-specific functions such as
'bytes_per_pixel' have been moved to the new 'Framebuffer::Mode' class.
This patch changes decouples the conversion of the terminal state to
pixels from the write RPC function. Intermediate terminal states
produced by sub sequential write operations do not end up on screen one
by one but only the final state becomes visible. This drastically
improves the speed of scrolling through large text output.
