MEM: Introduce the master/slave port roles in the Python classes

This patch classifies all ports in Python as either Master or Slave
and enforces a binding of master to slave. Conceptually, a master (such
as a CPU or DMA port) issues requests, and receives responses, and
conversely, a slave (such as a memory or a PIO device) receives
requests and sends back responses. Currently there is no
differentiation between coherent and non-coherent masters and slaves.

The classification as master/slave also involves splitting the dual
role port of the bus into a master and slave port and updating all the
system assembly scripts to use the appropriate port. Similarly, the
interrupt devices have to have their int_port split into a master and
slave port. The intdev and its children have minimal changes to
facilitate the extra port.

Note that this patch does not enforce any port typing in the C++
world, it merely ensures that the Python objects have a notion of the
port roles and are connected in an appropriate manner. This check is
carried when two ports are connected, e.g. bus.master =
memory.port. The following patches will make use of the
classifications and specialise the C++ ports into masters and slaves.

1 files changed, 7 insertions, 7 deletions

diff --git a/src/dev/x86/Pc.py b/src/dev/x86/Pc.py
index bb8c91ac6..5b7d0864e 100644
--- a/src/dev/x86/Pc.py
+++ b/src/dev/x86/Pc.py
@@ -71,12 +71,12 @@ class Pc(Platform):
 
     def attachIO(self, bus):
         self.south_bridge.attachIO(bus)
-        self.i_dont_exist.pio = bus.port
-        self.behind_pci.pio = bus.port
-        self.com_1.pio = bus.port
-        self.fake_com_2.pio = bus.port
-        self.fake_com_3.pio = bus.port
-        self.fake_com_4.pio = bus.port
-        self.fake_floppy.pio = bus.port
+        self.i_dont_exist.pio = bus.master
+        self.behind_pci.pio = bus.master
+        self.com_1.pio = bus.master
+        self.fake_com_2.pio = bus.master
+        self.fake_com_3.pio = bus.master
+        self.fake_com_4.pio = bus.master
+        self.fake_floppy.pio = bus.master
         self.pciconfig.pio = bus.default
         bus.use_default_range = True