This adds a udbg and an hvc console backend for supporting a console
using the OPAL console interfaces.
On OPAL v1 we have hvc0 mapped to whatever console the system was
configured for (network or hvsi serial port) via the service
processor.
On OPAL v2 we have hvcN mapped to the Nth console provided by OPAL
which generally corresponds to:
hvc0 : network console (raw protocol)
hvc1 : serial port S1 (hvsi)
hvc2 : serial port S2 (hvsi)
Note: At this point, early debug console only works with OPAL v1
and shouldn't be enabled in a normal kernel.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
A mix of think & mismerge on my side caused a problem where both the
new hvsi_lib and the old hvsi driver gets compiled and try to define
symbols with the same name.
This fixes it by renaming the hvsi_lib exported symbols.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>