There is no common standard for I/O-space access for non-x86 CPU
families, and non-MMIO peripherals are vanishingly rare.
Generalise the existing ARM definitions for dummy PIO to allow for
reuse by other CPU architectures.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The PAGE_SHIFT definition is an architectural property, rather than an
aspect of a particular I/O API implementation (of which, in theory,
there may be more than one per architecture).
Reflect this by moving the definition to the top-level bits/io.h for
each architecture.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
It is currently not possible to build the all-drivers iPXE binaries
for ARM, since there is no implementation for inb(), outb(), etc.
There is no common standard for accessing I/O space on ARM platforms,
and there are almost no ARM-compatible peripherals that actually
require I/O space accesses.
Provide dummy implementations that behave as though no device is
present (i.e. ignore writes, return all bits high for reads). This is
sufficient to allow the all-drivers binaries to link, and should cause
drivers to behave as though no I/O space peripherals are present in
the system.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown