We currently rely on the recursive nature of devicetree bus probing to
obtain the region cell size specification from the parent device.
This blocks the possibility of creating a standalone console device
based on /chosen/stdout-path before probing the whole bus.
Fix by using fdt_parent() to locate the parent device at the point of
use within dt_ioremap().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The "reg" property is also used by non-device nodes, such as the nodes
describing the system memory map.
Provide generalised functionality for parsing the "#address-cells",
"#size-cells", and "reg" properties.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Devicetree devices encode register address ranges within the "reg"
property, with the number of cells used for addresses and for sizes
determined by the #address-cells and #size-cells properties of the
immediate parent device.
Record the number of address and size cells for each device, and
provide a dt_ioremap() function to allow drivers to map a specified
range without having to directly handle the "reg" property.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add a basic model for devices instantiated by parsing the system
flattened device tree, with drivers matched via the "compatible"
property for any non-root node.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
