The efi_get_fdt_params() routine uses the early OF device tree
traversal helpers, that iterate over each node in the DT and invoke
a caller provided callback that can inspect the node's contents and
look for the required data. This requires a special param struct to
be passed around, with pointers into param enumeration structs that
contain (and duplicate) property names and offsets into yet another
struct that carries the collected data.
Since we know the data we look for is either under /hypervisor/uefi
or under /chosen, it is much simpler to use the libfdt routines, and
just try to grab a reference to either node directly, and read each
property in sequence.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Push the FDT params specific types and definition into fdtparams.c,
and instead, pass a reference to the memory map data structure and
populate it directly, and return the system table address as the
return value.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
On ARM systems, we discover the UEFI system table address and memory
map address from the /chosen node in the device tree, or in the Xen
case, from a similar node under /hypervisor.
Before making some functional changes to that code, move it into its
own file that only gets built if CONFIG_EFI_PARAMS_FROM_FDT=y.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
