The user_to_virt() function is now a straightforward wrapper around
addition, with the addend almost invariably being zero.
Remove this redundant wrapper.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add fdt_cells() to read scalar values encoded within a cell array,
reimplement fdt_u64() as a wrapper around this, and add fdt_u32() for
completeness.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Refactor device tree traversal to operate on the basis of describing
the token at a given offset, with no separate notion of a device tree
cursor.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Using fdt_path() to find the root node "/" currently fails, since it
will attempt to find a child node with the empty name "" within the
root node.
Fix by changing fdt_path() to ignore any trailing slashes in a device
tree path.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When creating a device tree to pass to a booted operating system,
ensure that the "chosen" node exists, and populate the "bootargs"
property with the image command line.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide fdt_create() to create a device tree to be passed to a booted
operating system. The device tree will be created from the FDT image
(if present), falling back to the system device tree (if present).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
EFI configuration tables may be freed at any time, and there is no way
to be notified when the table becomes invalidated. Create a copy of
the system flattened device tree (if present), so that we do not risk
being left with an invalid pointer.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow for parsing device trees where an external factor (such as a
downloaded image length) determines the maximum length, which must be
validated against the length within the device tree header.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When running on a platform that uses FDT as its hardware description
mechanism, we are likely to have multiple device tree structures. At
a minimum, there will be the device tree passed to us from the
previous boot stage (e.g. OpenSBI), and the device tree that we
construct to be passed to the booted operating system.
Update the internal FDT API to include an FDT pointer in all function
parameter lists.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Define the concept of an "FDT" image, representing a Flattened Device
Tree blob that has been downloaded in order to be provided to a kernel
or other executable image. FDT images are represented using an image
tag (as with other special-purpose images such as the UEFI shim), and
are similarly marked as hidden so that they will not be included in a
generated magic initrd or show up in a virtual filesystem directory
listing.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The Raspberry Pi NIC has no EEPROM to hold the MAC address. The
platform firmware (e.g. UEFI or U-Boot) will typically obtain the MAC
address from the VideoCore firmware and add it to the device tree,
which is then made available to subsequent programs such as iPXE or
the Linux kernel.
Add the ability to parse a flattened device tree and to extract the
MAC address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
