On 03/27/2017 10:58 AM, Thierry Reding wrote:
On Mon, Mar 27, 2017 at 09:39:43AM -0600, Stephen Warren wrote:
On 03/26/2017 04:49 PM, Martin Michlmayr wrote:
* Mikko Perttunen <cyndis@xxxxxxxx> [2017-03-25 10:32]:
It appears you need to have
fdt_copy_node_names=/cpus:/psci
fdt_copy_src_addr=0x83080000
in your U-Boot configuration. This is documented somewhere in the middle of
http://elinux.org/Jetson/TX1_Upstream_Kernel.
I can confirm that this works with u-boot from L4T R24.2.1.
However, it doesn't work with mainling u-boot (grepping for fdt_copy_
doesn't show anything in the source code).
Does anyone know how to get all 4 CPUs working with mainline u-boot?
Thierry, Jon, do you know?
The "fdt_copy" feature of U-Boot isn't upstreamed since I thought it was
only required to boot the L4T kernel, not mainline. We're also reworking L4T
so this feature won't be needed there either, so I don't expect to upstream
"fdt_copy".
I vaguely remember that we had discussed this a while ago and I think we
decided that we should hardcode the /psci and /cpus nodes within the DTS
file on the basis that firmware would be considered part of the hardware
as far as the device tree description of it is concerned.
Technically, hard-coding isn't quite correct because someone might end
up not using the firmware that ships with L4T and therefore not have a
working PSCI implementation, but I think it's fairly unlikely that
someone will do that.
It seems reasonable to expect PSCI, so hard-coding seems fine to me. If
someone does something unusual (like bringing up a new FW) they can
always temporarily adjust the default DT to suit their needs.
Equally, relying on copying the /psci and /cpus nodes from the
nvtboot-supplied DT likely doesn't avoid this assumption, since IIRC
those nodes are simply hard-coded into the DT that nvtboot uses anyway.
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