Hi Scott,
On 23/01/19 11:12, Scott Ellis wrote:
> Hi Manju,
>
> Thanks for answering.
>
> I will look at the meta-xilinx-tools layer. I think I finally understand
> what is required to boot.
>
> But I am still not clear on the meta-xilinx multiconfig...
Just to make sure we are on the same page, there are mainly two
workflows with respect to booting on ZynqMP: using the Xilinx-specific
bootloader (FSBL) and tools (meta-xilinx-tools layer), OR using U-Boot
SPL and a more standard yocto setup. A few more details in section
"Booting" here [0].
I suggest you first choose the workflow that is best for your needs.
> The meta-xilinx-bsp/README.building.md has no mention that a patch is
> required to the pmu-firmware which is confusing.
>
> Is this just an omission?
>
> Is the pmu-firmware recipe useful without the patch?
Short answer: only with the Xilinx workflow.
Long answer:
The pmufw needs a "configuration object" to know what it should do, and
it expects to receive it at runtime.
In the Xilinx workflow the FSBL has a file called pm_cfg_obj.c built
into itself. It is the PMUFW configuration object, and FSBL passes it to
PMUFW at runtime.
With the U-Boot SPL workflow there's no FSBL, and there are two problems:
1) passing a cfg obj to pmufw is just not implemented in U-Boot
2) the pm_cfg_obj.c file is generated by the Xilinx XSDK and its
license is not compatible with the GPL license of U-Boot
Clearly problem 2 prevents from fixing problem 1. :(
To work around this problem a small patch has been developed so that
pm_cfg_obj.c is linked into pmufw and loaded directly, without waiting
for it from the outside. Find the original patch on the meta-topic layer
[1] and the patch updated for pmufw 2018.x here [2].
> Excuse the dumb questions.
As you might guess from the reply, that was clearly not dumb at all! :)
Hope it helps.
[0]
https://archive.fosdem.org/2018/schedule/event/arm64_and_fpga/attachments/slides/2564/export/events/attachments/arm64_and_fpga/slides/2564/zynqmp_linux.pdf
[1]
https://github.com/topic-embedded-products/meta-topic/blob/master/recipes-bsp/pmu-firmware/pmu-firmware_2017.%25.bbappend
[2]
https://github.com/lucaceresoli/zynqmp-pmufw-builder/blob/master/0001-Load-XPm_ConfigObject-at-boot.patch
--
Luca
--
_______________________________________________
meta-xilinx mailing list
meta-xilinx@yoctoproject.org
https://lists.yoctoproject.org/listinfo/meta-xilinx
