Applying DTB Overlays from ATF on RZ/G2

[Heinrich Schuchardt]

Am 5. Januar 2023 00:19:36 MEZ schrieb Adam Ford <aford173 at gmail.com>:
>On Wed, Jan 4, 2023 at 5:15 PM Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>>
>> On 1/4/23 22:35, Adam Ford wrote:
>> > ATF generates a couple memory nodes based on how it's compiled and
>> > generates a reserved-memory node, and I want to overlay it with the
>> > device tree so Linux knows about this reserved memory.
>> >
>> > When I boot U-Boot, I can read the reserved-memory node:
>> >
>> > => fdt addr 0xe631e588
>> > Working FDT set to e631e588
>> > => fdt print /reserved-memory
>> > reserved-memory {
>> > lossy-decompression at 54000000 {
>> > renesas,formats = <0x00000000>;
>> > no-map;
>> > reg = <0x00000000 0x54000000 0x00000000 0x03000000>;
>> > compatible = "renesas,lossy-decompression", "shared-dma-pool";
>> > };
>> > };
>> > =>
>> >
>> > I attempt to overlay it with the following:
>> >
>> > => run loadfdt
>> > 65932 bytes read in 6 ms (10.5 MiB/s)
>> > => fdt addr $load_addr
>>
>> When actually setting the address you will see a message "Working FDT
>> set to %lx\n". So I assume $load_addr is empty.
>>
>> Did you mean $loadaddr or $fileaddr?
>
>Opps, that was a copy-paste error.  Even with that, I still get the
>failure to overlay:
>

Did you load a .dtbo file to apply? You cannot apply a devicetree.

Is the fdt that you want to apply the overlay to built with symbols (dtc parameter -@)?

Best regards

Heinrich 
>
>=> run loadfdt
>65932 bytes read in 6 ms (10.5 MiB/s)
>=> fdt addr $fdt_addr
>Working FDT set to 48000000
>=> fdt resize 8192
>=> fdt apply 0xe631e588
>=> fdt print /reserved-memory
>libfdt fdt_path_offset() returned FDT_ERR_NOTFOUND
>=>
>
>
>
>>
>> > Working fdt: e631e588
>> > => fdt resize 8192
>> > => fdt apply 0xe631e588
>>
>> Here you are apply the devicetree at e631e588 to itself which cannot work.
>>
>> Best regards
>>
>> Heinrich
>>
>> >
>> > At this point, I would expect the reserved-memory node to be merged
>> > with the main FDT, but it appears to be missing.
>> >
>> > => fdt print /reserved-memory
>> > libfdt fdt_path_offset() returned FDT_ERR_BADMAGIC
>> > =>
>> >
>> > There are no errors, but there are no overlays either.
>> >
>> > Does someone have any suggestions as to what I am doing wrong?
>> > Without the reserved memory node, Linux can crash if it tries to use
>> > the memory in that restricted area, and that node might change
>> > depending on how ATF is compiled.
>> >
>> > Thanks for any help.
>> >
>> > adam
>>