Applying DTB Overlays from ATF on RZ/G2

[Adam Ford]

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:


=> 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
>