[PATCH v2 4/4] riscv: Setup reserved-memory node for FU540

[Atish Patra]

On Sat, Mar 14, 2020 at 3:18 AM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Atish,
>
> On Sat, Mar 14, 2020 at 8:11 AM Atish Patra <atish.patra at wdc.com> wrote:
> >
> > FU540 uses OF_SEPARATE instead of OF_PRIOR.
> >
> > Enable OF_BOARD_FIXUP to update the DT with reserved-memory node.
> >
> > Signed-off-by: Atish Patra <atish.patra at wdc.com>
> > ---
> >  board/sifive/fu540/fu540.c     | 15 +++++++++++++++
> >  configs/sifive_fu540_defconfig |  1 +
> >  2 files changed, 16 insertions(+)
> >
> > diff --git a/board/sifive/fu540/fu540.c b/board/sifive/fu540/fu540.c
> > index 47a20902517c..82b3a9c8e729 100644
> > --- a/board/sifive/fu540/fu540.c
> > +++ b/board/sifive/fu540/fu540.c
> > @@ -141,6 +141,21 @@ int misc_init_r(void)
> >
> >  #endif
> >
> > +#ifdef CONFIG_OF_BOARD_FIXUP
> > +int board_fix_fdt(void *fdt)
>
> This is used to fix-up the DT that U-Boot uses, not the DT that
> operating system uses.
>

Ahh yes. User can load DT from sdcard or network for OS usage.
We should also update the arch_fixup_fdt as well so that OS sees
the reserved memory nodes.

> As I mentioned in
> https://github.com/riscv/riscv-sbi-doc/pull/37#issuecomment-596184723,
> we need consider U-Boot SPL usage.
>

If U-Boot SPL is built without a DT, OpenSBI should be built with a DT.
Here are the constraints to use reserved-memory:

For any DT based platform:
1. If the stage prior to OpenSBI i.e. FSBL, U-Boot SPL is built
without a DT, OpenSBI
must be built with a DT.

2. If U-boot proper is built with OF_SEPARATE, OF_BOARD_FIXUP should be enabled
as well so that U-Boot can copy the reserved-memory nodes from
previous stage DT and update
the current DT in use.

> > +{
> > +       int err;
> > +
> > +       err = riscv_board_reserved_mem_fixup(fdt);
> > +       if (err < 0) {
> > +               printf("failed to fixup DT for reserved memory: %d\n", err);
> > +               return err;
> > +       }
> > +
> > +       return 0;
> > +}
> > +#endif
> > +
> >  int board_init(void)
> >  {
> >         /* For now nothing to do here. */
> > diff --git a/configs/sifive_fu540_defconfig b/configs/sifive_fu540_defconfig
> > index 6d61e6c960ee..8fb3794cd578 100644
> > --- a/configs/sifive_fu540_defconfig
> > +++ b/configs/sifive_fu540_defconfig
> > @@ -12,3 +12,4 @@ CONFIG_DISPLAY_BOARDINFO=y
> >  CONFIG_DEFAULT_DEVICE_TREE="hifive-unleashed-a00"
> >  CONFIG_SYS_RELOC_GD_ENV_ADDR=y
> >  CONFIG_DM_MTD=y
> > +CONFIG_OF_BOARD_FIXUP=y
> > --
>
> Regards,
> Bin



-- 
Regards,
Atish