Re: [PATCH v2 03/12] gpu: nova-core: place the generic bootloader at the top of IMEM

[Eliot Courtney]

On Sat Nov 7, 2026 at 6:47 PM JST, Alexandre Courbot wrote:
> From: John Hubbard <jhubbard@xxxxxxxxxx>
>
> The generic bootloader was loaded right below the first 64 KiB of IMEM,
> on the assumption that every falcon it runs on has a 64 KiB IMEM. The
> r000 load-and-execute bootloader event can name any image for it to
> load, and the bootloader must then sit above the blocks that the image
> occupies, that is, in the last blocks of IMEM, regardless of its size.
>
> Place the bootloader at the top of the falcon's IMEM, using the IMEM
> size that the HWCFG register reports, instead of assuming a 64 KiB IMEM.
>
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> Reviewed-by: Timur Tabi <ttabi@xxxxxxxxxx>
> Reviewed-by: Zhi Wang <zhiw@xxxxxxxxxx>
> [acourbot: split out of the patch separating the bootloader from FWSEC;
>  convert the IMEM size with usize::from()]
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
> ---

[...]

>  impl GenericBootloader {
> -    /// Loads the generic bootloader image for `chipset`, placed right below the first 64 KiB of
> +    /// Loads the generic bootloader image for `chipset`, placed in the last blocks of `falcon`'s
>      /// IMEM.
>      ///
>      /// # Errors
>      ///
>      /// - `EINVAL` if a required TLV field is absent.
> -    /// - `EOVERFLOW` if the image does not fit below 64 KiB.
> +    /// - `EOVERFLOW` if the image does not fit in IMEM.
>      /// - `ENOMEM` if the padded copy of the code cannot be allocated.
> -    pub(crate) fn new(dev: &device::Device, chipset: Chipset) -> Result<Self> {
> +    pub(crate) fn new(
> +        dev: &device::Device,
> +        chipset: Chipset,
> +        falcon: &Falcon<'_, Gsp>,

optional nit: `falcon` is passed twice in (`new` and `run`), so we
could call `run` with a different `falcon` (which could have a
different `imem_size` to the first one). we could just compute
`imem_dst_start` in `run` and drop `falcon` from `new`.

Reviewed-by: Eliot Courtney <ecourtney@xxxxxxxxxx>