[PATCH 2/5] firmware: Add common FW_FDT_PATH compile-time option

[Atish Patra]

On Thu, Oct 15, 2020 at 1:12 AM Anup Patel <anup.patel at wdc.com> wrote:
>
> Currently, only FW_PAYLOAD has mechanism to embed external FDT
> using FW_PAYLOAD_FDT_PATH compile-time option.
>
> This patch adds a commong FW_FDT_PATH compile-time option to
> embed external FDT for all OpenSBI firmwares (i.e FW_JUMP,
> FW_PAYLOAD, and FW_DYNAMIC).
>

/s/commong/common

> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> ---
>  docs/firmware/fw.md       | 14 +++++++++-----
>  firmware/external_deps.mk |  4 ++++
>  firmware/fw_base.S        | 16 ++++++++++++++++
>  firmware/objects.mk       |  7 +++++++
>  4 files changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/docs/firmware/fw.md b/docs/firmware/fw.md
> index 4133c23..1efdadf 100644
> --- a/docs/firmware/fw.md
> +++ b/docs/firmware/fw.md
> @@ -51,11 +51,15 @@ case, a *FW_PAYLOAD* firmware allows embedding a flattened device tree in the
>  Firmware Configuration and Compilation
>  --------------------------------------
>
> -All firmware types mandate the definition of the following compile time
> -configuration parameter.
> -
> -* **FW_TEXT_ADDR** - Defines the address at which the previous booting stage
> -  loads OpenSBI firmware.
> +All firmware types support the following common compile time configuration
> +parameters:
> +
> +* **FW_TEXT_ADDR** - Defines the execution address of the OpenSBI firmware.
> +  This configuration parameter is mandatory.
> +* **FW_FDT_PATH** - Path to an external flattened device tree binary file to
> +  be embedded in the *.rodata* section of the final firmware. If this option
> +  is not provided then the firmware will expect the FDT to be passed as an
> +  argument by the prior booting stage.
>
>  Additionally, each firmware type as a set of type specific configuration
>  parameters. Detailed information for each firmware type can be found in the
> diff --git a/firmware/external_deps.mk b/firmware/external_deps.mk
> index 2b8f9f6..f43ac06 100644
> --- a/firmware/external_deps.mk
> +++ b/firmware/external_deps.mk
> @@ -7,5 +7,9 @@
>  #   Anup Patel <anup.patel at wdc.com>
>  #
>
> +$(platform_build_dir)/firmware/fw_dynamic.o: $(FW_FDT_PATH)
> +$(platform_build_dir)/firmware/fw_jump.o: $(FW_FDT_PATH)
> +$(platform_build_dir)/firmware/fw_payload.o: $(FW_FDT_PATH)
> +
>  $(platform_build_dir)/firmware/fw_payload.o: $(FW_PAYLOAD_PATH_FINAL)
>  $(platform_build_dir)/firmware/fw_payload.o: $(FW_PAYLOAD_FDT_PATH)
> diff --git a/firmware/fw_base.S b/firmware/fw_base.S
> index 0271d9a..95197da 100644
> --- a/firmware/fw_base.S
> +++ b/firmware/fw_base.S
> @@ -182,6 +182,11 @@ _bss_zero:
>         call    fw_save_info
>         MOV_5R  a0, s0, a1, s1, a2, s2, a3, s3, a4, s4
>
> +#ifdef FW_FDT_PATH
> +       /* Override previous arg1 */
> +       la      a1, fw_fdt_bin
> +#endif
> +
>         /* Override previous arg1 */
>         MOV_3R  s0, a0, s1, a1, s2, a2
>         call    fw_prev_arg1
> @@ -668,3 +673,14 @@ _reset_regs:
>         csrw CSR_MSCRATCH, 0
>
>         ret
> +
> +#ifdef FW_FDT_PATH
> +       .section .rodata
> +       .align 4
> +       .globl fw_fdt_bin
> +fw_fdt_bin:
> +       .incbin FW_FDT_PATH
> +#ifdef FW_FDT_PADDING
> +       .fill FW_FDT_PADDING, 1, 0
> +#endif
> +#endif
> diff --git a/firmware/objects.mk b/firmware/objects.mk
> index c980362..2eea54c 100644
> --- a/firmware/objects.mk
> +++ b/firmware/objects.mk
> @@ -17,6 +17,13 @@ ifdef FW_TEXT_START
>  firmware-genflags-y += -DFW_TEXT_START=$(FW_TEXT_START)
>  endif
>
> +ifdef FW_FDT_PATH
> +firmware-genflags-y += -DFW_FDT_PATH=\"$(FW_FDT_PATH)\"
> +ifdef FW_FDT_PADDING
> +firmware-genflags-y += -DFW_FDT_PADDING=$(FW_FDT_PADDING)
> +endif
> +endif
> +
>  firmware-bins-$(FW_DYNAMIC) += fw_dynamic.bin
>
>  firmware-bins-$(FW_JUMP) += fw_jump.bin
> --
> 2.25.1
>
>
> --
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> opensbi at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi

I think we should document FW_FDT_PADDING as well.

Other than that, looks good.

Reviewed-by: Atish Patra <atish.patra at wdc.com>


-- 
Regards,
Atish