Re: [PATCH RESEND 4/7] riscv: dts: introduce SPL_LOAD_FIT_OPENSBI_OS_BOOT symbol

[Simon Glass <sjg@google.com>]

Hi Randolph,

On Fri, 6 Oct 2023 at 05:27, Randolph <randolph@andestech.com> wrote:
>
> Introduce common Kconfig symbol for riscv architecture.
> This symbol SPL_LOAD_FIT_OPENSBI_OS_BOOT is like falcon mode on ARM,
> the Falcon boot is a shortcut boot method for SD/eMMC targets. It
> skips the loading the RAM version U-Boot. Instead, it will loads
> the FIT image and boots directly to Linux.
>
> When SPL_OPENSBI_OS_BOOT is enabled, linux.itb is created after
> compilation instead of the default u-boot.itb. It initialises memory
> with the U-Boot SPL at the first stage, just as a normal boot process
> does at the beginning. Instead of jumping to the U-Boot proper from
> OpenSBI before booting the Linux kernel, the RISC-V falcon mode
> process jumps directly to the Linux kernel to gain shorter booting time.
>
> When SPL_OPENSBI_OS_BOOT is enabled, it will change the default FIT
> configure file "binman.dtsi" to "binman_linux.dtsi"
> Default is not enabled.
>
> Signed-off-by: Randolph <randolph@andestech.com>
> ---
>  arch/riscv/Kconfig | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index ec1cfcaaa7..4f104789a7 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -422,8 +422,17 @@ config TPL_USE_ARCH_MEMSET
>
>  endmenu
>
> +config SPL_LOAD_FIT_OPENSBI_OS_BOOT
> +       bool "Enable SPL (OpenSBI OS boot mode) applying linux from FIT"
> +       depends on SPL_LOAD_FIT
> +       help
> +         Use fw_dynamic from the FIT image, and u-boot SPL will invoke it directly.
> +         This is a shortcut boot flow, from u-boot SPL -> OpenSBI -> u-boot proper
> +         -> linux to u-boot SPL -> OpenSBI -> linux.

This bit seems OK

> +
>  config SPL_LOAD_FIT_CONFIG
>         string "Default FIT configuration for SPL"
> +       default "binman_linux.dtsi" if SPL_LOAD_FIT_OPENSBI_OS_BOOT

But I'm hoping you can drop this and put the logic in binman.dtsi

>         default "binman.dtsi"
>         depends on SPL_LOAD_FIT
>         help
> --
> 2.34.1
>

Regards,
Simon