[PATCH v1] fastboot: introduce 'oem board' subcommand

[Sean Anderson]

On 12/28/23 10:25, Alexey Romanov wrote:
> Currently, fastboot protocol in U-Boot has no opportunity
> to execute vendor custom code with verifed boot.

Well, I would say the most conventional way to do this would be something like

=> fastboot 0
=> source \# CONFIG_FASTBOOT_BUF_ADDR

and on your host machine,

$ fastboot stage my_script.itb

where my_script.its looks like

/dts-v1/;

/ {
    description = "my script";
    #address-cells = <1>;

    images {
        my-script {
            data = /incbin/("my_script.scr");
            type = "script";
            arch = "arm64";
            compression = "none";
            hash-1 {
                algo = "sha256";
            };
        };
    };

    configurations {
        default = "conf";
        conf {
            description = "Load my script";
            script = "my-script";
            signature {
                algo = "sha256,rsa2048";
                key-name-hint = "vboot";
                sign-images = "script";
            };
        };
    };
};

This method is especially useful to pass complex parameters to your command.
This method of course requires commit bcc85b96b5f ("cmd: source: Support
specifying config name").

Would it be possible to use the above method for your use case?

--Sean

> This patch
> introduce new fastboot subcommand fastboot oem board:<cmd>,
> which allow to run custom oem_board function.
> =
> Default implementation is __weak. Vendor must redefine it in
> board/ folder with his own logic.
> 
> For example, some vendors have their custom nand/emmc partition
> flashing or erasing. Here some typical command for such use cases:
> 
> - flashing:
> 
>   $ fastboot stage bootloader.img
>   $ fastboot oem board:write_bootloader
> 
> - erasing:
> 
>   $ fastboot oem board:erase_env
> 
> Signed-off-by: Alexey Romanov <avromanov at salutedevices.com>
> ---
>  drivers/fastboot/Kconfig      |  7 +++++++
>  drivers/fastboot/fb_command.c | 15 +++++++++++++++
>  include/fastboot.h            |  1 +
>  3 files changed, 23 insertions(+)
> 
> diff --git a/drivers/fastboot/Kconfig b/drivers/fastboot/Kconfig
> index 3cfeea4837..4c955cabab 100644
> --- a/drivers/fastboot/Kconfig
> +++ b/drivers/fastboot/Kconfig
> @@ -241,6 +241,13 @@ config FASTBOOT_OEM_RUN
>  	  this feature if you are using verified boot, as it will allow an
>  	  attacker to bypass any restrictions you have in place.
>  
> +config FASTBOOT_OEM_BOARD
> +	bool "Enable the 'oem board' command"
> +	help
> +	  This extends the fastboot protocol with an "oem board" command. This
> +	  command allows running vendor custom code defined in board/ files.
> +	  Otherwise, it will do nothing and send fastboot fail.
> +
>  endif # FASTBOOT
>  
>  endmenu
> diff --git a/drivers/fastboot/fb_command.c b/drivers/fastboot/fb_command.c
> index 71cfaec6e9..4d2b451f46 100644
> --- a/drivers/fastboot/fb_command.c
> +++ b/drivers/fastboot/fb_command.c
> @@ -39,6 +39,7 @@ static void reboot_recovery(char *, char *);
>  static void oem_format(char *, char *);
>  static void oem_partconf(char *, char *);
>  static void oem_bootbus(char *, char *);
> +static void oem_board(char *, char *);
>  static void run_ucmd(char *, char *);
>  static void run_acmd(char *, char *);
>  
> @@ -106,6 +107,10 @@ static const struct {
>  		.command = "oem run",
>  		.dispatch = CONFIG_IS_ENABLED(FASTBOOT_OEM_RUN, (run_ucmd), (NULL))
>  	},
> +	[FASTBOOT_COMMAND_OEM_BOARD] = {
> +		.command = "oem board",
> +		.dispatch = CONFIG_IS_ENABLED(FASTBOOT_OEM_BOARD, (oem_board), (NULL))
> +	},
>  	[FASTBOOT_COMMAND_UCMD] = {
>  		.command = "UCmd",
>  		.dispatch = CONFIG_IS_ENABLED(FASTBOOT_UUU_SUPPORT, (run_ucmd), (NULL))
> @@ -489,3 +494,13 @@ static void __maybe_unused oem_bootbus(char *cmd_parameter, char *response)
>  	else
>  		fastboot_okay(NULL, response);
>  }
> +
> +void __weak fastboot_oem_board(char *cmd_parameter, void *data, u32 size, char *response)
> +{
> +	fastboot_fail("oem board function not defined", response);
> +}
> +
> +static void __maybe_unused oem_board(char *cmd_parameter, char *response)
> +{
> +	fastboot_oem_board(cmd_parameter, fastboot_buf_addr, image_size, response);
> +}
> diff --git a/include/fastboot.h b/include/fastboot.h
> index 296451f89d..06c1f26b6c 100644
> --- a/include/fastboot.h
> +++ b/include/fastboot.h
> @@ -37,6 +37,7 @@ enum {
>  	FASTBOOT_COMMAND_OEM_PARTCONF,
>  	FASTBOOT_COMMAND_OEM_BOOTBUS,
>  	FASTBOOT_COMMAND_OEM_RUN,
> +	FASTBOOT_COMMAND_OEM_BOARD,
>  	FASTBOOT_COMMAND_ACMD,
>  	FASTBOOT_COMMAND_UCMD,
>  	FASTBOOT_COMMAND_COUNT