[PATCH 7/7] stm32mp: cmd_stm32key: add subcommand close

[Patrice CHOTARD]

Hi Patrick

On 6/28/21 2:56 PM, Patrick Delaunay wrote:
> The expected sequence to close the device
> 
> 1/ Load key in DDR with any supported load command
> 2/ Update OTP with key: STM32MP> stm32key read <addr>
> 
> At this point the device is able to perform image authentication but
> non-authenticated images can still be used and executed.
> So it is the last moment to test boot with signed binary and
> check that the ROM code accepts them.
> 
> 3/ Close the device: only signed binary will be accepted !!
>    STM32MP> stm32key close
> 
> Warning: Programming these OTP is an irreversible operation!
>          This may brick your system if the HASH of key is invalid
> 
> This command should be deactivated by default in real product.
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> ---
> 
>  arch/arm/mach-stm32mp/cmd_stm32key.c | 54 ++++++++++++++++++++++++++--
>  1 file changed, 52 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/mach-stm32mp/cmd_stm32key.c b/arch/arm/mach-stm32mp/cmd_stm32key.c
> index 8c8d476b65..50840b0f38 100644
> --- a/arch/arm/mach-stm32mp/cmd_stm32key.c
> +++ b/arch/arm/mach-stm32mp/cmd_stm32key.c
> @@ -210,10 +210,60 @@ static int do_stm32key_fuse(struct cmd_tbl *cmdtp, int flag, int argc, char *con
>  	return CMD_RET_SUCCESS;
>  }
>  
> +static int do_stm32key_close(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> +{
> +	bool yes, lock, closed;
> +	struct udevice *dev;
> +	u32 val;
> +	int ret;
> +
> +	yes = false;
> +	if (argc == 2) {
> +		if (strcmp(argv[1], "-y"))
> +			return CMD_RET_USAGE;
> +		yes = true;
> +	}
> +
> +	ret = read_hash_otp(!yes, &lock, &closed);
> +	if (ret) {
> +		if (ret == -ENOENT)
> +			printf("Error: OTP not programmed!\n");
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	if (closed) {
> +		printf("Error: already closed!\n");
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	if (!lock)
> +		printf("Warning: OTP not locked!\n");
> +
> +	if (!yes && !confirm_prog())
> +		return CMD_RET_FAILURE;
> +
> +	ret = get_misc_dev(&dev);
> +	if (ret)
> +		return CMD_RET_FAILURE;
> +
> +	val = STM32_OTP_CLOSE_MASK;
> +	ret = misc_write(dev, STM32_BSEC_OTP(STM32_OTP_CLOSE_ID), &val, 4);
> +	if (ret != 4) {
> +		printf("Error: can't update OTP\n");
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	printf("Device is closed !\n");
> +
> +	return CMD_RET_SUCCESS;
> +}
> +
>  static char stm32key_help_text[] =
>  	"read [<addr>]: Read the hash stored at addr in memory or in OTP\n"
> -	"stm32key fuse [-y] <addr> : Fuse hash stored at addr in OTP\n";
> +	"stm32key fuse [-y] <addr> : Fuse hash stored at addr in OTP\n"
> +	"stm32key close [-y] : Close the device, the hash stored in OTP\n";
>  
>  U_BOOT_CMD_WITH_SUBCMDS(stm32key, "Fuse ST Hash key", stm32key_help_text,
>  	U_BOOT_SUBCMD_MKENT(read, 2, 0, do_stm32key_read),
> -	U_BOOT_SUBCMD_MKENT(fuse, 3, 0, do_stm32key_fuse));
> +	U_BOOT_SUBCMD_MKENT(fuse, 3, 0, do_stm32key_fuse),
> +	U_BOOT_SUBCMD_MKENT(close, 2, 0, do_stm32key_close));
> 
Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>

Thanks
Patrice