[PATCH] cmd: Add support for optee hello world ta command

[Jerome Forissier]

On 12/13/24 08:01, Venkatesh Yadav Abbarapu wrote:
> Enable "hello_world_ta" command which increments the value passed.
> This provides easy test for establishing a session with OPTEE

Spelling: OP-TEE

> TA and verify.
> 
> It includes following subcommands:
> hello_world_ta write_value value: value to increment via OPTEE HELLO
> WORLD TA.

How about calling the command 'optee' and the subcommand 'hello', with
the integer argument being optional? This would make for an easier
syntax and possible evolutions ('optee version' etc.)

=> optee hello
=> optee hello 42

> To enable the OPTEE side HELLO WORLD example please refer
> https://optee.readthedocs.io/en/latest/building/gits/optee_examples/optee_examples.html
> 
> Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
> ---
>  cmd/Kconfig                |  8 ++++
>  cmd/Makefile               |  1 +
>  cmd/optee_hello_world_ta.c | 98 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 107 insertions(+)
>  create mode 100644 cmd/optee_hello_world_ta.c
> 
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 1d7ddb4ed36..f1f8d1b9571 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -1446,6 +1446,14 @@ config CMD_OPTEE_RPMB
>  	  in the Replay Protection Memory Block partition in eMMC by
>  	  using Persistent Objects in OPTEE
>  
> +config CMD_OPTEE_HELLO_WORLD
> +	bool "Enable Hello world TA"
> +	depends on OPTEE
> +	default y
> +	help
> +	 Enable the hello world ta command to test the OPTEE by passing
> +	 a "value" which should increment by OPTEE TA example.
> +
>  config CMD_MTD
>  	bool "mtd"
>  	depends on MTD
> diff --git a/cmd/Makefile b/cmd/Makefile
> index d1f369deec0..049147a1442 100644
> --- a/cmd/Makefile
> +++ b/cmd/Makefile
> @@ -118,6 +118,7 @@ obj-$(CONFIG_CMD_PAUSE) += pause.o
>  obj-$(CONFIG_CMD_SLEEP) += sleep.o
>  obj-$(CONFIG_CMD_MMC) += mmc.o
>  obj-$(CONFIG_CMD_OPTEE_RPMB) += optee_rpmb.o
> +obj-$(CONFIG_CMD_OPTEE_HELLO_WORLD) += optee_hello_world_ta.o
>  obj-$(CONFIG_CMD_MP) += mp.o
>  obj-$(CONFIG_CMD_MTD) += mtd.o
>  obj-$(CONFIG_CMD_MTDPARTS) += mtdparts.o
> diff --git a/cmd/optee_hello_world_ta.c b/cmd/optee_hello_world_ta.c
> new file mode 100644
> index 00000000000..54342b90812
> --- /dev/null
> +++ b/cmd/optee_hello_world_ta.c
> @@ -0,0 +1,98 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * (C) Copyright 2024, Advanced Micro Devices, Inc.
> + */
> +#include <command.h>
> +#include <errno.h>
> +#include <tee.h>
> +#include <vsprintf.h>
> +
> +static struct udevice *tee;
> +static u32 session;
> +
> +#define TA_HELLO_WORLD_CMD_INC_VALUE 0
> +/* This needs to match the UUID of the Hello World TA. */
> +#define TA_HELLO_WORLD_UUID \
> +	{ 0x8aaaf200, 0x2450, 0x11e4, \
> +	{ 0xab, 0xe2, 0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b} }
> +
> +static int hello_world_ta_open_session(void)
> +{
> +	const struct tee_optee_ta_uuid uuid = TA_HELLO_WORLD_UUID;
> +	struct tee_open_session_arg arg;
> +	int rc;
> +
> +	tee = tee_find_device(tee, NULL, NULL, NULL);
> +	if (!tee)
> +		return -ENODEV;
> +
> +	memset(&arg, 0, sizeof(arg));
> +	tee_optee_ta_uuid_to_octets(arg.uuid, &uuid);
> +	rc = tee_open_session(tee, &arg, 0, NULL);
> +	if (!rc)
> +		session = arg.session;
> +
> +	return 0;

Should return an error if rc != 0

> +}
> +
> +static int hello_world_ta(unsigned int value)
> +{
> +	struct tee_param param[2];
> +	struct tee_invoke_arg arg;
> +	int status = -EACCES;
> +
> +	printf("The Hello World TA is going to be called\n");
> +
> +	status = hello_world_ta_open_session();
> +	if (status) {
> +		printf("HellWorldTA: OpenSession FAILED!\n");
"hello_world_ta_open_session() failed (%d)", status

> +		return status;
> +	}
> +
> +	arg.func = TA_HELLO_WORLD_CMD_INC_VALUE;
> +	arg.session = session;
> +
> +	param[0].attr = TEE_PARAM_ATTR_TYPE_VALUE_INOUT;
> +	param[0].u.value.a = value;
> +
> +	printf("TA value: %d\n", (int)param[0].u.value.a);
> +
> +	tee_invoke_func(tee, &arg, 1, param);
> +
> +	printf("TA value: %d\n", (int)param[0].u.value.a);
> +
> +	tee_invoke_func(tee, &arg, 1, param);
> +
> +	printf("TA value: %d\n", (int)param[0].u.value.a);
> +
> +	status = tee_close_session(tee, session);
> +
> +	return status;
> +}
> +
> +static int do_optee_hello_world_ta(struct cmd_tbl *cmdtp, int flag, int argc,
> +				   char * const argv[])
> +{
> +	int ret;
> +	int value;
> +
> +	if (argc != cmdtp->maxargs) {
> +		debug("hello_world_ta: incorrect parameters passed\n");
> +		return CMD_RET_USAGE;
> +	}
> +
> +	value = dectoul(argv[1], NULL);
> +	ret = hello_world_ta(value);
> +	if (ret)
> +		return CMD_RET_FAILURE;
> +
> +	return CMD_RET_SUCCESS;
> +}
> +
> +U_BOOT_LONGHELP(optee_hello_world_ta,
> +		"write_value value - Write value to increment\n"
> +		"Command for testing Hello World OPTEE TA\n"
> +		"pass the 'value' which needs to increment from OPTEE world\n");
> +
> +U_BOOT_CMD_WITH_SUBCMDS(hello_world_ta, "OPTEE hello world TA", optee_hello_world_ta_help_text,
> +			U_BOOT_SUBCMD_MKENT(write_value, 2, 1, do_optee_hello_world_ta));