imx8m: Add DEK blob encapsulation for imx8m

Add DEK blob encapsulation support for IMX8M through "dek_blob" command.
On ARMv8, u-boot runs in non-secure, thus cannot encapsulate a DEK blob
for encrypted boot.
The DEK blob is encapsulated by OP-TEE through a trusted application call.
U-boot sends and receives the DEK and the DEK blob binaries through OP-TEE
dynamic shared memory.

To enable the DEK blob encapsulation, add to the defconfig:
CONFIG_SECURE_BOOT=y
CONFIG_FAT_WRITE=y
CONFIG_CMD_DEKBLOB=y

Signed-off-by: Clement Faure <clement.faure@nxp.com>
Reviewed-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>

5 files changed, 125 insertions, 11 deletions

diff --git a/arch/arm/dts/imx8mm-evk-u-boot.dtsi b/arch/arm/dts/imx8mm-evk-u-boot.dtsi
index 7f48912b49..6d204526af 100644
--- a/arch/arm/dts/imx8mm-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mm-evk-u-boot.dtsi
@@ -9,6 +9,13 @@
 		wdt = <&wdog1>;
 		u-boot,dm-spl;
 	};
+
+	firmware {
+		optee {
+			compatible = "linaro,optee-tz";
+			method = "smc";
+		};
+	};
 };
 
 &{/soc@0} {
diff --git a/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi b/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
index 8cd15be7a8..a0fd2a3098 100644
--- a/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
@@ -9,6 +9,12 @@
 		wdt = <&wdog1>;
 		u-boot,dm-spl;
 	};
+	firmware {
+		optee {
+			compatible = "linaro,optee-tz";
+			method = "smc";
+		};
+	};
 };
 
 &{/soc@0} {
diff --git a/arch/arm/dts/imx8mp-evk-u-boot.dtsi b/arch/arm/dts/imx8mp-evk-u-boot.dtsi
index 6a91404d7b..27075c5217 100644
--- a/arch/arm/dts/imx8mp-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mp-evk-u-boot.dtsi
@@ -9,6 +9,12 @@
 		wdt = <&wdog1>;
 		u-boot,dm-spl;
 	};
+	firmware {
+		optee {
+			compatible = "linaro,optee-tz";
+			method = "smc";
+		};
+	};
 };
 
 &{/soc@0} {
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 27b0b081ad..3bcfced8f0 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -75,12 +75,29 @@ config CMD_BMODE
 
 config CMD_DEKBLOB
 	bool "Support the 'dek_blob' command"
+	select IMX_CAAM_DEK_ENCAP if ARCH_MX6 || ARCH_MX7 || ARCH_MX7ULP
+	select IMX_OPTEE_DEK_ENCAP if ARCH_IMX8M
 	help
 	  This enables the 'dek_blob' command which is used with the
 	  Freescale secure boot mechanism. This command encapsulates and
 	  creates a blob of data. See also CMD_BLOB and doc/imx/habv4/* for
 	  more information.
 
+config IMX_CAAM_DEK_ENCAP
+	bool "Support the DEK blob encapsulation with CAAM U-Boot driver"
+	help
+	  This enables the DEK blob encapsulation with the U-Boot CAAM driver.
+	  This option is only available on imx6, imx7 and imx7ulp.
+
+config IMX_OPTEE_DEK_ENCAP
+	select TEE
+	select OPTEE
+	bool "Support the DEK blob encapsulation with OP-TEE"
+	help
+	  This enabled the DEK blob encapsulation with OP-TEE. The communication
+	  with OP-TEE is done through a SMC call and OP-TEE shared memory. This
+	  option is available on imx8mm.
+
 config CMD_PRIBLOB
 	bool "Support the set_priblob_bitfield command"
 	depends on HAS_CAAM && IMX_HAB
diff --git a/arch/arm/mach-imx/cmd_dek.c b/arch/arm/mach-imx/cmd_dek.c
index bd380429c0..75aec2cef0 100644
--- a/arch/arm/mach-imx/cmd_dek.c
+++ b/arch/arm/mach-imx/cmd_dek.c
@@ -14,6 +14,7 @@
 #include <fsl_sec.h>
 #include <asm/arch/clock.h>
 #include <mapmem.h>
+#include <tee.h>
 
 /**
 * blob_dek() - Encapsulate the DEK as a blob using CAM's Key
@@ -23,9 +24,13 @@
 *
 * Returns zero on success,and negative on error.
 */
-static int blob_encap_dek(const u8 *src, u8 *dst, u32 len)
+#ifdef CONFIG_IMX_CAAM_DEK_ENCAP
+static int blob_encap_dek(u32 src_addr, u32 dst_addr, u32 len)
 {
-	int ret = 0;
+	u8 *src_ptr, *dst_ptr;
+
+	src_ptr = map_sysmem(src_addr, len / 8);
+	dst_ptr = map_sysmem(dst_addr, BLOB_SIZE(len / 8));
 
 	hab_caam_clock_enable(1);
 
@@ -40,10 +45,90 @@ static int blob_encap_dek(const u8 *src, u8 *dst, u32 len)
 	}
 
 	len /= 8;
-	ret = blob_dek(src, dst, len);
+	return blob_dek(src_ptr, dst_ptr, len);
+}
+#endif /* CONFIG_IMX_CAAM_DEK_ENCAP */
+
+#ifdef CONFIG_IMX_OPTEE_DEK_ENCAP
+
+#define PTA_DEK_BLOB_PTA_UUID {0xef477737, 0x0db1, 0x4a9d, \
+	{0x84, 0x37, 0xf2, 0xf5, 0x35, 0xc0, 0xbd, 0x92} }
+
+#define OPTEE_BLOB_HDR_SIZE		8
+
+static int blob_encap_dek(u32 src_addr, u32 dst_addr, u32 len)
+{
+	struct udevice *dev = NULL;
+	struct tee_shm *shm_input, *shm_output;
+	struct tee_open_session_arg arg = {0};
+	struct tee_invoke_arg arg_func = {0};
+	const struct tee_optee_ta_uuid uuid = PTA_DEK_BLOB_PTA_UUID;
+	struct tee_param param[4] = {0};
+	int ret;
+
+	/* Get tee device */
+	dev = tee_find_device(NULL, NULL, NULL, NULL);
+	if (!dev) {
+		printf("Cannot get OP-TEE device\n");
+		return -1;
+	}
+
+	/* Set TA UUID */
+	tee_optee_ta_uuid_to_octets(arg.uuid, &uuid);
+
+	/* Open TA session */
+	ret = tee_open_session(dev, &arg, 0, NULL);
+	if (ret < 0) {
+		printf("Cannot open session with PTA Blob 0x%X\n", ret);
+		return -1;
+	}
+
+	/* Allocate shared input and output buffers for TA */
+	ret = tee_shm_register(dev, (void *)(ulong)src_addr, len / 8, 0x0, &shm_input);
+	if (ret < 0) {
+		printf("Cannot register input shared memory 0x%X\n", ret);
+		goto error;
+	}
+
+	ret = tee_shm_register(dev, (void *)(ulong)dst_addr,
+			       BLOB_SIZE(len / 8) + OPTEE_BLOB_HDR_SIZE,
+			       0x0, &shm_output);
+	if (ret < 0) {
+		printf("Cannot register output shared memory 0x%X\n", ret);
+		goto error;
+	}
+
+	param[0].u.memref.shm	= shm_input;
+	param[0].u.memref.size	= shm_input->size;
+	param[0].attr		= TEE_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[1].u.memref.shm	= shm_output;
+	param[1].u.memref.size	= shm_output->size;
+	param[1].attr		= TEE_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[2].attr		= TEE_PARAM_ATTR_TYPE_NONE;
+	param[3].attr		= TEE_PARAM_ATTR_TYPE_NONE;
+
+	arg_func.func = 0;
+	arg_func.session = arg.session;
+
+	/* Generate DEK blob */
+	arg_func.session = arg.session;
+	ret = tee_invoke_func(dev, &arg_func, 4, param);
+	if (ret < 0)
+		printf("Cannot generate Blob with PTA DEK Blob 0x%X\n", ret);
+
+error:
+	/* Free shared memory */
+	tee_shm_free(shm_input);
+	tee_shm_free(shm_output);
+
+	/* Close session */
+	ret = tee_close_session(dev, arg.session);
+	if (ret < 0)
+		printf("Cannot close session with PTA DEK Blob 0x%X\n", ret);
 
 	return ret;
 }
+#endif /* CONFIG_IMX_OPTEE_DEK_ENCAP */
 
 /**
  * do_dek_blob() - Handle the "dek_blob" command-line command
@@ -59,8 +144,6 @@ static int do_dek_blob(struct cmd_tbl *cmdtp, int flag, int argc,
 		       char *const argv[])
 {
 	uint32_t src_addr, dst_addr, len;
-	uint8_t *src_ptr, *dst_ptr;
-	int ret = 0;
 
 	if (argc != 4)
 		return CMD_RET_USAGE;
@@ -69,12 +152,7 @@ static int do_dek_blob(struct cmd_tbl *cmdtp, int flag, int argc,
 	dst_addr = simple_strtoul(argv[2], NULL, 16);
 	len = simple_strtoul(argv[3], NULL, 10);
 
-	src_ptr = map_sysmem(src_addr, len/8);
-	dst_ptr = map_sysmem(dst_addr, BLOB_SIZE(len/8));
-
-	ret = blob_encap_dek(src_ptr, dst_ptr, len);
-
-	return ret;
+	return blob_encap_dek(src_addr, dst_addr, len);
 }
 
 /***************************************************/