Pull request efi-2022-01-rc4-2

UEFI:
 
 * correctly handle missing TPM device
 * prepare for block devices for U-Boot as EFI app
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Merge tag 'efi-2022-01-rc4-2' of https://source.denx.de/u-boot/custodians/u-boot-efi

Pull request efi-2022-01-rc4-2

UEFI:

* correctly handle missing TPM device
* prepare for block devices for U-Boot as EFI app

# gpg: Signature made Fri 10 Dec 2021 04:29:20 AM EST
# gpg:                using RSA key 6DC4F9C71F29A6FA06B76D33C481DBBC2C051AC4
# gpg: Good signature from "Heinrich Schuchardt <xypron.glpk@gmx.de>" [unknown]
# gpg:                 aka "[jpeg image of size 1389]" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 6DC4 F9C7 1F29 A6FA 06B7  6D33 C481 DBBC 2C05 1AC4

MAINTAINERS

@@ -713,8 +713,11 @@ W:	https://u-boot.readthedocs.io/en/latest/develop/uefi/u-boot_on_efi.html
 F:	board/efi/efi-x86_app
 F:	configs/efi-x86_app*
 F:	doc/develop/uefi/u-boot_on_efi.rst
+F:	drivers/block/efi-media-uclass.c
+F:	drivers/block/sb_efi_media.c
 F:	lib/efi/efi_app.c
 F:	scripts/build-efi.sh
+F:	test/dm/efi_media.c
 
 EFI PAYLOAD
 M:	Heinrich Schuchardt <xypron.glpk@gmx.de>

arch/sandbox/dts/test.dts

@@ -498,6 +498,10 @@
 		compatible = "sandbox,clk-ccf";
 	};
 
+	efi-media {
+		compatible = "sandbox,efi-media";
+	};
+
 	eth@10002000 {
 		compatible = "sandbox,eth";
 		reg = <0x10002000 0x1000>;

disk/part.c

@@ -296,8 +296,11 @@ static void print_part_header(const char *type, struct blk_desc *dev_desc)
 	case IF_TYPE_VIRTIO:
 		puts("VirtIO");
 		break;
+	case IF_TYPE_EFI_MEDIA:
+		puts("EFI");
+		break;
 	default:
-		puts ("UNKNOWN");
+		puts("UNKNOWN");
 		break;
 	}
 	printf (" device %d  --   Partition Type: %s\n\n",

doc/develop/uefi/uefi.rst

@@ -620,12 +620,12 @@ EFI_DRIVER_BINDING_PROTOCOL implementation for the UEFI drivers.
 
 A linker created list is used to keep track of the UEFI drivers. To create an
 entry in the list the UEFI driver uses the U_BOOT_DRIVER macro specifying
-UCLASS_EFI as the ID of its uclass, e.g::
+UCLASS_EFI_LOADER as the ID of its uclass, e.g::
 
     /* Identify as UEFI driver */
     U_BOOT_DRIVER(efi_block) = {
         .name  = "EFI block driver",
-        .id    = UCLASS_EFI,
+        .id    = UCLASS_EFI_LOADER,
         .ops   = &driver_ops,
     };
 
@@ -651,8 +651,8 @@ UEFI block IO driver
 The UEFI block IO driver supports devices exposing the EFI_BLOCK_IO_PROTOCOL.
 
 When connected it creates a new U-Boot block IO device with interface type
-IF_TYPE_EFI, adds child controllers mapping the partitions, and installs the
+IF_TYPE_EFI_LOADER, adds child controllers mapping the partitions, and installs
-EFI_SIMPLE_FILE_SYSTEM_PROTOCOL on these. This can be used together with the
+the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL on these. This can be used together with the
 software iPXE to boot from iSCSI network drives [4].
 
 This driver is only available if U-Boot is configured with::

doc/usage/fdt_overlays.rst

@@ -102,7 +102,7 @@ Manually Loading and Applying Overlays
 
 ::
 
-    => fdtaddr $fdtaddr
+    => fdt addr $fdtaddr
 
 4. Grow it enough so it can encompass all applied overlays
 

drivers/block/Kconfig

@@ -61,6 +61,39 @@ config TPL_BLOCK_CACHE
 	help
 	  This option enables the disk-block cache in TPL
 
+config EFI_MEDIA
+	bool "Support EFI media drivers"
+	default y if EFI || SANDBOX
+	help
+	  Enable this to support media devices on top of UEFI. This enables
+	  just the uclass so you also need a specific driver to make this do
+	  anything.
+
+	  For sandbox there is a test driver.
+
+if EFI_MEDIA
+
+config EFI_MEDIA_SANDBOX
+	bool "Sandbox EFI media driver"
+	depends on SANDBOX
+	default y
+	help
+	  Enables a simple sandbox media driver, used for testing just the
+	  EFI_MEDIA uclass. It does not do anything useful, since sandbox does
+	  not actually support running on top of UEFI.
+
+config EFI_MEDIA_BLK
+	bool "EFI media block driver"
+	depends on EFI_APP
+	default y
+	help
+	  Enables a block driver for providing access to UEFI devices. This
+	  allows use of block devices detected by the underlying UEFI
+	  implementation. With this it is possible to use filesystems on these
+	  devices, for example.
+
+endif  # EFI_MEDIA
+
 config IDE
 	bool "Support IDE controllers"
 	select HAVE_BLOCK_DEVICE

drivers/block/Makefile

@@ -14,3 +14,7 @@ obj-$(CONFIG_IDE) += ide.o
 endif
 obj-$(CONFIG_SANDBOX) += sandbox.o
 obj-$(CONFIG_$(SPL_TPL_)BLOCK_CACHE) += blkcache.o
+
+obj-$(CONFIG_EFI_MEDIA) += efi-media-uclass.o
+obj-$(CONFIG_EFI_MEDIA_SANDBOX) += sb_efi_media.o
+obj-$(CONFIG_EFI_MEDIA_BLK) += efi_blk.o

drivers/block/blk-uclass.c

@@ -28,7 +28,8 @@ static const char *if_typename_str[IF_TYPE_COUNT] = {
 	[IF_TYPE_SATA]		= "sata",
 	[IF_TYPE_HOST]		= "host",
 	[IF_TYPE_NVME]		= "nvme",
-	[IF_TYPE_EFI]		= "efi",
+	[IF_TYPE_EFI_MEDIA]	= "efi",
+	[IF_TYPE_EFI_LOADER]	= "efiloader",
 	[IF_TYPE_VIRTIO]	= "virtio",
 	[IF_TYPE_PVBLOCK]	= "pvblock",
 };
@@ -44,7 +45,8 @@ static enum uclass_id if_type_uclass_id[IF_TYPE_COUNT] = {
 	[IF_TYPE_SATA]		= UCLASS_AHCI,
 	[IF_TYPE_HOST]		= UCLASS_ROOT,
 	[IF_TYPE_NVME]		= UCLASS_NVME,
-	[IF_TYPE_EFI]		= UCLASS_EFI,
+	[IF_TYPE_EFI_MEDIA]	= UCLASS_EFI_MEDIA,
+	[IF_TYPE_EFI_LOADER]	= UCLASS_EFI_LOADER,
 	[IF_TYPE_VIRTIO]	= UCLASS_VIRTIO,
 	[IF_TYPE_PVBLOCK]	= UCLASS_PVBLOCK,
 };

drivers/block/efi-media-uclass.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Uclass for EFI media devices
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+
+UCLASS_DRIVER(efi_media) = {
+	.id		= UCLASS_EFI_MEDIA,
+	.name		= "efi_media",
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+};

drivers/block/efi_blk.c

@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Block driver for EFI devices
+ * This supports a media driver of UCLASS_EFI with a child UCLASS_BLK
+ * It allows block-level access to EFI devices made available via EFI boot
+ * services
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <common.h>
+#include <blk.h>
+#include <dm.h>
+#include <efi.h>
+#include <efi_api.h>
+
+struct efi_block_plat {
+	struct efi_block_io *blkio;
+};
+
+/**
+ * Read from block device
+ *
+ * @dev:	device
+ * @blknr:	first block to be read
+ * @blkcnt:	number of blocks to read
+ * @buffer:	output buffer
+ * Return:	number of blocks transferred
+ */
+static ulong efi_bl_read(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
+			 void *buffer)
+{
+	struct efi_block_plat *plat = dev_get_plat(dev);
+	struct efi_block_io *io = plat->blkio;
+	efi_status_t ret;
+
+	log_debug("read buf=%p, block=%lx, count=%lx: ", buffer, (ulong)blknr,
+		  (ulong)blkcnt);
+	ret = io->read_blocks(io, io->media->media_id, blknr,
+			      blkcnt * io->media->block_size, buffer);
+	log_debug("ret=%lx (dec %ld)\n", ret & ~EFI_ERROR_MASK,
+		  ret & ~EFI_ERROR_MASK);
+	if (ret)
+		return 0;
+
+	return blkcnt;
+}
+
+/**
+ * Write to block device
+ *
+ * @dev:	device
+ * @blknr:	first block to be write
+ * @blkcnt:	number of blocks to write
+ * @buffer:	input buffer
+ * Return:	number of blocks transferred
+ */
+static ulong efi_bl_write(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
+			  const void *buffer)
+{
+	struct efi_block_plat *plat = dev_get_plat(dev);
+	struct efi_block_io *io = plat->blkio;
+	efi_status_t ret;
+
+	log_debug("write buf=%p, block=%lx, count=%lx: ", buffer, (ulong)blknr,
+		  (ulong)blkcnt);
+	ret = io->write_blocks(io, io->media->media_id, blknr,
+			       blkcnt * io->media->block_size, (void *)buffer);
+	log_debug("ret=%lx (dec %ld)\n", ret & ~EFI_ERROR_MASK,
+		  ret & ~EFI_ERROR_MASK);
+	if (ret)
+		return 0;
+
+	return blkcnt;
+}
+
+/* Block device driver operators */
+static const struct blk_ops efi_blk_ops = {
+	.read	= efi_bl_read,
+	.write	= efi_bl_write,
+};
+
+U_BOOT_DRIVER(efi_block) = {
+	.name		= "efi_block",
+	.id		= UCLASS_BLK,
+	.ops		= &efi_blk_ops,
+	.plat_auto	= sizeof(struct efi_block_plat),
+};
+
+static int efi_media_bind(struct udevice *dev)
+{
+	struct efi_media_plat *plat = dev_get_plat(dev);
+	struct efi_block_plat *blk_plat;
+	struct udevice *blk;
+	int ret;
+
+	ret = blk_create_devicef(dev, "efi_block", "blk", IF_TYPE_EFI_MEDIA,
+				 dev_seq(dev), plat->blkio->media->block_size,
+				 plat->blkio->media->last_block, &blk);
+	if (ret) {
+		debug("Cannot create block device\n");
+		return ret;
+	}
+	blk_plat = dev_get_plat(blk);
+	blk_plat->blkio = plat->blkio;
+
+	return 0;
+}
+
+U_BOOT_DRIVER(efi_media) = {
+	.name		= "efi_media",
+	.id		= UCLASS_EFI_MEDIA,
+	.bind		= efi_media_bind,
+	.plat_auto	= sizeof(struct efi_media_plat),
+};

drivers/block/sb_efi_media.c

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * EFI_MEDIA driver for sandbox
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+
+static const struct udevice_id sandbox_efi_media_ids[] = {
+	{ .compatible = "sandbox,efi-media" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_efi_media) = {
+	.name		= "sandbox_efi_media",
+	.id		= UCLASS_EFI_MEDIA,
+	.of_match	= sandbox_efi_media_ids,
+};

include/blk.h

@@ -34,9 +34,10 @@ enum if_type {
 	IF_TYPE_SATA,
 	IF_TYPE_HOST,
 	IF_TYPE_NVME,
-	IF_TYPE_EFI,
+	IF_TYPE_EFI_LOADER,
 	IF_TYPE_PVBLOCK,
 	IF_TYPE_VIRTIO,
+	IF_TYPE_EFI_MEDIA,
 
 	IF_TYPE_COUNT,			/* Number of interface types */
 };

include/dm/uclass-id.h

@@ -48,7 +48,8 @@ enum uclass_id {
 	UCLASS_DMA,		/* Direct Memory Access */
 	UCLASS_DSA,		/* Distributed (Ethernet) Switch Architecture */
 	UCLASS_ECDSA,		/* Elliptic curve cryptographic device */
-	UCLASS_EFI,		/* EFI managed devices */
+	UCLASS_EFI_LOADER,	/* Devices created by UEFI applications */
+	UCLASS_EFI_MEDIA,	/* Devices provided by UEFI firmware */
 	UCLASS_ETH,		/* Ethernet device */
 	UCLASS_ETH_PHY,		/* Ethernet PHY device */
 	UCLASS_FIRMWARE,	/* Firmware */

include/efi.h

@@ -414,6 +414,17 @@ struct efi_priv {
 	void *next_hdr;
 };
 
+/*
+ * EFI attributes of the udevice handled by efi_media driver
+ *
+ * @handle: handle of the controller on which this driver is installed
+ * @blkio: block io protocol proxied by this driver
+ */
+struct efi_media_plat {
+	efi_handle_t		handle;
+	struct efi_block_io	*blkio;
+};
+
 /* Base address of the EFI image */
 extern char image_base[];
 

include/efi_loader.h

@@ -525,6 +525,8 @@ efi_status_t efi_disk_register(void);
 efi_status_t efi_rng_register(void);
 /* Called by efi_init_obj_list() to install EFI_TCG2_PROTOCOL */
 efi_status_t efi_tcg2_register(void);
+/* Called by efi_init_obj_list() to do initial measurement */
+efi_status_t efi_tcg2_do_initial_measurement(void);
 /* measure the pe-coff image, extend PCR and add Event Log */
 efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
 				   struct efi_loaded_image_obj *handle,

lib/efi_driver/efi_block_device.c

@@ -147,7 +147,7 @@ static int efi_bl_bind(efi_handle_t handle, void *interface)
 	if (!obj)
 		return -ENOENT;
 
-	devnum = blk_find_max_devnum(IF_TYPE_EFI);
+	devnum = blk_find_max_devnum(IF_TYPE_EFI_LOADER);
 	if (devnum == -ENODEV)
 		devnum = 0;
 	else if (devnum < 0)
@@ -159,8 +159,8 @@ static int efi_bl_bind(efi_handle_t handle, void *interface)
 	sprintf(name, "efiblk#%d", devnum);
 
 	/* Create driver model udevice for the EFI block io device */
-	ret = blk_create_device(parent, "efi_blk", name, IF_TYPE_EFI, devnum,
+	ret = blk_create_device(parent, "efi_blk", name, IF_TYPE_EFI_LOADER,
-				io->media->block_size,
+				devnum, io->media->block_size,
 				(lbaint_t)io->media->last_block, &bdev);
 	if (ret)
 		return ret;
@@ -209,6 +209,6 @@ static const struct efi_driver_ops driver_ops = {
 /* Identify as EFI driver */
 U_BOOT_DRIVER(efi_block) = {
 	.name		= "EFI block driver",
-	.id		= UCLASS_EFI,
+	.id		= UCLASS_EFI_LOADER,
 	.ops		= &driver_ops,
 };

lib/efi_driver/efi_uclass.c

@@ -308,7 +308,7 @@ efi_status_t efi_driver_init(void)
 	log_debug("Initializing EFI driver framework\n");
 	for (drv = ll_entry_start(struct driver, driver);
 	     drv < ll_entry_end(struct driver, driver); ++drv) {
-		if (drv->id == UCLASS_EFI) {
+		if (drv->id == UCLASS_EFI_LOADER) {
 			ret = efi_add_driver(drv);
 			if (ret != EFI_SUCCESS) {
 				log_err("Failed to add EFI driver %s\n",
@@ -328,7 +328,7 @@ efi_status_t efi_driver_init(void)
  */
 static int efi_uc_init(struct uclass *class)
 {
-	log_debug("Initializing UCLASS_EFI\n");
+	log_debug("Initializing UCLASS_EFI_LOADER\n");
 	return 0;
 }
 
@@ -340,13 +340,13 @@ static int efi_uc_init(struct uclass *class)
  */
 static int efi_uc_destroy(struct uclass *class)
 {
-	log_debug("Destroying UCLASS_EFI\n");
+	log_debug("Destroying UCLASS_EFI_LOADER\n");
 	return 0;
 }
 
 UCLASS_DRIVER(efi) = {
 	.name		= "efi",
-	.id		= UCLASS_EFI,
+	.id		= UCLASS_EFI_LOADER,
 	.init		= efi_uc_init,
 	.destroy	= efi_uc_destroy,
 };

lib/efi_loader/Kconfig

@@ -308,6 +308,8 @@ config EFI_TCG2_PROTOCOL
 	bool "EFI_TCG2_PROTOCOL support"
 	default y
 	depends on TPM_V2
+	# Sandbox TPM currently fails on GetCapabilities needed for TCG2
+	depends on !SANDBOX
 	select SHA1
 	select SHA256
 	select SHA384

lib/efi_loader/efi_boottime.c

@@ -3016,9 +3016,12 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
 	if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
 		if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
 			ret = efi_tcg2_measure_efi_app_invocation(image_obj);
-			if (ret != EFI_SUCCESS) {
+			if (ret == EFI_SECURITY_VIOLATION) {
-				log_warning("tcg2 measurement fails(0x%lx)\n",
+				/*
-					    ret);
+				 * TCG2 Protocol is installed but no TPM device found,
+				 * this is not expected.
+				 */
+				return EFI_EXIT(EFI_SECURITY_VIOLATION);
 			}
 		}
 	}

lib/efi_loader/efi_image_loader.c

@@ -934,9 +934,16 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
 
 #if CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL)
 	/* Measure an PE/COFF image */
-	if (tcg2_measure_pe_image(efi, efi_size, handle,
+	ret = tcg2_measure_pe_image(efi, efi_size, handle, loaded_image_info);
-				  loaded_image_info))
+	if (ret == EFI_SECURITY_VIOLATION) {
-		log_err("PE image measurement failed\n");
+		/*
+		 * TCG2 Protocol is installed but no TPM device found,
+		 * this is not expected.
+		 */
+		log_err("PE image measurement failed, no tpm device found\n");
+		goto err;
+	}
+
 #endif
 
 	/* Copy PE headers */

lib/efi_loader/efi_setup.c

@@ -241,6 +241,10 @@ efi_status_t efi_init_obj_list(void)
 		ret = efi_tcg2_register();
 		if (ret != EFI_SUCCESS)
 			goto out;
+
+		ret = efi_tcg2_do_initial_measurement();
+		if (ret == EFI_SECURITY_VIOLATION)
+			goto out;
 	}
 
 	/* Secure boot */

lib/efi_loader/efi_tcg2.c

@@ -153,6 +153,15 @@ static u16 alg_to_len(u16 hash_alg)
 	return 0;
 }
 
+static bool is_tcg2_protocol_installed(void)
+{
+	struct efi_handler *handler;
+	efi_status_t ret;
+
+	ret = efi_search_protocol(efi_root, &efi_guid_tcg2_protocol, &handler);
+	return ret == EFI_SUCCESS;
+}
+
 static u32 tcg_event_final_size(struct tpml_digest_values *digest_list)
 {
 	u32 len;
@@ -963,9 +972,12 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
 	IMAGE_NT_HEADERS32 *nt;
 	struct efi_handler *handler;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
-		return ret;
+		return EFI_SECURITY_VIOLATION;
 
 	switch (handle->image_type) {
 	case IMAGE_SUBSYSTEM_EFI_APPLICATION:
@@ -1664,6 +1676,14 @@ void tcg2_uninit(void)
 	event_log.buffer = NULL;
 	efi_free_pool(event_log.final_buffer);
 	event_log.final_buffer = NULL;
+
+	if (!is_tcg2_protocol_installed())
+		return;
+
+	ret = efi_remove_protocol(efi_root, &efi_guid_tcg2_protocol,
+				  (void *)&efi_tcg2_protocol);
+	if (ret != EFI_SUCCESS)
+		log_err("Failed to remove EFI TCG2 protocol\n");
 }
 
 /**
@@ -2172,12 +2192,15 @@ efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *ha
 	u32 event = 0;
 	struct smbios_entry *entry;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	if (tcg2_efi_app_invoked)
 		return EFI_SUCCESS;
 
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
-		return ret;
+		return EFI_SECURITY_VIOLATION;
 
 	ret = tcg2_measure_boot_variable(dev);
 	if (ret != EFI_SUCCESS)
@@ -2222,6 +2245,9 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void)
 	efi_status_t ret;
 	struct udevice *dev;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
 		return ret;
@@ -2247,6 +2273,12 @@ efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
 	EFI_ENTRY("%p, %p", event, context);
 
 	event_log.ebs_called = true;
+
+	if (!is_tcg2_protocol_installed()) {
+		ret = EFI_SUCCESS;
+		goto out;
+	}
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
 		goto out;
@@ -2276,6 +2308,9 @@ efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
 	struct udevice *dev;
 	efi_status_t ret;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
 		goto out;
@@ -2345,12 +2380,37 @@ error:
 	return ret;
 }
 
+/**
+ * efi_tcg2_do_initial_measurement() - do initial measurement
+ *
+ * Return:	status code
+ */
+efi_status_t efi_tcg2_do_initial_measurement(void)
+{
+	efi_status_t ret;
+	struct udevice *dev;
+
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		return EFI_SECURITY_VIOLATION;
+
+	ret = tcg2_measure_secure_boot_variable(dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+out:
+	return ret;
+}
+
 /**
  * efi_tcg2_register() - register EFI_TCG2_PROTOCOL
  *
  * If a TPM2 device is available, the TPM TCG2 Protocol is registered
  *
- * Return:	An error status is only returned if adding the protocol fails.
+ * Return:	status code
  */
 efi_status_t efi_tcg2_register(void)
 {
@@ -2373,8 +2433,10 @@ efi_status_t efi_tcg2_register(void)
 	}
 
 	ret = efi_init_event_log();
-	if (ret != EFI_SUCCESS)
+	if (ret != EFI_SUCCESS) {
+		tcg2_uninit();
 		goto fail;
+	}
 
 	ret = efi_add_protocol(efi_root, &efi_guid_tcg2_protocol,
 			       (void *)&efi_tcg2_protocol);
@@ -2391,24 +2453,9 @@ efi_status_t efi_tcg2_register(void)
 		goto fail;
 	}
 
-	ret = tcg2_measure_secure_boot_variable(dev);
-	if (ret != EFI_SUCCESS) {
-		tcg2_uninit();
-		goto fail;
-	}
-
 	return ret;
 
 fail:
 	log_err("Cannot install EFI_TCG2_PROTOCOL\n");
-	/*
+	return ret;
-	 * Return EFI_SUCCESS and don't stop the EFI subsystem.
-	 * That's done for 2 reasons
-	 * - If the protocol is not installed the PCRs won't be extended.  So
-	 *   someone later in the boot flow will notice that and take the
-	 *   necessary actions.
-	 * - The TPM sandbox is limited and we won't be able to run any efi
-	 *   related tests with TCG2 enabled
-	 */
-	return EFI_SUCCESS;
 }

test/dm/Makefile

@@ -37,6 +37,7 @@ obj-$(CONFIG_DMA) += dma.o
 obj-$(CONFIG_VIDEO_MIPI_DSI) += dsi_host.o
 obj-$(CONFIG_DM_DSA) += dsa.o
 obj-$(CONFIG_ECDSA_VERIFY) += ecdsa.o
+obj-$(CONFIG_EFI_MEDIA_SANDBOX) += efi_media.o
 obj-$(CONFIG_DM_ETH) += eth.o
 ifneq ($(CONFIG_EFI_PARTITION),)
 obj-$(CONFIG_FASTBOOT_FLASH_MMC) += fastboot.o

test/dm/efi_media.c

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test for EFI_MEDIA uclass
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/test.h>
+#include <dm/test.h>
+#include <test/test.h>
+#include <test/ut.h>
+
+/* Test that we can use the EFI_MEDIA uclass */
+static int dm_test_efi_media(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_first_device_err(UCLASS_EFI_MEDIA, &dev));
+
+	return 0;
+}
+DM_TEST(dm_test_efi_media, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);