[PATCH v7 0/3] efi_vars: Implement SPI Flash storage for EFI

[PATCH v7 0/3] efi_vars: Implement SPI Flash storage for EFI

[Michal Simek]

This is updated series based on v3 version sent here
https://lore.kernel.org/all/20231126220836.374956-1-i@shantur.com/

that's why I am continuing on v4 instead of starting from scratch.

Tested on kv260 with saving variables to location where User MTD partition
is.
CONFIG_EFI_VARIABLE_SF_STORE=y
CONFIG_EFI_RT_VOLATILE_STORE=y
CONFIG_EFI_VARIABLE_SF_OFFSET=0x22a0000

In Linux:
root@som:~# mount | grep efivars
none on /sys/firmware/efi/efivars type efivarfs (rw,relatime)
root@som:~# printf '\x07\x00\x00\x00Hello' \
  | sudo tee /sys/firmware/efi/efivars/TestVar-12345678-1234-1234-1234-123456789abc
Helloroot@som:~#
root@som:~# dd if=/sys/firmware/efi/efivars/VarToFile-b2ac5fc9-92b7-4acd-aeac-11e818c3130c \
       of=/tmp/vars skip=4 bs=1
1352+0 records in
1352+0 records out
1352 bytes (1.4 kB, 1.3 KiB) copied, 0.380992 s, 3.5 kB/s
root@som:~# flashcp /tmp/vars /dev/mtd16
root@som:~# reboot

Reboot and then in U-Boot:

ZynqMP> pri -e
...
TestVar:
    12345678-1234-1234-1234-123456789abc (12345678-1234-1234-1234-123456789abc)
    NV|BS|RT, DataSize = 0x5
    00000000: 48 65 6c 6c 6f                                   Hello
...

Thanks,
Michal

Changes in v7:
- sed -i 's/efi_var_from/efi_var_from_storage/g'
- sed -i 's/efi_var_from/efi_var_from_storage/g'

Changes in v6:
- Return EFI_SUCCESS in efi_set_variable_int() when
  CONFIG_EFI_VARIABLE_NO_STORE is enabled
- sed -i 's/efi_var_read/efi_var_from/g'
- sed -i 's/efi_var_write/efi_var_to_storage/g'
- sed -i 's/efi_var_read/efi_var_from/g'
- sed -i 's/efi_var_write/efi_var_to_storage/g'

Changes in v5:
- Invert logic in efi_variable.c and avoid #if

Changes in v4:
- New patch based on review comments from v3
- Extend Kconfig description
- Extend commit message and describe efivar missing part
- use unify methods for reading/writing variable

Changes in v3:
- Fixed compiler warnings.

Changes in v2:
- Refactored efi_var_file to move common parts out as requested
- Changed ifdefs to use CONFIG_IS_DEFINED
- Fixed typos

Michal Simek (1):
  efi_var: Unify read/write access helper function

Shantur Rathore (2):
  efi_var_file: refactor to move buffer functions
  efi_vars: Implement SPI Flash store

 include/efi_variable.h          | 18 +++----
 lib/efi_loader/Kconfig          | 34 +++++++++++-
 lib/efi_loader/Makefile         |  3 +-
 lib/efi_loader/efi_var_common.c | 42 +++++++++++++++
 lib/efi_loader/efi_var_file.c   | 65 ++---------------------
 lib/efi_loader/efi_var_sf.c     | 92 +++++++++++++++++++++++++++++++++
 lib/efi_loader/efi_variable.c   | 19 ++++---
 7 files changed, 195 insertions(+), 78 deletions(-)
 create mode 100644 lib/efi_loader/efi_var_sf.c

-- 
2.43.0

base-commit: e206e3ab2ad266935b81f5e9d3af2ed47b866826

[PATCH v7 1/3] efi_var_file: refactor to move buffer functions

[Michal Simek]

From: Shantur Rathore <i@shantur.com>

Currently efi_var_file.c has functions to store/read
EFI variables to/from memory buffer. These functions
can be used with other EFI variable stores so move
them out to efi_var_common.c

Signed-off-by: Shantur Rathore <i@shantur.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
---

(no changes since v6)

Changes in v6:
- Return EFI_SUCCESS in efi_set_variable_int() when
  CONFIG_EFI_VARIABLE_NO_STORE is enabled

Changes in v5:
- Invert logic in efi_variable.c and avoid #if

 include/efi_variable.h          |  5 +++
 lib/efi_loader/Makefile         |  2 +-
 lib/efi_loader/efi_var_common.c | 42 ++++++++++++++++++++++++
 lib/efi_loader/efi_var_file.c   | 57 ---------------------------------
 lib/efi_loader/efi_variable.c   | 17 +++++++---
 5 files changed, 60 insertions(+), 63 deletions(-)

diff --git a/include/efi_variable.h b/include/efi_variable.h
index 4065cf45ecaf..ee68fa4a885f 100644
--- a/include/efi_variable.h
+++ b/include/efi_variable.h
@@ -161,6 +161,11 @@ efi_status_t efi_var_to_file(void);
 efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *lenp,
 					    u32 check_attr_mask);
 
+/* GUID used by Shim to store the MOK database */
+#define SHIM_LOCK_GUID \
+	EFI_GUID(0x605dab50, 0xe046, 0x4300, \
+		 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
+
 /**
  * efi_var_restore() - restore EFI variables from buffer
  *
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index f490081f6542..ca1775eb03be 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -53,7 +53,7 @@ ifeq ($(CONFIG_EFI_MM_COMM_TEE),y)
 obj-y += efi_variable_tee.o
 else
 obj-y += efi_variable.o
-obj-y += efi_var_file.o
+obj-$(CONFIG_EFI_VARIABLE_FILE_STORE) += efi_var_file.o
 obj-$(CONFIG_EFI_VARIABLES_PRESEED) += efi_var_seed.o
 endif
 obj-y += efi_watchdog.o
diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index 4b34a58b4cf7..5ea1688dca3d 100644
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -41,6 +41,7 @@ static const struct efi_auth_var_name_type name_type[] = {
 
 static bool efi_secure_boot;
 static enum efi_secure_mode efi_secure_mode;
+static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
 
 /**
  * efi_efi_get_variable() - retrieve value of a UEFI variable
@@ -488,3 +489,44 @@ efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *
 
 	return EFI_SUCCESS;
 }
+
+efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
+{
+	struct efi_var_entry *var, *last_var;
+	u16 *data;
+	efi_status_t ret;
+
+	if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
+	    buf->crc32 != crc32(0, (u8 *)buf->var,
+				buf->length - sizeof(struct efi_var_file))) {
+		log_err("Invalid EFI variables file\n");
+		return EFI_INVALID_PARAMETER;
+	}
+
+	last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
+	for (var = buf->var; var < last_var;
+	     var = (struct efi_var_entry *)ALIGN((uintptr_t)data + var->length, 8)) {
+		data = var->name + u16_strlen(var->name) + 1;
+
+		/*
+		 * Secure boot related and volatile variables shall only be
+		 * restored from U-Boot's preseed.
+		 */
+		if (!safe &&
+		    (efi_auth_var_get_type(var->name, &var->guid) !=
+		     EFI_AUTH_VAR_NONE ||
+		     !guidcmp(&var->guid, &shim_lock_guid) ||
+		     !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
+			continue;
+		if (!var->length)
+			continue;
+		if (efi_var_mem_find(&var->guid, var->name, NULL))
+			continue;
+		ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
+				      var->length, data, 0, NULL,
+				      var->time);
+		if (ret != EFI_SUCCESS)
+			log_err("Failed to set EFI variable %ls\n", var->name);
+	}
+	return EFI_SUCCESS;
+}
diff --git a/lib/efi_loader/efi_var_file.c b/lib/efi_loader/efi_var_file.c
index ba0bf33ffbd1..d32edaac277d 100644
--- a/lib/efi_loader/efi_var_file.c
+++ b/lib/efi_loader/efi_var_file.c
@@ -14,17 +14,9 @@
 #include <mapmem.h>
 #include <efi_loader.h>
 #include <efi_variable.h>
-#include <u-boot/crc.h>
 
 #define PART_STR_LEN 10
 
-/* GUID used by Shim to store the MOK database */
-#define SHIM_LOCK_GUID \
-	EFI_GUID(0x605dab50, 0xe046, 0x4300, \
-		 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
-
-static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
-
 /**
  * efi_set_blk_dev_to_system_partition() - select EFI system partition
  *
@@ -59,7 +51,6 @@ static efi_status_t __maybe_unused efi_set_blk_dev_to_system_partition(void)
  */
 efi_status_t efi_var_to_file(void)
 {
-#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
 	efi_status_t ret;
 	struct efi_var_file *buf;
 	loff_t len;
@@ -91,52 +82,6 @@ error:
 out:
 	free(buf);
 	return ret;
-#else
-	return EFI_SUCCESS;
-#endif
-}
-
-efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
-{
-	struct efi_var_entry *var, *last_var;
-	u16 *data;
-	efi_status_t ret;
-
-	if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
-	    buf->crc32 != crc32(0, (u8 *)buf->var,
-				buf->length - sizeof(struct efi_var_file))) {
-		log_err("Invalid EFI variables file\n");
-		return EFI_INVALID_PARAMETER;
-	}
-
-	last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
-	for (var = buf->var; var < last_var;
-	     var = (struct efi_var_entry *)
-		   ALIGN((uintptr_t)data + var->length, 8)) {
-
-		data = var->name + u16_strlen(var->name) + 1;
-
-		/*
-		 * Secure boot related and volatile variables shall only be
-		 * restored from U-Boot's preseed.
-		 */
-		if (!safe &&
-		    (efi_auth_var_get_type(var->name, &var->guid) !=
-		     EFI_AUTH_VAR_NONE ||
-		     !guidcmp(&var->guid, &shim_lock_guid) ||
-		     !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
-			continue;
-		if (!var->length)
-			continue;
-		if (efi_var_mem_find(&var->guid, var->name, NULL))
-			continue;
-		ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
-				      var->length, data, 0, NULL,
-				      var->time);
-		if (ret != EFI_SUCCESS)
-			log_err("Failed to set EFI variable %ls\n", var->name);
-	}
-	return EFI_SUCCESS;
 }
 
 /**
@@ -155,7 +100,6 @@ efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
  */
 efi_status_t efi_var_from_file(void)
 {
-#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
 	struct efi_var_file *buf;
 	loff_t len;
 	efi_status_t ret;
@@ -180,6 +124,5 @@ efi_status_t efi_var_from_file(void)
 		log_err("Invalid EFI variables file\n");
 error:
 	free(buf);
-#endif
 	return EFI_SUCCESS;
 }
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index f3533f4def3a..6e45134c61bf 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -397,11 +397,15 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
 		ret = EFI_SUCCESS;
 
 	/*
-	 * Write non-volatile EFI variables to file
+	 * Write non-volatile EFI variables
 	 * TODO: check if a value change has occured to avoid superfluous writes
 	 */
-	if (attributes & EFI_VARIABLE_NON_VOLATILE)
+	if (attributes & EFI_VARIABLE_NON_VOLATILE) {
+		if (IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE))
+			return EFI_SUCCESS;
+
 		efi_var_to_file();
+	}
 
 	return EFI_SUCCESS;
 }
@@ -594,9 +598,12 @@ efi_status_t efi_init_variables(void)
 	if (ret != EFI_SUCCESS)
 		return ret;
 
-	ret = efi_var_from_file();
-	if (ret != EFI_SUCCESS)
-		return ret;
+	if (!IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE)) {
+		ret = efi_var_from_file();
+		if (ret != EFI_SUCCESS)
+			return ret;
+	}
+
 	if (IS_ENABLED(CONFIG_EFI_VARIABLES_PRESEED)) {
 		ret = efi_var_restore((struct efi_var_file *)
 				      __efi_var_file_begin, true);
-- 
2.43.0

[PATCH v7 2/3] efi_var: Unify read/write access helper function

[Michal Simek]

efi_var_to/from_file() suggest method where variables are placed. But there
is no reason for it and generic name can be used to wire also different
locations for variables.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---

Changes in v7:
- sed -i 's/efi_var_from/efi_var_from_storage/g'

Changes in v6:
- sed -i 's/efi_var_read/efi_var_from/g'
- sed -i 's/efi_var_write/efi_var_to_storage/g'

Changes in v4:
- New patch based on review comments from v3

 include/efi_variable.h        | 13 ++++---------
 lib/efi_loader/efi_var_file.c |  8 ++++----
 lib/efi_loader/efi_variable.c |  4 ++--
 3 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/include/efi_variable.h b/include/efi_variable.h
index ee68fa4a885f..fc1184e5ca1a 100644
--- a/include/efi_variable.h
+++ b/include/efi_variable.h
@@ -137,13 +137,11 @@ struct efi_var_file {
 };
 
 /**
- * efi_var_to_file() - save non-volatile variables as file
- *
- * File ubootefi.var is created on the EFI system partion.
+ * efi_var_to_storage() - save non-volatile variables
  *
  * Return:	status code
  */
-efi_status_t efi_var_to_file(void);
+efi_status_t efi_var_to_storage(void);
 
 /**
  * efi_var_collect() - collect variables in buffer
@@ -178,17 +176,14 @@ efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *
 efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe);
 
 /**
- * efi_var_from_file() - read variables from file
- *
- * File ubootefi.var is read from the EFI system partitions and the variables
- * stored in the file are created.
+ * efi_var_from_storage() - read variables
  *
  * In case the file does not exist yet or a variable cannot be set EFI_SUCCESS
  * is returned.
  *
  * Return:	status code
  */
-efi_status_t efi_var_from_file(void);
+efi_status_t efi_var_from_storage(void);
 
 /**
  * efi_var_mem_init() - set-up variable list
diff --git a/lib/efi_loader/efi_var_file.c b/lib/efi_loader/efi_var_file.c
index d32edaac277d..3b50911215eb 100644
--- a/lib/efi_loader/efi_var_file.c
+++ b/lib/efi_loader/efi_var_file.c
@@ -43,13 +43,13 @@ static efi_status_t __maybe_unused efi_set_blk_dev_to_system_partition(void)
 }
 
 /**
- * efi_var_to_file() - save non-volatile variables as file
+ * efi_var_to_storage() - save non-volatile variables as file
  *
  * File ubootefi.var is created on the EFI system partion.
  *
  * Return:	status code
  */
-efi_status_t efi_var_to_file(void)
+efi_status_t efi_var_to_storage(void)
 {
 	efi_status_t ret;
 	struct efi_var_file *buf;
@@ -85,7 +85,7 @@ out:
 }
 
 /**
- * efi_var_from_file() - read variables from file
+ * efi_var_from_storage() - read variables from file
  *
  * File ubootefi.var is read from the EFI system partitions and the variables
  * stored in the file are created.
@@ -98,7 +98,7 @@ out:
  *
  * Return:	status code
  */
-efi_status_t efi_var_from_file(void)
+efi_status_t efi_var_from_storage(void)
 {
 	struct efi_var_file *buf;
 	loff_t len;
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 6e45134c61bf..8512bc20f11e 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -404,7 +404,7 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
 		if (IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE))
 			return EFI_SUCCESS;
 
-		efi_var_to_file();
+		efi_var_to_storage();
 	}
 
 	return EFI_SUCCESS;
@@ -599,7 +599,7 @@ efi_status_t efi_init_variables(void)
 		return ret;
 
 	if (!IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE)) {
-		ret = efi_var_from_file();
+		ret = efi_var_from_storage();
 		if (ret != EFI_SUCCESS)
 			return ret;
 	}
-- 
2.43.0

[PATCH v7 3/3] efi_vars: Implement SPI Flash store

[Michal Simek]

From: Shantur Rathore <i@shantur.com>

Currently U-Boot uses ESP as storage for EFI variables.
Devices with SPI Flash are used for storing environment with this
commit we allow EFI variables to be stored on SPI Flash.

https://github.com/rhboot/efivar
is not updated to support this location that's why you can mimic it by
running:
dd if=/sys/firmware/efi/efivars/VarToFile-b2ac5fc9-92b7-4acd-aeac-11e818c3130c \
   of=/tmp/vars skip=4 bs=1
flashcp /tmp/vars /dev/mtdX

where mtdX should match location defined by
CONFIG_EFI_VARIABLE_SF_OFFSET/CONFIG_EFI_VAR_BUF_SIZE.

Signed-off-by: Shantur Rathore <i@shantur.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
---

Changes in v7:
- sed -i 's/efi_var_from/efi_var_from_storage/g'

Changes in v6:
- sed -i 's/efi_var_read/efi_var_from/g'
- sed -i 's/efi_var_write/efi_var_to_storage/g'

Changes in v4:
- Extend Kconfig description
- Extend commit message and describe efivar missing part
- use unify methods for reading/writing variable

Changes in v3:
- Fixed compiler warnings.

Changes in v2:
- Refactored efi_var_file to move common parts out as requested
- Changed ifdefs to use CONFIG_IS_DEFINED
- Fixed typos

 lib/efi_loader/Kconfig      | 34 +++++++++++++-
 lib/efi_loader/Makefile     |  1 +
 lib/efi_loader/efi_var_sf.c | 92 +++++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+), 1 deletion(-)
 create mode 100644 lib/efi_loader/efi_var_sf.c

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index 13e44be1d067..bb40cc899a13 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -123,6 +123,24 @@ config EFI_VARIABLE_FILE_STORE
 	  Select this option if you want non-volatile UEFI variables to be
 	  stored as file /ubootefi.var on the EFI system partition.
 
+config EFI_VARIABLE_SF_STORE
+	bool "Store non-volatile UEFI variables in SPI Flash"
+	depends on SPI_FLASH
+	help
+	  Select this option if you want non-volatile UEFI variables to be
+	  stored in SPI Flash.
+
+	  Define CONFIG_EFI_VARIABLE_SF_OFFSET as offset in SPI Flash to use as
+	  the storage for variables. CONFIG_EFI_VAR_BUF_SIZE defines the space
+	  needed.
+
+	  Note that SPI Flash devices have a limited number of program/erase
+	  cycles. Frequent updates to UEFI variables may cause excessive wear
+	  and can permanently damage the flash device, particularly on SPI NAND
+	  or low-end SPI NOR parts without wear leveling. This option should be
+	  used with care on such systems, and is not recommended for platforms
+	  where UEFI variables are updated frequently.
+
 config EFI_MM_COMM_TEE
 	bool "UEFI variables storage service via the trusted world"
 	depends on OPTEE
@@ -152,7 +170,7 @@ endchoice
 
 config EFI_RT_VOLATILE_STORE
 	bool "Allow variable runtime services in volatile storage (e.g RAM)"
-	depends on EFI_VARIABLE_FILE_STORE
+	depends on EFI_VARIABLE_FILE_STORE || EFI_VARIABLE_SF_STORE
 	help
 	  When EFI variables are stored on file we don't allow SetVariableRT,
 	  since the OS doesn't know how to write that file. At the same time
@@ -193,6 +211,20 @@ config FFA_SHARED_MM_BUF_ADDR
 	  the MM SP in secure world.
 	  It is assumed that the MM SP knows the address of the shared MM communication buffer.
 
+config EFI_VARIABLE_SF_OFFSET
+	hex "EFI variables in SPI flash offset"
+	depends on EFI_VARIABLE_SF_STORE
+	help
+	  Offset from the start of the SPI Flash where EFI variables will be stored.
+	  This should be aligned to the sector size of SPI Flash.
+
+config EFI_VARIABLE_SF_DEVICE_INDEX
+	int "Device Index for target SPI Flash"
+	default 0
+	help
+	  The index of SPI Flash device used for storing EFI variables. This would be
+	  needed if there are more than 1 SPI Flash devices available to use.
+
 config EFI_VARIABLES_PRESEED
 	bool "Initial values for UEFI variables"
 	depends on !COMPILE_TEST
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index ca1775eb03be..d73ad43951b1 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -54,6 +54,7 @@ obj-y += efi_variable_tee.o
 else
 obj-y += efi_variable.o
 obj-$(CONFIG_EFI_VARIABLE_FILE_STORE) += efi_var_file.o
+obj-$(CONFIG_EFI_VARIABLE_SF_STORE) += efi_var_sf.o
 obj-$(CONFIG_EFI_VARIABLES_PRESEED) += efi_var_seed.o
 endif
 obj-y += efi_watchdog.o
diff --git a/lib/efi_loader/efi_var_sf.c b/lib/efi_loader/efi_var_sf.c
new file mode 100644
index 000000000000..61d68f7c5c94
--- /dev/null
+++ b/lib/efi_loader/efi_var_sf.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SPI Flash interface for UEFI variables
+ *
+ * Copyright (c) 2023, Shantur Rathore
+ * Copyright (C) 2026, Advanced Micro Devices, Inc.
+ */
+
+#define LOG_CATEGORY LOGC_EFI
+
+#include <efi_loader.h>
+#include <efi_variable.h>
+#include <spi_flash.h>
+#include <dm.h>
+
+efi_status_t efi_var_to_storage(void)
+{
+	efi_status_t ret;
+	struct efi_var_file *buf;
+	loff_t len;
+	struct udevice *sfdev;
+
+	ret = efi_var_collect(&buf, &len, EFI_VARIABLE_NON_VOLATILE);
+	if (len > EFI_VAR_BUF_SIZE) {
+		log_err("EFI var buffer length more than target SPI Flash size");
+		ret = EFI_OUT_OF_RESOURCES;
+		goto error;
+	}
+
+	log_debug("%s - Got buffer to write buf->len : %d\n", __func__, buf->length);
+
+	if (ret != EFI_SUCCESS)
+		goto error;
+
+	ret = uclass_get_device(UCLASS_SPI_FLASH, CONFIG_EFI_VARIABLE_SF_DEVICE_INDEX, &sfdev);
+	if (ret)
+		goto error;
+
+	ret = spi_flash_erase_dm(sfdev, CONFIG_EFI_VARIABLE_SF_OFFSET, EFI_VAR_BUF_SIZE);
+	log_debug("%s - Erased SPI Flash offset %x\n", __func__, CONFIG_EFI_VARIABLE_SF_OFFSET);
+	if (ret)
+		goto error;
+
+	ret = spi_flash_write_dm(sfdev, CONFIG_EFI_VARIABLE_SF_OFFSET, len, buf);
+	log_debug("%s - Wrote buffer to SPI Flash : %ld\n", __func__, ret);
+
+	if (ret)
+		goto error;
+
+	ret = EFI_SUCCESS;
+error:
+	if (ret)
+		log_err("Failed to persist EFI variables in SF\n");
+	free(buf);
+	return ret;
+}
+
+efi_status_t efi_var_from_storage(void)
+{
+	struct efi_var_file *buf;
+	efi_status_t ret;
+	struct udevice *sfdev;
+
+	buf = calloc(1, EFI_VAR_BUF_SIZE);
+	if (!buf) {
+		log_err("%s - Unable to allocate buffer\n", __func__);
+		return EFI_OUT_OF_RESOURCES;
+	}
+
+	ret = uclass_get_device(UCLASS_SPI_FLASH, 0, &sfdev);
+	if (ret)
+		goto error;
+
+	ret = spi_flash_read_dm(sfdev, CONFIG_EFI_VARIABLE_SF_OFFSET,
+				EFI_VAR_BUF_SIZE, buf);
+
+	log_debug("%s - read buffer buf->length: %x\n", __func__, buf->length);
+
+	if (ret || buf->length < sizeof(struct efi_var_file)) {
+		log_err("%s - buffer read from SPI Flash isn't valid\n", __func__);
+		goto error;
+	}
+
+	ret = efi_var_restore(buf, false);
+	if (ret != EFI_SUCCESS)
+		log_err("%s - Unable to restore EFI variables from buffer\n", __func__);
+
+	ret = EFI_SUCCESS;
+error:
+	free(buf);
+	return ret;
+}
-- 
2.43.0

Re: [PATCH v7 3/3] efi_vars: Implement SPI Flash store

[Ilias Apalodimas]

On Tue, 3 Feb 2026 at 13:52, Michal Simek <michal.simek@amd.com> wrote:
>
> From: Shantur Rathore <i@shantur.com>
>
> Currently U-Boot uses ESP as storage for EFI variables.
> Devices with SPI Flash are used for storing environment with this
> commit we allow EFI variables to be stored on SPI Flash.
>
> https://github.com/rhboot/efivar
> is not updated to support this location that's why you can mimic it by
> running:
> dd if=/sys/firmware/efi/efivars/VarToFile-b2ac5fc9-92b7-4acd-aeac-11e818c3130c \
>    of=/tmp/vars skip=4 bs=1
> flashcp /tmp/vars /dev/mtdX
>
> where mtdX should match location defined by
> CONFIG_EFI_VARIABLE_SF_OFFSET/CONFIG_EFI_VAR_BUF_SIZE.
>
> Signed-off-by: Shantur Rathore <i@shantur.com>
> Signed-off-by: Michal Simek <michal.simek@amd.com>
> ---

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

>
> Changes in v7:
> - sed -i 's/efi_var_from/efi_var_from_storage/g'
>
> Changes in v6:
> - sed -i 's/efi_var_read/efi_var_from/g'
> - sed -i 's/efi_var_write/efi_var_to_storage/g'
>
> Changes in v4:
> - Extend Kconfig description
> - Extend commit message and describe efivar missing part
> - use unify methods for reading/writing variable
>
> Changes in v3:
> - Fixed compiler warnings.
>
> Changes in v2:
> - Refactored efi_var_file to move common parts out as requested
> - Changed ifdefs to use CONFIG_IS_DEFINED
> - Fixed typos
>
>  lib/efi_loader/Kconfig      | 34 +++++++++++++-
>  lib/efi_loader/Makefile     |  1 +
>  lib/efi_loader/efi_var_sf.c | 92 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 126 insertions(+), 1 deletion(-)
>  create mode 100644 lib/efi_loader/efi_var_sf.c
>
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index 13e44be1d067..bb40cc899a13 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -123,6 +123,24 @@ config EFI_VARIABLE_FILE_STORE
>           Select this option if you want non-volatile UEFI variables to be
>           stored as file /ubootefi.var on the EFI system partition.
>
> +config EFI_VARIABLE_SF_STORE
> +       bool "Store non-volatile UEFI variables in SPI Flash"
> +       depends on SPI_FLASH
> +       help
> +         Select this option if you want non-volatile UEFI variables to be
> +         stored in SPI Flash.
> +
> +         Define CONFIG_EFI_VARIABLE_SF_OFFSET as offset in SPI Flash to use as
> +         the storage for variables. CONFIG_EFI_VAR_BUF_SIZE defines the space
> +         needed.
> +
> +         Note that SPI Flash devices have a limited number of program/erase
> +         cycles. Frequent updates to UEFI variables may cause excessive wear
> +         and can permanently damage the flash device, particularly on SPI NAND
> +         or low-end SPI NOR parts without wear leveling. This option should be
> +         used with care on such systems, and is not recommended for platforms
> +         where UEFI variables are updated frequently.
> +
>  config EFI_MM_COMM_TEE
>         bool "UEFI variables storage service via the trusted world"
>         depends on OPTEE
> @@ -152,7 +170,7 @@ endchoice
>
>  config EFI_RT_VOLATILE_STORE
>         bool "Allow variable runtime services in volatile storage (e.g RAM)"
> -       depends on EFI_VARIABLE_FILE_STORE
> +       depends on EFI_VARIABLE_FILE_STORE || EFI_VARIABLE_SF_STORE
>         help
>           When EFI variables are stored on file we don't allow SetVariableRT,
>           since the OS doesn't know how to write that file. At the same time
> @@ -193,6 +211,20 @@ config FFA_SHARED_MM_BUF_ADDR
>           the MM SP in secure world.
>           It is assumed that the MM SP knows the address of the shared MM communication buffer.
>
> +config EFI_VARIABLE_SF_OFFSET
> +       hex "EFI variables in SPI flash offset"
> +       depends on EFI_VARIABLE_SF_STORE
> +       help
> +         Offset from the start of the SPI Flash where EFI variables will be stored.
> +         This should be aligned to the sector size of SPI Flash.
> +
> +config EFI_VARIABLE_SF_DEVICE_INDEX
> +       int "Device Index for target SPI Flash"
> +       default 0
> +       help
> +         The index of SPI Flash device used for storing EFI variables. This would be
> +         needed if there are more than 1 SPI Flash devices available to use.
> +
>  config EFI_VARIABLES_PRESEED
>         bool "Initial values for UEFI variables"
>         depends on !COMPILE_TEST
> diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> index ca1775eb03be..d73ad43951b1 100644
> --- a/lib/efi_loader/Makefile
> +++ b/lib/efi_loader/Makefile
> @@ -54,6 +54,7 @@ obj-y += efi_variable_tee.o
>  else
>  obj-y += efi_variable.o
>  obj-$(CONFIG_EFI_VARIABLE_FILE_STORE) += efi_var_file.o
> +obj-$(CONFIG_EFI_VARIABLE_SF_STORE) += efi_var_sf.o
>  obj-$(CONFIG_EFI_VARIABLES_PRESEED) += efi_var_seed.o
>  endif
>  obj-y += efi_watchdog.o
> diff --git a/lib/efi_loader/efi_var_sf.c b/lib/efi_loader/efi_var_sf.c
> new file mode 100644
> index 000000000000..61d68f7c5c94
> --- /dev/null
> +++ b/lib/efi_loader/efi_var_sf.c
> @@ -0,0 +1,92 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * SPI Flash interface for UEFI variables
> + *
> + * Copyright (c) 2023, Shantur Rathore
> + * Copyright (C) 2026, Advanced Micro Devices, Inc.
> + */
> +
> +#define LOG_CATEGORY LOGC_EFI
> +
> +#include <efi_loader.h>
> +#include <efi_variable.h>
> +#include <spi_flash.h>
> +#include <dm.h>
> +
> +efi_status_t efi_var_to_storage(void)
> +{
> +       efi_status_t ret;
> +       struct efi_var_file *buf;
> +       loff_t len;
> +       struct udevice *sfdev;
> +
> +       ret = efi_var_collect(&buf, &len, EFI_VARIABLE_NON_VOLATILE);
> +       if (len > EFI_VAR_BUF_SIZE) {
> +               log_err("EFI var buffer length more than target SPI Flash size");
> +               ret = EFI_OUT_OF_RESOURCES;
> +               goto error;
> +       }
> +
> +       log_debug("%s - Got buffer to write buf->len : %d\n", __func__, buf->length);
> +
> +       if (ret != EFI_SUCCESS)
> +               goto error;
> +
> +       ret = uclass_get_device(UCLASS_SPI_FLASH, CONFIG_EFI_VARIABLE_SF_DEVICE_INDEX, &sfdev);
> +       if (ret)
> +               goto error;
> +
> +       ret = spi_flash_erase_dm(sfdev, CONFIG_EFI_VARIABLE_SF_OFFSET, EFI_VAR_BUF_SIZE);
> +       log_debug("%s - Erased SPI Flash offset %x\n", __func__, CONFIG_EFI_VARIABLE_SF_OFFSET);
> +       if (ret)
> +               goto error;
> +
> +       ret = spi_flash_write_dm(sfdev, CONFIG_EFI_VARIABLE_SF_OFFSET, len, buf);
> +       log_debug("%s - Wrote buffer to SPI Flash : %ld\n", __func__, ret);
> +
> +       if (ret)
> +               goto error;
> +
> +       ret = EFI_SUCCESS;
> +error:
> +       if (ret)
> +               log_err("Failed to persist EFI variables in SF\n");
> +       free(buf);
> +       return ret;
> +}
> +
> +efi_status_t efi_var_from_storage(void)
> +{
> +       struct efi_var_file *buf;
> +       efi_status_t ret;
> +       struct udevice *sfdev;
> +
> +       buf = calloc(1, EFI_VAR_BUF_SIZE);
> +       if (!buf) {
> +               log_err("%s - Unable to allocate buffer\n", __func__);
> +               return EFI_OUT_OF_RESOURCES;
> +       }
> +
> +       ret = uclass_get_device(UCLASS_SPI_FLASH, 0, &sfdev);
> +       if (ret)
> +               goto error;
> +
> +       ret = spi_flash_read_dm(sfdev, CONFIG_EFI_VARIABLE_SF_OFFSET,
> +                               EFI_VAR_BUF_SIZE, buf);
> +
> +       log_debug("%s - read buffer buf->length: %x\n", __func__, buf->length);
> +
> +       if (ret || buf->length < sizeof(struct efi_var_file)) {
> +               log_err("%s - buffer read from SPI Flash isn't valid\n", __func__);
> +               goto error;
> +       }
> +
> +       ret = efi_var_restore(buf, false);
> +       if (ret != EFI_SUCCESS)
> +               log_err("%s - Unable to restore EFI variables from buffer\n", __func__);
> +
> +       ret = EFI_SUCCESS;
> +error:
> +       free(buf);
> +       return ret;
> +}
> --
> 2.43.0
>

Re: [PATCH v7 0/3] efi_vars: Implement SPI Flash storage for EFI

[Neil Armstrong]

On 2/3/26 12:51, Michal Simek wrote:
> 
> This is updated series based on v3 version sent here
> https://lore.kernel.org/all/20231126220836.374956-1-i@shantur.com/
> 
> that's why I am continuing on v4 instead of starting from scratch.
> 
> Tested on kv260 with saving variables to location where User MTD partition
> is.
> CONFIG_EFI_VARIABLE_SF_STORE=y
> CONFIG_EFI_RT_VOLATILE_STORE=y
> CONFIG_EFI_VARIABLE_SF_OFFSET=0x22a0000
> 
> In Linux:
> root@som:~# mount | grep efivars
> none on /sys/firmware/efi/efivars type efivarfs (rw,relatime)
> root@som:~# printf '\x07\x00\x00\x00Hello' \
>    | sudo tee /sys/firmware/efi/efivars/TestVar-12345678-1234-1234-1234-123456789abc
> Helloroot@som:~#
> root@som:~# dd if=/sys/firmware/efi/efivars/VarToFile-b2ac5fc9-92b7-4acd-aeac-11e818c3130c \
>         of=/tmp/vars skip=4 bs=1
> 1352+0 records in
> 1352+0 records out
> 1352 bytes (1.4 kB, 1.3 KiB) copied, 0.380992 s, 3.5 kB/s
> root@som:~# flashcp /tmp/vars /dev/mtd16
> root@som:~# reboot
> 
> Reboot and then in U-Boot:
> 
> ZynqMP> pri -e
> ...
> TestVar:
>      12345678-1234-1234-1234-123456789abc (12345678-1234-1234-1234-123456789abc)
>      NV|BS|RT, DataSize = 0x5
>      00000000: 48 65 6c 6c 6f                                   Hello
> ...
> 
> Thanks,
> Michal
> 
> Changes in v7:
> - sed -i 's/efi_var_from/efi_var_from_storage/g'
> - sed -i 's/efi_var_from/efi_var_from_storage/g'
> 
> Changes in v6:
> - Return EFI_SUCCESS in efi_set_variable_int() when
>    CONFIG_EFI_VARIABLE_NO_STORE is enabled
> - sed -i 's/efi_var_read/efi_var_from/g'
> - sed -i 's/efi_var_write/efi_var_to_storage/g'
> - sed -i 's/efi_var_read/efi_var_from/g'
> - sed -i 's/efi_var_write/efi_var_to_storage/g'
> 
> Changes in v5:
> - Invert logic in efi_variable.c and avoid #if
> 
> Changes in v4:
> - New patch based on review comments from v3
> - Extend Kconfig description
> - Extend commit message and describe efivar missing part
> - use unify methods for reading/writing variable
> 
> Changes in v3:
> - Fixed compiler warnings.
> 
> Changes in v2:
> - Refactored efi_var_file to move common parts out as requested
> - Changed ifdefs to use CONFIG_IS_DEFINED
> - Fixed typos
> 
> Michal Simek (1):
>    efi_var: Unify read/write access helper function
> 
> Shantur Rathore (2):
>    efi_var_file: refactor to move buffer functions
>    efi_vars: Implement SPI Flash store
> 
>   include/efi_variable.h          | 18 +++----
>   lib/efi_loader/Kconfig          | 34 +++++++++++-
>   lib/efi_loader/Makefile         |  3 +-
>   lib/efi_loader/efi_var_common.c | 42 +++++++++++++++
>   lib/efi_loader/efi_var_file.c   | 65 ++---------------------
>   lib/efi_loader/efi_var_sf.c     | 92 +++++++++++++++++++++++++++++++++
>   lib/efi_loader/efi_variable.c   | 19 ++++---
>   7 files changed, 195 insertions(+), 78 deletions(-)
>   create mode 100644 lib/efi_loader/efi_var_sf.c
> 

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on AML-S905D3-CC

Thanks,
Neil

Re: [PATCH v7 1/3] efi_var_file: refactor to move buffer functions

[Ilias Apalodimas]

Hi Michael

The CI seems to fail on this one for some reason.
https://source.denx.de/u-boot/custodians/u-boot-tpm/-/pipelines/29248

Can you take a look ?

Thanks
/Ilias




On Tue, 3 Feb 2026 at 13:51, Michal Simek <michal.simek@amd.com> wrote:
>
> From: Shantur Rathore <i@shantur.com>
>
> Currently efi_var_file.c has functions to store/read
> EFI variables to/from memory buffer. These functions
> can be used with other EFI variable stores so move
> them out to efi_var_common.c
>
> Signed-off-by: Shantur Rathore <i@shantur.com>
> Signed-off-by: Michal Simek <michal.simek@amd.com>
> ---
>
> (no changes since v6)
>
> Changes in v6:
> - Return EFI_SUCCESS in efi_set_variable_int() when
>   CONFIG_EFI_VARIABLE_NO_STORE is enabled
>
> Changes in v5:
> - Invert logic in efi_variable.c and avoid #if
>
>  include/efi_variable.h          |  5 +++
>  lib/efi_loader/Makefile         |  2 +-
>  lib/efi_loader/efi_var_common.c | 42 ++++++++++++++++++++++++
>  lib/efi_loader/efi_var_file.c   | 57 ---------------------------------
>  lib/efi_loader/efi_variable.c   | 17 +++++++---
>  5 files changed, 60 insertions(+), 63 deletions(-)
>
> diff --git a/include/efi_variable.h b/include/efi_variable.h
> index 4065cf45ecaf..ee68fa4a885f 100644
> --- a/include/efi_variable.h
> +++ b/include/efi_variable.h
> @@ -161,6 +161,11 @@ efi_status_t efi_var_to_file(void);
>  efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *lenp,
>                                             u32 check_attr_mask);
>
> +/* GUID used by Shim to store the MOK database */
> +#define SHIM_LOCK_GUID \
> +       EFI_GUID(0x605dab50, 0xe046, 0x4300, \
> +                0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
> +
>  /**
>   * efi_var_restore() - restore EFI variables from buffer
>   *
> diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> index f490081f6542..ca1775eb03be 100644
> --- a/lib/efi_loader/Makefile
> +++ b/lib/efi_loader/Makefile
> @@ -53,7 +53,7 @@ ifeq ($(CONFIG_EFI_MM_COMM_TEE),y)
>  obj-y += efi_variable_tee.o
>  else
>  obj-y += efi_variable.o
> -obj-y += efi_var_file.o
> +obj-$(CONFIG_EFI_VARIABLE_FILE_STORE) += efi_var_file.o
>  obj-$(CONFIG_EFI_VARIABLES_PRESEED) += efi_var_seed.o
>  endif
>  obj-y += efi_watchdog.o
> diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
> index 4b34a58b4cf7..5ea1688dca3d 100644
> --- a/lib/efi_loader/efi_var_common.c
> +++ b/lib/efi_loader/efi_var_common.c
> @@ -41,6 +41,7 @@ static const struct efi_auth_var_name_type name_type[] = {
>
>  static bool efi_secure_boot;
>  static enum efi_secure_mode efi_secure_mode;
> +static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
>
>  /**
>   * efi_efi_get_variable() - retrieve value of a UEFI variable
> @@ -488,3 +489,44 @@ efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *
>
>         return EFI_SUCCESS;
>  }
> +
> +efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
> +{
> +       struct efi_var_entry *var, *last_var;
> +       u16 *data;
> +       efi_status_t ret;
> +
> +       if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
> +           buf->crc32 != crc32(0, (u8 *)buf->var,
> +                               buf->length - sizeof(struct efi_var_file))) {
> +               log_err("Invalid EFI variables file\n");
> +               return EFI_INVALID_PARAMETER;
> +       }
> +
> +       last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
> +       for (var = buf->var; var < last_var;
> +            var = (struct efi_var_entry *)ALIGN((uintptr_t)data + var->length, 8)) {
> +               data = var->name + u16_strlen(var->name) + 1;
> +
> +               /*
> +                * Secure boot related and volatile variables shall only be
> +                * restored from U-Boot's preseed.
> +                */
> +               if (!safe &&
> +                   (efi_auth_var_get_type(var->name, &var->guid) !=
> +                    EFI_AUTH_VAR_NONE ||
> +                    !guidcmp(&var->guid, &shim_lock_guid) ||
> +                    !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
> +                       continue;
> +               if (!var->length)
> +                       continue;
> +               if (efi_var_mem_find(&var->guid, var->name, NULL))
> +                       continue;
> +               ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
> +                                     var->length, data, 0, NULL,
> +                                     var->time);
> +               if (ret != EFI_SUCCESS)
> +                       log_err("Failed to set EFI variable %ls\n", var->name);
> +       }
> +       return EFI_SUCCESS;
> +}
> diff --git a/lib/efi_loader/efi_var_file.c b/lib/efi_loader/efi_var_file.c
> index ba0bf33ffbd1..d32edaac277d 100644
> --- a/lib/efi_loader/efi_var_file.c
> +++ b/lib/efi_loader/efi_var_file.c
> @@ -14,17 +14,9 @@
>  #include <mapmem.h>
>  #include <efi_loader.h>
>  #include <efi_variable.h>
> -#include <u-boot/crc.h>
>
>  #define PART_STR_LEN 10
>
> -/* GUID used by Shim to store the MOK database */
> -#define SHIM_LOCK_GUID \
> -       EFI_GUID(0x605dab50, 0xe046, 0x4300, \
> -                0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
> -
> -static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
> -
>  /**
>   * efi_set_blk_dev_to_system_partition() - select EFI system partition
>   *
> @@ -59,7 +51,6 @@ static efi_status_t __maybe_unused efi_set_blk_dev_to_system_partition(void)
>   */
>  efi_status_t efi_var_to_file(void)
>  {
> -#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
>         efi_status_t ret;
>         struct efi_var_file *buf;
>         loff_t len;
> @@ -91,52 +82,6 @@ error:
>  out:
>         free(buf);
>         return ret;
> -#else
> -       return EFI_SUCCESS;
> -#endif
> -}
> -
> -efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
> -{
> -       struct efi_var_entry *var, *last_var;
> -       u16 *data;
> -       efi_status_t ret;
> -
> -       if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
> -           buf->crc32 != crc32(0, (u8 *)buf->var,
> -                               buf->length - sizeof(struct efi_var_file))) {
> -               log_err("Invalid EFI variables file\n");
> -               return EFI_INVALID_PARAMETER;
> -       }
> -
> -       last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
> -       for (var = buf->var; var < last_var;
> -            var = (struct efi_var_entry *)
> -                  ALIGN((uintptr_t)data + var->length, 8)) {
> -
> -               data = var->name + u16_strlen(var->name) + 1;
> -
> -               /*
> -                * Secure boot related and volatile variables shall only be
> -                * restored from U-Boot's preseed.
> -                */
> -               if (!safe &&
> -                   (efi_auth_var_get_type(var->name, &var->guid) !=
> -                    EFI_AUTH_VAR_NONE ||
> -                    !guidcmp(&var->guid, &shim_lock_guid) ||
> -                    !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
> -                       continue;
> -               if (!var->length)
> -                       continue;
> -               if (efi_var_mem_find(&var->guid, var->name, NULL))
> -                       continue;
> -               ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
> -                                     var->length, data, 0, NULL,
> -                                     var->time);
> -               if (ret != EFI_SUCCESS)
> -                       log_err("Failed to set EFI variable %ls\n", var->name);
> -       }
> -       return EFI_SUCCESS;
>  }
>
>  /**
> @@ -155,7 +100,6 @@ efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
>   */
>  efi_status_t efi_var_from_file(void)
>  {
> -#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
>         struct efi_var_file *buf;
>         loff_t len;
>         efi_status_t ret;
> @@ -180,6 +124,5 @@ efi_status_t efi_var_from_file(void)
>                 log_err("Invalid EFI variables file\n");
>  error:
>         free(buf);
> -#endif
>         return EFI_SUCCESS;
>  }
> diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> index f3533f4def3a..6e45134c61bf 100644
> --- a/lib/efi_loader/efi_variable.c
> +++ b/lib/efi_loader/efi_variable.c
> @@ -397,11 +397,15 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
>                 ret = EFI_SUCCESS;
>
>         /*
> -        * Write non-volatile EFI variables to file
> +        * Write non-volatile EFI variables
>          * TODO: check if a value change has occured to avoid superfluous writes
>          */
> -       if (attributes & EFI_VARIABLE_NON_VOLATILE)
> +       if (attributes & EFI_VARIABLE_NON_VOLATILE) {
> +               if (IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE))
> +                       return EFI_SUCCESS;
> +
>                 efi_var_to_file();
> +       }
>
>         return EFI_SUCCESS;
>  }
> @@ -594,9 +598,12 @@ efi_status_t efi_init_variables(void)
>         if (ret != EFI_SUCCESS)
>                 return ret;
>
> -       ret = efi_var_from_file();
> -       if (ret != EFI_SUCCESS)
> -               return ret;
> +       if (!IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE)) {
> +               ret = efi_var_from_file();
> +               if (ret != EFI_SUCCESS)
> +                       return ret;
> +       }
> +
>         if (IS_ENABLED(CONFIG_EFI_VARIABLES_PRESEED)) {
>                 ret = efi_var_restore((struct efi_var_file *)
>                                       __efi_var_file_begin, true);
> --
> 2.43.0
>

Re: [PATCH v7 3/3] efi_vars: Implement SPI Flash store

[Ilias Apalodimas]

Apologies I just noticed a few things

[...]

> >
> > +config EFI_VARIABLE_SF_STORE
> > +       bool "Store non-volatile UEFI variables in SPI Flash"
> > +       depends on SPI_FLASH
> > +       help
> > +         Select this option if you want non-volatile UEFI variables to be
> > +         stored in SPI Flash.
> > +
> > +         Define CONFIG_EFI_VARIABLE_SF_OFFSET as offset in SPI Flash to use as
> > +         the storage for variables. CONFIG_EFI_VAR_BUF_SIZE defines the space
> > +         needed.
> > +
> > +         Note that SPI Flash devices have a limited number of program/erase
> > +         cycles. Frequent updates to UEFI variables may cause excessive wear
> > +         and can permanently damage the flash device, particularly on SPI NAND
> > +         or low-end SPI NOR parts without wear leveling. This option should be
> > +         used with care on such systems, and is not recommended for platforms
> > +         where UEFI variables are updated frequently.
> > +
> >  config EFI_MM_COMM_TEE
> >         bool "UEFI variables storage service via the trusted world"
> >         depends on OPTEE
> > @@ -152,7 +170,7 @@ endchoice
> >
> >  config EFI_RT_VOLATILE_STORE
> >         bool "Allow variable runtime services in volatile storage (e.g RAM)"
> > -       depends on EFI_VARIABLE_FILE_STORE
> > +       depends on EFI_VARIABLE_FILE_STORE || EFI_VARIABLE_SF_STORE
> >         help
> >           When EFI variables are stored on file we don't allow SetVariableRT,
> >           since the OS doesn't know how to write that file. At the same time
> > @@ -193,6 +211,20 @@ config FFA_SHARED_MM_BUF_ADDR
> >           the MM SP in secure world.
> >           It is assumed that the MM SP knows the address of the shared MM communication buffer.
> >
> > +config EFI_VARIABLE_SF_OFFSET
> > +       hex "EFI variables in SPI flash offset"
> > +       depends on EFI_VARIABLE_SF_STORE
> > +       help
> > +         Offset from the start of the SPI Flash where EFI variables will be stored.
> > +         This should be aligned to the sector size of SPI Flash.
> > +
> > +config EFI_VARIABLE_SF_DEVICE_INDEX
> > +       int "Device Index for target SPI Flash"

Dont we need a depend here as well?

[...]

Thanks
/Ilias

Re: [PATCH v7 1/3] efi_var_file: refactor to move buffer functions

[Ilias Apalodimas]

So this fails for a weird reason

Some boards don't have FAT_WRTE. It seems that the Kconfig order
matters and those boards pick the new option if SPI is enabled.

This fixes it

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index c13cb8952caa..0f6f927ddaf1 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -112,7 +112,8 @@ menu "UEFI Variables"

 choice
        prompt "Store for non-volatile UEFI variables"
-       default EFI_VARIABLE_FILE_STORE
+       default EFI_VARIABLE_FILE_STORE if FAT_WRITE
+       default EFI_VARIABLE_NO_STORE
        help
          Select where non-volatile UEFI variables shall be stored.

On Wed, 11 Feb 2026 at 11:53, Ilias Apalodimas
<ilias.apalodimas@linaro.org> wrote:
>
> Hi Michael
>
> The CI seems to fail on this one for some reason.
> https://source.denx.de/u-boot/custodians/u-boot-tpm/-/pipelines/29248
>
> Can you take a look ?
>
> Thanks
> /Ilias
>
>
>
>
> On Tue, 3 Feb 2026 at 13:51, Michal Simek <michal.simek@amd.com> wrote:
> >
> > From: Shantur Rathore <i@shantur.com>
> >
> > Currently efi_var_file.c has functions to store/read
> > EFI variables to/from memory buffer. These functions
> > can be used with other EFI variable stores so move
> > them out to efi_var_common.c
> >
> > Signed-off-by: Shantur Rathore <i@shantur.com>
> > Signed-off-by: Michal Simek <michal.simek@amd.com>
> > ---
> >
> > (no changes since v6)
> >
> > Changes in v6:
> > - Return EFI_SUCCESS in efi_set_variable_int() when
> >   CONFIG_EFI_VARIABLE_NO_STORE is enabled
> >
> > Changes in v5:
> > - Invert logic in efi_variable.c and avoid #if
> >
> >  include/efi_variable.h          |  5 +++
> >  lib/efi_loader/Makefile         |  2 +-
> >  lib/efi_loader/efi_var_common.c | 42 ++++++++++++++++++++++++
> >  lib/efi_loader/efi_var_file.c   | 57 ---------------------------------
> >  lib/efi_loader/efi_variable.c   | 17 +++++++---
> >  5 files changed, 60 insertions(+), 63 deletions(-)
> >
> > diff --git a/include/efi_variable.h b/include/efi_variable.h
> > index 4065cf45ecaf..ee68fa4a885f 100644
> > --- a/include/efi_variable.h
> > +++ b/include/efi_variable.h
> > @@ -161,6 +161,11 @@ efi_status_t efi_var_to_file(void);
> >  efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *lenp,
> >                                             u32 check_attr_mask);
> >
> > +/* GUID used by Shim to store the MOK database */
> > +#define SHIM_LOCK_GUID \
> > +       EFI_GUID(0x605dab50, 0xe046, 0x4300, \
> > +                0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
> > +
> >  /**
> >   * efi_var_restore() - restore EFI variables from buffer
> >   *
> > diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> > index f490081f6542..ca1775eb03be 100644
> > --- a/lib/efi_loader/Makefile
> > +++ b/lib/efi_loader/Makefile
> > @@ -53,7 +53,7 @@ ifeq ($(CONFIG_EFI_MM_COMM_TEE),y)
> >  obj-y += efi_variable_tee.o
> >  else
> >  obj-y += efi_variable.o
> > -obj-y += efi_var_file.o
> > +obj-$(CONFIG_EFI_VARIABLE_FILE_STORE) += efi_var_file.o
> >  obj-$(CONFIG_EFI_VARIABLES_PRESEED) += efi_var_seed.o
> >  endif
> >  obj-y += efi_watchdog.o
> > diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
> > index 4b34a58b4cf7..5ea1688dca3d 100644
> > --- a/lib/efi_loader/efi_var_common.c
> > +++ b/lib/efi_loader/efi_var_common.c
> > @@ -41,6 +41,7 @@ static const struct efi_auth_var_name_type name_type[] = {
> >
> >  static bool efi_secure_boot;
> >  static enum efi_secure_mode efi_secure_mode;
> > +static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
> >
> >  /**
> >   * efi_efi_get_variable() - retrieve value of a UEFI variable
> > @@ -488,3 +489,44 @@ efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *
> >
> >         return EFI_SUCCESS;
> >  }
> > +
> > +efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
> > +{
> > +       struct efi_var_entry *var, *last_var;
> > +       u16 *data;
> > +       efi_status_t ret;
> > +
> > +       if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
> > +           buf->crc32 != crc32(0, (u8 *)buf->var,
> > +                               buf->length - sizeof(struct efi_var_file))) {
> > +               log_err("Invalid EFI variables file\n");
> > +               return EFI_INVALID_PARAMETER;
> > +       }
> > +
> > +       last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
> > +       for (var = buf->var; var < last_var;
> > +            var = (struct efi_var_entry *)ALIGN((uintptr_t)data + var->length, 8)) {
> > +               data = var->name + u16_strlen(var->name) + 1;
> > +
> > +               /*
> > +                * Secure boot related and volatile variables shall only be
> > +                * restored from U-Boot's preseed.
> > +                */
> > +               if (!safe &&
> > +                   (efi_auth_var_get_type(var->name, &var->guid) !=
> > +                    EFI_AUTH_VAR_NONE ||
> > +                    !guidcmp(&var->guid, &shim_lock_guid) ||
> > +                    !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
> > +                       continue;
> > +               if (!var->length)
> > +                       continue;
> > +               if (efi_var_mem_find(&var->guid, var->name, NULL))
> > +                       continue;
> > +               ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
> > +                                     var->length, data, 0, NULL,
> > +                                     var->time);
> > +               if (ret != EFI_SUCCESS)
> > +                       log_err("Failed to set EFI variable %ls\n", var->name);
> > +       }
> > +       return EFI_SUCCESS;
> > +}
> > diff --git a/lib/efi_loader/efi_var_file.c b/lib/efi_loader/efi_var_file.c
> > index ba0bf33ffbd1..d32edaac277d 100644
> > --- a/lib/efi_loader/efi_var_file.c
> > +++ b/lib/efi_loader/efi_var_file.c
> > @@ -14,17 +14,9 @@
> >  #include <mapmem.h>
> >  #include <efi_loader.h>
> >  #include <efi_variable.h>
> > -#include <u-boot/crc.h>
> >
> >  #define PART_STR_LEN 10
> >
> > -/* GUID used by Shim to store the MOK database */
> > -#define SHIM_LOCK_GUID \
> > -       EFI_GUID(0x605dab50, 0xe046, 0x4300, \
> > -                0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
> > -
> > -static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
> > -
> >  /**
> >   * efi_set_blk_dev_to_system_partition() - select EFI system partition
> >   *
> > @@ -59,7 +51,6 @@ static efi_status_t __maybe_unused efi_set_blk_dev_to_system_partition(void)
> >   */
> >  efi_status_t efi_var_to_file(void)
> >  {
> > -#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
> >         efi_status_t ret;
> >         struct efi_var_file *buf;
> >         loff_t len;
> > @@ -91,52 +82,6 @@ error:
> >  out:
> >         free(buf);
> >         return ret;
> > -#else
> > -       return EFI_SUCCESS;
> > -#endif
> > -}
> > -
> > -efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
> > -{
> > -       struct efi_var_entry *var, *last_var;
> > -       u16 *data;
> > -       efi_status_t ret;
> > -
> > -       if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
> > -           buf->crc32 != crc32(0, (u8 *)buf->var,
> > -                               buf->length - sizeof(struct efi_var_file))) {
> > -               log_err("Invalid EFI variables file\n");
> > -               return EFI_INVALID_PARAMETER;
> > -       }
> > -
> > -       last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
> > -       for (var = buf->var; var < last_var;
> > -            var = (struct efi_var_entry *)
> > -                  ALIGN((uintptr_t)data + var->length, 8)) {
> > -
> > -               data = var->name + u16_strlen(var->name) + 1;
> > -
> > -               /*
> > -                * Secure boot related and volatile variables shall only be
> > -                * restored from U-Boot's preseed.
> > -                */
> > -               if (!safe &&
> > -                   (efi_auth_var_get_type(var->name, &var->guid) !=
> > -                    EFI_AUTH_VAR_NONE ||
> > -                    !guidcmp(&var->guid, &shim_lock_guid) ||
> > -                    !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
> > -                       continue;
> > -               if (!var->length)
> > -                       continue;
> > -               if (efi_var_mem_find(&var->guid, var->name, NULL))
> > -                       continue;
> > -               ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
> > -                                     var->length, data, 0, NULL,
> > -                                     var->time);
> > -               if (ret != EFI_SUCCESS)
> > -                       log_err("Failed to set EFI variable %ls\n", var->name);
> > -       }
> > -       return EFI_SUCCESS;
> >  }
> >
> >  /**
> > @@ -155,7 +100,6 @@ efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
> >   */
> >  efi_status_t efi_var_from_file(void)
> >  {
> > -#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
> >         struct efi_var_file *buf;
> >         loff_t len;
> >         efi_status_t ret;
> > @@ -180,6 +124,5 @@ efi_status_t efi_var_from_file(void)
> >                 log_err("Invalid EFI variables file\n");
> >  error:
> >         free(buf);
> > -#endif
> >         return EFI_SUCCESS;
> >  }
> > diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> > index f3533f4def3a..6e45134c61bf 100644
> > --- a/lib/efi_loader/efi_variable.c
> > +++ b/lib/efi_loader/efi_variable.c
> > @@ -397,11 +397,15 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
> >                 ret = EFI_SUCCESS;
> >
> >         /*
> > -        * Write non-volatile EFI variables to file
> > +        * Write non-volatile EFI variables
> >          * TODO: check if a value change has occured to avoid superfluous writes
> >          */
> > -       if (attributes & EFI_VARIABLE_NON_VOLATILE)
> > +       if (attributes & EFI_VARIABLE_NON_VOLATILE) {
> > +               if (IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE))
> > +                       return EFI_SUCCESS;
> > +
> >                 efi_var_to_file();
> > +       }
> >
> >         return EFI_SUCCESS;
> >  }
> > @@ -594,9 +598,12 @@ efi_status_t efi_init_variables(void)
> >         if (ret != EFI_SUCCESS)
> >                 return ret;
> >
> > -       ret = efi_var_from_file();
> > -       if (ret != EFI_SUCCESS)
> > -               return ret;
> > +       if (!IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE)) {
> > +               ret = efi_var_from_file();
> > +               if (ret != EFI_SUCCESS)
> > +                       return ret;
> > +       }
> > +
> >         if (IS_ENABLED(CONFIG_EFI_VARIABLES_PRESEED)) {
> >                 ret = efi_var_restore((struct efi_var_file *)
> >                                       __efi_var_file_begin, true);
> > --
> > 2.43.0
> >

Re: [PATCH v7 2/3] efi_var: Unify read/write access helper function

[Ilias Apalodimas]

Hi Michal

Since you'll have to send a v8 a few nits.


[...]


>  }
>
>  /**
> - * efi_var_to_file() - save non-volatile variables as file
> + * efi_var_to_storage() - save non-volatile variables as file

it's not 'as file' anymore right?

>   *
>   * File ubootefi.var is created on the EFI system partion.

And this needs an update "If they are stored to file..." etc

>   *
>   * Return:     status code
>   */
> -efi_status_t efi_var_to_file(void)
> +efi_status_t efi_var_to_storage(void)
>  {
>         efi_status_t ret;
>         struct efi_var_file *buf;
> @@ -85,7 +85,7 @@ out:
>  }
>
>  /**
> - * efi_var_from_file() - read variables from file
> + * efi_var_from_storage() - read variables from file

same here

>   *
>   * File ubootefi.var is read from the EFI system partitions and the variables
>   * stored in the file are created.

and here

[...]

You can keep the r-b tags, as it's just comment updates


Thanks
/Ilias

Re: [PATCH v7 1/3] efi_var_file: refactor to move buffer functions

[Tom Rini]

[-- Attachment #1: Type: text/plain, Size: 1245 bytes --]

On Wed, Feb 11, 2026 at 05:04:00PM +0200, Ilias Apalodimas wrote:
> So this fails for a weird reason
> 
> Some boards don't have FAT_WRTE. It seems that the Kconfig order
> matters and those boards pick the new option if SPI is enabled.
> 
> This fixes it
> 
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index c13cb8952caa..0f6f927ddaf1 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -112,7 +112,8 @@ menu "UEFI Variables"
> 
>  choice
>         prompt "Store for non-volatile UEFI variables"
> -       default EFI_VARIABLE_FILE_STORE
> +       default EFI_VARIABLE_FILE_STORE if FAT_WRITE
> +       default EFI_VARIABLE_NO_STORE
>         help
>           Select where non-volatile UEFI variables shall be stored.

The behavior of a choice statement is such that if there's no default
(and in this case, platforms don't set FAT_WRITE, so there's effectively
no default) they select the first presented valid option. Before this
patch, that ends up being EFI_VARIABLE_NO_STORE but after this patch it
ends up being the SPI option. So making it clear that the fallback is
NO_STORE is a correct general clarification / bugfix. It can be its own
patch even :)

-- 
Tom

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH v7 1/3] efi_var_file: refactor to move buffer functions

[Ilias Apalodimas]

On Wed, 11 Feb 2026 at 17:13, Tom Rini <trini@konsulko.com> wrote:
>
> On Wed, Feb 11, 2026 at 05:04:00PM +0200, Ilias Apalodimas wrote:
> > So this fails for a weird reason
> >
> > Some boards don't have FAT_WRTE. It seems that the Kconfig order
> > matters and those boards pick the new option if SPI is enabled.
> >
> > This fixes it
> >
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index c13cb8952caa..0f6f927ddaf1 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -112,7 +112,8 @@ menu "UEFI Variables"
> >
> >  choice
> >         prompt "Store for non-volatile UEFI variables"
> > -       default EFI_VARIABLE_FILE_STORE
> > +       default EFI_VARIABLE_FILE_STORE if FAT_WRITE
> > +       default EFI_VARIABLE_NO_STORE
> >         help
> >           Select where non-volatile UEFI variables shall be stored.
>
> The behavior of a choice statement is such that if there's no default
> (and in this case, platforms don't set FAT_WRITE, so there's effectively
> no default) they select the first presented valid option. Before this
> patch, that ends up being EFI_VARIABLE_NO_STORE but after this patch it
> ends up being the SPI option. So making it clear that the fallback is
> NO_STORE is a correct general clarification / bugfix. It can be its own
> patch even :)\

Yep, we already discussed this with Michal over IRC. He'll send it as
a separate patch with your Suggested-by etc

Thanks
/Ilias
>
> --
> Tom

Re: [PATCH v7 2/3] efi_var: Unify read/write access helper function

[Michal Simek]

On 2/11/26 16:06, Ilias Apalodimas wrote:
> Hi Michal
> 
> Since you'll have to send a v8 a few nits.
> 
> 
> [...]
> 
> 
>>   }
>>
>>   /**
>> - * efi_var_to_file() - save non-volatile variables as file
>> + * efi_var_to_storage() - save non-volatile variables as file
> 
> it's not 'as file' anymore right?
> 
>>    *
>>    * File ubootefi.var is created on the EFI system partion.
> 
> And this needs an update "If they are stored to file..." etc
> 
>>    *
>>    * Return:     status code
>>    */
>> -efi_status_t efi_var_to_file(void)
>> +efi_status_t efi_var_to_storage(void)
>>   {
>>          efi_status_t ret;
>>          struct efi_var_file *buf;
>> @@ -85,7 +85,7 @@ out:
>>   }
>>
>>   /**
>> - * efi_var_from_file() - read variables from file
>> + * efi_var_from_storage() - read variables from file
> 
> same here
> 
>>    *
>>    * File ubootefi.var is read from the EFI system partitions and the variables
>>    * stored in the file are created.
> 
> and here
> 
> [...]
> 
> You can keep the r-b tags, as it's just comment updates

This is actually correct. Because this code is used only for storing variables 
as file on filesystem.

I updated include/efi_variable.h which is generic and shared between fs/sf but
lib/efi_loader/efi_var_file.c is only for saving/reading file on FS.

M

Re: [PATCH v7 2/3] efi_var: Unify read/write access helper function

[Ilias Apalodimas]

On Wed, 11 Feb 2026 at 17:30, Michal Simek <michal.simek@amd.com> wrote:
>
>
>
> On 2/11/26 16:06, Ilias Apalodimas wrote:
> > Hi Michal
> >
> > Since you'll have to send a v8 a few nits.
> >
> >
> > [...]
> >
> >
> >>   }
> >>
> >>   /**
> >> - * efi_var_to_file() - save non-volatile variables as file
> >> + * efi_var_to_storage() - save non-volatile variables as file
> >
> > it's not 'as file' anymore right?
> >
> >>    *
> >>    * File ubootefi.var is created on the EFI system partion.
> >
> > And this needs an update "If they are stored to file..." etc
> >
> >>    *
> >>    * Return:     status code
> >>    */
> >> -efi_status_t efi_var_to_file(void)
> >> +efi_status_t efi_var_to_storage(void)
> >>   {
> >>          efi_status_t ret;
> >>          struct efi_var_file *buf;
> >> @@ -85,7 +85,7 @@ out:
> >>   }
> >>
> >>   /**
> >> - * efi_var_from_file() - read variables from file
> >> + * efi_var_from_storage() - read variables from file
> >
> > same here
> >
> >>    *
> >>    * File ubootefi.var is read from the EFI system partitions and the variables
> >>    * stored in the file are created.
> >
> > and here
> >
> > [...]
> >
> > You can keep the r-b tags, as it's just comment updates
>
> This is actually correct. Because this code is used only for storing variables
> as file on filesystem.
>
> I updated include/efi_variable.h which is generic and shared between fs/sf but
> lib/efi_loader/efi_var_file.c is only for saving/reading file on FS.

Ah yes, you are right. Ignore the comments above then

Thanks
/Ilias
>
> M
>