[U-Boot] [RFC,PATCH v4 14/16] env: fat: support UEFI context

[AKASHI Takahiro]

With this patch, UEFI will be allowed to save/load variables to
fat filesystem. The following configurations should be defined.
    CONFIG_EFI_ENV_FAT
    CONFIG_EFI_ENV_FAT_INTERFACE
    CONFIG_EFI_ENV_FAT_DEVICE_AND_PART
    CONFIG_EFI_ENV_FAT_FILE

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 env/Kconfig           | 42 +++++++++++++++++++++++++++++++++++++++++-
 env/fat.c             | 11 ++++++++++-
 include/environment.h |  4 ++++
 3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/env/Kconfig b/env/Kconfig
index b9439171fd56..23e450a3e5bd 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -402,7 +402,7 @@ config ENV_FAT_INTERFACE
 	  Define this to a string that is the name of the block device.
 
 config ENV_FAT_DEVICE_AND_PART
-	string "Device and partition for where to store the environemt in FAT"
+	string "Device and partition for where to store the environment in FAT"
 	depends on ENV_IS_IN_FAT
 	default "0:1" if TI_COMMON_CMD_OPTIONS
 	default "0:auto" if ARCH_ZYNQMP
@@ -432,6 +432,46 @@ config ENV_FAT_FILE
 	  It's a string of the FAT file name. This file use to store the
 	  environment.
 
+config ENV_EFI_FAT
+	bool "Enable UEFI variable context on a FAT filesystem"
+	depends on ENV_IS_IN_FAT
+	depends on EFI_VARIABLE_USE_ENV
+	help
+	  Enable this option if you want to load/save UEFI variables
+	  from/to fat file system.
+
+if ENV_EFI_FAT
+config ENV_EFI_FAT_INTERFACE
+	string "UEFI: Name of the block device for the environment"
+	help
+	  Define this to a string that is the name of the block device.
+
+config ENV_EFI_FAT_DEVICE_AND_PART
+	string "UEFI: Device and partition for where to store the environemt in FAT"
+	help
+	  Define this to a string to specify the partition of the device. It can
+	  be as following:
+
+	    "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
+	       - "D:P": device D partition P. Error occurs if device D has no
+	                partition table.
+	       - "D:0": device D.
+	       - "D" or "D:": device D partition 1 if device D has partition
+	                      table, or the whole device D if has no partition
+	                      table.
+	       - "D:auto": first partition in device D with bootable flag set.
+	                   If none, first valid partition in device D. If no
+	                   partition table then means device D.
+
+config ENV_EFI_FAT_FILE
+	string "UEFI: Name of the FAT file to use for the environment"
+	default "uboot_efi.env"
+	help
+	  It's a string of the FAT file name. This file use to store the
+	  environment.
+
+endif
+
 config ENV_EXT4_INTERFACE
 	string "Name of the block device for the environment"
 	depends on ENV_IS_IN_EXT4
diff --git a/env/fat.c b/env/fat.c
index e4a672d2730a..963ddaf8e9f6 100644
--- a/env/fat.c
+++ b/env/fat.c
@@ -30,7 +30,7 @@
 # endif
 #endif
 
-static struct evn_fat_context {
+static struct env_fat_context {
 	char *interface;
 	char *dev_and_part;
 	char *file;
@@ -43,6 +43,15 @@ static struct evn_fat_context {
 		CONFIG_ENV_FAT_FILE,
 	},
 #endif
+#if defined(CONFIG_ENV_EFI_FAT_INTERFACE) && \
+	defined(CONFIG_ENV_FAT_DEVICE_AND_PART) && \
+	defined(CONFIG_ENV_EFI_FAT_FILE)
+	[ENVCTX_UEFI] = {
+		CONFIG_ENV_EFI_FAT_INTERFACE,
+		CONFIG_ENV_EFI_FAT_DEVICE_AND_PART,
+		CONFIG_ENV_EFI_FAT_FILE,
+	},
+#endif
 };
 
 #ifdef CMD_SAVEENV
diff --git a/include/environment.h b/include/environment.h
index 9fa085a9b728..12b562823eb0 100644
--- a/include/environment.h
+++ b/include/environment.h
@@ -214,6 +214,10 @@ enum env_operation {
 
 enum env_context {
 	ENVCTX_UBOOT,
+#ifdef CONFIG_EFI_LOADER
+	/* Even if !EFI_VARIABLE_USE_ENV, "env -e" should work */
+	ENVCTX_UEFI,
+#endif
 	ENVCTX_COUNT,
 };
 
-- 
2.21.0