common: Add support for environment file in EXT4.

This is an enhancement that permits storing the environment file on an
EXT4 partition such as the root filesystem.  It is based on the existing
FAT environment file code.

cmd/nvedit.c

@@ -45,6 +45,7 @@ DECLARE_GLOBAL_DATA_PTR;
 	!defined(CONFIG_ENV_IS_IN_DATAFLASH)	&& \
 	!defined(CONFIG_ENV_IS_IN_MMC)		&& \
 	!defined(CONFIG_ENV_IS_IN_FAT)		&& \
+	!defined(CONFIG_ENV_IS_IN_EXT4)		&& \
 	!defined(CONFIG_ENV_IS_IN_NAND)		&& \
 	!defined(CONFIG_ENV_IS_IN_NVRAM)	&& \
 	!defined(CONFIG_ENV_IS_IN_ONENAND)	&& \
@@ -53,7 +54,7 @@ DECLARE_GLOBAL_DATA_PTR;
 	!defined(CONFIG_ENV_IS_IN_UBI)		&& \
 	!defined(CONFIG_ENV_IS_NOWHERE)
 # error Define one of CONFIG_ENV_IS_IN_{EEPROM|FLASH|DATAFLASH|ONENAND|\
-SPI_FLASH|NVRAM|MMC|FAT|REMOTE|UBI} or CONFIG_ENV_IS_NOWHERE
+SPI_FLASH|NVRAM|MMC|FAT|EXT4|REMOTE|UBI} or CONFIG_ENV_IS_NOWHERE
 #endif
 
 /*

common/Makefile

@@ -46,6 +46,7 @@ obj-$(CONFIG_ENV_IS_IN_NVRAM) += env_embedded.o
 obj-$(CONFIG_ENV_IS_IN_FLASH) += env_flash.o
 obj-$(CONFIG_ENV_IS_IN_MMC) += env_mmc.o
 obj-$(CONFIG_ENV_IS_IN_FAT) += env_fat.o
+obj-$(CONFIG_ENV_IS_IN_EXT4) += env_ext4.o
 obj-$(CONFIG_ENV_IS_IN_NAND) += env_nand.o
 obj-$(CONFIG_ENV_IS_IN_NVRAM) += env_nvram.o
 obj-$(CONFIG_ENV_IS_IN_ONENAND) += env_onenand.o
@@ -105,6 +106,7 @@ obj-$(CONFIG_SPL_ENV_SUPPORT) += env_callback.o
 obj-$(CONFIG_ENV_IS_NOWHERE) += env_nowhere.o
 obj-$(CONFIG_ENV_IS_IN_MMC) += env_mmc.o
 obj-$(CONFIG_ENV_IS_IN_FAT) += env_fat.o
+obj-$(CONFIG_ENV_IS_IN_EXT4) += env_ext4.o
 obj-$(CONFIG_ENV_IS_IN_NAND) += env_nand.o
 obj-$(CONFIG_ENV_IS_IN_SPI_FLASH) += env_sf.o
 obj-$(CONFIG_ENV_IS_IN_FLASH) += env_flash.o

common/env_ext4.c

@@ -0,0 +1,127 @@
+/*
+ * (c) Copyright 2016 by VRT Technology
+ *
+ * Author:
+ *  Stuart Longland <stuartl@vrt.com.au>
+ *
+ * Based on FAT environment driver
+ * (c) Copyright 2011 by Tigris Elektronik GmbH
+ *
+ * Author:
+ *  Maximilian Schwerin <mvs@tigris.de>
+ *
+ * and EXT4 filesystem implementation
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+
+#include <command.h>
+#include <environment.h>
+#include <linux/stddef.h>
+#include <malloc.h>
+#include <search.h>
+#include <errno.h>
+#include <ext4fs.h>
+#include <mmc.h>
+
+char *env_name_spec = "EXT4";
+
+env_t *env_ptr;
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int env_init(void)
+{
+	/* use default */
+	gd->env_addr = (ulong)&default_environment[0];
+	gd->env_valid = 1;
+
+	return 0;
+}
+
+#ifdef CONFIG_CMD_SAVEENV
+int saveenv(void)
+{
+	env_t	env_new;
+	block_dev_desc_t *dev_desc = NULL;
+	disk_partition_t info;
+	int dev, part;
+	int err;
+
+	err = env_export(&env_new);
+	if (err)
+		return err;
+
+	part = get_device_and_partition(EXT4_ENV_INTERFACE,
+					EXT4_ENV_DEVICE_AND_PART,
+					&dev_desc, &info, 1);
+	if (part < 0)
+		return 1;
+
+	dev = dev_desc->dev;
+	ext4fs_set_blk_dev(dev_desc, &info);
+
+	if (!ext4fs_mount(info.size)) {
+		printf("\n** Unable to use %s %s for saveenv **\n",
+		       EXT4_ENV_INTERFACE, EXT4_ENV_DEVICE_AND_PART);
+		return 1;
+	}
+
+	err = ext4fs_write(EXT4_ENV_FILE, (void *)&env_new, sizeof(env_t));
+	ext4fs_close();
+
+	if (err == -1) {
+		printf("\n** Unable to write \"%s\" from %s%d:%d **\n",
+			EXT4_ENV_FILE, EXT4_ENV_INTERFACE, dev, part);
+		return 1;
+	}
+
+	puts("done\n");
+	return 0;
+}
+#endif /* CONFIG_CMD_SAVEENV */
+
+void env_relocate_spec(void)
+{
+	ALLOC_CACHE_ALIGN_BUFFER(char, buf, CONFIG_ENV_SIZE);
+	block_dev_desc_t *dev_desc = NULL;
+	disk_partition_t info;
+	int dev, part;
+	int err;
+
+	part = get_device_and_partition(EXT4_ENV_INTERFACE,
+					EXT4_ENV_DEVICE_AND_PART,
+					&dev_desc, &info, 1);
+	if (part < 0)
+		goto err_env_relocate;
+
+	dev = dev_desc->dev;
+	ext4fs_set_blk_dev(dev_desc, &info);
+
+	if (!ext4fs_mount(info.size)) {
+		printf("\n** Unable to use %s %s for loading the env **\n",
+		       EXT4_ENV_INTERFACE, EXT4_ENV_DEVICE_AND_PART);
+		goto err_env_relocate;
+	}
+
+	err = ext4_read_file(EXT4_ENV_FILE, buf, 0, CONFIG_ENV_SIZE);
+	ext4fs_close();
+
+	if (err == -1) {
+		printf("\n** Unable to read \"%s\" from %s%d:%d **\n",
+			EXT4_ENV_FILE, EXT4_ENV_INTERFACE, dev, part);
+		goto err_env_relocate;
+	}
+
+	env_import(buf, 1);
+	return;
+
+err_env_relocate:
+	set_default_env(NULL);
+}