fs: Adds diskio interface

Adds the diskio interface for the FAT file system.  This
revision uses RAM to emulate disk storage.

Origin: Original
Jira: ZEP-285
Change-Id: I7a30c8761d5ed9b564f1d1e08482c5ef199d7372
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>

Kconfig.zephyr

@@ -32,6 +32,8 @@ source "misc/Kconfig"
 
 source "lib/Kconfig"
 
+source "fs/Kconfig"
+
 source "ext/Kconfig"
 
 source "usb/Kconfig"

Makefile

@@ -518,7 +518,7 @@ scripts: scripts_basic include/config/auto.conf include/config/tristate.conf
 
 # arch/ must be last here so that .gnu.linkonce magic for interrupts/exceptions
 # works as expected
-core-y := lib/ kernel/ misc/ net/ boards/ ext/ usb/ arch/
+core-y := lib/ kernel/ misc/ net/ boards/ ext/ usb/ fs/ arch/
 drivers-y := drivers/
 
 ifneq ($(strip $(MAKEFILE_APP_DIR)),)

ext/fs/fat/Kbuild

@@ -1,2 +1,2 @@
 obj-$(CONFIG_FAT_FILESYSTEM_ELM) += ff.o
-obj-$(CONFIG_FAT_FILESYSTEM_ELM) += diskio.o
+obj-$(CONFIG_FAT_FILESYSTEM_ELM) += zfs_diskio.o

ext/fs/fat/zfs_diskio.c

@@ -0,0 +1,75 @@
+/*-----------------------------------------------------------------------*/
+/* Low level disk I/O module skeleton for FatFs     (C)ChaN, 2016        */
+/*-----------------------------------------------------------------------*/
+/* If a working storage control module is available, it should be        */
+/* attached to the FatFs via a glue function rather than modifying it.   */
+/* This is an example of glue functions to attach various exsisting      */
+/* storage control modules to the FatFs module with a defined API.       */
+/*-----------------------------------------------------------------------*/
+/*----------------------------------------------------------------------------/
+/  FatFs - Generic FAT file system module  R0.12a                             /
+/-----------------------------------------------------------------------------/
+/
+/ Copyright (C) 2016, ChaN, all right reserved.
+/
+/ FatFs module is an open source software. Redistribution and use of FatFs in
+/ source and binary forms, with or without modification, are permitted provided
+/ that the following condition is met:
+
+/ 1. Redistributions of source code must retain the above copyright notice,
+/    this condition and the following disclaimer.
+/
+/ This software is provided by the copyright holder and contributors "AS IS"
+/ and any warranties related to this software are DISCLAIMED.
+/ The copyright owner or contributors be NOT LIABLE for any damages caused
+/ by use of this software.
+/----------------------------------------------------------------------------*/
+
+#include <diskio.h>	/* FatFs lower layer API */
+#include <fs/fat_diskio.h>
+
+/*-----------------------------------------------------------------------*/
+/* Get Drive Status                                                      */
+/*-----------------------------------------------------------------------*/
+
+DSTATUS disk_status(uint8_t pdrv)
+{
+	return fat_disk_status();
+}
+
+/*-----------------------------------------------------------------------*/
+/* Inidialize a Drive                                                    */
+/*-----------------------------------------------------------------------*/
+
+DSTATUS disk_initialize(uint8_t pdrv)
+{
+	return fat_disk_initialize();
+}
+
+/*-----------------------------------------------------------------------*/
+/* Read Sector(s)                                                        */
+/*-----------------------------------------------------------------------*/
+
+DRESULT disk_read(uint8_t pdrv, uint8_t *buff, unsigned long sector,
+		  uint32_t count)
+{
+	return fat_disk_read(buff, sector, count);
+}
+
+/*-----------------------------------------------------------------------*/
+/* Write Sector(s)                                                       */
+/*-----------------------------------------------------------------------*/
+DRESULT disk_write(uint8_t pdrv,
+		   const uint8_t *buff, unsigned long sector, uint32_t count)
+{
+	return fat_disk_write(buff, sector, count);
+}
+
+/*-----------------------------------------------------------------------*/
+/* Miscellaneous Functions                                               */
+/*-----------------------------------------------------------------------*/
+
+DRESULT disk_ioctl(uint8_t pdrv, uint8_t cmd, void *buff)
+{
+	return fat_disk_ioctl(cmd, buff);
+}

fs/Kconfig

@@ -0,0 +1,67 @@
+#
+# Copyright (c) 2016 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+menu "File System"
+
+config FILE_SYSTEM
+	bool "File system support"
+	default n
+	help
+	Enables support for file system.
+
+config FILE_SYSTEM_FAT
+	bool "FAT file system support"
+	default y
+	depends on FILE_SYSTEM
+	help
+	Enables FAT file system support.
+
+choice
+	prompt "Select file system storage device"
+	depends on FILE_SYSTEM_FAT
+	default FS_FAT_RAM_DISK
+	help
+	The storage device where the file system
+	resides
+
+config FS_FAT_RAM_DISK
+	bool
+	prompt "RAM Disk"
+	help
+	RAM buffer used to emulate storage disk.
+	This option can used to test the file
+	system.
+
+endchoice
+
+if FS_FAT_RAM_DISK
+
+config FS_VOLUME_SIZE
+	hex
+	default 0x18000
+	help
+	This is the file system volume size in bytes.
+
+config FS_BLOCK_SIZE
+	hex
+	default 0x1000
+	help
+	This is typically the minimum block size that
+	is erased at one time in flash storage.
+
+endif # FS_RAM_DISK
+
+endmenu

fs/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_FS_FAT_RAM_DISK) += fat_ram_diskio.o

fs/fat_ram_diskio.c

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <string.h>
+#include <stdint.h>
+#include <misc/__assert.h>
+#include <diskio.h>
+#include <ff.h>
+
+static uint8_t file_buff[CONFIG_FS_VOLUME_SIZE];
+
+static void *lba_to_address(uint32_t lba)
+{
+	__ASSERT(((lba * _MIN_SS) < CONFIG_FS_VOLUME_SIZE), "FS bound error");
+	return &file_buff[(lba * _MIN_SS)];
+}
+
+DSTATUS fat_disk_status(void)
+{
+	return RES_OK;
+}
+
+DSTATUS fat_disk_initialize(void)
+{
+	return RES_OK;
+}
+
+DRESULT fat_disk_read(void *buff, uint32_t sector, uint32_t count)
+{
+	memcpy(buff, lba_to_address(sector), count * _MIN_SS);
+
+	return RES_OK;
+}
+
+DRESULT fat_disk_write(void *buff, uint32_t sector, uint32_t count)
+{
+	memcpy(lba_to_address(sector), buff, count * _MIN_SS);
+
+	return RES_OK;
+}
+
+DRESULT fat_disk_ioctl(uint8_t cmd, void *buff)
+{
+	switch (cmd) {
+	case CTRL_SYNC:
+		return RES_OK;
+	case GET_SECTOR_COUNT:
+		*(uint32_t *) buff = CONFIG_FS_VOLUME_SIZE / _MIN_SS;
+		return RES_OK;
+	case GET_BLOCK_SIZE:
+		*(uint32_t *) buff = CONFIG_FS_BLOCK_SIZE / _MIN_SS;
+		return RES_OK;
+	case CTRL_TRIM:
+		break;
+	}
+
+	return RES_PARERR;
+}

include/fs/fat_diskio.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _FAT_DISKIO_H_
+#define _FAT_DISKIO_H_
+
+#include <diskio.h>
+#include <stdint.h>
+
+DSTATUS fat_disk_status(void);
+DSTATUS fat_disk_initialize(void);
+DRESULT fat_disk_read(uint8_t *buff, unsigned long sector, uint32_t count);
+DRESULT fat_disk_write(const uint8_t *buff, unsigned long sector,
+		       uint32_t count);
+DRESULT fat_disk_ioctl(uint8_t cmd, void *buff);
+
+#endif /* _FAT_DISKIO_H_ */