drivers: ramdisk: use devicetree to instantiate RAM disk

Rework RAM disk driver to be configured using devicetree and
support multiple instances.

This patch also removes a copy of the RAM disk driver,
tests/subsys/fs/fat_fs_dual_drive/src/disk_access_test_drv.c,
that was there for testing multiple disk drivers support.

Bonus: one SYS_INIT() less and a memory region can be exported to the
host.

Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>

doc/connectivity/usb/device/usb_device.rst

@@ -286,10 +286,11 @@ access and expose a RAM disk, emulated block device on a flash partition,
 or SD Card to the host. Only one disk instance can be exported at a time.
 
 The disc to be used by the implementation is set by the
-:kconfig:option:`CONFIG_MASS_STORAGE_DISK_NAME` and should be equal to one
+:kconfig:option:`CONFIG_MASS_STORAGE_DISK_NAME` and should be the same as the name
-of the options used by the disc access driver that the application wants to expose to
+used by the disc access driver that the application wants to expose to the host.
-the host, :kconfig:option:`CONFIG_DISK_RAM_VOLUME_NAME`,
+SD card disk drivers use options :kconfig:option:`CONFIG_MMC_VOLUME_NAME` or
-:kconfig:option:`CONFIG_MMC_VOLUME_NAME`, or :kconfig:option:`CONFIG_SDMMC_VOLUME_NAME`.
+:kconfig:option:`CONFIG_SDMMC_VOLUME_NAME`, and flash and RAM disk drivers use
+node property ``disk-name`` to set the disk name.
 
 For the emulated block device on a flash partition, the flash partition and
 flash disk to be used must be described in the devicetree. If a storage partition

drivers/disk/Kconfig.ram

@@ -3,6 +3,7 @@
 
 config DISK_DRIVER_RAM
 	bool "RAM Disk"
+	default y if DT_HAS_ZEPHYR_RAM_DISK_ENABLED
 	help
 	  RAM buffer used to emulate storage disk.
 	  This option can be used to test the file
@@ -10,18 +11,6 @@ config DISK_DRIVER_RAM
 
 if DISK_DRIVER_RAM
 
-config DISK_RAM_VOLUME_SIZE
-	int "RAM Disk size in kilobytes"
-	default 96
-	help
-	  Size of the RAM Disk.
-
-config DISK_RAM_VOLUME_NAME
-	string "RAM Disk mount point or drive name"
-	default "RAM"
-	help
-	  Disk name as per file system naming guidelines.
-
 module = RAMDISK
 module-str = ramdisk
 source "subsys/logging/Kconfig.template.log_config"

drivers/disk/ramdisk.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2016 Intel Corporation.
- * Copyright (c) 2021, Nordic Semiconductor ASA
+ * Copyright (c) 2021,2023 Nordic Semiconductor ASA
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -15,15 +15,25 @@
 
 LOG_MODULE_REGISTER(ramdisk, CONFIG_RAMDISK_LOG_LEVEL);
 
-#define RAMDISK_SECTOR_SIZE 512
+struct ram_disk_data {
-#define RAMDISK_VOLUME_SIZE (CONFIG_DISK_RAM_VOLUME_SIZE * 1024)
+	struct disk_info info;
-#define RAMDISK_SECTOR_COUNT (RAMDISK_VOLUME_SIZE / RAMDISK_SECTOR_SIZE)
+	const size_t sector_size;
+	const size_t sector_count;
+	uint8_t *const buf;
+};
 
-static uint8_t ramdisk_buf[RAMDISK_VOLUME_SIZE];
+struct ram_disk_config {
+	const size_t sector_size;
+	const size_t sector_count;
+	const size_t size;
+	uint8_t *const buf;
+};
 
-static void *lba_to_address(uint32_t lba)
+static void *lba_to_address(const struct device *dev, uint32_t lba)
 {
-	return &ramdisk_buf[lba * RAMDISK_SECTOR_SIZE];
+	const struct ram_disk_config *config = dev->config;
+
+	return &config->buf[lba * config->sector_size];
 }
 
 static int disk_ram_access_status(struct disk_info *disk)
@@ -39,15 +49,17 @@ static int disk_ram_access_init(struct disk_info *disk)
 static int disk_ram_access_read(struct disk_info *disk, uint8_t *buff,
 				uint32_t sector, uint32_t count)
 {
+	const struct device *dev = disk->dev;
+	const struct ram_disk_config *config = dev->config;
 	uint32_t last_sector = sector + count;
 
-	if (last_sector < sector || last_sector > RAMDISK_SECTOR_COUNT) {
+	if (last_sector < sector || last_sector > config->sector_count) {
-		LOG_ERR("Sector %" PRIu32 " is outside the range %u",
+		LOG_ERR("Sector %" PRIu32 " is outside the range %zu",
-			last_sector, RAMDISK_SECTOR_COUNT);
+			last_sector, config->sector_count);
 		return -EIO;
 	}
 
-	memcpy(buff, lba_to_address(sector), count * RAMDISK_SECTOR_SIZE);
+	memcpy(buff, lba_to_address(dev, sector), count * config->sector_size);
 
 	return 0;
 }
@@ -55,29 +67,33 @@ static int disk_ram_access_read(struct disk_info *disk, uint8_t *buff,
 static int disk_ram_access_write(struct disk_info *disk, const uint8_t *buff,
 				 uint32_t sector, uint32_t count)
 {
+	const struct device *dev = disk->dev;
+	const struct ram_disk_config *config = dev->config;
 	uint32_t last_sector = sector + count;
 
-	if (last_sector < sector || last_sector > RAMDISK_SECTOR_COUNT) {
+	if (last_sector < sector || last_sector > config->sector_count) {
-		LOG_ERR("Sector %" PRIu32 " is outside the range %u",
+		LOG_ERR("Sector %" PRIu32 " is outside the range %zu",
-			last_sector, RAMDISK_SECTOR_COUNT);
+			last_sector, config->sector_count);
 		return -EIO;
 	}
 
-	memcpy(lba_to_address(sector), buff, count * RAMDISK_SECTOR_SIZE);
+	memcpy(lba_to_address(dev, sector), buff, count * config->sector_size);
 
 	return 0;
 }
 
 static int disk_ram_access_ioctl(struct disk_info *disk, uint8_t cmd, void *buff)
 {
+	const struct ram_disk_config *config = disk->dev->config;
+
 	switch (cmd) {
 	case DISK_IOCTL_CTRL_SYNC:
 		break;
 	case DISK_IOCTL_GET_SECTOR_COUNT:
-		*(uint32_t *)buff = RAMDISK_SECTOR_COUNT;
+		*(uint32_t *)buff = config->sector_count;
 		break;
 	case DISK_IOCTL_GET_SECTOR_SIZE:
-		*(uint32_t *)buff = RAMDISK_SECTOR_SIZE;
+		*(uint32_t *)buff = config->sector_size;
 		break;
 	case DISK_IOCTL_GET_ERASE_BLOCK_SZ:
 		*(uint32_t *)buff  = 1U;
@@ -89,6 +105,15 @@ static int disk_ram_access_ioctl(struct disk_info *disk, uint8_t cmd, void *buff
 	return 0;
 }
 
+static int disk_ram_init(const struct device *dev)
+{
+	struct disk_info *info = dev->data;
+
+	info->dev = dev;
+
+	return disk_access_register(info);
+}
+
 static const struct disk_operations ram_disk_ops = {
 	.init = disk_ram_access_init,
 	.status = disk_ram_access_status,
@@ -97,15 +122,51 @@ static const struct disk_operations ram_disk_ops = {
 	.ioctl = disk_ram_access_ioctl,
 };
 
-static struct disk_info ram_disk = {
+#define DT_DRV_COMPAT zephyr_ram_disk
-	.name = CONFIG_DISK_RAM_VOLUME_NAME,
-	.ops = &ram_disk_ops,
-};
 
-static int disk_ram_init(void)
+#define RAMDISK_DEVICE_SIZE(n)								\
-{
+	(DT_INST_PROP(n, sector_size) * DT_INST_PROP(n, sector_count))
 
-	return disk_access_register(&ram_disk);
+#define RAMDISK_DEVICE_CONFIG_DEFINE_MEMREG(n)						\
-}
+	BUILD_ASSERT(RAMDISK_DEVICE_SIZE(n) <=						\
+		     DT_REG_SIZE(DT_INST_PHANDLE(n, ram_region)),			\
+		     "Disk size is smaller than memory region");			\
+											\
+	static struct ram_disk_config disk_config_##n = {				\
+		.sector_size = DT_INST_PROP(n, sector_size),				\
+		.sector_count = DT_INST_PROP(n, sector_count),				\
+		.size = RAMDISK_DEVICE_SIZE(n),						\
+		.buf = UINT_TO_POINTER(DT_REG_ADDR(DT_INST_PHANDLE(n, ram_region))),	\
+	}
 
-SYS_INIT(disk_ram_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
+#define RAMDISK_DEVICE_CONFIG_DEFINE_LOCAL(n)						\
+	static uint8_t disk_buf_##n[DT_INST_PROP(n, sector_size) *			\
+				    DT_INST_PROP(n, sector_count)];			\
+											\
+	static struct ram_disk_config disk_config_##n = {				\
+		.sector_size = DT_INST_PROP(n, sector_size),				\
+		.sector_count = DT_INST_PROP(n, sector_count),				\
+		.size = RAMDISK_DEVICE_SIZE(n),						\
+		.buf = disk_buf_##n,							\
+	}
+
+#define RAMDISK_DEVICE_CONFIG_DEFINE(n)							\
+	COND_CODE_1(DT_INST_NODE_HAS_PROP(n, ram_region),				\
+		    (RAMDISK_DEVICE_CONFIG_DEFINE_MEMREG(n)),				\
+		    (RAMDISK_DEVICE_CONFIG_DEFINE_LOCAL(n)))
+
+#define RAMDISK_DEVICE_DEFINE(n)							\
+											\
+	static struct disk_info disk_info_##n  = {					\
+		.name = DT_INST_PROP(n, disk_name),					\
+		.ops = &ram_disk_ops,							\
+	};										\
+											\
+	RAMDISK_DEVICE_CONFIG_DEFINE(n);						\
+											\
+	DEVICE_DT_INST_DEFINE(n, disk_ram_init, NULL,					\
+			      &disk_info_##n, &disk_config_##n,				\
+			      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,		\
+			      &ram_disk_ops);
+
+DT_INST_FOREACH_STATUS_OKAY(RAMDISK_DEVICE_DEFINE)

dts/bindings/disk/zephyr,ram-disk.yaml

@@ -0,0 +1,35 @@
+# Copyright (c) 2023 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+description: RAM disk
+
+compatible: "zephyr,ram-disk"
+
+include: ["base.yaml", "memory-region.yaml"]
+
+properties:
+  disk-name:
+    type: string
+    required: true
+    description: |
+      Disk name.
+
+  sector-size:
+    type: int
+    required: true
+    enum: [512, 1024, 2048, 4096, 8192, 16384, 32768, 65536]
+    description: |
+      Disk sector size in bytes.
+
+  sector-count:
+    type: int
+    required: true
+    description: |
+      Number of sectors.
+
+  ram-region:
+    type: phandle
+    description: |
+      Optional phandle to the memory region to be used as a RAM disk,
+      if not used a local buffer is defined for each disk instance.
+      Use it with caution as it makes memory contents easily accessible.

samples/subsys/fs/format/prj_ram.conf

@@ -1,7 +1,5 @@
 CONFIG_DISK_ACCESS=y
 CONFIG_DISK_DRIVERS=y
-CONFIG_DISK_DRIVER_RAM=y
-CONFIG_DISK_RAM_VOLUME_SIZE=64
 
 CONFIG_LOG=y
 CONFIG_LOG_MODE_MINIMAL=y

samples/subsys/fs/format/ramdisk.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <128>;
+	};
+};

samples/subsys/fs/format/sample.yaml

@@ -12,5 +12,7 @@ tests:
       - native_posix
       - mimxrt1064_evk
     build_only: true
-    extra_args: CONF_FILE="prj_ram.conf"
+    extra_args:
+      - CONF_FILE="prj_ram.conf"
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
     tags: filesystem

samples/subsys/usb/cdc_acm/overlay-composite-cdc-msc.conf

@@ -3,6 +3,3 @@
 
 CONFIG_USB_MASS_STORAGE=y
 CONFIG_USB_MASS_STORAGE_LOG_LEVEL_ERR=y
-
-#RAM DISK
-CONFIG_DISK_DRIVER_RAM=y

samples/subsys/usb/cdc_acm/ramdisk.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <128>;
+	};
+};

samples/subsys/usb/cdc_acm/sample.yaml

@@ -27,7 +27,9 @@ tests:
     depends_on: usb_device
     tags: usb
     arch_exclude: posix
-    extra_args: OVERLAY_CONFIG=overlay-composite-cdc-msc.conf
+    extra_args:
+      - OVERLAY_CONFIG=overlay-composite-cdc-msc.conf
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
     harness: console
     harness_config:
       type: one_line

samples/subsys/usb/mass/Kconfig

@@ -14,11 +14,9 @@ choice
 
 config APP_MSC_STORAGE_NONE
 	bool "Use RAM disk as block device"
-	imply DISK_DRIVER_RAM
 
 config APP_MSC_STORAGE_RAM
 	bool "Use RAM disk and FAT file system"
-	imply DISK_DRIVER_RAM
 	imply FILE_SYSTEM
 	imply FAT_FILESYSTEM_ELM
 
@@ -42,9 +40,6 @@ config APP_MSC_STORAGE_SDCARD
 
 endchoice
 
-config DISK_RAM_VOLUME_SIZE
-	default 32 if APP_MSC_STORAGE_NONE
-
 config MASS_STORAGE_DISK_NAME
 	default "NAND" if DISK_DRIVER_FLASH
 	default "RAM" if DISK_DRIVER_RAM

samples/subsys/usb/mass/ramdisk.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <192>;
+	};
+};

samples/subsys/usb/mass/sample.yaml

@@ -2,9 +2,11 @@ sample:
   name: Mass Storage
 tests:
   sample.usb.mass_ram_none:
-    min_ram: 64
+    min_ram: 128
     depends_on: usb_device
     arch_exclude: posix
+    extra_args:
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
     extra_configs:
       - CONFIG_LOG_DEFAULT_LEVEL=3
     tags:
@@ -18,12 +20,14 @@ tests:
         - "No file system selected"
         - "The device is put in USB mass storage mode."
   sample.usb_device_next.mass_ram_none:
-    min_ram: 64
+    min_ram: 128
     depends_on: usb_device
     platform_allow:
       - nrf52840dk_nrf52840
       - frdm_k64f
-    extra_args: CONF_FILE="usbd_next_prj.conf"
+    extra_args:
+      - CONF_FILE="usbd_next_prj.conf"
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
     extra_configs:
       - CONFIG_LOG_DEFAULT_LEVEL=3
     tags:
@@ -40,6 +44,8 @@ tests:
     min_ram: 128
     depends_on: usb_device
     arch_exclude: posix
+    extra_args:
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
     extra_configs:
       - CONFIG_LOG_DEFAULT_LEVEL=3
       - CONFIG_APP_MSC_STORAGE_RAM=y

tests/drivers/disk/disk_access/boards/qemu_x86_64.overlay

@@ -18,4 +18,11 @@
 			status = "okay";
 		};
 	};
+
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <192>;
+	};
 };

tests/drivers/disk/disk_access/src/main.c

@@ -19,7 +19,7 @@
 #elif IS_ENABLED(CONFIG_DISK_DRIVER_MMC)
 #define DISK_NAME CONFIG_MMC_VOLUME_NAME
 #elif IS_ENABLED(CONFIG_DISK_DRIVER_RAM)
-#define DISK_NAME CONFIG_DISK_RAM_VOLUME_NAME
+#define DISK_NAME "RAM"
 #elif IS_ENABLED(CONFIG_NVME)
 #define DISK_NAME "nvme0n0"
 #else

tests/drivers/disk/disk_access/testcase.yaml

@@ -14,8 +14,6 @@ tests:
       - mimxrt1050_evk
       - mimxrt1064_evk
   drivers.disk.ram:
-    extra_configs:
-      - CONFIG_DISK_DRIVER_RAM=y
     platform_allow: qemu_x86_64
   drivers.disk.nvme:
     extra_configs:

tests/drivers/disk/disk_performance/src/main.c

@@ -16,8 +16,6 @@
 #define DISK_NAME CONFIG_SDMMC_VOLUME_NAME
 #elif IS_ENABLED(CONFIG_DISK_DRIVER_MMC)
 #define DISK_NAME CONFIG_MMC_VOLUME_NAME
-#elif IS_ENABLED(CONFIG_DISK_DRIVER_RAM)
-#define DISK_NAME CONFIG_DISK_RAM_VOLUME_NAME
 #elif IS_ENABLED(CONFIG_NVME)
 #define DISK_NAME "nvme0n0"
 #else

tests/posix/fs/app.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <160>;
+	};
+};

tests/posix/fs/prj.conf

@@ -1,8 +1,6 @@
 CONFIG_FILE_SYSTEM=y
 CONFIG_LOG=y
 CONFIG_FAT_FILESYSTEM_ELM=y
-CONFIG_DISK_DRIVER_RAM=y
-CONFIG_DISK_RAM_VOLUME_SIZE=80
 CONFIG_POSIX_API=y
 CONFIG_POSIX_FS=y
 CONFIG_ZTEST=y

tests/subsys/fs/ext2/prj.conf

@@ -4,7 +4,6 @@ CONFIG_FILE_SYSTEM_MKFS=y
 
 CONFIG_DISK_ACCESS=y
 CONFIG_DISK_DRIVER_RAM=y
-CONFIG_DISK_RAM_VOLUME_SIZE=200
 
 CONFIG_TEST_RANDOM_GENERATOR=y
 

tests/subsys/fs/ext2/prj_big.conf

@@ -4,7 +4,6 @@ CONFIG_FILE_SYSTEM_MKFS=y
 
 CONFIG_DISK_ACCESS=y
 CONFIG_DISK_DRIVER_RAM=y
-CONFIG_DISK_RAM_VOLUME_SIZE=9000
 
 CONFIG_EXT2_MAX_BLOCK_COUNT=20
 

tests/subsys/fs/ext2/ramdisk_big.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <18000>;
+	};
+};

tests/subsys/fs/ext2/ramdisk_small.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <400>;
+	};
+};

tests/subsys/fs/ext2/testcase.yaml

@@ -3,10 +3,14 @@ common:
 tests:
   filesystem.ext2.default:
     platform_allow: native_posix native_posix_64 hifive_unmatched bl5340_dvk_cpuapp
+    extra_args:
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk_small.overlay"
 
   filesystem.ext2.big:
     platform_allow: native_posix native_posix_64
-    extra_args: CONF_FILE=prj_big.conf
+    extra_args:
+      - CONF_FILE=prj_big.conf
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk_big.overlay"
 
   filesystem.ext2.sdcard:
     platform_allow: hifive_unmatched bl5340_dvk_cpuapp

tests/subsys/fs/fat_fs_api/prj_native_posix_ram.conf

@@ -2,7 +2,6 @@ CONFIG_FILE_SYSTEM=y
 CONFIG_FILE_SYSTEM_MKFS=y
 CONFIG_LOG=y
 CONFIG_FAT_FILESYSTEM_ELM=y
-CONFIG_DISK_DRIVER_RAM=y
 CONFIG_ZTEST=y
 CONFIG_ZTEST_NEW_API=y
 CONFIG_FLASH=y

tests/subsys/fs/fat_fs_api/ramdisk.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <128>;
+	};
+};

tests/subsys/fs/fat_fs_api/src/test_fat.h

@@ -12,7 +12,7 @@
 #include <ff.h>
 
 #ifdef CONFIG_DISK_DRIVER_RAM
-#define DISK_NAME CONFIG_DISK_RAM_VOLUME_NAME
+#define DISK_NAME "RAM"
 #elif defined(CONFIG_DISK_DRIVER_FLASH)
 #define DISK_NAME DT_PROP(DT_NODELABEL(test_disk), disk_name)
 #elif defined(CONFIG_DISK_DRIVER_SDMMC)

tests/subsys/fs/fat_fs_api/testcase.yaml

@@ -15,7 +15,9 @@ tests:
     filter: dt_compat_enabled("zephyr,mmc-disk")
   filesystem.fat.ram.api:
     platform_allow: native_posix
-    extra_args: CONF_FILE="prj_native_posix_ram.conf"
+    extra_args:
+      - CONF_FILE="prj_native_posix_ram.conf"
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
   filesystem.fat.api.reentrant:
     platform_allow: native_posix
     extra_configs:

tests/subsys/fs/fat_fs_dual_drive/app.overlay

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <160>;
+	};
+
+	ramdisk1 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "CF";
+		sector-size = <512>;
+		sector-count = <160>;
+	};
+};

tests/subsys/fs/fat_fs_dual_drive/prj.conf

@@ -3,7 +3,6 @@ CONFIG_LOG=y
 CONFIG_FAT_FILESYSTEM_ELM=y
 CONFIG_FS_FATFS_NUM_FILES=8
 CONFIG_FS_FATFS_NUM_DIRS=8
-CONFIG_DISK_DRIVER_RAM=y
 CONFIG_ZTEST=y
 CONFIG_ZTEST_NEW_API=y
 CONFIG_MAIN_STACK_SIZE=2048

tests/subsys/fs/fat_fs_dual_drive/src/disk_access_test_drv.c

@@ -1,97 +0,0 @@
-/*
- * Copyright (c) 2018 Intel Corporation.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-#include <string.h>
-#include <zephyr/types.h>
-#include <zephyr/sys/__assert.h>
-#include <zephyr/storage/disk_access.h>
-#include <errno.h>
-#include <zephyr/init.h>
-#include <zephyr/device.h>
-
-#define RAMDISK_SECTOR_SIZE 512
-
-/* A 96KB RAM Disk, which meets ELM FAT fs's minimum block requirement. Fit for
- * qemu testing (as it may exceed target's RAM limits).
- */
-#define RAMDISK_VOLUME_SIZE (192 * RAMDISK_SECTOR_SIZE)
-static uint8_t ramdisk_buf[RAMDISK_VOLUME_SIZE];
-
-static void *lba_to_address(uint32_t lba)
-{
-	__ASSERT(((lba * RAMDISK_SECTOR_SIZE) < RAMDISK_VOLUME_SIZE),
-		 "FS bound error");
-
-	return &ramdisk_buf[(lba * RAMDISK_SECTOR_SIZE)];
-}
-
-static int disk_ram_access_status(struct disk_info *disk)
-{
-	return DISK_STATUS_OK;
-}
-
-static int disk_ram_access_init(struct disk_info *disk)
-{
-	return 0;
-}
-
-static int disk_ram_access_read(struct disk_info *disk, uint8_t *buff,
-				uint32_t sector, uint32_t count)
-{
-	memcpy(buff, lba_to_address(sector), count * RAMDISK_SECTOR_SIZE);
-
-	return 0;
-}
-
-static int disk_ram_access_write(struct disk_info *disk, const uint8_t *buff,
-				 uint32_t sector, uint32_t count)
-{
-	memcpy(lba_to_address(sector), buff, count * RAMDISK_SECTOR_SIZE);
-
-	return 0;
-}
-
-static int disk_ram_access_ioctl(struct disk_info *disk, uint8_t cmd, void *buff)
-{
-	switch (cmd) {
-	case DISK_IOCTL_CTRL_SYNC:
-		break;
-	case DISK_IOCTL_GET_SECTOR_COUNT:
-		*(uint32_t *)buff = RAMDISK_VOLUME_SIZE / RAMDISK_SECTOR_SIZE;
-		break;
-	case DISK_IOCTL_GET_SECTOR_SIZE:
-		*(uint32_t *)buff = RAMDISK_SECTOR_SIZE;
-		break;
-	case DISK_IOCTL_GET_ERASE_BLOCK_SZ:
-		*(uint32_t *)buff  = 1U;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static struct disk_operations ram_disk_ops = {
-	.init = disk_ram_access_init,
-	.status = disk_ram_access_status,
-	.read = disk_ram_access_read,
-	.write = disk_ram_access_write,
-	.ioctl = disk_ram_access_ioctl,
-};
-
-static struct disk_info ram_disk = {
-	.name = "CF",
-	.ops = &ram_disk_ops,
-};
-
-static int disk_ram_test_init(void)
-{
-
-	return disk_access_register(&ram_disk);
-}
-
-SYS_INIT(disk_ram_test_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);

tests/subsys/fs/multi-fs/prj.conf

@@ -6,8 +6,6 @@ CONFIG_FILE_SYSTEM_LITTLEFS=y
 CONFIG_LOG=y
 CONFIG_FS_LITTLEFS_FC_HEAP_SIZE=16384
 CONFIG_FAT_FILESYSTEM_ELM=y
-CONFIG_DISK_DRIVER_RAM=y
-CONFIG_DISK_RAM_VOLUME_SIZE=80
 CONFIG_HEAP_MEM_POOL_SIZE=4096
 CONFIG_MAIN_STACK_SIZE=4096
 CONFIG_ZTEST_STACK_SIZE=4096

tests/subsys/fs/multi-fs/prj_fs_shell.conf

@@ -10,8 +10,6 @@ CONFIG_SHELL_BACKEND_DUMMY=y
 CONFIG_SHELL_CMD_BUFF_SIZE=90
 CONFIG_FILE_SYSTEM_SHELL=y
 CONFIG_FAT_FILESYSTEM_ELM=y
-CONFIG_DISK_DRIVER_RAM=y
-CONFIG_DISK_RAM_VOLUME_SIZE=80
 CONFIG_HEAP_MEM_POOL_SIZE=1024
 CONFIG_MAIN_STACK_SIZE=1024
 CONFIG_ZTEST_STACK_SIZE=4096

tests/subsys/fs/multi-fs/ramdisk.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	ramdisk0 {
+		compatible = "zephyr,ram-disk";
+		disk-name = "RAM";
+		sector-size = <512>;
+		sector-count = <160>;
+	};
+};

tests/subsys/fs/multi-fs/testcase.yaml

@@ -8,13 +8,17 @@ common:
     - littlefs
 tests:
   filesystem.multifs:
+    extra_args:
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
     platform_allow:
       - native_posix
       - qemu_x86
     integration_platforms:
       - native_posix
   filesystem.fs_shell:
-    extra_args: CONF_FILE="prj_fs_shell.conf"
+    extra_args:
+      - CONF_FILE="prj_fs_shell.conf"
+      - EXTRA_DTC_OVERLAY_FILE="ramdisk.overlay"
     platform_allow:
       - native_posix
       - qemu_x86