ROMFS for STM32F4 Discovery board

configs/stm32f4discovery/Kconfig

@@ -12,6 +12,28 @@ config STM32F4DISBB
 		Select if you are using the STM32F4DIS-BB base board with the
 		STM32F4Discovery.
 
+config STM32_ROMFS
+	bool "Automount baked-in ROMFS image"
+	default n
+	depends on FS_ROMFS
+	---help---
+		Select STM32_ROMFS_IMAGEFILE, STM32_ROMFS_DEV_MINOR, STM32_ROMFS_MOUNTPOINT
+
+config STM32_ROMFS_DEV_MINOR
+	int "Minor for the block device backing the data"
+	depends on STM32_ROMFS
+	default 64
+
+config STM32_ROMFS_MOUNTPOINT
+	string "Mountpoint of the custom romfs image"
+	depends on STM32_ROMFS
+	default "/rom"
+
+config STM32_ROMFS_IMAGEFILE
+	string "ROMFS image file to include into build"
+	depends on STM32_ROMFS
+	default "../../../rom.img"
+
 config STM32F4DISCO_USBHOST_STACKSIZE
 	int "USB host waiter stack size"
 	default 1024

configs/stm32f4discovery/src/Makefile

@@ -156,6 +156,10 @@ ifeq ($(CONFIG_TIMER),y)
 CSRCS += stm32_timer.c
 endif
 
+ifeq ($(CONFIG_STM32_ROMFS),y)
+CSRCS += stm32_romfs_initialize.c
+endif
+
 ifeq ($(CONFIG_BOARDCTL_UNIQUEID),y)
 CSRCS += stm32_uid.c
 endif

configs/stm32f4discovery/src/stm32_bringup.c

@@ -52,6 +52,7 @@
 #include <nuttx/binfmt/elf.h>
 
 #include "stm32.h"
+#include "stm32_romfs.h"
 
 #ifdef CONFIG_STM32_OTGFS
 #  include "stm32_usbhost.h"
@@ -287,6 +288,15 @@ int stm32_bringup(void)
     }
 #endif
 
+#ifdef CONFIG_STM32_ROMFS
+  ret = stm32_romfs_initialize();
+  if (ret < 0)
+    {
+      serr("ERROR: Failed to mount romfs at %s: %d\n",
+           STM32_ROMFS_MOUNTPOINT, ret);
+    }
+#endif
+
 #ifdef CONFIG_SENSORS_XEN1210
   ret = xen1210_archinitialize(0);
   if (ret < 0)

configs/stm32f4discovery/src/stm32_romfs.h

@@ -0,0 +1,62 @@
+/****************************************************************************
+ * configs/stm32f4discovery/src/stm32_romfs.h
+ *
+ *   Copyright (C) 2017 Tomasz Wozniak. All rights reserved.
+ *   Author: Tomasz Wozniak <t.wozniak@samsung.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+#ifndef __CONFIGS_STM32F4DISCOVERY_SRC_STM32_ROMFS_H
+#define __CONFIGS_STM32F4DISCOVERY_SRC_STM32_ROMFS_H
+
+#ifdef CONFIG_STM32_ROMFS
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+#define ROMFS_SECTOR_SIZE 64
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_romfs_initialize
+ *
+ * Description:
+ *   Registers built-in ROMFS image as block device and mounts it.
+ *
+ * Returned Value:
+ *   0 on success, <0 on error.
+ ****************************************************************************/
+int stm32_romfs_initialize(void);
+
+#endif /* CONFIG_STM32_ROMFS */
+
+#endif /* __CONFIGS_STM32F4DISCOVERY_SRC_STM32_ROMFS_H */

configs/stm32f4discovery/src/stm32_romfs_initialize.c

@@ -0,0 +1,145 @@
+/*****************************************************************************
+ * configs/stm32f4discovery/src/stm32_romfs_initialize.c
+ * This file provides contents of an optional ROMFS volume, mounted at boot.
+ *
+ *   Copyright (C) 2017 Tomasz Wozniak. All rights reserved.
+ *   Author: Tomasz Wozniak <t.wozniak@samsung.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/*****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/drivers/ramdisk.h>
+#include "stm32_romfs.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+#ifndef CONFIG_STM32_ROMFS
+#error "CONFIG_STM32_ROMFS must be defined"
+#else
+
+#ifndef CONFIG_STM32_ROMFS_IMAGEFILE
+#error "CONFIG_STM32_ROMFS_IMAGEFILE must be defined"
+#endif
+#ifndef CONFIG_STM32_ROMFS_DEV_MINOR
+#error "CONFIG_STM32_ROMFS_DEV_MINOR must be defined"
+#endif
+#ifndef CONFIG_STM32_ROMFS_MOUNTPOINT
+#error "CONFIG_STM32_ROMFS_MOUNTPOINT must be defined"
+#endif
+
+#define NSECTORS(size) (((size) + ROMFS_SECTOR_SIZE - 1)/ROMFS_SECTOR_SIZE)
+
+#define STR2(m)  #m
+#define STR(m) STR2(m)
+
+#define MKMOUNT_DEVNAME(m) "/dev/ram" STR(m)
+#define MOUNT_DEVNAME      MKMOUNT_DEVNAME(CONFIG_STM32_ROMFS_DEV_MINOR)
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+__asm__ (
+    ".section .rodata\n"
+    ".balign  16\n"
+    ".globl   romfs_data_begin\n"
+"romfs_data_begin:\n"
+    ".incbin " STR(CONFIG_STM32_ROMFS_IMAGEFILE) "\n"\
+    \
+    ".balign " STR(ROMFS_SECTOR_SIZE) "\n"
+    ".globl   romfs_data_end\n"
+"romfs_data_end:\n"
+    ".globl   romfs_data_size\n"
+"romfs_data_size:\n"
+    ".word romfs_data_end - romfs_data_begin\n");
+
+extern const char romfs_data_begin;
+extern const char romfs_data_end;
+extern const int romfs_data_size;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_romfs_initialize
+ *
+ * Description:
+ *   Registers the aboveincluded binary file as block device.
+ *   Then mounts the block device as ROMFS filesystems.
+ *
+ * Returned Value:
+ *   0 on success, <0 on error.
+ *
+ * Assumptions/Limitations:
+ *   Memory addresses [&romfs_data_begin .. &romfs_data_begin) should contain
+ *   ROMFS volume data, as included in the assembly snippet above (l. 84).
+ *
+ ****************************************************************************/
+int stm32_romfs_initialize(void)
+{
+  int  ret;
+
+  /* Create a ROM disk for the /etc filesystem */
+  long int romfs_data_len = &romfs_data_end - &romfs_data_begin;
+  ret = romdisk_register(CONFIG_STM32_ROMFS_DEV_MINOR, &romfs_data_begin,
+                         NSECTORS(romfs_data_len), ROMFS_SECTOR_SIZE);
+  if (ret < 0)
+    {
+      ferr("ERROR: romdisk_register failed: %d\n", -ret);
+      return -1;
+    }
+
+  /* Mount the file system */
+  finfo("Mounting ROMFS filesystem at target=%s with source=%s\n",
+      CONFIG_STM32_ROMFS_MOUNTPOINT, MOUNT_DEVNAME);
+
+  ret = mount(MOUNT_DEVNAME, CONFIG_STM32_ROMFS_MOUNTPOINT,
+              "romfs", MS_RDONLY, NULL);
+  if (ret < 0)
+    {
+      ferr("ERROR: mount(%s,%s,romfs) failed: %d\n",
+           MOUNT_DEVNAME, CONFIG_STM32_ROMFS_MOUNTPOINT, errno);
+      return -1;
+    }
+  return 0;
+}
+
+#endif /* CONFIG_STM32_ROMFS */