SAMA5D4-EK kernel config can now boot from a ROMFS file system

configs/sama5d4-ek/Kconfig

@@ -286,6 +286,38 @@ config SAMA5D4EK_HSMCI1_MOUNT_MOUNTPOINT
 
 endif # SAMA5D4EK_HSMCI1_MOUNT
 
+config SAMA5D4EK_ROMFS_MOUNT
+	bool "ROMFS boot mount"
+	default n
+	depends on FS_ROMFS
+	---help---
+		By selecting this option, you an build mount a ROMFS file system as
+		part of the system boot operation.  NOTE that the board logic
+		contains no a priori ROMFS file system.  In order to use this option,
+		you must provide the file nuttx/configs/sama5d4-ek/include/boot_romfsimg.h.
+		You might use logic in the tool at apps/tools/mkromfsimg.sh to create
+		this header file.
+
+if SAMA5D4EK_ROMFS_MOUNT
+
+config SAMA5D4EK_ROMFS_ROMDISK_MINOR
+	int "ROM disk minor device number"
+	default 0
+
+config SAMA5D4EK_ROMFS_ROMDISK_DEVNAME
+	string "ROM disk block device"
+	default "/dev/ram0"
+
+config SAMA5D4EK_ROMFS_ROMDISK_SECTSIZE
+	int "ROM disk sector size"
+	default 512
+
+config SAMA5D4EK_ROMFS_MOUNT_MOUNTPOINT
+	string "ROMFS mount point"
+	default "/bin"
+
+endif # SAMA5D4EK_ROMFS_MOUNT
+
 if INPUT_MXT
 
 config SAMA5D4EK_MXT_I2CFREQUENCY

configs/sama5d4-ek/README.txt

@@ -3776,17 +3776,69 @@ Configurations
         CONFIG_MM_KERNEL_HEAP=y                : Enable a kernel heap
         CONFIG_MM_KERNEL_HEAPSIZE=8192         : (temporary.. will change)
 
-    4. Board initialization is performed performed before the application
+    4. By default, this configuration is setup to boot from an SD card.
+       Unfortunately, there some issues when using the SD card that prevent
+       this from working properly (see STATUS below).  And alternative is to
+       use a built-in ROMFS file system that does not suffer from the
+       (assumed) HSMCI bug.
+
+       So why isn't this the default configuration?  Because it does not
+       build out-of-the-box.  You have to take special steps in the build
+       process as described below.
+
+       Assuming that you will want to reconfigure to use the ROMFS (rather than debugging HSCMI), you will need to disable all of these settings:
+
+       System Type->ATSAMA5 Peripheral Support
+         CONFIG_SAMA5_HSMCI0=n           : Disable HSMCI0 support
+         CONFIG_SAMA5_XDMAC0=n           : XDMAC0 is no longer needed
+
+       System Type
+         CONFIG_SAMA5_PIO_IRQ=n          : PIO interrupts are no longer needed
+
+       Device Drivers -> MMC/SD Driver Support
+         CONFIG_MMCSD=n                  : Disable MMC/SD support
+
+       File System
+         CONFIG_FS_FAT=n                 : FAT file system no longer needed
+
+       Board Selection
+         CONFIG_SAMA5D4EK_HSMCI0_MOUNT=y : Don't mount HSMCI0 at boot
+
+       And then enable these features in order to use the ROMFS boot file
+       system:
+
+       File System
+         CONFIG_FS_ROMFS=y               : Enable the ROMFS file system
+
+       Board Selection
+         CONFIG_SAMA5D4EK_ROMFS_MOUNT=y  : Mount the ROMFS file system at boot
+         CONFIG_SAMA5D4EK_ROMFS_MOUNT_MOUNTPOINT="/bin"
+         CONFIG_SAMA5D4EK_ROMFS_ROMDISK_DEVNAME="/dev/ram0"
+         CONFIG_SAMA5D4EK_ROMFS_ROMDISK_MINOR=0
+         CONFIG_SAMA5D4EK_ROMFS_ROMDISK_SECTSIZE=512
+
+       Then you will need to follow some special build instructions below
+       in order to build and install the ROMFS file system image.
+
+       UPDATE: The ROMFS configuration is pre-configured in the the
+       file nuttx/configs/sama5d4-ek/knsh/defconfig.ROMFS
+
+    5. Board initialization is performed performed before the application
        is started:
 
        RTOS Features -> RTOS Hooks
          CONFIG_BOARD_INITITIALIZE=y
 
-       The board initialization will mount the FAT filesystem on an SD card
+       In the special ROMFS boot configuration, you need to do nothing
-       inserted int the HSMCI0 slot (full size).  The SAMA4D4-EK provides
+       additional: The board initialization will mount the ROMFS file
-       two SD memory card slots:  (1) a full size SD card slot (J10), and
+       system at boot time.
-       (2) a microSD memory card slot (J11).  The full size SD card slot
+
-       connects via HSMCI0; the microSD connects vi HSMCI1.  See the relevant
+       In the default configuration, however, the board initialization
+       will instead mount the FAT filesystem on an SD card inserted in
+       the HSMCI0 slot (full size).  The SAMA4D4-EK provides two SD
+       memory card slots:  (1) a full size SD card slot (J10), and (2) a
+       microSD memory card slot (J11).  The full size SD card slot connects
+       via HSMCI0; the microSD connects vi HSMCI1.  See the relevant
        configuration settings above in the paragraph entitled "HSMCI Card
        Slots" above.
 
@@ -3809,20 +3861,45 @@ Configurations
          CONFIG_SAMA5D4EK_HSMCI0_MOUNT_FSTYPE="vfat"
          CONFIG_SAMA5D4EK_HSMCI0_MOUNT_MOUNTPOINT="/bin"
 
-    5. General build directions:
+    6a. General build directions (boot from SD card):
 
-       $ cd nuttx/tools                    : Go to the tools sub-directory
+        $ cd nuttx/tools                    : Go to the tools sub-directory
-       $ ./configure.sh sama5d4-ek/kernel  : Establish this configuration
+        $ ./configure.sh sama5d4-ek/kernel  : Establish this configuration
-       $ cd ..                             : Back to the NuttX build directory
+        $ cd ..                             : Back to the NuttX build directory
-                                           : Edit setenv.sh to use the correct path
+                                            : Edit setenv.sh to use the correct path
-       $ . ./setenv.sh                     : Set up the PATH variable
+        $ . ./setenv.sh                     : Set up the PATH variable
-       $ make                              : Build the kernel
+        $ make                              : Build the kerne with a dummy ROMFS image
-                                           : This should create the nuttx ELF
+                                            : This should create the nuttx ELF
-       $ make export                       : Create the kernel export package
+        $ make export                       : Create the kernel export package
-                                           : You should have a file like nuttx-export-*.zip
+                                            : You should have a file like
-       $ cd apps/                          : Go to the apps/ directory
+                                            : nuttx-export-*.zip
-       $ tools/mkimport.sh -x <zip-file>   : Use the full path to nuttx-export-*.zip
+        $ cd apps/                          : Go to the apps/ directory
-       $ make import                       : This will build the file system
+        $ tools/mkimport.sh -x <zip-file>   : Use the full path to nuttx-export-*.zip
+        $ make import                       : This will build the file system.
+
+      You will then need to copy the files from apps/bin to an SD card to
+      create the the bootable SD card.
+
+    6b. General build directions (boot from ROMFS image):
+
+        $ cd nuttx/tools                    : Go to the tools sub-directory
+        $ ./configure.sh sama5d4-ek/kernel  : Establish this configuration
+        $ cd ..                             : Back to the NuttX build directory
+                                            : Edit setenv.sh to use the correct path
+        $ . ./setenv.sh                     : Set up the PATH variable
+        $ touch configs/sama5d4-ek/include/boot_romfsimg.h
+        $ make                              : Build the kernel with a dummy ROMFS image
+                                            : This should create the nuttx ELF
+        $ make export                       : Create the kernel export package
+                                            : You should have a file like
+                                            : nuttx-export-*.zip
+        $ cd apps/                          : Go to the apps/ directory
+        $ tools/mkimport.sh -x <zip-file>   : Use the full path to nuttx-export-*.zip
+        $ make import                       : This will build the file system
+        $ tools/mkromfsimg.sh               : Create the real ROMFS image
+        $ mv boot_romfsimg.h ../nuttx/configs/sama5d4-ek/include/boot_romfsimg.h
+        $ cd nuttx/                         : Rebuild the system with the correct
+        $ make clean_context all            : ROMFS file system
 
     STATUS:
 

configs/sama5d4-ek/include/.gitignore

@@ -0,0 +1 @@
+/boot_romfsimg.h

configs/sama5d4-ek/knsh/defconfig

@@ -180,7 +180,7 @@ CONFIG_ARCH_CHIP_ATSAMA5D44=y
 # CONFIG_SAMA5_WDT is not set
 CONFIG_SAMA5_RTC=y
 # CONFIG_SAMA5_ICM is not set
-CONFIG_SAMA5_HSMC=y
+# CONFIG_SAMA5_HSMC is not set
 # CONFIG_SAMA5_SMD is not set
 # CONFIG_SAMA5_SAIC is not set
 # CONFIG_SAMA5_UART0 is not set
@@ -477,13 +477,7 @@ CONFIG_DEV_RANDOM=y
 # CONFIG_ARCH_HAVE_PWM_PULSECOUNT is not set
 # CONFIG_PWM is not set
 CONFIG_ARCH_HAVE_I2CRESET=y
-CONFIG_I2C=y
+# CONFIG_I2C is not set
-# CONFIG_I2C_SLAVE is not set
-CONFIG_I2C_TRANSFER=y
-CONFIG_I2C_WRITEREAD=y
-# CONFIG_I2C_POLLED is not set
-# CONFIG_I2C_TRACE is not set
-CONFIG_I2C_RESET=y
 # CONFIG_SPI is not set
 # CONFIG_I2S is not set
 CONFIG_RTC=y
@@ -492,7 +486,7 @@ CONFIG_RTC_DATETIME=y
 # CONFIG_WATCHDOG is not set
 # CONFIG_TIMER is not set
 # CONFIG_ANALOG is not set
-CONFIG_AUDIO_DEVICES=y
+# CONFIG_AUDIO_DEVICES is not set
 # CONFIG_VIDEO_DEVICES is not set
 # CONFIG_BCH is not set
 # CONFIG_INPUT is not set

configs/sama5d4-ek/src/sam_bringup.c

@@ -50,14 +50,23 @@
 #  include <apps/usbmonitor.h>
 #endif
 
+#include <nuttx/fs/ramdisk.h>
 #include <nuttx/binfmt/elf.h>
 
 #include "sama5d4-ek.h"
 
+#ifdef HAVE_ROMFS
+#  include <arch/board/boot_romfsimg.h>
+#endif
+
 /****************************************************************************
  * Pre-Processor Definitions
  ****************************************************************************/
 
+#define NSECTORS(n) \
+  (((n)+CONFIG_SAMA5D4EK_ROMFS_ROMDISK_SECTSIZE-1) / \
+   CONFIG_SAMA5D4EK_ROMFS_ROMDISK_SECTSIZE)
+
 /* Debug ********************************************************************/
 
 #ifdef CONFIG_BOARD_INITIALIZE
@@ -86,7 +95,7 @@ int sam_bringup(void)
 {
 #if defined(HAVE_NAND) || defined(HAVE_AT25) || defined(HAVE_HSMCI)  || \
     defined(HAVE_USBHOST) || defined(HAVE_USBMONITOR) || defined(HAVE_WM8904) || \
-    defined(HAVE_AUTOMOUNTER) || defined(HAVE_ELF)
+    defined(HAVE_AUTOMOUNTER) || defined(HAVE_ELF) || defined(HAVE_ROMFS)
   int ret;
 #endif
 
@@ -178,6 +187,32 @@ int sam_bringup(void)
   sam_automount_initialize();
 #endif
 
+#ifdef HAVE_ROMFS
+  /* Create a ROM disk for the /etc filesystem */
+
+  ret = romdisk_register(CONFIG_SAMA5D4EK_ROMFS_ROMDISK_MINOR, romfs_img,
+                         NSECTORS(romfs_img_len),
+                         CONFIG_SAMA5D4EK_ROMFS_ROMDISK_SECTSIZE);
+  if (ret < 0)
+    {
+      message("ERROR: romdisk_register failed: %d\n", -ret);
+    }
+  else
+    {
+      /* Mount the file system */
+
+      ret = mount(CONFIG_SAMA5D4EK_ROMFS_ROMDISK_DEVNAME,
+                  CONFIG_SAMA5D4EK_ROMFS_MOUNT_MOUNTPOINT,
+                  "romfs", MS_RDONLY, NULL);
+      if (ret < 0)
+        {
+          message("ERROR: mount(%s,%s,romfs) failed: %d\n",
+                  CONFIG_SAMA5D4EK_ROMFS_ROMDISK_DEVNAME,
+                  CONFIG_SAMA5D4EK_ROMFS_MOUNT_MOUNTPOINT, errno);
+        }
+    }
+#endif
+
 #ifdef HAVE_USBHOST
   /* Initialize USB host operation.  sam_usbhost_initialize() starts a thread
    * will monitor for USB connection and disconnection events.

configs/sama5d4-ek/src/sama5d4-ek.h

@@ -69,6 +69,7 @@
 #define HAVE_AUDIO_NULL  1
 #define HAVE_PMIC        1
 #define HAVE_ELF         1
+#define HAVE_ROMFS       1
 
 /* HSMCI */
 /* Can't support MMC/SD if the card interface(s) are not enable */
@@ -462,6 +463,12 @@
 #  undef HAVE_ELF
 #endif
 
+/* ROMFS */
+
+#ifndef CONFIG_FS_ROMFS
+#  undef HAVE_ROMFS
+#endif
+
 /* LEDs *****************************************************************************/
 /* There are 3 LEDs on the SAMA5D4-EK:
  *