fs/mnemofs: Add mnemofs version 1 support.

Documentation/applications/testing/nand_sim/index.rst

@@ -152,20 +152,23 @@ is still the wrapper, not the actual upper half, as the upper half methods
 may call the other methods as well internally and we might want to log
 them as well*.
 
-Registering Device & Daemon
-===========================
+Registering Device & Background Task
+====================================
 
 This wrapper is then registered using ``register_mtddriver``, and this
-whole thing is converted to be a daemon, so that the device can keep running
-in the background.
+whole thing is launched as a background task, so that the device can keep
+running after the ``nand`` command returns to the shell.
 
-Making it a daemon is achieved by using ``fork()``, killing the parent, and
-using ``daemon()`` in child.
+The ``nand`` command starts a dedicated NuttX task with ``task_create()``,
+waits until the device registration finishes, and then returns control to
+the shell. This keeps the simulator alive in the background without relying
+on ``fork()``, whose post-fork execution model is not appropriate for this
+kind of long-running initialization in the flat build used by the simulator.
 
 Known Issues
 ============
 
 * ECC is not implemented yet.
 * MLC NAND Flash is not implemented yet.
 * Due to the fixed name of the device, there can't be more than one instance
-  of this virtual device.
+  of this virtual device.

drivers/mtd/mtd_nandram.c

@@ -332,12 +332,10 @@ int nand_ram_eraseblock(FAR struct nand_raw_s *raw, off_t block)
 int nand_ram_rawread(FAR struct nand_raw_s *raw, off_t block,
                       unsigned int page, FAR void *data, FAR void *spare)
 {
-  int                     ret;
   uint32_t                read_page;
   struct nand_ram_data_s  *read_page_data;
   struct nand_ram_spare_s *read_page_spare;
 
-  ret             = OK;
   read_page       = (block << NAND_RAM_LOG_PAGES_PER_BLOCK) + page;
   read_page_data  = nand_ram_flash_data + read_page;
   read_page_spare = nand_ram_flash_spare + read_page;
@@ -349,14 +347,6 @@ int nand_ram_rawread(FAR struct nand_raw_s *raw, off_t block,
               nand_ram_ins_i, "rawread", read_page);
   nand_ram_status();
 
-  if (nand_ram_flash_spare[read_page].bad != NAND_RAM_BLOCK_GOOD)
-    {
-      ret = -EFAULT;
-      NAND_RAM_LOG("[LOWER %" PRIu64 " | %s] Failed: %s\n",
-                    nand_ram_ins_i, "rawread", EFAULT_STR);
-      goto errout;
-    }
-
   nand_ram_flash_spare[read_page].n_read++;
 
   if (data != NULL)
@@ -378,11 +368,9 @@ int nand_ram_rawread(FAR struct nand_raw_s *raw, off_t block,
     }
 
   NAND_RAM_LOG("[LOWER %" PRIu64 " | %s] Done\n", nand_ram_ins_i, "rawread");
-
-errout:
   nxmutex_unlock(&nand_ram_dev_mut);
 
-  return ret;
+  return OK;
 }
 
 /****************************************************************************
@@ -444,7 +432,7 @@ int nand_ram_rawwrite(FAR struct nand_raw_s *raw, off_t block,
 
   if (spare != NULL)
     {
-      memcpy((FAR void *)write_page_spare, data, NAND_RAM_SPARE_SIZE);
+      memcpy((FAR void *)write_page_spare, spare, NAND_RAM_SPARE_SIZE);
     }
 
   NAND_RAM_LOG("[LOWER %" PRIu64 " | %s] Done\n", nand_ram_ins_i,

drivers/mtd/mtd_nandwrapper.c

@@ -272,6 +272,7 @@ int nand_wrapper_ioctl(FAR struct mtd_dev_s *dev, int cmd,
                        unsigned long arg)
 {
   int ret;
+  FAR uint8_t *erasestate;
   FAR struct nand_wrapper_dev_s *nand_dev;
 
   nand_dev = (struct nand_wrapper_dev_s *)dev;
@@ -282,7 +283,28 @@ int nand_wrapper_ioctl(FAR struct mtd_dev_s *dev, int cmd,
                    ", Arg : %zu\n", nand_wrapper_ins_i, "ioctl", cmd, arg);
   DEBUGASSERT(nand_dev && nand_dev->under.mtd.ioctl);
 
-  ret = nand_dev->under.mtd.ioctl(dev, cmd, arg);
+  if (cmd == MTDIOC_ERASESTATE)
+    {
+      erasestate = (FAR uint8_t *)arg;
+      if (erasestate == NULL)
+        {
+          ret = -EINVAL;
+        }
+      else
+        {
+          /* The wrapped bread path exposes blank NAND pages as zero-filled
+           * buffers after ECC handling, so report the same visible erase
+           * state to higher layers.
+           */
+
+          *erasestate = 0x00;
+          ret = OK;
+        }
+    }
+  else
+    {
+      ret = nand_dev->under.mtd.ioctl(dev, cmd, arg);
+    }
 
   if (ret >= 0)
     {

fs/mnemofs/CMakeLists.txt

@@ -49,15 +49,6 @@
 # ##############################################################################
 
 if(CONFIG_FS_MNEMOFS)
-  target_sources(
-    fs
-    PRIVATE mnemofs_blkalloc.c
-            mnemofs_ctz.c
-            mnemofs_fsobj.c
-            mnemofs_journal.c
-            mnemofs_lru.c
-            mnemofs_master.c
-            mnemofs_rw.c
-            mnemofs_util.c
-            mnemofs.c)
+  target_sources(fs PRIVATE mnemofs.c mnemofs_alloc.c mnemofs_ctz.c
+                            mnemofs_dirent.c mnemofs_file.c mnemofs_rw.c)
 endif()

fs/mnemofs/Kconfig

@@ -9,44 +9,3 @@ config FS_MNEMOFS
 	depends on !DISABLE_MOUNTPOINT && MTD_NAND
 	---help---
 		Build the mnemofs NAND flash file system.
-
-if FS_MNEMOFS
-config MNEMOFS_EXTRA_DEBUG
-	bool "MNEMOFS Extra Debug Logs"
-	default n
-	depends on FS_MNEMOFS
-	---help---
-		Prints extra log information related to mnemofs.
-
-config MNEMOFS_JOURNAL_NBLKS
-	int "MNEMOFS Journal Block Count"
-	default 20
-	range 4 65536
-	depends on FS_MNEMOFS
-	---help---
-		Number of blocks that mnemofs will use for the journal. Specifying
-		this will only work on formatting a NAND flash using mnemofs. If the
-		device is already formatted, the on-flash journal block count will
-		be considered instead. Two additional blocks will be allocated for
-		the master blocks.
-
-config MNEMOFS_NLRU
-	int "MNEMOFS LRU Node Count"
-	default 20
-	range 1 255
-	depends on FS_MNEMOFS
-	---help---
-		Number of nodes used by mnemofs for LRU. The higher the value is,
-		the lesser would be the wear on device with higher RAM
-		consumption.
-
-config MNEMOFS_NLRUDELTA
-	int "MNEMOFS LRU Delta Count"
-	default 20
-	range 1 255
-	depends on FS_MNEMOFS
-	---help---
-		Number of deltas used by mnemofs for LRU for every node. The higher
-		the value is, the lesser would be the wear on device with higher RAM
-		consumption.
-endif # FS_MNEMOFS

fs/mnemofs/Make.defs

@@ -54,15 +54,12 @@ ifeq ($(CONFIG_FS_MNEMOFS),y)
 
 # Add the mnemofs C files to the build
 
-CSRCS += mnemofs_blkalloc.c
+CSRCS += mnemofs.c
+CSRCS += mnemofs_alloc.c
 CSRCS += mnemofs_ctz.c
-CSRCS += mnemofs_fsobj.c
-CSRCS += mnemofs_journal.c
-CSRCS += mnemofs_lru.c
-CSRCS += mnemofs_master.c
+CSRCS += mnemofs_dirent.c
+CSRCS += mnemofs_file.c
 CSRCS += mnemofs_rw.c
-CSRCS += mnemofs_util.c
-CSRCS += mnemofs.c
 
 # Add the mnemofs directory to the build