Start to implement battfs_init (incomplete).

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@1027 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/fs/battfs.c b/fs/battfs.c
new file mode 100644 (file)
index 0000000..d4ee723
--- /dev/null
+++ b/fs/battfs.c
@@ -0,0 +1,156 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \version $Id:$
+ *
+ * \author Francesco Sacchi <batt@develer.com>
+ *
+ * \brief BattFS: a filesystem for embedded platforms (implementation).
+ */
+
+#include "battfs.h"
+
+#include <mware/byteorder.h> /* cpu_to_xx */
+
+#include <string.h> /* memset */
+
+/**
+ * Convert from cpu endianess to filesystem endianness.
+ * \note filesystem is in little-endian format.
+ */
+INLINE void cpu_to_battfs(struct BattFsPageHeader *hdr)
+{
+       STATIC_ASSERT(sizeof(hdr->inode) == 1);
+       STATIC_ASSERT(sizeof(hdr->seq) == 1);
+
+       STATIC_ASSERT(sizeof(hdr->mark) == 2);
+       hdr->mark = cpu_to_le16(hdr->mark);
+
+       STATIC_ASSERT(sizeof(hdr->fill) == 2);
+       hdr->fill = cpu_to_le16(hdr->fill);
+
+       STATIC_ASSERT(sizeof(hdr->pgoff) == 2);
+       hdr->pgoff = cpu_to_le16(hdr->pgoff);
+
+       STATIC_ASSERT(sizeof(hdr->fcs) == 2);
+       hdr->fcs = cpu_to_le16(hdr->fcs);
+
+       STATIC_ASSERT(sizeof(hdr->rfu) == 2);
+       hdr->rfu = cpu_to_le16(hdr->rfu);
+}
+
+
+/**
+ * Convert from filesystem endianness to cpu endianess.
+ * \note filesystem is in little-endian format.
+ */
+INLINE void battfs_to_cpu(struct BattFsPageHeader *hdr)
+{
+       STATIC_ASSERT(sizeof(hdr->inode) == 1);
+       STATIC_ASSERT(sizeof(hdr->seq) == 1);
+
+       STATIC_ASSERT(sizeof(hdr->mark) == 2);
+       hdr->mark = le16_to_cpu(hdr->mark);
+
+       STATIC_ASSERT(sizeof(hdr->fill) == 2);
+       hdr->fill = le16_to_cpu(hdr->fill);
+
+       STATIC_ASSERT(sizeof(hdr->pgoff) == 2);
+       hdr->pgoff = le16_to_cpu(hdr->pgoff);
+
+       STATIC_ASSERT(sizeof(hdr->fcs) == 2);
+       hdr->fcs = le16_to_cpu(hdr->fcs);
+
+       STATIC_ASSERT(sizeof(hdr->rfu) == 2);
+       hdr->rfu = le16_to_cpu(hdr->rfu);
+}
+
+
+/**
+ * Read header of page \a page.
+ * \return true on success, false otherwise.
+ * \note \a hdr is dirtyed even on errors.
+ */
+static bool battfs_readHeader(struct BattFsSuper *disk, pgcnt_t page, struct BattFsPageHeader *hdr)
+{
+       /*
+        * Read header from disk.
+        * header is actually a footer, and so
+        * resides at page end.
+        */
+       if (disk->read(disk, page, disk->page_size - sizeof(BattFsPageHeader), hdr, sizeof(BattFsPageHeader))
+           != sizeof(BattFsPageHeader))
+               return false;
+
+       /* Fix endianess */
+       battfs_to_cpu(hdr);
+       return true;
+}
+
+/**
+ * Initialize and mount disk described by
+ * \a d.
+ * \return false on errors, true otherwise.
+ */
+bool battfs_init(struct BattFsSuper *disk)
+{
+       BattFsPageHeader hdr;
+       rotating_t cks;
+       pgoff_t filelen_table[BATTFS_MAX_FILES];
+
+       /* Init disk device */
+       if (!disk->open(disk))
+               return false;
+
+       memset(filelen_table, 0, BATTFS_MAX_FILES * sizeof(pgoff_t));
+
+       for (pgcnt_t page = 0; page < disk->page_count; page++)
+       {
+               if (!battfs_readHeader(disk, page, &hdr))
+                       return false;
+
+               /* Check header FCS */
+               rotating_init(&cks);
+               rotating_update(&hdr, sizeof(BattFsPageHeader) - sizeof(rotating_t), &cks);
+               if (cks == hdr.fcs)
+                       filelen_table[page]++;
+               else
+               {
+                       #warning Finish me!
+               }
+       }
+
+       
+       return true;    
+}
+
+