--- /dev/null
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2011 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * yaffs_ramdisk.c: yaffs ram disk component
+ * This provides a ram disk under yaffs.
+ * NB this is not intended for NAND emulation.
+ * Use this with dev->use_nand_ecc enabled, then ECC overheads are not required.
+ */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_ramdisk.h"
+#include "yaffs_guts.h"
+#include "yaffs_packedtags1.h"
+
+
+
+#define SIZE_IN_MB 2
+
+#define BLOCK_SIZE (32 * 528)
+#define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
+
+
+
+
+
+typedef struct
+{
+ u8 data[528]; // Data + spare
+} yramdisk_page;
+
+typedef struct
+{
+ yramdisk_page page[32]; // The pages in the block
+
+} yramdisk_block;
+
+
+
+typedef struct
+{
+ yramdisk_block **block;
+ int nBlocks;
+} yramdisk_device;
+
+static yramdisk_device ramdisk;
+
+static int CheckInit(struct yaffs_dev *dev)
+{
+ static int initialised = 0;
+
+ int i;
+ int fail = 0;
+ //int nBlocks;
+ int nAllocated = 0;
+
+ if(initialised)
+ {
+ return YAFFS_OK;
+ }
+
+ initialised = 1;
+
+
+ ramdisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);
+
+ ramdisk.block = malloc(sizeof(yramdisk_block *) * ramdisk.nBlocks);
+
+ if(!ramdisk.block) return 0;
+
+ for(i=0; i <ramdisk.nBlocks; i++)
+ {
+ ramdisk.block[i] = NULL;
+ }
+
+ for(i=0; i <ramdisk.nBlocks && !fail; i++)
+ {
+ if((ramdisk.block[i] = malloc(sizeof(yramdisk_block))) == 0)
+ {
+ fail = 1;
+ }
+ else
+ {
+ yramdisk_erase(dev,i);
+ nAllocated++;
+ }
+ }
+
+ if(fail)
+ {
+ for(i = 0; i < nAllocated; i++)
+ {
+ kfree(ramdisk.block[i]);
+ }
+ kfree(ramdisk.block);
+
+ yaffs_trace(YAFFS_TRACE_ALWAYS,
+ "Allocation failed, could only allocate %dMB of %dMB requested.\n",
+ nAllocated/64,ramdisk.nBlocks * 528);
+ return 0;
+ }
+
+
+ return 1;
+}
+
+int yramdisk_wr_chunk(struct yaffs_dev *dev,int nand_chunk,const u8 *data, const struct yaffs_ext_tags *tags)
+{
+ int blk;
+ int pg;
+
+
+ CheckInit(dev);
+
+ blk = nand_chunk/32;
+ pg = nand_chunk%32;
+
+
+ if(data)
+ {
+ memcpy(ramdisk.block[blk]->page[pg].data,data,512);
+ }
+
+
+ if(tags)
+ {
+ struct yaffs_packed_tags1 pt;
+
+ yaffs_pack_tags1(&pt,tags);
+ memcpy(&ramdisk.block[blk]->page[pg].data[512],&pt,sizeof(pt));
+ }
+
+ return YAFFS_OK;
+
+}
+
+
+int yramdisk_rd_chunk(struct yaffs_dev *dev,int nand_chunk, u8 *data, struct yaffs_ext_tags *tags)
+{
+ int blk;
+ int pg;
+
+
+ CheckInit(dev);
+
+ blk = nand_chunk/32;
+ pg = nand_chunk%32;
+
+
+ if(data)
+ {
+ memcpy(data,ramdisk.block[blk]->page[pg].data,512);
+ }
+
+
+ if(tags)
+ {
+ struct yaffs_packed_tags1 pt;
+
+ memcpy(&pt,&ramdisk.block[blk]->page[pg].data[512],sizeof(pt));
+ yaffs_unpack_tags1(tags,&pt);
+
+ }
+
+ return YAFFS_OK;
+}
+
+
+int yramdisk_check_chunk_erased(struct yaffs_dev *dev,int nand_chunk)
+{
+ int blk;
+ int pg;
+ int i;
+
+
+ CheckInit(dev);
+
+ blk = nand_chunk/32;
+ pg = nand_chunk%32;
+
+
+ for(i = 0; i < 528; i++)
+ {
+ if(ramdisk.block[blk]->page[pg].data[i] != 0xFF)
+ {
+ return YAFFS_FAIL;
+ }
+ }
+
+ return YAFFS_OK;
+
+}
+
+int yramdisk_erase(struct yaffs_dev *dev, int blockNumber)
+{
+
+ CheckInit(dev);
+
+ if(blockNumber < 0 || blockNumber >= ramdisk.nBlocks)
+ {
+ yaffs_trace(YAFFS_TRACE_ALWAYS,
+ "Attempt to erase non-existant block %d\n",
+ blockNumber);
+ return YAFFS_FAIL;
+ }
+ else
+ {
+ memset(ramdisk.block[blockNumber],0xFF,sizeof(yramdisk_block));
+ return YAFFS_OK;
+ }
+
+}
+
+int yramdisk_initialise(struct yaffs_dev *dev)
+{
+ //dev->use_nand_ecc = 1; // force on use_nand_ecc which gets faked.
+ // This saves us doing ECC checks.
+
+ return YAFFS_OK;
+}
+