5 files changed, 873 insertions, 12 deletions

diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 027054dea032..843a1cbe0866 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -1,4 +1,4 @@
-# $Id: Kconfig,v 1.7 2004/11/22 11:33:56 ijc Exp $
+# $Id: Kconfig,v 1.9 2005/06/16 08:49:29 sean Exp $
 
 menu "Memory Technology Devices (MTD)"
 
@@ -253,6 +253,16 @@ config INFTL
           permitted to copy, modify and distribute the code as you wish. Just
           not use it.
 
+config RFD_FTL
+        tristate "Resident Flash Disk (Flash Translation Layer) support"
+        depends on MTD
+        ---help---
+          This provides support for the flash translation layer known 
+          as the Resident Flash Disk (RFD), as used by the Embedded BIOS 
+          of General Software.
+          See http://www.gensw.com/pages/prod/bios/rfd.htm for further
+          information.
+
 source "drivers/mtd/chips/Kconfig"
 
 source "drivers/mtd/maps/Kconfig"
diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index e4ad588327f7..cb16b7d478ce 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -1,7 +1,7 @@
 #
 # Makefile for the memory technology device drivers.
 #
-# $Id: Makefile.common,v 1.5 2004/08/10 20:51:49 dwmw2 Exp $
+# $Id: Makefile.common,v 1.6 2005/06/16 08:49:29 sean Exp $
 
 # Core functionality.
 mtd-y                           := mtdcore.o
@@ -20,6 +20,7 @@ obj-$(CONFIG_MTD_BLOCK_RO)	+= mtdblock_ro.o mtd_blkdevs.o
 obj-$(CONFIG_FTL)               += ftl.o mtd_blkdevs.o
 obj-$(CONFIG_NFTL)              += nftl.o mtd_blkdevs.o
 obj-$(CONFIG_INFTL)             += inftl.o mtd_blkdevs.o
+obj-$(CONFIG_RFD_FTL)           += rfd_ftl.o mtd_blkdevs.o
 
 nftl-objs               := nftlcore.o nftlmount.o
 inftl-objs              := inftlcore.o inftlmount.o
diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index 44781a83b2e7..aa5d71f8d812 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -97,14 +97,11 @@ config MTD_TS5500
         depends on X86 && MTD_JEDECPROBE && MTD_PARTITIONS
         help
           This provides a driver for the on-board flash of the Technologic
-          System's TS-5500 board. The flash is split into 3 partitions
+          System's TS-5500 board. The 2MB flash is split into 3 partitions
           which are accessed as separate MTD devices.
 
-          mtd0 and mtd2 are the two BIOS drives. Unfortunately the BIOS
-          uses a proprietary flash translation layer from General Software,
-          which is not supported (the drives cannot be mounted). You can
-          create your own file system (jffs for example), but the BIOS
-          won't be able to boot from it.
+          mtd0 and mtd2 are the two BIOS drives, which use the resident
+          flash disk (RFD) flash translation layer.
 
           mtd1 allows you to reprogram your BIOS. BE VERY CAREFUL.
 
diff --git a/drivers/mtd/maps/ts5500_flash.c b/drivers/mtd/maps/ts5500_flash.c
index 3ebd90f56503..286dd82e8b83 100644
--- a/drivers/mtd/maps/ts5500_flash.c
+++ b/drivers/mtd/maps/ts5500_flash.c
@@ -19,13 +19,11 @@
  *
  * Note:
  * - In order for detection to work, jumper 3 must be set.
- * - Drive A and B use a proprietary FTL from General Software which isn't 
- *   supported as of yet so standard drives can't be mounted; you can create 
- *   your own (e.g. jffs) file system.
+ * - Drive A and B use the resident flash disk (RFD) flash translation layer. 
  * - If you have created your own jffs file system and the bios overwrites 
  *   it during boot, try disabling Drive A: and B: in the boot order.
  *
- * $Id: ts5500_flash.c,v 1.2 2004/11/28 09:40:40 dwmw2 Exp $
+ * $Id: ts5500_flash.c,v 1.3 2005/06/16 08:49:30 sean Exp $
  */
 
 #include <linux/config.h>
diff --git a/drivers/mtd/rfd_ftl.c b/drivers/mtd/rfd_ftl.c
new file mode 100644
index 000000000000..7b9f359f04b7
--- /dev/null
+++ b/drivers/mtd/rfd_ftl.c
@@ -0,0 +1,855 @@
+/*
+ * rfd_ftl.c -- resident flash disk (flash translation layer)
+ *
+ * Copyright (C) 2005  Sean Young <sean@mess.org>
+ *
+ * $Id: rfd_ftl.c,v 1.4 2005/07/31 22:49:14 sean Exp $
+ *
+ * This type of flash translation layer (FTL) is used by the Embedded BIOS
+ * by General Software. It is known as the Resident Flash Disk (RFD), see:
+ *
+ *      http://www.gensw.com/pages/prod/bios/rfd.htm
+ *
+ * based on ftl.c
+ */
+
+#include <linux/hdreg.h>
+#include <linux/init.h>
+#include <linux/mtd/blktrans.h>
+#include <linux/mtd/mtd.h>
+#include <linux/vmalloc.h>
+
+#include <asm/types.h>
+
+#define const_cpu_to_le16       __constant_cpu_to_le16
+
+static int block_size = 0;
+module_param(block_size, int, 0);
+MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
+
+#define PREFIX "rfd_ftl: "
+
+/* Major device # for FTL device */
+
+/* A request for this major has been sent to device@lanana.org */
+#ifndef RFD_FTL_MAJOR
+#define RFD_FTL_MAJOR           95
+#endif
+
+/* Maximum number of partitions in an FTL region */
+#define PART_BITS               4
+
+/* An erase unit should start with this value */
+#define RFD_MAGIC               0x9193
+
+/* the second value is 0xffff or 0xffc8; function unknown */
+
+/* the third value is always 0xffff, ignored */
+
+/* next is an array of mapping for each corresponding sector */
+#define HEADER_MAP_OFFSET       3
+#define SECTOR_DELETED          0x0000
+#define SECTOR_ZERO             0xfffe
+#define SECTOR_FREE             0xffff
+
+#define SECTOR_SIZE             512
+
+#define SECTORS_PER_TRACK       63
+
+struct block {
+        enum {
+                BLOCK_OK,
+                BLOCK_ERASING,
+                BLOCK_ERASED,
+                BLOCK_FAILED
+        } state;
+        int free_sectors;
+        int used_sectors;
+        int erases;
+        u_long offset;
+};
+
+struct partition {
+        struct mtd_blktrans_dev mbd;
+
+        u_int block_size;               /* size of erase unit */
+        u_int total_blocks;             /* number of erase units */
+        u_int header_sectors_per_block; /* header sectors in erase unit */
+        u_int data_sectors_per_block;   /* data sectors in erase unit */
+        u_int sector_count;             /* sectors in translated disk */
+        u_int header_size;              /* bytes in header sector */
+        int reserved_block;             /* block next up for reclaim */
+        int current_block;              /* block to write to */
+        u16 *header_cache;              /* cached header */
+
+        int is_reclaiming;
+        int cylinders;
+        int errors;
+        u_long *sector_map;
+        struct block *blocks;
+};
+
+static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
+
+static int build_block_map(struct partition *part, int block_no)
+{
+        struct block *block = &part->blocks[block_no];
+        int i;
+        
+        block->offset = part->block_size * block_no;
+
+        if (le16_to_cpu(part->header_cache[0]) != RFD_MAGIC) {
+                block->state = BLOCK_ERASED; /* assumption */
+                block->free_sectors = part->data_sectors_per_block;
+                part->reserved_block = block_no;
+                return 1;
+        }
+
+        block->state = BLOCK_OK;
+
+        for (i=0; i<part->data_sectors_per_block; i++) {
+                u16 entry;
+                
+                entry = le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i]);
+
+                if (entry == SECTOR_DELETED)
+                        continue;
+        
+                if (entry == SECTOR_FREE) {
+                        block->free_sectors++;
+                        continue;
+                }
+
+                if (entry == SECTOR_ZERO)
+                        entry = 0;
+        
+                if (entry >= part->sector_count) {
+                        printk(KERN_NOTICE PREFIX 
+                                "'%s': unit #%d: entry %d corrupt, "
+                                "sector %d out of range\n",
+                                part->mbd.mtd->name, block_no, i, entry);
+                        continue;
+                }
+
+                if (part->sector_map[entry] != -1) {
+                        printk(KERN_NOTICE PREFIX 
+                                "'%s': more than one entry for sector %d\n",
+                                part->mbd.mtd->name, entry);
+                        part->errors = 1;
+                        continue;
+                }
+
+                part->sector_map[entry] = block->offset + 
+                        (i + part->header_sectors_per_block) * SECTOR_SIZE;
+
+                block->used_sectors++;
+        }
+
+        if (block->free_sectors == part->data_sectors_per_block)
+                part->reserved_block = block_no;
+
+        return 0;
+}
+
+static int scan_header(struct partition *part)
+{
+        int sectors_per_block;
+        int i, rc = -ENOMEM;
+        int blocks_found;
+        size_t retlen;
+
+        sectors_per_block = part->block_size / SECTOR_SIZE;
+        part->total_blocks = part->mbd.mtd->size / part->block_size;
+
+        if (part->total_blocks < 2)
+                return -ENOENT;
+
+        /* each erase block has three bytes header, followed by the map */
+        part->header_sectors_per_block = 
+                        ((HEADER_MAP_OFFSET + sectors_per_block) * 
+                        sizeof(u16) + SECTOR_SIZE - 1) / SECTOR_SIZE;
+
+        part->data_sectors_per_block = sectors_per_block - 
+                        part->header_sectors_per_block;
+
+        part->header_size = (HEADER_MAP_OFFSET + 
+                        part->data_sectors_per_block) * sizeof(u16);
+
+        part->cylinders = (part->data_sectors_per_block *
+                        (part->total_blocks - 1) - 1) / SECTORS_PER_TRACK;
+
+        part->sector_count = part->cylinders * SECTORS_PER_TRACK;
+
+        part->current_block = -1;
+        part->reserved_block = -1;
+        part->is_reclaiming = 0;
+
+        part->header_cache = kmalloc(part->header_size, GFP_KERNEL);
+        if (!part->header_cache)
+                goto err;
+
+        part->blocks = kcalloc(part->total_blocks, sizeof(struct block), 
+                        GFP_KERNEL);
+        if (!part->blocks)
+                goto err;
+
+        part->sector_map = vmalloc(part->sector_count * sizeof(u_long));
+        if (!part->sector_map) {
+                printk(KERN_ERR PREFIX "'%s': unable to allocate memory for "
+                        "sector map", part->mbd.mtd->name);
+                goto err;
+        }
+
+        for (i=0; i<part->sector_count; i++) 
+                part->sector_map[i] = -1;
+
+        for (i=0, blocks_found=0; i<part->total_blocks; i++) {
+                rc = part->mbd.mtd->read(part->mbd.mtd, 
+                                i * part->block_size, part->header_size,
+                                &retlen, (u_char*)part->header_cache);
+
+                if (!rc && retlen != part->header_size)
+                        rc = -EIO;
+
+                if (rc) 
+                        goto err;
+
+                if (!build_block_map(part, i))
+                        blocks_found++;
+        }
+
+        if (blocks_found == 0) {
+                printk(KERN_NOTICE PREFIX "no RFD magic found in '%s'\n",
+                                part->mbd.mtd->name);
+                rc = -ENOENT;
+                goto err;
+        }
+
+        if (part->reserved_block == -1) {
+                printk(KERN_NOTICE PREFIX "'%s': no empty erase unit found\n", 
+                                part->mbd.mtd->name);
+
+                part->errors = 1;
+        }
+
+        return 0;
+
+err:
+        vfree(part->sector_map);
+        kfree(part->header_cache);
+        kfree(part->blocks);
+
+        return rc;
+}
+
+static int rfd_ftl_readsect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
+{
+        struct partition *part = (struct partition*)dev;
+        u_long addr;
+        size_t retlen;
+        int rc;
+        
+        if (sector >= part->sector_count)
+                return -EIO;
+
+        addr = part->sector_map[sector];
+        if (addr != -1) {
+                rc = part->mbd.mtd->read(part->mbd.mtd, addr, SECTOR_SIZE,
+                                                &retlen, (u_char*)buf);
+                if (!rc && retlen != SECTOR_SIZE)
+                        rc = -EIO;
+
+                if (rc) {
+                        printk(KERN_WARNING PREFIX "error reading '%s' at "
+                                "0x%lx\n", part->mbd.mtd->name, addr);
+                        return rc;
+                }
+        } else
+                memset(buf, 0, SECTOR_SIZE);
+        
+        return 0;
+} 
+
+static void erase_callback(struct erase_info *erase)
+{
+        struct partition *part;
+        u16 magic;
+        int i, rc;
+        size_t retlen;
+
+        part = (struct partition*)erase->priv;
+
+        i = erase->addr / part->block_size;
+        if (i >= part->total_blocks || part->blocks[i].offset != erase->addr) {
+                printk(KERN_ERR PREFIX "erase callback for unknown offset %x "
+                                "on '%s'\n", erase->addr, part->mbd.mtd->name);
+                return;
+        }
+
+        if (erase->state != MTD_ERASE_DONE) {
+                printk(KERN_WARNING PREFIX "erase failed at 0x%x on '%s', "
+                                "state %d\n", erase->addr, 
+                                part->mbd.mtd->name, erase->state);
+
+                part->blocks[i].state = BLOCK_FAILED;
+                part->blocks[i].free_sectors = 0;
+                part->blocks[i].used_sectors = 0;
+
+                kfree(erase);
+
+                return;
+        }
+
+        magic = const_cpu_to_le16(RFD_MAGIC);
+
+        part->blocks[i].state = BLOCK_ERASED;
+        part->blocks[i].free_sectors = part->data_sectors_per_block;
+        part->blocks[i].used_sectors = 0;
+        part->blocks[i].erases++;
+
+        rc = part->mbd.mtd->write(part->mbd.mtd, 
+                part->blocks[i].offset, sizeof(magic), &retlen, 
+                (u_char*)&magic);
+        
+        if (!rc && retlen != sizeof(magic))
+                rc = -EIO;
+
+        if (rc) {
+                printk(KERN_NOTICE PREFIX "'%s': unable to write RFD "
+                                "header at 0x%lx\n",
+                                part->mbd.mtd->name, 
+                                part->blocks[i].offset);
+                part->blocks[i].state = BLOCK_FAILED;
+        }
+        else
+                part->blocks[i].state = BLOCK_OK;
+
+        kfree(erase);
+}
+
+static int erase_block(struct partition *part, int block)
+{
+        struct erase_info *erase;
+        int rc = -ENOMEM;
+
+        erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
+        if (!erase)
+                goto err;
+
+        erase->mtd = part->mbd.mtd;
+        erase->callback = erase_callback;
+        erase->addr = part->blocks[block].offset;
+        erase->len = part->block_size;
+        erase->priv = (u_long)part;
+
+        part->blocks[block].state = BLOCK_ERASING;
+        part->blocks[block].free_sectors = 0;
+
+        rc = part->mbd.mtd->erase(part->mbd.mtd, erase);
+
+        if (rc) {
+                printk(KERN_WARNING PREFIX "erase of region %x,%x on '%s' "
+                                "failed\n", erase->addr, erase->len,
+                                part->mbd.mtd->name);
+                kfree(erase);
+        }
+
+err:
+        return rc;
+}
+
+static int move_block_contents(struct partition *part, int block_no, u_long *old_sector)
+{
+        void *sector_data;
+        u16 *map;
+        size_t retlen;
+        int i, rc = -ENOMEM;
+
+        part->is_reclaiming = 1;
+
+        sector_data = kmalloc(SECTOR_SIZE, GFP_KERNEL);
+        if (!sector_data)
+                goto err3;
+
+        map = kmalloc(part->header_size, GFP_KERNEL);
+        if (!map)
+                goto err2;
+        
+        rc = part->mbd.mtd->read(part->mbd.mtd, 
+                part->blocks[block_no].offset, part->header_size, 
+                &retlen, (u_char*)map);
+        
+        if (!rc && retlen != part->header_size)
+                rc = -EIO;
+
+        if (rc) {
+                printk(KERN_NOTICE PREFIX "error reading '%s' at "
+                        "0x%lx\n", part->mbd.mtd->name, 
+                        part->blocks[block_no].offset);
+
+                goto err;
+        }
+
+        for (i=0; i<part->data_sectors_per_block; i++) {
+                u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
+                u_long addr;
+
+
+                if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
+                        continue;
+
+                if (entry == SECTOR_ZERO) 
+                        entry = 0;
+
+                /* already warned about and ignored in build_block_map() */
+                if (entry >= part->sector_count) 
+                        continue;
+
+                addr = part->blocks[block_no].offset +
+                        (i + part->header_sectors_per_block) * SECTOR_SIZE;
+
+                if (*old_sector == addr) {
+                        *old_sector = -1;
+                        if (!part->blocks[block_no].used_sectors--) {
+                                rc = erase_block(part, block_no);
+                                break;
+                        }
+                        continue;
+                }
+                rc = part->mbd.mtd->read(part->mbd.mtd, addr,
+                        SECTOR_SIZE, &retlen, sector_data);
+        
+                if (!rc && retlen != SECTOR_SIZE)
+                        rc = -EIO;
+
+                if (rc) {
+                        printk(KERN_NOTICE PREFIX "'%s': Unable to "
+                                "read sector for relocation\n",
+                                part->mbd.mtd->name);
+
+                        goto err;
+                }
+                
+                rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
+                                entry, sector_data);
+                
+                if (rc) 
+                        goto err;
+        }
+
+err:
+        kfree(map);
+err2:
+        kfree(sector_data);
+err3:
+        part->is_reclaiming = 0;
+
+        return rc;
+}
+
+static int reclaim_block(struct partition *part, u_long *old_sector) 
+{
+        int block, best_block, score, old_sector_block;
+        int rc;
+        
+        /* we have a race if sync doesn't exist */
+        if (part->mbd.mtd->sync)
+                part->mbd.mtd->sync(part->mbd.mtd);
+
+        score = 0x7fffffff; /* MAX_INT */
+        best_block = -1;
+        if (*old_sector != -1)
+                old_sector_block = *old_sector / part->block_size;
+        else
+                old_sector_block = -1;
+
+        for (block=0; block<part->total_blocks; block++) {
+                int this_score;
+
+                if (block == part->reserved_block)
+                        continue;
+
+                /*
+                 * Postpone reclaiming if there is a free sector as
+                 * more removed sectors is more efficient (have to move
+                 * less).
+                 */
+                if (part->blocks[block].free_sectors) 
+                        return 0;
+
+                this_score = part->blocks[block].used_sectors;
+
+                if (block == old_sector_block) 
+                        this_score--;
+                else {
+                        /* no point in moving a full block */
+                        if (part->blocks[block].used_sectors == 
+                                        part->data_sectors_per_block)
+                                continue;
+                }
+
+                this_score += part->blocks[block].erases;
+
+                if (this_score < score) {
+                        best_block = block;
+                        score = this_score;
+                }
+        }
+
+        if (best_block == -1)
+                return -ENOSPC;
+
+        part->current_block = -1;
+        part->reserved_block = best_block;
+
+        pr_debug("reclaim_block: reclaiming block #%d with %d used "
+                 "%d free sectors\n", best_block,
+                 part->blocks[best_block].used_sectors,
+                 part->blocks[best_block].free_sectors);
+
+        if (part->blocks[best_block].used_sectors)
+                rc = move_block_contents(part, best_block, old_sector);
+        else
+                rc = erase_block(part, best_block);
+
+        return rc;
+}
+
+/*
+ * IMPROVE: It would be best to choose the block with the most deleted sectors,
+ * because if we fill that one up first it'll have the most chance of having
+ * the least live sectors at reclaim.
+ */
+static int find_free_block(const struct partition *part)
+{
+        int block, stop;
+
+        block = part->current_block == -1 ?
+                        jiffies % part->total_blocks : part->current_block;
+        stop = block;
+
+        do {
+                if (part->blocks[block].free_sectors && 
+                                block != part->reserved_block)
+                        return block;
+
+                if (++block >= part->total_blocks)
+                        block = 0;
+
+        } while (block != stop);
+
+        return -1;
+}
+
+static int find_writeable_block(struct partition *part, u_long *old_sector)
+{
+        int rc, block;
+        size_t retlen;
+
+        block = find_free_block(part);
+
+        if (block == -1) {
+                if (!part->is_reclaiming) {
+                        rc = reclaim_block(part, old_sector);
+                        if (rc)
+                                goto err;
+
+                        block = find_free_block(part);
+                }
+
+                if (block == -1) {
+                        rc = -ENOSPC;
+                        goto err;
+                }
+        }
+
+        rc = part->mbd.mtd->read(part->mbd.mtd, part->blocks[block].offset, 
+                part->header_size, &retlen, (u_char*)part->header_cache);
+
+        if (!rc && retlen != part->header_size)
+                rc = -EIO;
+
+        if (rc) {
+                printk(KERN_NOTICE PREFIX "'%s': unable to read header at "
+                                "0x%lx\n", part->mbd.mtd->name, 
+                                part->blocks[block].offset);
+                goto err;
+        }
+
+        part->current_block = block;
+
+err:
+        return rc;
+}       
+
+static int mark_sector_deleted(struct partition *part, u_long old_addr)
+{
+        int block, offset, rc;
+        u_long addr;
+        size_t retlen;
+        u16 del = const_cpu_to_le16(SECTOR_DELETED);
+
+        block = old_addr / part->block_size;
+        offset = (old_addr % part->block_size) / SECTOR_SIZE - 
+                part->header_sectors_per_block;
+
+        addr = part->blocks[block].offset +
+                        (HEADER_MAP_OFFSET + offset) * sizeof(u16);
+        rc = part->mbd.mtd->write(part->mbd.mtd, addr,
+                sizeof(del), &retlen, (u_char*)&del);
+
+        if (!rc && retlen != sizeof(del))
+                rc = -EIO;
+
+        if (rc) {
+                printk(KERN_WARNING PREFIX "error writing '%s' at "
+                        "0x%lx\n", part->mbd.mtd->name, addr);
+                if (rc) 
+                        goto err;
+        }
+        if (block == part->current_block)
+                part->header_cache[offset + HEADER_MAP_OFFSET] = del;
+
+        part->blocks[block].used_sectors--;
+
+        if (!part->blocks[block].used_sectors &&
+            !part->blocks[block].free_sectors)
+                rc = erase_block(part, block);
+
+err:
+        return rc;
+}
+
+static int find_free_sector(const struct partition *part, const struct block *block)
+{
+        int i, stop;
+
+        i = stop = part->data_sectors_per_block - block->free_sectors;
+
+        do {
+                if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i]) 
+                                == SECTOR_FREE)
+                        return i;
+
+                if (++i == part->data_sectors_per_block)
+                        i = 0;
+        }
+        while(i != stop);
+
+        return -1;
+}
+
+static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
+{
+        struct partition *part = (struct partition*)dev;
+        struct block *block;
+        u_long addr;
+        int i;
+        int rc;
+        size_t retlen;
+        u16 entry;
+
+        if (part->current_block == -1 ||
+                !part->blocks[part->current_block].free_sectors) {
+
+                rc = find_writeable_block(part, old_addr);
+                if (rc) 
+                        goto err;
+        }
+
+        block = &part->blocks[part->current_block];
+
+        i = find_free_sector(part, block);
+
+        if (i < 0) {
+                rc = -ENOSPC;
+                goto err;
+        }
+                
+        addr = (i + part->header_sectors_per_block) * SECTOR_SIZE + 
+                block->offset;
+        rc = part->mbd.mtd->write(part->mbd.mtd, 
+                addr, SECTOR_SIZE, &retlen, (u_char*)buf);
+
+        if (!rc && retlen != SECTOR_SIZE)
+                rc = -EIO;
+
+        if (rc) {
+                printk(KERN_WARNING PREFIX "error writing '%s' at 0x%lx\n",
+                                part->mbd.mtd->name, addr);
+                if (rc) 
+                        goto err;
+        }
+
+        part->sector_map[sector] = addr;
+
+        entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
+
+        part->header_cache[i + HEADER_MAP_OFFSET] = entry;
+
+        addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
+        rc = part->mbd.mtd->write(part->mbd.mtd, addr,
+                        sizeof(entry), &retlen, (u_char*)&entry);
+
+        if (!rc && retlen != sizeof(entry))
+                rc = -EIO;
+
+        if (rc) {
+                printk(KERN_WARNING PREFIX "error writing '%s' at 0x%lx\n",
+                                part->mbd.mtd->name, addr);
+                if (rc) 
+                        goto err;
+        }
+        block->used_sectors++;
+        block->free_sectors--;
+
+err:
+        return rc;
+}
+
+static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
+{
+        struct partition *part = (struct partition*)dev;
+        u_long old_addr;
+        int i;
+        int rc = 0;
+
+        pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
+
+        if (part->reserved_block == -1) {
+                rc = -EACCES;
+                goto err;
+        }
+
+        if (sector >= part->sector_count) {
+                rc = -EIO;
+                goto err;
+        }
+
+        old_addr = part->sector_map[sector];
+
+        for (i=0; i<SECTOR_SIZE; i++) {
+                if (!buf[i])
+                        continue;
+
+                rc = do_writesect(dev, sector, buf, &old_addr);
+                if (rc)
+                        goto err;
+                break;
+        }
+
+        if (i == SECTOR_SIZE) 
+                part->sector_map[sector] = -1;
+
+        if (old_addr != -1)
+                rc = mark_sector_deleted(part, old_addr);
+
+err:
+        return rc;
+}
+
+static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
+{
+        struct partition *part = (struct partition*)dev;
+
+        geo->heads = 1;
+        geo->sectors = SECTORS_PER_TRACK;
+        geo->cylinders = part->cylinders;
+
+        return 0;
+}
+
+static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
+{
+        struct partition *part;
+
+        if (mtd->type != MTD_NORFLASH)
+                return;
+
+        part = kcalloc(1, sizeof(struct partition), GFP_KERNEL);
+        if (!part)
+                return;
+
+        part->mbd.mtd = mtd;
+
+        if (block_size)
+                part->block_size = block_size;
+        else {
+                if (!mtd->erasesize) {
+                        printk(KERN_NOTICE PREFIX "please provide block_size");
+                        return;
+                }
+                else
+                        part->block_size = mtd->erasesize;
+        }
+
+        if (scan_header(part) == 0) {
+                part->mbd.size = part->sector_count;
+                part->mbd.blksize = SECTOR_SIZE;
+                part->mbd.tr = tr;
+                part->mbd.devnum = -1;
+                if (!(mtd->flags & MTD_WRITEABLE))
+                        part->mbd.readonly = 1;
+                else if (part->errors) {
+                        printk(KERN_NOTICE PREFIX "'%s': errors found, "
+                                        "setting read-only", mtd->name);
+                        part->mbd.readonly = 1;
+                }
+
+                printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
+                                mtd->name, mtd->type, mtd->flags);
+
+                if (!add_mtd_blktrans_dev((void*)part))
+                        return;
+        } 
+
+        kfree(part);
+}
+
+static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
+{
+        struct partition *part = (struct partition*)dev;
+        int i;
+
+        for (i=0; i<part->total_blocks; i++) {
+                pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
+                        part->mbd.mtd->name, i, part->blocks[i].erases);
+        }
+
+        del_mtd_blktrans_dev(dev);
+        vfree(part->sector_map);
+        kfree(part->header_cache);
+        kfree(part->blocks);
+        kfree(part);
+}
+
+struct mtd_blktrans_ops rfd_ftl_tr = {
+        .name           = "rfd",
+        .major          = RFD_FTL_MAJOR,
+        .part_bits      = PART_BITS,
+        .readsect       = rfd_ftl_readsect,
+        .writesect      = rfd_ftl_writesect, 
+        .getgeo         = rfd_ftl_getgeo,
+        .add_mtd        = rfd_ftl_add_mtd,
+        .remove_dev     = rfd_ftl_remove_dev,
+        .owner          = THIS_MODULE,
+};
+
+static int __init init_rfd_ftl(void)
+{
+        return register_mtd_blktrans(&rfd_ftl_tr);
+}
+
+static void __exit cleanup_rfd_ftl(void)
+{
+        deregister_mtd_blktrans(&rfd_ftl_tr);
+}
+
+module_init(init_rfd_ftl);
+module_exit(cleanup_rfd_ftl);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sean Young <sean@mess.org>");
+MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
+                "used by General Software's Embedded BIOS");
+