[U-Boot] sandbox: block driver using host file/device as backing store

diff --git a/common/cmd_sandbox.c b/common/cmd_sandbox.c
index 206a486..492d569 100644
--- a/common/cmd_sandbox.c
+++ b/common/cmd_sandbox.c
@@ -32,9 +32,16 @@  static int do_sandbox_ls(cmd_tbl_t *cmdtp, int flag, int argc,
 	return do_ls(cmdtp, flag, argc, argv, FS_TYPE_SANDBOX);
 }
 
+static int do_sandbox_bind(cmd_tbl_t *cmdtp, int flag, int argc,
+			   char * const argv[])
+{
+	return host_dev_bind(atoi(argv[1]), argv[2]);
+}
+
 static cmd_tbl_t cmd_sandbox_sub[] = {
 	U_BOOT_CMD_MKENT(load, 3, 0, do_sandbox_load, "", ""),
 	U_BOOT_CMD_MKENT(ls, 3, 0, do_sandbox_ls, "", ""),
+	U_BOOT_CMD_MKENT(bind, 3, 0, do_sandbox_bind, "", ""),
 };
 
 static int do_sandbox(cmd_tbl_t *cmdtp, int flag, int argc,
@@ -59,5 +66,6 @@  U_BOOT_CMD(
 	sb,	6,	1,	do_sandbox,
 	"Miscellaneous sandbox commands",
 	"load host <addr> <filename> [<bytes> <offset>]  - load a file from host\n"
-	"sb ls host <filename>      - save a file to host"
+	"ls host <filename>      - save a file to host\n"
+	"bind dev <filename>     - bind \"host\" device to file"
 );
diff --git a/disk/part.c b/disk/part.c
index d73625c..648839b 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -59,6 +59,9 @@  static const struct block_drvr block_drvr[] = {
 #if defined(CONFIG_SYSTEMACE)
 	{ .name = "ace", .get_dev = systemace_get_dev, },
 #endif
+#if defined(CONFIG_SANDBOX)
+	{ .name = "host", .get_dev = host_get_dev, },
+#endif
 	{ },
 };
 
@@ -462,23 +465,6 @@  int get_device_and_partition(const char *ifname, const char *dev_part_str,
 	int part;
 	disk_partition_t tmpinfo;
 
-	/*
-	 * For now, we have a special case for sandbox, since there is no
-	 * real block device support.
-	 */
-	if (0 == strcmp(ifname, "host")) {
-		*dev_desc = NULL;
-		info->start = info->size =  info->blksz = 0;
-		info->bootable = 0;
-		strcpy((char *)info->type, BOOT_PART_TYPE);
-		strcpy((char *)info->name, "Sandbox host");
-#ifdef CONFIG_PARTITION_UUIDS
-		info->uuid[0] = 0;
-#endif
-
-		return 0;
-	}
-
 	/* If no dev_part_str, use bootdevice environment variable */
 	if (!dev_part_str || !strlen(dev_part_str) ||
 	    !strcmp(dev_part_str, "-"))
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index f1ebdcc..2d2fb55 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -40,6 +40,7 @@  COBJS-$(CONFIG_SATA_SIL) += sata_sil.o
 COBJS-$(CONFIG_IDE_SIL680) += sil680.o
 COBJS-$(CONFIG_SCSI_SYM53C8XX) += sym53c8xx.o
 COBJS-$(CONFIG_SYSTEMACE) += systemace.o
+COBJS-$(CONFIG_SANDBOX) += sandbox.o
 
 COBJS	:= $(COBJS-y)
 SRCS	:= $(COBJS:.o=.c)
diff --git a/drivers/block/sandbox.c b/drivers/block/sandbox.c
new file mode 100644
index 0000000..185cee8
--- /dev/null
+++ b/drivers/block/sandbox.c
@@ -0,0 +1,130 @@ 
+/*
+ * Copyright (C) 2013 Henrik Nordstrom <henrik@henriknordstrom.net>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <config.h>
+#include <common.h>
+#include <part.h>
+#include <os.h>
+
+#ifndef CONFIG_HOST_MAX_DEVICES
+#define CONFIG_HOST_MAX_DEVICES 4
+#endif
+
+static struct host_block_dev {
+	block_dev_desc_t blk_dev;
+	char *filename;
+	int fd;
+} host_devices[CONFIG_HOST_MAX_DEVICES];
+
+static struct host_block_dev *
+find_host_device(int dev)
+{
+	if (dev >= 0 && dev < CONFIG_HOST_MAX_DEVICES)
+		return &host_devices[dev];
+
+	printf("Invalid host device number\n");
+	return NULL;
+}
+
+static unsigned long host_block_read(int dev, unsigned long start,
+				     lbaint_t blkcnt, void *buffer)
+{
+	struct host_block_dev *host_dev = find_host_device(dev);
+	if (os_lseek(host_dev->fd,
+		     start * host_dev->blk_dev.blksz,
+		     OS_SEEK_SET) == -1) {
+		printf("ERROR: Invalid position\n");
+		return -1;
+	}
+	ssize_t len = os_read(host_dev->fd, buffer,
+			      blkcnt * host_dev->blk_dev.blksz);
+	if (len >= 0)
+		return len / host_dev->blk_dev.blksz;
+	return -1;
+}
+
+static unsigned long host_block_write(int dev, unsigned long start,
+				      lbaint_t blkcnt, const void *buffer)
+{
+	struct host_block_dev *host_dev = find_host_device(dev);
+	if (os_lseek(host_dev->fd,
+		     start * host_dev->blk_dev.blksz,
+		     OS_SEEK_SET) == -1) {
+		printf("ERROR: Invalid position\n");
+		return -1;
+	}
+	ssize_t len = os_write(host_dev->fd, buffer, blkcnt *
+			       host_dev->blk_dev.blksz);
+	if (len >= 0)
+		return len / host_dev->blk_dev.blksz;
+	return -1;
+}
+
+int host_dev_bind(int dev, char *filename)
+{
+	struct host_block_dev *host_dev = find_host_device(dev);
+	if (host_dev->blk_dev.priv) {
+		os_close(host_dev->fd);
+		host_dev->blk_dev.priv = NULL;
+	}
+	if (host_dev->filename)
+		free(host_dev->filename);
+	if (filename && *filename)
+		host_dev->filename = strdup(filename);
+	else
+		host_dev->filename = NULL;
+	return 0;
+}
+
+block_dev_desc_t *host_get_dev(int dev)
+{
+	struct host_block_dev *host_dev = find_host_device(dev);
+
+	if (!host_dev)
+		return NULL;
+
+	if (!host_dev->filename) {
+		printf("Not bound to a backing file\n");
+		return NULL;
+	}
+
+	block_dev_desc_t *blk_dev = &host_dev->blk_dev;
+	if (!host_dev->blk_dev.priv) {
+		host_dev->fd = os_open(host_dev->filename, OS_O_RDWR);
+		if (host_dev->fd == -1) {
+			printf("Failed to access host backing file '%s'\n",
+			       host_dev->filename);
+			return NULL;
+		}
+		blk_dev->if_type = IF_TYPE_HOST;
+		blk_dev->priv = host_dev;
+		blk_dev->blksz = 512;
+		blk_dev->lba = os_lseek(host_dev->fd, 0, OS_SEEK_END) /
+				blk_dev->blksz;
+		blk_dev->block_read = host_block_read;
+		blk_dev->block_write = host_block_write;
+		blk_dev->dev = dev;
+		blk_dev->part_type = PART_TYPE_UNKNOWN;
+		init_part(blk_dev);
+	}
+	return blk_dev;
+}
diff --git a/include/config_fallbacks.h b/include/config_fallbacks.h
index 269b5c2..33affd7 100644
--- a/include/config_fallbacks.h
+++ b/include/config_fallbacks.h
@@ -49,7 +49,8 @@ 
 	defined(CONFIG_CMD_USB) || \
 	defined(CONFIG_CMD_PART) || \
 	defined(CONFIG_MMC) || \
-	defined(CONFIG_SYSTEMACE)
+	defined(CONFIG_SYSTEMACE) || \
+	defined(CONFIG_SANDBOX)
 #define HAVE_BLOCK_DEVICE
 #endif
 
diff --git a/include/configs/sandbox.h b/include/configs/sandbox.h
index 406da43..b73fbac 100644
--- a/include/configs/sandbox.h
+++ b/include/configs/sandbox.h
@@ -39,6 +39,8 @@ 
 #define CONFIG_CMD_EXT4
 #define CONFIG_CMD_EXT4_WRITE
 
+#define CONFIG_DOS_PARTITION
+
 #define CONFIG_SYS_VSNPRINTF
 
 #define CONFIG_CMD_GPIO
diff --git a/include/part.h b/include/part.h
index c58a734..40a34c8 100644
--- a/include/part.h
+++ b/include/part.h
@@ -65,6 +65,7 @@  typedef struct block_dev_desc {
 #define IF_TYPE_MMC		6
 #define IF_TYPE_SD		7
 #define IF_TYPE_SATA		8
+#define IF_TYPE_HOST		9
 
 /* Part types */
 #define PART_TYPE_UNKNOWN	0x00
@@ -109,6 +110,7 @@  block_dev_desc_t* usb_stor_get_dev(int dev);
 block_dev_desc_t* mmc_get_dev(int dev);
 block_dev_desc_t* systemace_get_dev(int dev);
 block_dev_desc_t* mg_disk_get_dev(int dev);
+block_dev_desc_t *host_get_dev(int dev);
 
 /* disk/part.c */
 int get_partition_info (block_dev_desc_t * dev_desc, int part, disk_partition_t *info);
@@ -130,6 +132,7 @@  static inline block_dev_desc_t* usb_stor_get_dev(int dev) { return NULL; }
 static inline block_dev_desc_t* mmc_get_dev(int dev) { return NULL; }
 static inline block_dev_desc_t* systemace_get_dev(int dev) { return NULL; }
 static inline block_dev_desc_t* mg_disk_get_dev(int dev) { return NULL; }
+static inline block_dev_desc_t *host_get_dev(int dev) { return NULL; }
 
 static inline int get_partition_info (block_dev_desc_t * dev_desc, int part,
 	disk_partition_t *info) { return -1; }