diff --git a/ext4_utils/Android.mk b/ext4_utils/Android.mk
index 3f82e4e..ab0f26b 100644
--- a/ext4_utils/Android.mk
+++ b/ext4_utils/Android.mk
@@ -95,6 +95,25 @@
 
 include $(BUILD_EXECUTABLE)
 
+ifeq ($(HOST_OS),linux)
+# Darwin doesn't have endian.h, and img2simg is just a convenience
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := img2simg.c
+LOCAL_MODULE := img2simg
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_HOST_EXECUTABLE)
+endif
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := img2simg.c
+LOCAL_MODULE := img2simg
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_EXECUTABLE)
+
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := setup_fs.c
 LOCAL_MODULE := setup_fs
diff --git a/ext4_utils/img2simg.c b/ext4_utils/img2simg.c
new file mode 100644
index 0000000..8c3b9ff
--- /dev/null
+++ b/ext4_utils/img2simg.c
@@ -0,0 +1,321 @@
+/*
+ * Copyright (C) 2010-2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define DEFAULT_BLOCK_SIZE	"4K"
+#define DEFAULT_CHUNK_SIZE	"64M"
+#define DEFAULT_SUFFIX		"%03d"
+
+#include "ext4_utils.h"
+#include "sparse_format.h"
+#include <endian.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#define COPY_BUF_SIZE (1024*1024)
+static char *copy_buf;
+
+static const char *progname(const char *argv0)
+{
+    const char *prog_name;
+    if ((prog_name = strrchr(argv0, '/')))
+	return(prog_name + 1);	/* Advance beyond '/'. */
+    return(argv0);		/* No '/' in argv0, use it as is. */
+}
+
+static void error_exit(const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    vfprintf(stderr, fmt, ap);
+    fputc('\n', stderr);
+    va_end(ap);
+
+    exit(EXIT_FAILURE);
+}
+
+static void usage(const char *argv0, const char *error_fmt, ...)
+{
+    fprintf(stderr,
+	    "Usage: %s [OPTIONS] <raw_image_file>\n",
+	    progname(argv0));
+    fprintf(stderr, "The <raw_image_file> will be split into as many sparse\n");
+    fprintf(stderr, "files as needed.  Each sparse file will contain a single\n");
+    fprintf(stderr, "DONT CARE chunk to offset to the correct block and then\n");
+    fprintf(stderr, "a single RAW chunk containing a portion of the data from\n");
+    fprintf(stderr, "the raw image file.  The sparse files will be named by\n");
+    fprintf(stderr, "appending a number to the name of the raw image file.\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "OPTIONS (Defaults are enclosed by square brackets):\n");
+    fprintf(stderr, "  -s SUFFIX      Format appended number with SUFFIX [%s]\n",
+	    DEFAULT_SUFFIX);
+    fprintf(stderr, "  -B SIZE        Use a block size of SIZE [%s]\n",
+	    DEFAULT_BLOCK_SIZE);
+    fprintf(stderr, "  -C SIZE        Use a chunk size of SIZE [%s]\n",
+	    DEFAULT_CHUNK_SIZE);
+    fprintf(stderr, "SIZE is a decimal integer that may optionally be\n");
+    fprintf(stderr, "followed by a suffix that specifies a multiplier for\n");
+    fprintf(stderr, "the integer:\n");
+    fprintf(stderr, "       c         1 byte (the default when omitted)\n");
+    fprintf(stderr, "       w         2 bytes\n");
+    fprintf(stderr, "       b         512 bytes\n");
+    fprintf(stderr, "       kB        1000 bytes\n");
+    fprintf(stderr, "       K         1024 bytes\n");
+    fprintf(stderr, "       MB        1000*1000 bytes\n");
+    fprintf(stderr, "       M         1024*1024 bytes\n");
+    fprintf(stderr, "       GB        1000*1000*1000 bytes\n");
+    fprintf(stderr, "       G         1024*1024*1024 bytes\n");
+
+    if (error_fmt && *error_fmt)
+    {
+	fprintf(stderr, "\n");
+	va_list ap;
+	va_start(ap, error_fmt);
+	vfprintf(stderr, error_fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+    }
+
+    exit(EXIT_FAILURE);
+}
+
+static void cpy_file(int out_fd, char *out_path, int in_fd, char *in_path,
+		     size_t len)
+{
+    ssize_t s, cpy_len = COPY_BUF_SIZE;
+
+    while (len) {
+	if (len < COPY_BUF_SIZE)
+	    cpy_len = len;
+
+	s = read(in_fd, copy_buf, cpy_len);
+	if (s < 0)
+	    error_exit("\"%s\": %s", in_path, strerror(errno));
+	if (!s)
+	    error_exit("\"%s\": Unexpected EOF", in_path);
+
+	cpy_len = s;
+
+	s = write(out_fd, copy_buf, cpy_len);
+	if (s < 0)
+	    error_exit("\"%s\": %s", out_path, strerror(errno));
+	if (s != cpy_len)
+	    error_exit("\"%s\": Short data write (%lu)", out_path,
+		       (unsigned long)s);
+
+	len -= cpy_len;
+    }
+}
+
+static int parse_size(const char *size_str, size_t *size)
+{
+    static const size_t MAX_SIZE_T = ~(size_t)0;
+    size_t mult;
+    unsigned long long int value;
+    const char *end;
+    errno = 0;
+    value = strtoull(size_str, (char **)&end, 10);
+    if (errno != 0 || end == size_str || value > MAX_SIZE_T)
+	return -1;
+    if (*end == '\0') {
+	*size = value;
+	return 0;
+    }
+    if (!strcmp(end, "c"))
+	mult = 1;
+    else if (!strcmp(end, "w"))
+	mult = 2;
+    else if (!strcmp(end, "b"))
+	mult = 512;
+    else if (!strcmp(end, "kB"))
+	mult = 1000;
+    else if (!strcmp(end, "K"))
+	mult = 1024;
+    else if (!strcmp(end, "MB"))
+	mult = (size_t)1000*1000;
+    else if (!strcmp(end, "M"))
+	mult = (size_t)1024*1024;
+    else if (!strcmp(end, "GB"))
+	mult = (size_t)1000*1000*1000;
+    else if (!strcmp(end, "G"))
+	mult = (size_t)1024*1024*1024;
+    else
+	return -1;
+
+    if (value > MAX_SIZE_T / mult)
+	return -1;
+    *size = value * mult;
+    return 0;
+}
+
+int main(int argc, char *argv[])
+{
+    char *suffix = DEFAULT_SUFFIX;
+    char *block_size_str = DEFAULT_BLOCK_SIZE;
+    char *chunk_size_str = DEFAULT_CHUNK_SIZE;
+    size_t block_size, chunk_size, blocks_per_chunk, to_write;
+    char *in_path, *out_path, *out_fmt;
+    int in_fd, out_fd;
+    struct stat in_st;
+    off_t left_to_write;
+    struct {
+	sparse_header_t sparse_hdr;
+	chunk_header_t dont_care_hdr;
+	chunk_header_t raw_hdr;
+    } file_hdr;
+    unsigned int file_count;
+    ssize_t s;
+    int i;
+
+    /* Parse the command line. */
+    while ((i = getopt(argc, argv, "s:B:C:")) != -1)
+    {
+	switch (i) {
+	case 's':
+	    suffix = optarg;
+	    break;
+	case 'B':
+	    block_size_str = optarg;
+	    break;
+	case 'C':
+	    chunk_size_str = optarg;
+	    break;
+	default:
+	    usage(argv[0], NULL);
+	    break;
+	}
+    }
+
+    if (parse_size(block_size_str, &block_size))
+	usage(argv[0], "Can not parse \"%s\" as a block size.",
+	      block_size_str);
+    if (block_size % 4096)
+	usage(argv[0], "Block size is not a multiple of 4096.");
+
+    if (parse_size(chunk_size_str, &chunk_size))
+	usage(argv[0], "Can not parse \"%s\" as a chunk size.",
+	      chunk_size_str);
+    if (chunk_size % block_size)
+	usage(argv[0], "Chunk size is not a multiple of the block size.");
+    blocks_per_chunk = chunk_size / block_size;
+
+    if ((argc - optind) != 1)
+	usage(argv[0], "Missing or extra arguments.");
+    in_path = argv[optind];
+
+    /* Open the input file and validate it. */
+    if ((in_fd = open(in_path, O_RDONLY)) < 0)
+	error_exit("open \"%s\": %s", in_path, strerror(errno));
+    if (fstat(in_fd, &in_st))
+	error_exit("fstat \"%s\": %s", in_path, strerror(errno));
+    left_to_write = in_st.st_size;
+    if (left_to_write % block_size)
+	error_exit(
+	    "\"%s\" size (%llu) is not a multiple of the block size (%llu).\n",
+	    in_path,
+	    (unsigned long long)left_to_write, (unsigned long long)block_size);
+
+    /* Get a buffer for copying the chunks. */
+    if ((copy_buf = malloc(COPY_BUF_SIZE)) == 0)
+	error_exit("malloc copy buffer: %s", strerror(errno));
+
+    /* Get a buffer for a sprintf format to form output paths. */
+    if ((out_fmt = malloc(sizeof("%s") + strlen(suffix))) == 0)
+	error_exit("malloc format buffer: %s", strerror(errno));
+    out_fmt[0] = '%';
+    out_fmt[1] = 's';
+    strcpy(out_fmt + 2, suffix);
+
+    /* Get a buffer for an output path. */
+    i = snprintf(copy_buf, COPY_BUF_SIZE, out_fmt, in_path, UINT_MAX);
+    if (i >= COPY_BUF_SIZE)
+	error_exit("Ridulously long suffix: %s", suffix);
+    if ((out_path = malloc(i + 1)) == 0)
+	error_exit("malloc output path buffer: %s", strerror(errno));
+
+    /*
+     * Each file gets a sparse_header, a Don't Care chunk to offset to
+     * where the data belongs and then a Raw chunk with the actual data.
+     */
+    memset((void *)&file_hdr.sparse_hdr, 0, sizeof(file_hdr.sparse_hdr));
+    file_hdr.sparse_hdr.magic = htole32(SPARSE_HEADER_MAGIC);
+    file_hdr.sparse_hdr.major_version = htole16(1);
+    file_hdr.sparse_hdr.minor_version = htole16(0);
+    file_hdr.sparse_hdr.file_hdr_sz = htole16(sizeof(sparse_header_t));
+    file_hdr.sparse_hdr.chunk_hdr_sz = htole16(sizeof(chunk_header_t));
+    file_hdr.sparse_hdr.blk_sz = htole32(block_size);
+    /* The total_blks will be set in the file loop below. */
+    file_hdr.sparse_hdr.total_chunks = htole32(2);
+    file_hdr.sparse_hdr.image_checksum = htole32(0); /* Typically unused. */
+
+    memset((void *)&file_hdr.dont_care_hdr, 0, sizeof(file_hdr.dont_care_hdr));
+    file_hdr.dont_care_hdr.chunk_type = htole16(CHUNK_TYPE_DONT_CARE);
+    /* The Don't Care's chunk_sz will be set in the file loop below. */
+    file_hdr.dont_care_hdr.total_sz = htole32(sizeof(chunk_header_t));
+
+    memset((void *)&file_hdr.raw_hdr, 0, sizeof(file_hdr.raw_hdr));
+    file_hdr.raw_hdr.chunk_type = htole16(CHUNK_TYPE_RAW);
+    file_hdr.raw_hdr.chunk_sz = htole32(blocks_per_chunk);
+    file_hdr.raw_hdr.total_sz = htole32(chunk_size + sizeof(chunk_header_t));
+
+    /* Loop through writing chunk_size to each of the output files. */
+    to_write = chunk_size;
+    for (file_count = 1; left_to_write ; file_count++) {
+	/* Fix up the headers on the last block. */
+	if (left_to_write < (off_t)chunk_size) {
+	    to_write = left_to_write;
+	    file_hdr.raw_hdr.chunk_sz = htole32(left_to_write / block_size);
+	    file_hdr.raw_hdr.total_sz = htole32(left_to_write
+						+ sizeof(chunk_header_t));
+	}
+
+	/* Form the pathname for this output file and open it. */
+	sprintf(out_path, out_fmt, in_path, file_count);
+	if ((out_fd = creat(out_path, 0666)) < 0)
+	    error_exit("\"%s\": %s", out_path, strerror(errno));
+
+	/* Update and write the headers to this output file. */
+	s = (file_count-1) * blocks_per_chunk;
+	file_hdr.dont_care_hdr.chunk_sz = htole32(s);
+	file_hdr.sparse_hdr.total_blks = htole32(s + (to_write / block_size));
+	s = write(out_fd, (void *)&file_hdr, sizeof(file_hdr));
+	if (s < 0)
+	    error_exit("\"%s\": %s", out_path, strerror(errno));
+	if (s != sizeof(file_hdr))
+	    error_exit("\"%s\": Short write (%lu)", out_path, (unsigned long)s);
+
+	/* Copy this chunk from the input file to the output file. */
+	cpy_file(out_fd, out_path, in_fd, in_path, to_write);
+
+	/* Close this output file and update the amount left to write. */
+	if (close(out_fd))
+	    error_exit("close \"%s\": %s", out_path, strerror(errno));
+	left_to_write -= to_write;
+    }
+
+    if (close(in_fd))
+	error_exit("close \"%s\": %s", in_path, strerror(errno));
+
+    exit(EXIT_SUCCESS);
+}