diff --git a/applypatch/Android.mk b/applypatch/Android.mk
index d20d6c8..bb024f6 100644
--- a/applypatch/Android.mk
+++ b/applypatch/Android.mk
@@ -29,6 +29,7 @@
 
 LOCAL_SRC_FILES := main.c
 LOCAL_MODULE := applypatch
+LOCAL_C_INCLUDES += bootable/recovery
 LOCAL_STATIC_LIBRARIES += libapplypatch libmtdutils libmincrypt libbz
 LOCAL_SHARED_LIBRARIES += libz libcutils libstdc++ libc
 
@@ -40,6 +41,7 @@
 LOCAL_MODULE := applypatch_static
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_MODULE_TAGS := eng
+LOCAL_C_INCLUDES += bootable/recovery
 LOCAL_STATIC_LIBRARIES += libapplypatch libmtdutils libmincrypt libbz
 LOCAL_STATIC_LIBRARIES += libz libcutils libstdc++ libc
 
diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c
index daf3729..99d3661 100644
--- a/applypatch/applypatch.c
+++ b/applypatch/applypatch.c
@@ -28,6 +28,7 @@
 #include "mincrypt/sha.h"
 #include "applypatch.h"
 #include "mtdutils/mtdutils.h"
+#include "edify/expr.h"
 
 int SaveFileContents(const char* filename, FileContents file);
 int LoadMTDContents(const char* filename, FileContents* file);
@@ -39,57 +40,57 @@
 // Read a file into memory; store it and its associated metadata in
 // *file.  Return 0 on success.
 int LoadFileContents(const char* filename, FileContents* file) {
-  file->data = NULL;
-
-  // A special 'filename' beginning with "MTD:" means to load the
-  // contents of an MTD partition.
-  if (strncmp(filename, "MTD:", 4) == 0) {
-    return LoadMTDContents(filename, file);
-  }
-
-  if (stat(filename, &file->st) != 0) {
-    printf("failed to stat \"%s\": %s\n", filename, strerror(errno));
-    return -1;
-  }
-
-  file->size = file->st.st_size;
-  file->data = malloc(file->size);
-
-  FILE* f = fopen(filename, "rb");
-  if (f == NULL) {
-    printf("failed to open \"%s\": %s\n", filename, strerror(errno));
-    free(file->data);
     file->data = NULL;
-    return -1;
-  }
 
-  size_t bytes_read = fread(file->data, 1, file->size, f);
-  if (bytes_read != file->size) {
-    printf("short read of \"%s\" (%d bytes of %d)\n",
-            filename, bytes_read, file->size);
-    free(file->data);
-    file->data = NULL;
-    return -1;
-  }
-  fclose(f);
+    // A special 'filename' beginning with "MTD:" means to load the
+    // contents of an MTD partition.
+    if (strncmp(filename, "MTD:", 4) == 0) {
+        return LoadMTDContents(filename, file);
+    }
 
-  SHA(file->data, file->size, file->sha1);
-  return 0;
+    if (stat(filename, &file->st) != 0) {
+        printf("failed to stat \"%s\": %s\n", filename, strerror(errno));
+        return -1;
+    }
+
+    file->size = file->st.st_size;
+    file->data = malloc(file->size);
+
+    FILE* f = fopen(filename, "rb");
+    if (f == NULL) {
+        printf("failed to open \"%s\": %s\n", filename, strerror(errno));
+        free(file->data);
+        file->data = NULL;
+        return -1;
+    }
+
+    ssize_t bytes_read = fread(file->data, 1, file->size, f);
+    if (bytes_read != file->size) {
+        printf("short read of \"%s\" (%ld bytes of %ld)\n",
+               filename, (long)bytes_read, (long)file->size);
+        free(file->data);
+        file->data = NULL;
+        return -1;
+    }
+    fclose(f);
+
+    SHA(file->data, file->size, file->sha1);
+    return 0;
 }
 
 static size_t* size_array;
 // comparison function for qsort()ing an int array of indexes into
 // size_array[].
 static int compare_size_indices(const void* a, const void* b) {
-  int aa = *(int*)a;
-  int bb = *(int*)b;
-  if (size_array[aa] < size_array[bb]) {
-    return -1;
-  } else if (size_array[aa] > size_array[bb]) {
-    return 1;
-  } else {
-    return 0;
-  }
+    int aa = *(int*)a;
+    int bb = *(int*)b;
+    if (size_array[aa] < size_array[bb]) {
+        return -1;
+    } else if (size_array[aa] > size_array[bb]) {
+        return 1;
+    } else {
+        return 0;
+    }
 }
 
 void FreeFileContents(FileContents* file) {
@@ -113,239 +114,240 @@
 // hash of the data, and we'll do the load expecting to find one of
 // those hashes.
 int LoadMTDContents(const char* filename, FileContents* file) {
-  char* copy = strdup(filename);
-  const char* magic = strtok(copy, ":");
-  if (strcmp(magic, "MTD") != 0) {
-    printf("LoadMTDContents called with bad filename (%s)\n",
-            filename);
-    return -1;
-  }
-  const char* partition = strtok(NULL, ":");
-
-  int i;
-  int colons = 0;
-  for (i = 0; filename[i] != '\0'; ++i) {
-    if (filename[i] == ':') {
-      ++colons;
+    char* copy = strdup(filename);
+    const char* magic = strtok(copy, ":");
+    if (strcmp(magic, "MTD") != 0) {
+        printf("LoadMTDContents called with bad filename (%s)\n",
+               filename);
+        return -1;
     }
-  }
-  if (colons < 3 || colons%2 == 0) {
-    printf("LoadMTDContents called with bad filename (%s)\n",
-            filename);
-  }
+    const char* partition = strtok(NULL, ":");
 
-  int pairs = (colons-1)/2;     // # of (size,sha1) pairs in filename
-  int* index = malloc(pairs * sizeof(int));
-  size_t* size = malloc(pairs * sizeof(size_t));
-  char** sha1sum = malloc(pairs * sizeof(char*));
-
-  for (i = 0; i < pairs; ++i) {
-    const char* size_str = strtok(NULL, ":");
-    size[i] = strtol(size_str, NULL, 10);
-    if (size[i] == 0) {
-      printf("LoadMTDContents called with bad size (%s)\n", filename);
-      return -1;
+    int i;
+    int colons = 0;
+    for (i = 0; filename[i] != '\0'; ++i) {
+        if (filename[i] == ':') {
+            ++colons;
+        }
     }
-    sha1sum[i] = strtok(NULL, ":");
-    index[i] = i;
-  }
+    if (colons < 3 || colons%2 == 0) {
+        printf("LoadMTDContents called with bad filename (%s)\n",
+               filename);
+    }
 
-  // sort the index[] array so it indexes the pairs in order of
-  // increasing size.
-  size_array = size;
-  qsort(index, pairs, sizeof(int), compare_size_indices);
+    int pairs = (colons-1)/2;     // # of (size,sha1) pairs in filename
+    int* index = malloc(pairs * sizeof(int));
+    size_t* size = malloc(pairs * sizeof(size_t));
+    char** sha1sum = malloc(pairs * sizeof(char*));
 
-  if (!mtd_partitions_scanned) {
-    mtd_scan_partitions();
-    mtd_partitions_scanned = 1;
-  }
+    for (i = 0; i < pairs; ++i) {
+        const char* size_str = strtok(NULL, ":");
+        size[i] = strtol(size_str, NULL, 10);
+        if (size[i] == 0) {
+            printf("LoadMTDContents called with bad size (%s)\n", filename);
+            return -1;
+        }
+        sha1sum[i] = strtok(NULL, ":");
+        index[i] = i;
+    }
 
-  const MtdPartition* mtd = mtd_find_partition_by_name(partition);
-  if (mtd == NULL) {
-    printf("mtd partition \"%s\" not found (loading %s)\n",
-            partition, filename);
-    return -1;
-  }
+    // sort the index[] array so it indexes the pairs in order of
+    // increasing size.
+    size_array = size;
+    qsort(index, pairs, sizeof(int), compare_size_indices);
 
-  MtdReadContext* ctx = mtd_read_partition(mtd);
-  if (ctx == NULL) {
-    printf("failed to initialize read of mtd partition \"%s\"\n",
-            partition);
-    return -1;
-  }
+    if (!mtd_partitions_scanned) {
+        mtd_scan_partitions();
+        mtd_partitions_scanned = 1;
+    }
 
-  SHA_CTX sha_ctx;
-  SHA_init(&sha_ctx);
-  uint8_t parsed_sha[SHA_DIGEST_SIZE];
+    const MtdPartition* mtd = mtd_find_partition_by_name(partition);
+    if (mtd == NULL) {
+        printf("mtd partition \"%s\" not found (loading %s)\n",
+               partition, filename);
+        return -1;
+    }
 
-  // allocate enough memory to hold the largest size.
-  file->data = malloc(size[index[pairs-1]]);
-  char* p = (char*)file->data;
-  file->size = 0;                // # bytes read so far
+    MtdReadContext* ctx = mtd_read_partition(mtd);
+    if (ctx == NULL) {
+        printf("failed to initialize read of mtd partition \"%s\"\n",
+               partition);
+        return -1;
+    }
 
-  for (i = 0; i < pairs; ++i) {
-    // Read enough additional bytes to get us up to the next size
-    // (again, we're trying the possibilities in order of increasing
-    // size).
-    size_t next = size[index[i]] - file->size;
-    size_t read = 0;
-    if (next > 0) {
-      read = mtd_read_data(ctx, p, next);
-      if (next != read) {
-        printf("short read (%d bytes of %d) for partition \"%s\"\n",
-                read, next, partition);
+    SHA_CTX sha_ctx;
+    SHA_init(&sha_ctx);
+    uint8_t parsed_sha[SHA_DIGEST_SIZE];
+
+    // allocate enough memory to hold the largest size.
+    file->data = malloc(size[index[pairs-1]]);
+    char* p = (char*)file->data;
+    file->size = 0;                // # bytes read so far
+
+    for (i = 0; i < pairs; ++i) {
+        // Read enough additional bytes to get us up to the next size
+        // (again, we're trying the possibilities in order of increasing
+        // size).
+        size_t next = size[index[i]] - file->size;
+        size_t read = 0;
+        if (next > 0) {
+            read = mtd_read_data(ctx, p, next);
+            if (next != read) {
+                printf("short read (%d bytes of %d) for partition \"%s\"\n",
+                       read, next, partition);
+                free(file->data);
+                file->data = NULL;
+                return -1;
+            }
+            SHA_update(&sha_ctx, p, read);
+            file->size += read;
+        }
+
+        // Duplicate the SHA context and finalize the duplicate so we can
+        // check it against this pair's expected hash.
+        SHA_CTX temp_ctx;
+        memcpy(&temp_ctx, &sha_ctx, sizeof(SHA_CTX));
+        const uint8_t* sha_so_far = SHA_final(&temp_ctx);
+
+        if (ParseSha1(sha1sum[index[i]], parsed_sha) != 0) {
+            printf("failed to parse sha1 %s in %s\n",
+                   sha1sum[index[i]], filename);
+            free(file->data);
+            file->data = NULL;
+            return -1;
+        }
+
+        if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) {
+            // we have a match.  stop reading the partition; we'll return
+            // the data we've read so far.
+            printf("mtd read matched size %d sha %s\n",
+                   size[index[i]], sha1sum[index[i]]);
+            break;
+        }
+
+        p += read;
+    }
+
+    mtd_read_close(ctx);
+
+    if (i == pairs) {
+        // Ran off the end of the list of (size,sha1) pairs without
+        // finding a match.
+        printf("contents of MTD partition \"%s\" didn't match %s\n",
+               partition, filename);
         free(file->data);
         file->data = NULL;
         return -1;
-      }
-      SHA_update(&sha_ctx, p, read);
-      file->size += read;
     }
 
-    // Duplicate the SHA context and finalize the duplicate so we can
-    // check it against this pair's expected hash.
-    SHA_CTX temp_ctx;
-    memcpy(&temp_ctx, &sha_ctx, sizeof(SHA_CTX));
-    const uint8_t* sha_so_far = SHA_final(&temp_ctx);
-
-    if (ParseSha1(sha1sum[index[i]], parsed_sha) != 0) {
-      printf("failed to parse sha1 %s in %s\n",
-              sha1sum[index[i]], filename);
-      free(file->data);
-      file->data = NULL;
-      return -1;
+    const uint8_t* sha_final = SHA_final(&sha_ctx);
+    for (i = 0; i < SHA_DIGEST_SIZE; ++i) {
+        file->sha1[i] = sha_final[i];
     }
 
-    if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) {
-      // we have a match.  stop reading the partition; we'll return
-      // the data we've read so far.
-      printf("mtd read matched size %d sha %s\n",
-             size[index[i]], sha1sum[index[i]]);
-      break;
-    }
+    // Fake some stat() info.
+    file->st.st_mode = 0644;
+    file->st.st_uid = 0;
+    file->st.st_gid = 0;
 
-    p += read;
-  }
+    free(copy);
+    free(index);
+    free(size);
+    free(sha1sum);
 
-  mtd_read_close(ctx);
-
-  if (i == pairs) {
-    // Ran off the end of the list of (size,sha1) pairs without
-    // finding a match.
-    printf("contents of MTD partition \"%s\" didn't match %s\n",
-            partition, filename);
-    free(file->data);
-    file->data = NULL;
-    return -1;
-  }
-
-  const uint8_t* sha_final = SHA_final(&sha_ctx);
-  for (i = 0; i < SHA_DIGEST_SIZE; ++i) {
-    file->sha1[i] = sha_final[i];
-  }
-
-  // Fake some stat() info.
-  file->st.st_mode = 0644;
-  file->st.st_uid = 0;
-  file->st.st_gid = 0;
-
-  free(copy);
-  free(index);
-  free(size);
-  free(sha1sum);
-
-  return 0;
+    return 0;
 }
 
 
 // Save the contents of the given FileContents object under the given
 // filename.  Return 0 on success.
 int SaveFileContents(const char* filename, FileContents file) {
-  int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC);
-  if (fd < 0) {
-    printf("failed to open \"%s\" for write: %s\n",
-            filename, strerror(errno));
-    return -1;
-  }
+    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC);
+    if (fd < 0) {
+        printf("failed to open \"%s\" for write: %s\n",
+               filename, strerror(errno));
+        return -1;
+    }
 
-  size_t bytes_written = FileSink(file.data, file.size, &fd);
-  if (bytes_written != file.size) {
-    printf("short write of \"%s\" (%d bytes of %d) (%s)\n",
-           filename, bytes_written, file.size, strerror(errno));
+    ssize_t bytes_written = FileSink(file.data, file.size, &fd);
+    if (bytes_written != file.size) {
+        printf("short write of \"%s\" (%ld bytes of %ld) (%s)\n",
+               filename, (long)bytes_written, (long)file.size,
+               strerror(errno));
+        close(fd);
+        return -1;
+    }
+    fsync(fd);
     close(fd);
-    return -1;
-  }
-  fsync(fd);
-  close(fd);
 
-  if (chmod(filename, file.st.st_mode) != 0) {
-    printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno));
-    return -1;
-  }
-  if (chown(filename, file.st.st_uid, file.st.st_gid) != 0) {
-    printf("chown of \"%s\" failed: %s\n", filename, strerror(errno));
-    return -1;
-  }
+    if (chmod(filename, file.st.st_mode) != 0) {
+        printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno));
+        return -1;
+    }
+    if (chown(filename, file.st.st_uid, file.st.st_gid) != 0) {
+        printf("chown of \"%s\" failed: %s\n", filename, strerror(errno));
+        return -1;
+    }
 
-  return 0;
+    return 0;
 }
 
 // Write a memory buffer to target_mtd partition, a string of the form
 // "MTD:<partition>[:...]".  Return 0 on success.
 int WriteToMTDPartition(unsigned char* data, size_t len,
                         const char* target_mtd) {
-  char* partition = strchr(target_mtd, ':');
-  if (partition == NULL) {
-    printf("bad MTD target name \"%s\"\n", target_mtd);
-    return -1;
-  }
-  ++partition;
-  // Trim off anything after a colon, eg "MTD:boot:blah:blah:blah...".
-  // We want just the partition name "boot".
-  partition = strdup(partition);
-  char* end = strchr(partition, ':');
-  if (end != NULL)
-    *end = '\0';
+    char* partition = strchr(target_mtd, ':');
+    if (partition == NULL) {
+        printf("bad MTD target name \"%s\"\n", target_mtd);
+        return -1;
+    }
+    ++partition;
+    // Trim off anything after a colon, eg "MTD:boot:blah:blah:blah...".
+    // We want just the partition name "boot".
+    partition = strdup(partition);
+    char* end = strchr(partition, ':');
+    if (end != NULL)
+        *end = '\0';
 
-  if (!mtd_partitions_scanned) {
-    mtd_scan_partitions();
-    mtd_partitions_scanned = 1;
-  }
+    if (!mtd_partitions_scanned) {
+        mtd_scan_partitions();
+        mtd_partitions_scanned = 1;
+    }
 
-  const MtdPartition* mtd = mtd_find_partition_by_name(partition);
-  if (mtd == NULL) {
-    printf("mtd partition \"%s\" not found for writing\n", partition);
-    return -1;
-  }
+    const MtdPartition* mtd = mtd_find_partition_by_name(partition);
+    if (mtd == NULL) {
+        printf("mtd partition \"%s\" not found for writing\n", partition);
+        return -1;
+    }
 
-  MtdWriteContext* ctx = mtd_write_partition(mtd);
-  if (ctx == NULL) {
-    printf("failed to init mtd partition \"%s\" for writing\n",
-            partition);
-    return -1;
-  }
+    MtdWriteContext* ctx = mtd_write_partition(mtd);
+    if (ctx == NULL) {
+        printf("failed to init mtd partition \"%s\" for writing\n",
+               partition);
+        return -1;
+    }
 
-  size_t written = mtd_write_data(ctx, (char*)data, len);
-  if (written != len) {
-    printf("only wrote %d of %d bytes to MTD %s\n",
-            written, len, partition);
-    mtd_write_close(ctx);
-    return -1;
-  }
+    size_t written = mtd_write_data(ctx, (char*)data, len);
+    if (written != len) {
+        printf("only wrote %d of %d bytes to MTD %s\n",
+               written, len, partition);
+        mtd_write_close(ctx);
+        return -1;
+    }
 
-  if (mtd_erase_blocks(ctx, -1) < 0) {
-    printf("error finishing mtd write of %s\n", partition);
-    mtd_write_close(ctx);
-    return -1;
-  }
+    if (mtd_erase_blocks(ctx, -1) < 0) {
+        printf("error finishing mtd write of %s\n", partition);
+        mtd_write_close(ctx);
+        return -1;
+    }
 
-  if (mtd_write_close(ctx)) {
-    printf("error closing mtd write of %s\n", partition);
-    return -1;
-  }
+    if (mtd_write_close(ctx)) {
+        printf("error closing mtd write of %s\n", partition);
+        return -1;
+    }
 
-  free(partition);
-  return 0;
+    free(partition);
+    return 0;
 }
 
 
@@ -354,547 +356,460 @@
 // the form "<digest>:<anything>".  Return 0 on success, -1 on any
 // error.
 int ParseSha1(const char* str, uint8_t* digest) {
-  int i;
-  const char* ps = str;
-  uint8_t* pd = digest;
-  for (i = 0; i < SHA_DIGEST_SIZE * 2; ++i, ++ps) {
-    int digit;
-    if (*ps >= '0' && *ps <= '9') {
-      digit = *ps - '0';
-    } else if (*ps >= 'a' && *ps <= 'f') {
-      digit = *ps - 'a' + 10;
-    } else if (*ps >= 'A' && *ps <= 'F') {
-      digit = *ps - 'A' + 10;
-    } else {
-      return -1;
+    int i;
+    const char* ps = str;
+    uint8_t* pd = digest;
+    for (i = 0; i < SHA_DIGEST_SIZE * 2; ++i, ++ps) {
+        int digit;
+        if (*ps >= '0' && *ps <= '9') {
+            digit = *ps - '0';
+        } else if (*ps >= 'a' && *ps <= 'f') {
+            digit = *ps - 'a' + 10;
+        } else if (*ps >= 'A' && *ps <= 'F') {
+            digit = *ps - 'A' + 10;
+        } else {
+            return -1;
+        }
+        if (i % 2 == 0) {
+            *pd = digit << 4;
+        } else {
+            *pd |= digit;
+            ++pd;
+        }
     }
-    if (i % 2 == 0) {
-      *pd = digit << 4;
-    } else {
-      *pd |= digit;
-      ++pd;
-    }
-  }
-  if (*ps != '\0' && *ps != ':') return -1;
-  return 0;
+    if (*ps != '\0') return -1;
+    return 0;
 }
 
-// Parse arguments (which should be of the form "<sha1>" or
-// "<sha1>:<filename>" into the array *patches, returning the number
-// of Patch objects in *num_patches.  Return 0 on success.
-int ParseShaArgs(int argc, char** argv, Patch** patches, int* num_patches) {
-  *num_patches = argc;
-  *patches = malloc(*num_patches * sizeof(Patch));
-
-  int i;
-  for (i = 0; i < *num_patches; ++i) {
-    if (ParseSha1(argv[i], (*patches)[i].sha1) != 0) {
-      printf("failed to parse sha1 \"%s\"\n", argv[i]);
-      return -1;
+// Search an array of sha1 strings for one matching the given sha1.
+// Return the index of the match on success, or -1 if no match is
+// found.
+int FindMatchingPatch(uint8_t* sha1, char** const patch_sha1_str,
+                      int num_patches) {
+    int i;
+    uint8_t patch_sha1[SHA_DIGEST_SIZE];
+    for (i = 0; i < num_patches; ++i) {
+        if (ParseSha1(patch_sha1_str[i], patch_sha1) == 0 &&
+            memcmp(patch_sha1, sha1, SHA_DIGEST_SIZE) == 0) {
+            return i;
+        }
     }
-    if (argv[i][SHA_DIGEST_SIZE*2] == '\0') {
-      (*patches)[i].patch_filename = NULL;
-    } else if (argv[i][SHA_DIGEST_SIZE*2] == ':') {
-      (*patches)[i].patch_filename = argv[i] + (SHA_DIGEST_SIZE*2+1);
-    } else {
-      printf("failed to parse filename \"%s\"\n", argv[i]);
-      return -1;
-    }
-  }
-
-  return 0;
-}
-
-// Search an array of Patch objects for one matching the given sha1.
-// Return the Patch object on success, or NULL if no match is found.
-const Patch* FindMatchingPatch(uint8_t* sha1, Patch* patches, int num_patches) {
-  int i;
-  for (i = 0; i < num_patches; ++i) {
-    if (memcmp(patches[i].sha1, sha1, SHA_DIGEST_SIZE) == 0) {
-      return patches+i;
-    }
-  }
-  return NULL;
+    return -1;
 }
 
 // Returns 0 if the contents of the file (argv[2]) or the cached file
 // match any of the sha1's on the command line (argv[3:]).  Returns
 // nonzero otherwise.
-int CheckMode(int argc, char** argv) {
-  if (argc < 3) {
-    printf("no filename given\n");
-    return 2;
-  }
+int applypatch_check(const char* filename,
+                     int num_patches, char** const patch_sha1_str) {
+    FileContents file;
+    file.data = NULL;
 
-  int num_patches;
-  Patch* patches;
-  if (ParseShaArgs(argc-3, argv+3, &patches, &num_patches) != 0) { return 1; }
+    // It's okay to specify no sha1s; the check will pass if the
+    // LoadFileContents is successful.  (Useful for reading MTD
+    // partitions, where the filename encodes the sha1s; no need to
+    // check them twice.)
+    if (LoadFileContents(filename, &file) != 0 ||
+        (num_patches > 0 &&
+         FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0)) {
+        printf("file \"%s\" doesn't have any of expected "
+               "sha1 sums; checking cache\n", filename);
 
-  FileContents file;
-  file.data = NULL;
+        free(file.data);
 
-  // It's okay to specify no sha1s; the check will pass if the
-  // LoadFileContents is successful.  (Useful for reading MTD
-  // partitions, where the filename encodes the sha1s; no need to
-  // check them twice.)
-  if (LoadFileContents(argv[2], &file) != 0 ||
-      (num_patches > 0 &&
-       FindMatchingPatch(file.sha1, patches, num_patches) == NULL)) {
-    printf("file \"%s\" doesn't have any of expected "
-            "sha1 sums; checking cache\n", argv[2]);
+        // If the source file is missing or corrupted, it might be because
+        // we were killed in the middle of patching it.  A copy of it
+        // should have been made in CACHE_TEMP_SOURCE.  If that file
+        // exists and matches the sha1 we're looking for, the check still
+        // passes.
+
+        if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) {
+            printf("failed to load cache file\n");
+            return 1;
+        }
+
+        if (FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0) {
+            printf("cache bits don't match any sha1 for \"%s\"\n", filename);
+            free(file.data);
+            return 1;
+        }
+    }
 
     free(file.data);
-
-    // If the source file is missing or corrupted, it might be because
-    // we were killed in the middle of patching it.  A copy of it
-    // should have been made in CACHE_TEMP_SOURCE.  If that file
-    // exists and matches the sha1 we're looking for, the check still
-    // passes.
-
-    if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) {
-      printf("failed to load cache file\n");
-      return 1;
-    }
-
-    if (FindMatchingPatch(file.sha1, patches, num_patches) == NULL) {
-      printf("cache bits don't match any sha1 for \"%s\"\n",
-              argv[2]);
-      return 1;
-    }
-  }
-
-  free(file.data);
-  return 0;
+    return 0;
 }
 
 int ShowLicenses() {
-  ShowBSDiffLicense();
-  return 0;
+    ShowBSDiffLicense();
+    return 0;
 }
 
 ssize_t FileSink(unsigned char* data, ssize_t len, void* token) {
-  int fd = *(int *)token;
-  ssize_t done = 0;
-  ssize_t wrote;
-  while (done < (ssize_t) len) {
-    wrote = write(fd, data+done, len-done);
-    if (wrote <= 0) {
-      printf("error writing %d bytes: %s\n", (int)(len-done), strerror(errno));
-      return done;
+    int fd = *(int *)token;
+    ssize_t done = 0;
+    ssize_t wrote;
+    while (done < (ssize_t) len) {
+        wrote = write(fd, data+done, len-done);
+        if (wrote <= 0) {
+            printf("error writing %d bytes: %s\n", (int)(len-done), strerror(errno));
+            return done;
+        }
+        done += wrote;
     }
-    done += wrote;
-  }
-  printf("wrote %d bytes to output\n", (int)done);
-  return done;
+    return done;
 }
 
 typedef struct {
-  unsigned char* buffer;
-  ssize_t size;
-  ssize_t pos;
+    unsigned char* buffer;
+    ssize_t size;
+    ssize_t pos;
 } MemorySinkInfo;
 
 ssize_t MemorySink(unsigned char* data, ssize_t len, void* token) {
-  MemorySinkInfo* msi = (MemorySinkInfo*)token;
-  if (msi->size - msi->pos < len) {
-    return -1;
-  }
-  memcpy(msi->buffer + msi->pos, data, len);
-  msi->pos += len;
-  return len;
+    MemorySinkInfo* msi = (MemorySinkInfo*)token;
+    if (msi->size - msi->pos < len) {
+        return -1;
+    }
+    memcpy(msi->buffer + msi->pos, data, len);
+    msi->pos += len;
+    return len;
 }
 
 // Return the amount of free space (in bytes) on the filesystem
 // containing filename.  filename must exist.  Return -1 on error.
 size_t FreeSpaceForFile(const char* filename) {
-  struct statfs sf;
-  if (statfs(filename, &sf) != 0) {
-    printf("failed to statfs %s: %s\n", filename, strerror(errno));
-    return -1;
-  }
-  return sf.f_bsize * sf.f_bfree;
+    struct statfs sf;
+    if (statfs(filename, &sf) != 0) {
+        printf("failed to statfs %s: %s\n", filename, strerror(errno));
+        return -1;
+    }
+    return sf.f_bsize * sf.f_bfree;
 }
 
-// This program applies binary patches to files in a way that is safe
+int CacheSizeCheck(size_t bytes) {
+    if (MakeFreeSpaceOnCache(bytes) < 0) {
+        printf("unable to make %ld bytes available on /cache\n", (long)bytes);
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+
+// This function applies binary patches to files in a way that is safe
 // (the original file is not touched until we have the desired
 // replacement for it) and idempotent (it's okay to run this program
 // multiple times).
 //
-// - if the sha1 hash of <tgt-file> is <tgt-sha1>, does nothing and exits
-//   successfully.
+// - if the sha1 hash of <target_filename> is <target_sha1_string>,
+//   does nothing and exits successfully.
 //
-// - otherwise, if the sha1 hash of <src-file> is <src-sha1>, applies the
-//   bsdiff <patch> to <src-file> to produce a new file (the type of patch
-//   is automatically detected from the file header).  If that new
-//   file has sha1 hash <tgt-sha1>, moves it to replace <tgt-file>, and
-//   exits successfully.  Note that if <src-file> and <tgt-file> are
-//   not the same, <src-file> is NOT deleted on success.  <tgt-file>
-//   may be the string "-" to mean "the same as src-file".
+// - otherwise, if the sha1 hash of <source_filename> is one of the
+//   entries in <patch_sha1_str>, the corresponding patch from
+//   <patch_data> (which must be a VAL_BLOB) is applied to produce a
+//   new file (the type of patch is automatically detected from the
+//   blob daat).  If that new file has sha1 hash <target_sha1_str>,
+//   moves it to replace <target_filename>, and exits successfully.
+//   Note that if <source_filename> and <target_filename> are not the
+//   same, <source_filename> is NOT deleted on success.
+//   <target_filename> may be the string "-" to mean "the same as
+//   source_filename".
 //
 // - otherwise, or if any error is encountered, exits with non-zero
 //   status.
 //
-// <src-file> (or <file> in check mode) may refer to an MTD partition
-// to read the source data.  See the comments for the
-// LoadMTDContents() function above for the format of such a filename.
-//
-//
-// As you might guess from the arguments, this function used to be
-// main(); it was split out this way so applypatch could be built as a
-// static library and linked into other executables as well.  In the
-// future only the library form will exist; we will not need to build
-// this as a standalone executable.
-//
-// The arguments to this function are just the command-line of the
-// standalone executable:
-//
-// <src-file> <tgt-file> <tgt-sha1> <tgt-size> [<src-sha1>:<patch> ...]
-//    to apply a patch.  Returns 0 on success, 1 on failure.
-//
-// "-c" <file> [<sha1> ...]
-//    to check a file's contents against zero or more sha1s.  Returns
-//    0 if it matches any of them, 1 if it doesn't.
-//
-// "-s" <bytes>
-//    returns 0 if enough free space is available on /cache; 1 if it
-//    does not.
-//
-// "-l"
-//    shows open-source license information and returns 0.
-//
-// This function returns 2 if the arguments are not understood (in the
-// standalone executable, this causes the usage message to be
-// printed).
-//
-// TODO: make the interface more sensible for use as a library.
+// <source_filename> may refer to an MTD partition to read the source
+// data.  See the comments for the LoadMTDContents() function above
+// for the format of such a filename.
 
-int applypatch(int argc, char** argv) {
-  if (argc < 2) {
-    return 2;
-  }
+int applypatch(const char* source_filename,
+               const char* target_filename,
+               const char* target_sha1_str,
+               size_t target_size,
+               int num_patches,
+               char** const patch_sha1_str,
+               Value** patch_data) {
+    printf("\napplying patch to %s\n", source_filename);
 
-  if (strncmp(argv[1], "-l", 3) == 0) {
-    return ShowLicenses();
-  }
-
-  if (strncmp(argv[1], "-c", 3) == 0) {
-    return CheckMode(argc, argv);
-  }
-
-  if (strncmp(argv[1], "-s", 3) == 0) {
-    if (argc != 3) {
-      return 2;
-    }
-    size_t bytes = strtol(argv[2], NULL, 10);
-    if (MakeFreeSpaceOnCache(bytes) < 0) {
-      printf("unable to make %ld bytes available on /cache\n", (long)bytes);
-      return 1;
-    } else {
-      return 0;
-    }
-  }
-
-  uint8_t target_sha1[SHA_DIGEST_SIZE];
-
-  const char* source_filename = argv[1];
-  const char* target_filename = argv[2];
-  if (target_filename[0] == '-' &&
-      target_filename[1] == '\0') {
-    target_filename = source_filename;
-  }
-
-  printf("\napplying patch to %s\n", source_filename);
-
-  if (ParseSha1(argv[3], target_sha1) != 0) {
-    printf("failed to parse tgt-sha1 \"%s\"\n", argv[3]);
-    return 1;
-  }
-
-  unsigned long target_size = strtoul(argv[4], NULL, 0);
-
-  int num_patches;
-  Patch* patches;
-  if (ParseShaArgs(argc-5, argv+5, &patches, &num_patches) < 0) { return 1; }
-
-  FileContents copy_file;
-  FileContents source_file;
-  const char* source_patch_filename = NULL;
-  const char* copy_patch_filename = NULL;
-  int made_copy = 0;
-
-  // We try to load the target file into the source_file object.
-  if (LoadFileContents(target_filename, &source_file) == 0) {
-    if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) {
-      // The early-exit case:  the patch was already applied, this file
-      // has the desired hash, nothing for us to do.
-      printf("\"%s\" is already target; no patch needed\n",
-              target_filename);
-      return 0;
-    }
-  }
-
-  if (source_file.data == NULL ||
-      (target_filename != source_filename &&
-       strcmp(target_filename, source_filename) != 0)) {
-    // Need to load the source file:  either we failed to load the
-    // target file, or we did but it's different from the source file.
-    free(source_file.data);
-    LoadFileContents(source_filename, &source_file);
-  }
-
-  if (source_file.data != NULL) {
-    const Patch* to_use =
-        FindMatchingPatch(source_file.sha1, patches, num_patches);
-    if (to_use != NULL) {
-      source_patch_filename = to_use->patch_filename;
-    }
-  }
-
-  if (source_patch_filename == NULL) {
-    free(source_file.data);
-    printf("source file is bad; trying copy\n");
-
-    if (LoadFileContents(CACHE_TEMP_SOURCE, &copy_file) < 0) {
-      // fail.
-      printf("failed to read copy file\n");
-      return 1;
+    if (target_filename[0] == '-' &&
+        target_filename[1] == '\0') {
+        target_filename = source_filename;
     }
 
-    const Patch* to_use =
-        FindMatchingPatch(copy_file.sha1, patches, num_patches);
-    if (to_use != NULL) {
-      copy_patch_filename = to_use->patch_filename;
-    }
-
-    if (copy_patch_filename == NULL) {
-      // fail.
-      printf("copy file doesn't match source SHA-1s either\n");
-      return 1;
-    }
-  }
-
-  int retry = 1;
-  SHA_CTX ctx;
-  int output;
-  MemorySinkInfo msi;
-  FileContents* source_to_use;
-  char* outname;
-
-  // assume that target_filename (eg "/system/app/Foo.apk") is located
-  // on the same filesystem as its top-level directory ("/system").
-  // We need something that exists for calling statfs().
-  char target_fs[strlen(target_filename)+1];
-  char* slash = strchr(target_filename+1, '/');
-  if (slash != NULL) {
-    int count = slash - target_filename;
-    strncpy(target_fs, target_filename, count);
-    target_fs[count] = '\0';
-  } else {
-    strcpy(target_fs, target_filename);
-  }
-
-  do {
-    // Is there enough room in the target filesystem to hold the patched
-    // file?
-
-    if (strncmp(target_filename, "MTD:", 4) == 0) {
-      // If the target is an MTD partition, we're actually going to
-      // write the output to /tmp and then copy it to the partition.
-      // statfs() always returns 0 blocks free for /tmp, so instead
-      // we'll just assume that /tmp has enough space to hold the file.
-
-      // We still write the original source to cache, in case the MTD
-      // write is interrupted.
-      if (MakeFreeSpaceOnCache(source_file.size) < 0) {
-        printf("not enough free space on /cache\n");
+    uint8_t target_sha1[SHA_DIGEST_SIZE];
+    if (ParseSha1(target_sha1_str, target_sha1) != 0) {
+        printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str);
         return 1;
-      }
-      if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
-        printf("failed to back up source file\n");
-        return 1;
-      }
-      made_copy = 1;
-      retry = 0;
-    } else {
-      int enough_space = 0;
-      if (retry > 0) {
-        size_t free_space = FreeSpaceForFile(target_fs);
-        int enough_space =
-          (free_space > (target_size * 3 / 2));  // 50% margin of error
-        printf("target %ld bytes; free space %ld bytes; retry %d; enough %d\n",
-               (long)target_size, (long)free_space, retry, enough_space);
-      }
+    }
 
-      if (!enough_space) {
-        retry = 0;
-      }
+    FileContents copy_file;
+    FileContents source_file;
+    const Value* source_patch_value = NULL;
+    const Value* copy_patch_value = NULL;
+    int made_copy = 0;
 
-      if (!enough_space && source_patch_filename != NULL) {
-        // Using the original source, but not enough free space.  First
-        // copy the source file to cache, then delete it from the original
-        // location.
+    // We try to load the target file into the source_file object.
+    if (LoadFileContents(target_filename, &source_file) == 0) {
+        if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) {
+            // The early-exit case:  the patch was already applied, this file
+            // has the desired hash, nothing for us to do.
+            printf("\"%s\" is already target; no patch needed\n",
+                   target_filename);
+            return 0;
+        }
+    }
 
-        if (strncmp(source_filename, "MTD:", 4) == 0) {
-          // It's impossible to free space on the target filesystem by
-          // deleting the source if the source is an MTD partition.  If
-          // we're ever in a state where we need to do this, fail.
-          printf("not enough free space for target but source is MTD\n");
-          return 1;
+    if (source_file.data == NULL ||
+        (target_filename != source_filename &&
+         strcmp(target_filename, source_filename) != 0)) {
+        // Need to load the source file:  either we failed to load the
+        // target file, or we did but it's different from the source file.
+        free(source_file.data);
+        LoadFileContents(source_filename, &source_file);
+    }
+
+    if (source_file.data != NULL) {
+        int to_use = FindMatchingPatch(source_file.sha1,
+                                       patch_sha1_str, num_patches);
+        if (to_use >= 0) {
+            source_patch_value = patch_data[to_use];
+        }
+    }
+
+    if (source_patch_value == NULL) {
+        free(source_file.data);
+        printf("source file is bad; trying copy\n");
+
+        if (LoadFileContents(CACHE_TEMP_SOURCE, &copy_file) < 0) {
+            // fail.
+            printf("failed to read copy file\n");
+            return 1;
         }
 
-        if (MakeFreeSpaceOnCache(source_file.size) < 0) {
-          printf("not enough free space on /cache\n");
-          return 1;
+        int to_use = FindMatchingPatch(copy_file.sha1,
+                                       patch_sha1_str, num_patches);
+        if (to_use > 0) {
+            copy_patch_value = patch_data[to_use];
         }
 
-        if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
-          printf("failed to back up source file\n");
-          return 1;
+        if (copy_patch_value == NULL) {
+            // fail.
+            printf("copy file doesn't match source SHA-1s either\n");
+            return 1;
         }
-        made_copy = 1;
-        unlink(source_filename);
-
-        size_t free_space = FreeSpaceForFile(target_fs);
-        printf("(now %ld bytes free for target)\n", (long)free_space);
-      }
     }
 
-    const char* patch_filename;
-    if (source_patch_filename != NULL) {
-      source_to_use = &source_file;
-      patch_filename = source_patch_filename;
+    int retry = 1;
+    SHA_CTX ctx;
+    int output;
+    MemorySinkInfo msi;
+    FileContents* source_to_use;
+    char* outname;
+
+    // assume that target_filename (eg "/system/app/Foo.apk") is located
+    // on the same filesystem as its top-level directory ("/system").
+    // We need something that exists for calling statfs().
+    char target_fs[strlen(target_filename)+1];
+    char* slash = strchr(target_filename+1, '/');
+    if (slash != NULL) {
+        int count = slash - target_filename;
+        strncpy(target_fs, target_filename, count);
+        target_fs[count] = '\0';
     } else {
-      source_to_use = &copy_file;
-      patch_filename = copy_patch_filename;
+        strcpy(target_fs, target_filename);
     }
 
-    SinkFn sink = NULL;
-    void* token = NULL;
-    output = -1;
-    outname = NULL;
-    if (strncmp(target_filename, "MTD:", 4) == 0) {
-      // We store the decoded output in memory.
-      msi.buffer = malloc(target_size);
-      if (msi.buffer == NULL) {
-        printf("failed to alloc %ld bytes for output\n",
-               (long)target_size);
+    do {
+        // Is there enough room in the target filesystem to hold the patched
+        // file?
+
+        if (strncmp(target_filename, "MTD:", 4) == 0) {
+            // If the target is an MTD partition, we're actually going to
+            // write the output to /tmp and then copy it to the partition.
+            // statfs() always returns 0 blocks free for /tmp, so instead
+            // we'll just assume that /tmp has enough space to hold the file.
+
+            // We still write the original source to cache, in case the MTD
+            // write is interrupted.
+            if (MakeFreeSpaceOnCache(source_file.size) < 0) {
+                printf("not enough free space on /cache\n");
+                return 1;
+            }
+            if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
+                printf("failed to back up source file\n");
+                return 1;
+            }
+            made_copy = 1;
+            retry = 0;
+        } else {
+            int enough_space = 0;
+            if (retry > 0) {
+                size_t free_space = FreeSpaceForFile(target_fs);
+                int enough_space =
+                    (free_space > (target_size * 3 / 2));  // 50% margin of error
+                printf("target %ld bytes; free space %ld bytes; retry %d; enough %d\n",
+                       (long)target_size, (long)free_space, retry, enough_space);
+            }
+
+            if (!enough_space) {
+                retry = 0;
+            }
+
+            if (!enough_space && source_patch_value != NULL) {
+                // Using the original source, but not enough free space.  First
+                // copy the source file to cache, then delete it from the original
+                // location.
+
+                if (strncmp(source_filename, "MTD:", 4) == 0) {
+                    // It's impossible to free space on the target filesystem by
+                    // deleting the source if the source is an MTD partition.  If
+                    // we're ever in a state where we need to do this, fail.
+                    printf("not enough free space for target but source is MTD\n");
+                    return 1;
+                }
+
+                if (MakeFreeSpaceOnCache(source_file.size) < 0) {
+                    printf("not enough free space on /cache\n");
+                    return 1;
+                }
+
+                if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
+                    printf("failed to back up source file\n");
+                    return 1;
+                }
+                made_copy = 1;
+                unlink(source_filename);
+
+                size_t free_space = FreeSpaceForFile(target_fs);
+                printf("(now %ld bytes free for target)\n", (long)free_space);
+            }
+        }
+
+        const Value* patch;
+        if (source_patch_value != NULL) {
+            source_to_use = &source_file;
+            patch = source_patch_value;
+        } else {
+            source_to_use = &copy_file;
+            patch = copy_patch_value;
+        }
+
+        if (patch->type != VAL_BLOB) {
+            printf("patch is not a blob\n");
+            return 1;
+        }
+
+        SinkFn sink = NULL;
+        void* token = NULL;
+        output = -1;
+        outname = NULL;
+        if (strncmp(target_filename, "MTD:", 4) == 0) {
+            // We store the decoded output in memory.
+            msi.buffer = malloc(target_size);
+            if (msi.buffer == NULL) {
+                printf("failed to alloc %ld bytes for output\n",
+                       (long)target_size);
+                return 1;
+            }
+            msi.pos = 0;
+            msi.size = target_size;
+            sink = MemorySink;
+            token = &msi;
+        } else {
+            // We write the decoded output to "<tgt-file>.patch".
+            outname = (char*)malloc(strlen(target_filename) + 10);
+            strcpy(outname, target_filename);
+            strcat(outname, ".patch");
+
+            output = open(outname, O_WRONLY | O_CREAT | O_TRUNC);
+            if (output < 0) {
+                printf("failed to open output file %s: %s\n",
+                       outname, strerror(errno));
+                return 1;
+            }
+            sink = FileSink;
+            token = &output;
+        }
+
+        char* header = patch->data;
+        ssize_t header_bytes_read = patch->size;
+
+        SHA_init(&ctx);
+
+        int result;
+
+        if (header_bytes_read >= 8 &&
+            memcmp(header, "BSDIFF40", 8) == 0) {
+            result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size,
+                                      patch, 0, sink, token, &ctx);
+        } else if (header_bytes_read >= 8 &&
+                   memcmp(header, "IMGDIFF2", 8) == 0) {
+            result = ApplyImagePatch(source_to_use->data, source_to_use->size,
+                                     patch, sink, token, &ctx);
+        } else {
+            printf("Unknown patch file format\n");
+            return 1;
+        }
+
+        if (output >= 0) {
+            fsync(output);
+            close(output);
+        }
+
+        if (result != 0) {
+            if (retry == 0) {
+                printf("applying patch failed\n");
+                return result != 0;
+            } else {
+                printf("applying patch failed; retrying\n");
+            }
+            if (outname != NULL) {
+                unlink(outname);
+            }
+        } else {
+            // succeeded; no need to retry
+            break;
+        }
+    } while (retry-- > 0);
+
+    const uint8_t* current_target_sha1 = SHA_final(&ctx);
+    if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) {
+        printf("patch did not produce expected sha1\n");
         return 1;
-      }
-      msi.pos = 0;
-      msi.size = target_size;
-      sink = MemorySink;
-      token = &msi;
+    }
+
+    if (output < 0) {
+        // Copy the temp file to the MTD partition.
+        if (WriteToMTDPartition(msi.buffer, msi.pos, target_filename) != 0) {
+            printf("write of patched data to %s failed\n", target_filename);
+            return 1;
+        }
+        free(msi.buffer);
     } else {
-      // We write the decoded output to "<tgt-file>.patch".
-      outname = (char*)malloc(strlen(target_filename) + 10);
-      strcpy(outname, target_filename);
-      strcat(outname, ".patch");
+        // Give the .patch file the same owner, group, and mode of the
+        // original source file.
+        if (chmod(outname, source_to_use->st.st_mode) != 0) {
+            printf("chmod of \"%s\" failed: %s\n", outname, strerror(errno));
+            return 1;
+        }
+        if (chown(outname, source_to_use->st.st_uid,
+                  source_to_use->st.st_gid) != 0) {
+            printf("chown of \"%s\" failed: %s\n", outname, strerror(errno));
+            return 1;
+        }
 
-      output = open(outname, O_WRONLY | O_CREAT | O_TRUNC);
-      if (output < 0) {
-        printf("failed to open output file %s: %s\n",
-               outname, strerror(errno));
-        return 1;
-      }
-      sink = FileSink;
-      token = &output;
+        // Finally, rename the .patch file to replace the target file.
+        if (rename(outname, target_filename) != 0) {
+            printf("rename of .patch to \"%s\" failed: %s\n",
+                   target_filename, strerror(errno));
+            return 1;
+        }
     }
 
-#define MAX_HEADER_LENGTH 8
-    unsigned char header[MAX_HEADER_LENGTH];
-    FILE* patchf = fopen(patch_filename, "rb");
-    if (patchf == NULL) {
-      printf("failed to open patch file %s: %s\n",
-             patch_filename, strerror(errno));
-      return 1;
-    }
-    int header_bytes_read = fread(header, 1, MAX_HEADER_LENGTH, patchf);
-    fclose(patchf);
+    // If this run of applypatch created the copy, and we're here, we
+    // can delete it.
+    if (made_copy) unlink(CACHE_TEMP_SOURCE);
 
-    SHA_init(&ctx);
-
-    int result;
-
-    if (header_bytes_read >= 4 &&
-        header[0] == 0xd6 && header[1] == 0xc3 &&
-        header[2] == 0xc4 && header[3] == 0) {
-      // xdelta3 patches begin "VCD" (with the high bits set) followed
-      // by a zero byte (the version number).
-      printf("error:  xdelta3 patches no longer supported\n");
-      return 1;
-    } else if (header_bytes_read >= 8 &&
-               memcmp(header, "BSDIFF40", 8) == 0) {
-      result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size,
-                                    patch_filename, 0, sink, token, &ctx);
-    } else if (header_bytes_read >= 8 &&
-               memcmp(header, "IMGDIFF", 7) == 0 &&
-               (header[7] == '1' || header[7] == '2')) {
-      result = ApplyImagePatch(source_to_use->data, source_to_use->size,
-                                   patch_filename, sink, token, &ctx);
-    } else {
-      printf("Unknown patch file format\n");
-      return 1;
-    }
-
-    if (output >= 0) {
-      fsync(output);
-      close(output);
-    }
-
-    if (result != 0) {
-      if (retry == 0) {
-        printf("applying patch failed\n");
-        return result != 0;
-      } else {
-        printf("applying patch failed; retrying\n");
-      }
-      if (outname != NULL) {
-        unlink(outname);
-      }
-    } else {
-      // succeeded; no need to retry
-      break;
-    }
-  } while (retry-- > 0);
-
-  const uint8_t* current_target_sha1 = SHA_final(&ctx);
-  if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) {
-    printf("patch did not produce expected sha1\n");
-    return 1;
-  }
-
-  if (output < 0) {
-    // Copy the temp file to the MTD partition.
-    if (WriteToMTDPartition(msi.buffer, msi.pos, target_filename) != 0) {
-      printf("write of patched data to %s failed\n", target_filename);
-      return 1;
-    }
-    free(msi.buffer);
-  } else {
-    // Give the .patch file the same owner, group, and mode of the
-    // original source file.
-    if (chmod(outname, source_to_use->st.st_mode) != 0) {
-      printf("chmod of \"%s\" failed: %s\n", outname, strerror(errno));
-      return 1;
-    }
-    if (chown(outname, source_to_use->st.st_uid,
-              source_to_use->st.st_gid) != 0) {
-      printf("chown of \"%s\" failed: %s\n", outname, strerror(errno));
-      return 1;
-    }
-
-    // Finally, rename the .patch file to replace the target file.
-    if (rename(outname, target_filename) != 0) {
-      printf("rename of .patch to \"%s\" failed: %s\n",
-              target_filename, strerror(errno));
-      return 1;
-    }
-  }
-
-  // If this run of applypatch created the copy, and we're here, we
-  // can delete it.
-  if (made_copy) unlink(CACHE_TEMP_SOURCE);
-
-  // Success!
-  return 0;
+    // Success!
+    return 0;
 }
diff --git a/applypatch/applypatch.h b/applypatch/applypatch.h
index 3cb8021..10c0125 100644
--- a/applypatch/applypatch.h
+++ b/applypatch/applypatch.h
@@ -19,6 +19,7 @@
 
 #include <sys/stat.h>
 #include "mincrypt/sha.h"
+#include "edify/expr.h"
 
 typedef struct _Patch {
   uint8_t sha1[SHA_DIGEST_SIZE];
@@ -42,8 +43,21 @@
 typedef ssize_t (*SinkFn)(unsigned char*, ssize_t, void*);
 
 // applypatch.c
+int ShowLicenses();
 size_t FreeSpaceForFile(const char* filename);
-int applypatch(int argc, char** argv);
+int CacheSizeCheck(size_t bytes);
+int ParseSha1(const char* str, uint8_t* digest);
+
+int applypatch(const char* source_filename,
+               const char* target_filename,
+               const char* target_sha1_str,
+               size_t target_size,
+               int num_patches,
+               char** const patch_sha1_str,
+               Value** patch_data);
+int applypatch_check(const char* filename,
+                     int num_patches,
+                     char** const patch_sha1_str);
 
 // Read a file into memory; store it and its associated metadata in
 // *file.  Return 0 on success.
@@ -53,15 +67,15 @@
 // bsdiff.c
 void ShowBSDiffLicense();
 int ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size,
-                     const char* patch_filename, ssize_t offset,
+                     const Value* patch, ssize_t patch_offset,
                      SinkFn sink, void* token, SHA_CTX* ctx);
 int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size,
-                        const char* patch_filename, ssize_t patch_offset,
+                        const Value* patch, ssize_t patch_offset,
                         unsigned char** new_data, ssize_t* new_size);
 
 // imgpatch.c
 int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
-                    const char* patch_filename,
+                    const Value* patch,
                     SinkFn sink, void* token, SHA_CTX* ctx);
 
 // freecache.c
diff --git a/applypatch/applypatch.sh b/applypatch/applypatch.sh
index 88f3025..8ea68a1 100755
--- a/applypatch/applypatch.sh
+++ b/applypatch/applypatch.sh
@@ -11,7 +11,7 @@
 # the tests.
 
 EMULATOR_PORT=5580
-DATA_DIR=$ANDROID_BUILD_TOP/build/tools/applypatch/testdata
+DATA_DIR=$ANDROID_BUILD_TOP/bootable/recovery/applypatch/testdata
 
 # This must be the filename that applypatch uses for its copies.
 CACHE_TEMP_SOURCE=/cache/saved.file
@@ -81,6 +81,7 @@
   testname "removing test files"
   run_command rm $WORK_DIR/bloat.dat
   run_command rm $WORK_DIR/old.file
+  run_command rm $WORK_DIR/foo
   run_command rm $WORK_DIR/patch.bsdiff
   run_command rm $WORK_DIR/applypatch
   run_command rm $CACHE_TEMP_SOURCE
@@ -88,10 +89,12 @@
 
   [ "$pid_emulator" == "" ] || kill $pid_emulator
 
-  rm -rf $tmpdir
+  if [ $# == 0 ]; then
+    rm -rf $tmpdir
+  fi
 }
 
-cleanup
+cleanup leave_tmp
 
 $ADB push $ANDROID_PRODUCT_OUT/system/bin/applypatch $WORK_DIR/applypatch
 
@@ -153,6 +156,8 @@
 
 $ADB push $DATA_DIR/old.file $WORK_DIR
 $ADB push $DATA_DIR/patch.bsdiff $WORK_DIR
+echo hello > $tmpdir/foo
+$ADB push $tmpdir/foo $WORK_DIR
 
 # Check that the partition has enough space to apply the patch without
 # copying.  If it doesn't, we'll be testing the low-space condition
diff --git a/applypatch/bspatch.c b/applypatch/bspatch.c
index d5cd617..2e80f81 100644
--- a/applypatch/bspatch.c
+++ b/applypatch/bspatch.c
@@ -32,221 +32,221 @@
 #include "applypatch.h"
 
 void ShowBSDiffLicense() {
-  puts("The bsdiff library used herein is:\n"
-       "\n"
-       "Copyright 2003-2005 Colin Percival\n"
-       "All rights reserved\n"
-       "\n"
-       "Redistribution and use in source and binary forms, with or without\n"
-       "modification, are permitted providing that the following conditions\n"
-       "are met:\n"
-       "1. Redistributions of source code must retain the above copyright\n"
-       "   notice, this list of conditions and the following disclaimer.\n"
-       "2. Redistributions in binary form must reproduce the above copyright\n"
-       "   notice, this list of conditions and the following disclaimer in the\n"
-       "   documentation and/or other materials provided with the distribution.\n"
-       "\n"
-       "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"
-       "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED\n"
-       "WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\n"
-       "ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY\n"
-       "DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n"
-       "DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\n"
-       "OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\n"
-       "HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,\n"
-       "STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING\n"
-       "IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\n"
-       "POSSIBILITY OF SUCH DAMAGE.\n"
-       "\n------------------\n\n"
-       "This program uses Julian R Seward's \"libbzip2\" library, available\n"
-       "from http://www.bzip.org/.\n"
-       );
+    puts("The bsdiff library used herein is:\n"
+         "\n"
+         "Copyright 2003-2005 Colin Percival\n"
+         "All rights reserved\n"
+         "\n"
+         "Redistribution and use in source and binary forms, with or without\n"
+         "modification, are permitted providing that the following conditions\n"
+         "are met:\n"
+         "1. Redistributions of source code must retain the above copyright\n"
+         "   notice, this list of conditions and the following disclaimer.\n"
+         "2. Redistributions in binary form must reproduce the above copyright\n"
+         "   notice, this list of conditions and the following disclaimer in the\n"
+         "   documentation and/or other materials provided with the distribution.\n"
+         "\n"
+         "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"
+         "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED\n"
+         "WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\n"
+         "ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY\n"
+         "DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n"
+         "DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\n"
+         "OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\n"
+         "HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,\n"
+         "STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING\n"
+         "IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\n"
+         "POSSIBILITY OF SUCH DAMAGE.\n"
+         "\n------------------\n\n"
+         "This program uses Julian R Seward's \"libbzip2\" library, available\n"
+         "from http://www.bzip.org/.\n"
+        );
 }
 
 static off_t offtin(u_char *buf)
 {
-  off_t y;
+    off_t y;
 
-  y=buf[7]&0x7F;
-  y=y*256;y+=buf[6];
-  y=y*256;y+=buf[5];
-  y=y*256;y+=buf[4];
-  y=y*256;y+=buf[3];
-  y=y*256;y+=buf[2];
-  y=y*256;y+=buf[1];
-  y=y*256;y+=buf[0];
+    y=buf[7]&0x7F;
+    y=y*256;y+=buf[6];
+    y=y*256;y+=buf[5];
+    y=y*256;y+=buf[4];
+    y=y*256;y+=buf[3];
+    y=y*256;y+=buf[2];
+    y=y*256;y+=buf[1];
+    y=y*256;y+=buf[0];
 
-  if(buf[7]&0x80) y=-y;
+    if(buf[7]&0x80) y=-y;
 
-  return y;
+    return y;
 }
 
+int FillBuffer(unsigned char* buffer, int size, bz_stream* stream) {
+    stream->next_out = (char*)buffer;
+    stream->avail_out = size;
+    while (stream->avail_out > 0) {
+        int bzerr = BZ2_bzDecompress(stream);
+        if (bzerr != BZ_OK && bzerr != BZ_STREAM_END) {
+            printf("bz error %d decompressing\n", bzerr);
+            return -1;
+        }
+        if (stream->avail_out > 0) {
+            printf("need %d more bytes\n", stream->avail_out);
+        }
+    }
+    return 0;
+}
 
 int ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size,
-                     const char* patch_filename, ssize_t patch_offset,
+                     const Value* patch, ssize_t patch_offset,
                      SinkFn sink, void* token, SHA_CTX* ctx) {
 
-  unsigned char* new_data;
-  ssize_t new_size;
-  if (ApplyBSDiffPatchMem(old_data, old_size, patch_filename, patch_offset,
-                          &new_data, &new_size) != 0) {
-    return -1;
-  }
+    unsigned char* new_data;
+    ssize_t new_size;
+    if (ApplyBSDiffPatchMem(old_data, old_size, patch, patch_offset,
+                            &new_data, &new_size) != 0) {
+        return -1;
+    }
 
-  if (sink(new_data, new_size, token) < new_size) {
-    fprintf(stderr, "short write of output: %d (%s)\n", errno, strerror(errno));
-    return 1;
-  }
-  if (ctx) {
-    SHA_update(ctx, new_data, new_size);
-  }
-  free(new_data);
+    if (sink(new_data, new_size, token) < new_size) {
+        printf("short write of output: %d (%s)\n", errno, strerror(errno));
+        return 1;
+    }
+    if (ctx) {
+        SHA_update(ctx, new_data, new_size);
+    }
+    free(new_data);
 
-  return 0;
+    return 0;
 }
 
 int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size,
-                        const char* patch_filename, ssize_t patch_offset,
+                        const Value* patch, ssize_t patch_offset,
                         unsigned char** new_data, ssize_t* new_size) {
+    // Patch data format:
+    //   0       8       "BSDIFF40"
+    //   8       8       X
+    //   16      8       Y
+    //   24      8       sizeof(newfile)
+    //   32      X       bzip2(control block)
+    //   32+X    Y       bzip2(diff block)
+    //   32+X+Y  ???     bzip2(extra block)
+    // with control block a set of triples (x,y,z) meaning "add x bytes
+    // from oldfile to x bytes from the diff block; copy y bytes from the
+    // extra block; seek forwards in oldfile by z bytes".
 
-  FILE* f;
-  if ((f = fopen(patch_filename, "rb")) == NULL) {
-    fprintf(stderr, "failed to open patch file\n");
-    return 1;
-  }
-
-  // File format:
-  //   0       8       "BSDIFF40"
-  //   8       8       X
-  //   16      8       Y
-  //   24      8       sizeof(newfile)
-  //   32      X       bzip2(control block)
-  //   32+X    Y       bzip2(diff block)
-  //   32+X+Y  ???     bzip2(extra block)
-  // with control block a set of triples (x,y,z) meaning "add x bytes
-  // from oldfile to x bytes from the diff block; copy y bytes from the
-  // extra block; seek forwards in oldfile by z bytes".
-
-  fseek(f, patch_offset, SEEK_SET);
-
-  unsigned char header[32];
-  if (fread(header, 1, 32, f) < 32) {
-    fprintf(stderr, "failed to read patch file header\n");
-    return 1;
-  }
-
-  if (memcmp(header, "BSDIFF40", 8) != 0) {
-    fprintf(stderr, "corrupt bsdiff patch file header (magic number)\n");
-    return 1;
-  }
-
-  ssize_t ctrl_len, data_len;
-  ctrl_len = offtin(header+8);
-  data_len = offtin(header+16);
-  *new_size = offtin(header+24);
-
-  if (ctrl_len < 0 || data_len < 0 || *new_size < 0) {
-    fprintf(stderr, "corrupt patch file header (data lengths)\n");
-    return 1;
-  }
-
-  fclose(f);
-
-  int bzerr;
-
-#define OPEN_AT(f, bzf, offset)                                          \
-  FILE* f;                                                               \
-  BZFILE* bzf;                                                           \
-  if ((f = fopen(patch_filename, "rb")) == NULL) {                       \
-    fprintf(stderr, "failed to open patch file\n");                      \
-    return 1;                                                            \
-  }                                                                      \
-  if (fseeko(f, offset+patch_offset, SEEK_SET)) {                        \
-    fprintf(stderr, "failed to seek in patch file\n");                   \
-    return 1;                                                            \
-  }                                                                      \
-  if ((bzf = BZ2_bzReadOpen(&bzerr, f, 0, 0, NULL, 0)) == NULL) {        \
-    fprintf(stderr, "failed to bzReadOpen in patch file (%d)\n", bzerr); \
-    return 1;                                                            \
-  }
-
-  OPEN_AT(cpf, cpfbz2, 32);
-  OPEN_AT(dpf, dpfbz2, 32+ctrl_len);
-  OPEN_AT(epf, epfbz2, 32+ctrl_len+data_len);
-
-#undef OPEN_AT
-
-  *new_data = malloc(*new_size);
-  if (*new_data == NULL) {
-    fprintf(stderr, "failed to allocate %d bytes of memory for output file\n",
-            (int)*new_size);
-    return 1;
-  }
-
-  off_t oldpos = 0, newpos = 0;
-  off_t ctrl[3];
-  off_t len_read;
-  int i;
-  unsigned char buf[8];
-  while (newpos < *new_size) {
-    // Read control data
-    for (i = 0; i < 3; ++i) {
-      len_read = BZ2_bzRead(&bzerr, cpfbz2, buf, 8);
-      if (len_read < 8 || !(bzerr == BZ_OK || bzerr == BZ_STREAM_END)) {
-        fprintf(stderr, "corrupt patch (read control)\n");
+    unsigned char* header = (unsigned char*) patch->data + patch_offset;
+    if (memcmp(header, "BSDIFF40", 8) != 0) {
+        printf("corrupt bsdiff patch file header (magic number)\n");
         return 1;
-      }
-      ctrl[i] = offtin(buf);
     }
 
-    // Sanity check
-    if (newpos + ctrl[0] > *new_size) {
-      fprintf(stderr, "corrupt patch (new file overrun)\n");
-      return 1;
+    ssize_t ctrl_len, data_len;
+    ctrl_len = offtin(header+8);
+    data_len = offtin(header+16);
+    *new_size = offtin(header+24);
+
+    if (ctrl_len < 0 || data_len < 0 || *new_size < 0) {
+        printf("corrupt patch file header (data lengths)\n");
+        return 1;
     }
 
-    // Read diff string
-    len_read = BZ2_bzRead(&bzerr, dpfbz2, *new_data + newpos, ctrl[0]);
-    if (len_read < ctrl[0] || !(bzerr == BZ_OK || bzerr == BZ_STREAM_END)) {
-      fprintf(stderr, "corrupt patch (read diff)\n");
-      return 1;
+    int bzerr;
+
+    bz_stream cstream;
+    cstream.next_in = patch->data + patch_offset + 32;
+    cstream.avail_in = ctrl_len;
+    cstream.bzalloc = NULL;
+    cstream.bzfree = NULL;
+    cstream.opaque = NULL;
+    if ((bzerr = BZ2_bzDecompressInit(&cstream, 0, 0)) != BZ_OK) {
+        printf("failed to bzinit control stream (%d)\n", bzerr);
     }
 
-    // Add old data to diff string
-    for (i = 0; i < ctrl[0]; ++i) {
-      if ((oldpos+i >= 0) && (oldpos+i < old_size)) {
-        (*new_data)[newpos+i] += old_data[oldpos+i];
-      }
+    bz_stream dstream;
+    dstream.next_in = patch->data + patch_offset + 32 + ctrl_len;
+    dstream.avail_in = data_len;
+    dstream.bzalloc = NULL;
+    dstream.bzfree = NULL;
+    dstream.opaque = NULL;
+    if ((bzerr = BZ2_bzDecompressInit(&dstream, 0, 0)) != BZ_OK) {
+        printf("failed to bzinit diff stream (%d)\n", bzerr);
     }
 
-    // Adjust pointers
-    newpos += ctrl[0];
-    oldpos += ctrl[0];
-
-    // Sanity check
-    if (newpos + ctrl[1] > *new_size) {
-      fprintf(stderr, "corrupt patch (new file overrun)\n");
-      return 1;
+    bz_stream estream;
+    estream.next_in = patch->data + patch_offset + 32 + ctrl_len + data_len;
+    estream.avail_in = patch->size - (patch_offset + 32 + ctrl_len + data_len);
+    estream.bzalloc = NULL;
+    estream.bzfree = NULL;
+    estream.opaque = NULL;
+    if ((bzerr = BZ2_bzDecompressInit(&estream, 0, 0)) != BZ_OK) {
+        printf("failed to bzinit extra stream (%d)\n", bzerr);
     }
 
-    // Read extra string
-    len_read = BZ2_bzRead(&bzerr, epfbz2, *new_data + newpos, ctrl[1]);
-    if (len_read < ctrl[1] || !(bzerr == BZ_OK || bzerr == BZ_STREAM_END)) {
-      fprintf(stderr, "corrupt patch (read extra)\n");
-      return 1;
+    *new_data = malloc(*new_size);
+    if (*new_data == NULL) {
+        printf("failed to allocate %ld bytes of memory for output file\n",
+               (long)*new_size);
+        return 1;
     }
 
-    // Adjust pointers
-    newpos += ctrl[1];
-    oldpos += ctrl[2];
-  }
+    off_t oldpos = 0, newpos = 0;
+    off_t ctrl[3];
+    off_t len_read;
+    int i;
+    unsigned char buf[24];
+    while (newpos < *new_size) {
+        // Read control data
+        if (FillBuffer(buf, 24, &cstream) != 0) {
+            printf("error while reading control stream\n");
+            return 1;
+        }
+        ctrl[0] = offtin(buf);
+        ctrl[1] = offtin(buf+8);
+        ctrl[2] = offtin(buf+16);
 
-  BZ2_bzReadClose(&bzerr, cpfbz2);
-  BZ2_bzReadClose(&bzerr, dpfbz2);
-  BZ2_bzReadClose(&bzerr, epfbz2);
-  fclose(cpf);
-  fclose(dpf);
-  fclose(epf);
+        // Sanity check
+        if (newpos + ctrl[0] > *new_size) {
+            printf("corrupt patch (new file overrun)\n");
+            return 1;
+        }
 
-  return 0;
+        // Read diff string
+        if (FillBuffer(*new_data + newpos, ctrl[0], &dstream) != 0) {
+            printf("error while reading diff stream\n");
+            return 1;
+        }
+
+        // Add old data to diff string
+        for (i = 0; i < ctrl[0]; ++i) {
+            if ((oldpos+i >= 0) && (oldpos+i < old_size)) {
+                (*new_data)[newpos+i] += old_data[oldpos+i];
+            }
+        }
+
+        // Adjust pointers
+        newpos += ctrl[0];
+        oldpos += ctrl[0];
+
+        // Sanity check
+        if (newpos + ctrl[1] > *new_size) {
+            printf("corrupt patch (new file overrun)\n");
+            return 1;
+        }
+
+        // Read extra string
+        if (FillBuffer(*new_data + newpos, ctrl[1], &estream) != 0) {
+            printf("error while reading extra stream\n");
+            return 1;
+        }
+
+        // Adjust pointers
+        newpos += ctrl[1];
+        oldpos += ctrl[2];
+    }
+
+    BZ2_bzDecompressEnd(&cstream);
+    BZ2_bzDecompressEnd(&dstream);
+    BZ2_bzDecompressEnd(&estream);
+    return 0;
 }
diff --git a/applypatch/imgpatch.c b/applypatch/imgpatch.c
index 5322817..e3ee80a 100644
--- a/applypatch/imgpatch.c
+++ b/applypatch/imgpatch.c
@@ -36,329 +36,184 @@
  * Return 0 on success.
  */
 int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
-                    const char* patch_filename,
+                    const Value* patch,
                     SinkFn sink, void* token, SHA_CTX* ctx) {
-  FILE* f;
-  if ((f = fopen(patch_filename, "rb")) == NULL) {
-    printf("failed to open patch file\n");
-    return -1;
-  }
-
-  unsigned char header[12];
-  if (fread(header, 1, 12, f) != 12) {
-    printf("failed to read patch file header\n");
-    return -1;
-  }
-
-  // IMGDIFF1 uses CHUNK_NORMAL and CHUNK_GZIP.
-  // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
-  if (memcmp(header, "IMGDIFF", 7) != 0 ||
-      (header[7] != '1' && header[7] != '2')) {
-    printf("corrupt patch file header (magic number)\n");
-    return -1;
-  }
-
-  int num_chunks = Read4(header+8);
-
-  int i;
-  for (i = 0; i < num_chunks; ++i) {
-    // each chunk's header record starts with 4 bytes.
-    unsigned char chunk[4];
-    if (fread(chunk, 1, 4, f) != 4) {
-      printf("failed to read chunk %d record\n", i);
-      return -1;
+    ssize_t pos = 12;
+    char* header = patch->data;
+    if (patch->size < 12) {
+        printf("patch too short to contain header\n");
+        return -1;
     }
 
-    int type = Read4(chunk);
-
-    if (type == CHUNK_NORMAL) {
-      unsigned char normal_header[24];
-      if (fread(normal_header, 1, 24, f) != 24) {
-        printf("failed to read chunk %d normal header data\n", i);
+    // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
+    // (IMGDIFF1, which is no longer supported, used CHUNK_NORMAL and
+    // CHUNK_GZIP.)
+    if (memcmp(header, "IMGDIFF2", 8) != 0) {
+        printf("corrupt patch file header (magic number)\n");
         return -1;
-      }
-
-      size_t src_start = Read8(normal_header);
-      size_t src_len = Read8(normal_header+8);
-      size_t patch_offset = Read8(normal_header+16);
-
-      printf("CHUNK %d:  normal   patch offset %d\n", i, patch_offset);
-
-      ApplyBSDiffPatch(old_data + src_start, src_len,
-                       patch_filename, patch_offset,
-                       sink, token, ctx);
-    } else if (type == CHUNK_GZIP) {
-      // This branch is basically a duplicate of the CHUNK_DEFLATE
-      // branch, with a bit of extra processing for the gzip header
-      // and footer.  I've avoided factoring the common code out since
-      // this branch will just be deleted when we drop support for
-      // IMGDIFF1.
-
-      // gzip chunks have an additional 64 + gzip_header_len + 8 bytes
-      // in their chunk header.
-      unsigned char* gzip = malloc(64);
-      if (fread(gzip, 1, 64, f) != 64) {
-        printf("failed to read chunk %d initial gzip header data\n",
-                i);
-        return -1;
-      }
-      size_t gzip_header_len = Read4(gzip+60);
-      gzip = realloc(gzip, 64 + gzip_header_len + 8);
-      if (fread(gzip+64, 1, gzip_header_len+8, f) != gzip_header_len+8) {
-        printf("failed to read chunk %d remaining gzip header data\n",
-                i);
-        return -1;
-      }
-
-      size_t src_start = Read8(gzip);
-      size_t src_len = Read8(gzip+8);
-      size_t patch_offset = Read8(gzip+16);
-
-      size_t expanded_len = Read8(gzip+24);
-      size_t target_len = Read8(gzip+32);
-      int gz_level = Read4(gzip+40);
-      int gz_method = Read4(gzip+44);
-      int gz_windowBits = Read4(gzip+48);
-      int gz_memLevel = Read4(gzip+52);
-      int gz_strategy = Read4(gzip+56);
-
-      printf("CHUNK %d:  gzip     patch offset %d\n", i, patch_offset);
-
-      // Decompress the source data; the chunk header tells us exactly
-      // how big we expect it to be when decompressed.
-
-      unsigned char* expanded_source = malloc(expanded_len);
-      if (expanded_source == NULL) {
-        printf("failed to allocate %d bytes for expanded_source\n",
-                expanded_len);
-        return -1;
-      }
-
-      z_stream strm;
-      strm.zalloc = Z_NULL;
-      strm.zfree = Z_NULL;
-      strm.opaque = Z_NULL;
-      strm.avail_in = src_len - (gzip_header_len + 8);
-      strm.next_in = (unsigned char*)(old_data + src_start + gzip_header_len);
-      strm.avail_out = expanded_len;
-      strm.next_out = expanded_source;
-
-      int ret;
-      ret = inflateInit2(&strm, -15);
-      if (ret != Z_OK) {
-        printf("failed to init source inflation: %d\n", ret);
-        return -1;
-      }
-
-      // Because we've provided enough room to accommodate the output
-      // data, we expect one call to inflate() to suffice.
-      ret = inflate(&strm, Z_SYNC_FLUSH);
-      if (ret != Z_STREAM_END) {
-        printf("source inflation returned %d\n", ret);
-        return -1;
-      }
-      // We should have filled the output buffer exactly.
-      if (strm.avail_out != 0) {
-        printf("source inflation short by %d bytes\n", strm.avail_out);
-        return -1;
-      }
-      inflateEnd(&strm);
-
-      // Next, apply the bsdiff patch (in memory) to the uncompressed
-      // data.
-      unsigned char* uncompressed_target_data;
-      ssize_t uncompressed_target_size;
-      if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
-                              patch_filename, patch_offset,
-                              &uncompressed_target_data,
-                              &uncompressed_target_size) != 0) {
-        return -1;
-      }
-
-      // Now compress the target data and append it to the output.
-
-      // start with the gzip header.
-      sink(gzip+64, gzip_header_len, token);
-      SHA_update(ctx, gzip+64, gzip_header_len);
-
-      // we're done with the expanded_source data buffer, so we'll
-      // reuse that memory to receive the output of deflate.
-      unsigned char* temp_data = expanded_source;
-      ssize_t temp_size = expanded_len;
-      if (temp_size < 32768) {
-        // ... unless the buffer is too small, in which case we'll
-        // allocate a fresh one.
-        free(temp_data);
-        temp_data = malloc(32768);
-        temp_size = 32768;
-      }
-
-      // now the deflate stream
-      strm.zalloc = Z_NULL;
-      strm.zfree = Z_NULL;
-      strm.opaque = Z_NULL;
-      strm.avail_in = uncompressed_target_size;
-      strm.next_in = uncompressed_target_data;
-      ret = deflateInit2(&strm, gz_level, gz_method, gz_windowBits,
-                         gz_memLevel, gz_strategy);
-      do {
-        strm.avail_out = temp_size;
-        strm.next_out = temp_data;
-        ret = deflate(&strm, Z_FINISH);
-        size_t have = temp_size - strm.avail_out;
-
-        if (sink(temp_data, have, token) != have) {
-          printf("failed to write %d compressed bytes to output\n",
-                  have);
-          return -1;
-        }
-        SHA_update(ctx, temp_data, have);
-      } while (ret != Z_STREAM_END);
-      deflateEnd(&strm);
-
-      // lastly, the gzip footer.
-      sink(gzip+64+gzip_header_len, 8, token);
-      SHA_update(ctx, gzip+64+gzip_header_len, 8);
-
-      free(temp_data);
-      free(uncompressed_target_data);
-      free(gzip);
-    } else if (type == CHUNK_RAW) {
-      unsigned char raw_header[4];
-      if (fread(raw_header, 1, 4, f) != 4) {
-        printf("failed to read chunk %d raw header data\n", i);
-        return -1;
-      }
-
-      size_t data_len = Read4(raw_header);
-
-      printf("CHUNK %d:  raw      data %d\n", i, data_len);
-
-      unsigned char* temp = malloc(data_len);
-      if (fread(temp, 1, data_len, f) != data_len) {
-          printf("failed to read chunk %d raw data\n", i);
-          return -1;
-      }
-      SHA_update(ctx, temp, data_len);
-      if (sink(temp, data_len, token) != data_len) {
-          printf("failed to write chunk %d raw data\n", i);
-          return -1;
-      }
-    } else if (type == CHUNK_DEFLATE) {
-      // deflate chunks have an additional 60 bytes in their chunk header.
-      unsigned char deflate_header[60];
-      if (fread(deflate_header, 1, 60, f) != 60) {
-        printf("failed to read chunk %d deflate header data\n", i);
-        return -1;
-      }
-
-      size_t src_start = Read8(deflate_header);
-      size_t src_len = Read8(deflate_header+8);
-      size_t patch_offset = Read8(deflate_header+16);
-      size_t expanded_len = Read8(deflate_header+24);
-      size_t target_len = Read8(deflate_header+32);
-      int level = Read4(deflate_header+40);
-      int method = Read4(deflate_header+44);
-      int windowBits = Read4(deflate_header+48);
-      int memLevel = Read4(deflate_header+52);
-      int strategy = Read4(deflate_header+56);
-
-      printf("CHUNK %d:  deflate  patch offset %d\n", i, patch_offset);
-
-      // Decompress the source data; the chunk header tells us exactly
-      // how big we expect it to be when decompressed.
-
-      unsigned char* expanded_source = malloc(expanded_len);
-      if (expanded_source == NULL) {
-        printf("failed to allocate %d bytes for expanded_source\n",
-                expanded_len);
-        return -1;
-      }
-
-      z_stream strm;
-      strm.zalloc = Z_NULL;
-      strm.zfree = Z_NULL;
-      strm.opaque = Z_NULL;
-      strm.avail_in = src_len;
-      strm.next_in = (unsigned char*)(old_data + src_start);
-      strm.avail_out = expanded_len;
-      strm.next_out = expanded_source;
-
-      int ret;
-      ret = inflateInit2(&strm, -15);
-      if (ret != Z_OK) {
-        printf("failed to init source inflation: %d\n", ret);
-        return -1;
-      }
-
-      // Because we've provided enough room to accommodate the output
-      // data, we expect one call to inflate() to suffice.
-      ret = inflate(&strm, Z_SYNC_FLUSH);
-      if (ret != Z_STREAM_END) {
-        printf("source inflation returned %d\n", ret);
-        return -1;
-      }
-      // We should have filled the output buffer exactly.
-      if (strm.avail_out != 0) {
-        printf("source inflation short by %d bytes\n", strm.avail_out);
-        return -1;
-      }
-      inflateEnd(&strm);
-
-      // Next, apply the bsdiff patch (in memory) to the uncompressed
-      // data.
-      unsigned char* uncompressed_target_data;
-      ssize_t uncompressed_target_size;
-      if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
-                              patch_filename, patch_offset,
-                              &uncompressed_target_data,
-                              &uncompressed_target_size) != 0) {
-        return -1;
-      }
-
-      // Now compress the target data and append it to the output.
-
-      // we're done with the expanded_source data buffer, so we'll
-      // reuse that memory to receive the output of deflate.
-      unsigned char* temp_data = expanded_source;
-      ssize_t temp_size = expanded_len;
-      if (temp_size < 32768) {
-        // ... unless the buffer is too small, in which case we'll
-        // allocate a fresh one.
-        free(temp_data);
-        temp_data = malloc(32768);
-        temp_size = 32768;
-      }
-
-      // now the deflate stream
-      strm.zalloc = Z_NULL;
-      strm.zfree = Z_NULL;
-      strm.opaque = Z_NULL;
-      strm.avail_in = uncompressed_target_size;
-      strm.next_in = uncompressed_target_data;
-      ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
-      do {
-        strm.avail_out = temp_size;
-        strm.next_out = temp_data;
-        ret = deflate(&strm, Z_FINISH);
-        size_t have = temp_size - strm.avail_out;
-
-        if (sink(temp_data, have, token) != have) {
-          printf("failed to write %d compressed bytes to output\n",
-                  have);
-          return -1;
-        }
-        SHA_update(ctx, temp_data, have);
-      } while (ret != Z_STREAM_END);
-      deflateEnd(&strm);
-
-      free(temp_data);
-      free(uncompressed_target_data);
-    } else {
-      printf("patch chunk %d is unknown type %d\n", i, type);
-      return -1;
     }
-  }
 
-  return 0;
+    int num_chunks = Read4(header+8);
+
+    int i;
+    for (i = 0; i < num_chunks; ++i) {
+        // each chunk's header record starts with 4 bytes.
+        if (pos + 4 > patch->size) {
+            printf("failed to read chunk %d record\n", i);
+            return -1;
+        }
+        int type = Read4(patch->data + pos);
+        pos += 4;
+
+        if (type == CHUNK_NORMAL) {
+            char* normal_header = patch->data + pos;
+            pos += 24;
+            if (pos > patch->size) {
+                printf("failed to read chunk %d normal header data\n", i);
+                return -1;
+            }
+
+            size_t src_start = Read8(normal_header);
+            size_t src_len = Read8(normal_header+8);
+            size_t patch_offset = Read8(normal_header+16);
+
+            ApplyBSDiffPatch(old_data + src_start, src_len,
+                             patch, patch_offset, sink, token, ctx);
+        } else if (type == CHUNK_RAW) {
+            char* raw_header = patch->data + pos;
+            pos += 4;
+            if (pos > patch->size) {
+                printf("failed to read chunk %d raw header data\n", i);
+                return -1;
+            }
+
+            ssize_t data_len = Read4(raw_header);
+
+            if (pos + data_len > patch->size) {
+                printf("failed to read chunk %d raw data\n", i);
+                return -1;
+            }
+            SHA_update(ctx, patch->data + pos, data_len);
+            if (sink((unsigned char*)patch->data + pos,
+                     data_len, token) != data_len) {
+                printf("failed to write chunk %d raw data\n", i);
+                return -1;
+            }
+            pos += data_len;
+        } else if (type == CHUNK_DEFLATE) {
+            // deflate chunks have an additional 60 bytes in their chunk header.
+            char* deflate_header = patch->data + pos;
+            pos += 60;
+            if (pos > patch->size) {
+                printf("failed to read chunk %d deflate header data\n", i);
+                return -1;
+            }
+
+            size_t src_start = Read8(deflate_header);
+            size_t src_len = Read8(deflate_header+8);
+            size_t patch_offset = Read8(deflate_header+16);
+            size_t expanded_len = Read8(deflate_header+24);
+            size_t target_len = Read8(deflate_header+32);
+            int level = Read4(deflate_header+40);
+            int method = Read4(deflate_header+44);
+            int windowBits = Read4(deflate_header+48);
+            int memLevel = Read4(deflate_header+52);
+            int strategy = Read4(deflate_header+56);
+
+            // Decompress the source data; the chunk header tells us exactly
+            // how big we expect it to be when decompressed.
+
+            unsigned char* expanded_source = malloc(expanded_len);
+            if (expanded_source == NULL) {
+                printf("failed to allocate %d bytes for expanded_source\n",
+                       expanded_len);
+                return -1;
+            }
+
+            z_stream strm;
+            strm.zalloc = Z_NULL;
+            strm.zfree = Z_NULL;
+            strm.opaque = Z_NULL;
+            strm.avail_in = src_len;
+            strm.next_in = (unsigned char*)(old_data + src_start);
+            strm.avail_out = expanded_len;
+            strm.next_out = expanded_source;
+
+            int ret;
+            ret = inflateInit2(&strm, -15);
+            if (ret != Z_OK) {
+                printf("failed to init source inflation: %d\n", ret);
+                return -1;
+            }
+
+            // Because we've provided enough room to accommodate the output
+            // data, we expect one call to inflate() to suffice.
+            ret = inflate(&strm, Z_SYNC_FLUSH);
+            if (ret != Z_STREAM_END) {
+                printf("source inflation returned %d\n", ret);
+                return -1;
+            }
+            // We should have filled the output buffer exactly.
+            if (strm.avail_out != 0) {
+                printf("source inflation short by %d bytes\n", strm.avail_out);
+                return -1;
+            }
+            inflateEnd(&strm);
+
+            // Next, apply the bsdiff patch (in memory) to the uncompressed
+            // data.
+            unsigned char* uncompressed_target_data;
+            ssize_t uncompressed_target_size;
+            if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
+                                    patch, patch_offset,
+                                    &uncompressed_target_data,
+                                    &uncompressed_target_size) != 0) {
+                return -1;
+            }
+
+            // Now compress the target data and append it to the output.
+
+            // we're done with the expanded_source data buffer, so we'll
+            // reuse that memory to receive the output of deflate.
+            unsigned char* temp_data = expanded_source;
+            ssize_t temp_size = expanded_len;
+            if (temp_size < 32768) {
+                // ... unless the buffer is too small, in which case we'll
+                // allocate a fresh one.
+                free(temp_data);
+                temp_data = malloc(32768);
+                temp_size = 32768;
+            }
+
+            // now the deflate stream
+            strm.zalloc = Z_NULL;
+            strm.zfree = Z_NULL;
+            strm.opaque = Z_NULL;
+            strm.avail_in = uncompressed_target_size;
+            strm.next_in = uncompressed_target_data;
+            ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
+            do {
+                strm.avail_out = temp_size;
+                strm.next_out = temp_data;
+                ret = deflate(&strm, Z_FINISH);
+                ssize_t have = temp_size - strm.avail_out;
+
+                if (sink(temp_data, have, token) != have) {
+                    printf("failed to write %ld compressed bytes to output\n",
+                           (long)have);
+                    return -1;
+                }
+                SHA_update(ctx, temp_data, have);
+            } while (ret != Z_STREAM_END);
+            deflateEnd(&strm);
+
+            free(temp_data);
+            free(uncompressed_target_data);
+        } else {
+            printf("patch chunk %d is unknown type %d\n", i, type);
+            return -1;
+        }
+    }
+
+    return 0;
 }
diff --git a/applypatch/main.c b/applypatch/main.c
index e08f5c1..3917f86 100644
--- a/applypatch/main.c
+++ b/applypatch/main.c
@@ -15,8 +15,126 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
-extern int applypatch(int argc, char** argv);
+#include "applypatch.h"
+#include "edify/expr.h"
+#include "mincrypt/sha.h"
+
+int CheckMode(int argc, char** argv) {
+    if (argc < 3) {
+        return 2;
+    }
+    return applypatch_check(argv[2], argc-3, argv+3);
+}
+
+int SpaceMode(int argc, char** argv) {
+    if (argc != 3) {
+        return 2;
+    }
+    char* endptr;
+    size_t bytes = strtol(argv[2], &endptr, 10);
+    if (bytes == 0 && endptr == argv[2]) {
+        printf("can't parse \"%s\" as byte count\n\n", argv[2]);
+        return 1;
+    }
+    return CacheSizeCheck(bytes);
+}
+
+// Parse arguments (which should be of the form "<sha1>" or
+// "<sha1>:<filename>" into the new parallel arrays *sha1s and
+// *patches (loading file contents into the patches).  Returns 0 on
+// success.
+static int ParsePatchArgs(int argc, char** argv,
+                          char*** sha1s, Value*** patches, int* num_patches) {
+    *num_patches = argc;
+    *sha1s = malloc(*num_patches * sizeof(char*));
+    *patches = malloc(*num_patches * sizeof(Value*));
+    memset(*patches, 0, *num_patches * sizeof(Value*));
+
+    uint8_t digest[SHA_DIGEST_SIZE];
+
+    int i;
+    for (i = 0; i < *num_patches; ++i) {
+        char* colon = strchr(argv[i], ':');
+        if (colon != NULL) {
+            *colon = '\0';
+            ++colon;
+        }
+
+        if (ParseSha1(argv[i], digest) != 0) {
+            printf("failed to parse sha1 \"%s\"\n", argv[i]);
+            return -1;
+        }
+
+        (*sha1s)[i] = argv[i];
+        if (colon == NULL) {
+            (*patches)[i] = NULL;
+        } else {
+            FileContents fc;
+            if (LoadFileContents(colon, &fc) != 0) {
+                goto abort;
+            }
+            (*patches)[i] = malloc(sizeof(Value));
+            (*patches)[i]->type = VAL_BLOB;
+            (*patches)[i]->size = fc.size;
+            (*patches)[i]->data = (char*)fc.data;
+        }
+    }
+
+    return 0;
+
+  abort:
+    for (i = 0; i < *num_patches; ++i) {
+        Value* p = (*patches)[i];
+        if (p != NULL) {
+            free(p->data);
+            free(p);
+        }
+    }
+    free(*sha1s);
+    free(*patches);
+    return -1;
+}
+
+int PatchMode(int argc, char** argv) {
+    if (argc < 6) {
+        return 2;
+    }
+
+    char* endptr;
+    size_t target_size = strtol(argv[4], &endptr, 10);
+    if (target_size == 0 && endptr == argv[4]) {
+        printf("can't parse \"%s\" as byte count\n\n", argv[4]);
+        return 1;
+    }
+
+    char** sha1s;
+    Value** patches;
+    int num_patches;
+    if (ParsePatchArgs(argc-5, argv+5, &sha1s, &patches, &num_patches) != 0) {
+        printf("failed to parse patch args\n");
+        return 1;
+    }
+
+    int result = applypatch(argv[1], argv[2], argv[3], target_size,
+                            num_patches, sha1s, patches);
+
+    int i;
+    for (i = 0; i < num_patches; ++i) {
+        Value* p = patches[i];
+        if (p != NULL) {
+            free(p->data);
+            free(p);
+        }
+    }
+    free(sha1s);
+    free(patches);
+
+    return result;
+}
 
 // This program applies binary patches to files in a way that is safe
 // (the original file is not touched until we have the desired
@@ -42,9 +160,9 @@
 // LoadMTDContents() function above for the format of such a filename.
 
 int main(int argc, char** argv) {
-  int result = applypatch(argc, argv);
-  if (result == 2) {
-    printf(
+    if (argc < 2) {
+      usage:
+        printf(
             "usage: %s <src-file> <tgt-file> <tgt-sha1> <tgt-size> "
             "[<src-sha1>:<patch> ...]\n"
             "   or  %s -c <file> [<sha1> ...]\n"
@@ -55,6 +173,23 @@
             "  MTD:<partition>:<len_1>:<sha1_1>:<len_2>:<sha1_2>:...\n"
             "to specify reading from or writing to an MTD partition.\n\n",
             argv[0], argv[0], argv[0], argv[0]);
-  }
-  return result;
+        return 2;
+    }
+
+    int result;
+
+    if (strncmp(argv[1], "-l", 3) == 0) {
+        result = ShowLicenses();
+    } else if (strncmp(argv[1], "-c", 3) == 0) {
+        result = CheckMode(argc, argv);
+    } else if (strncmp(argv[1], "-s", 3) == 0) {
+        result = SpaceMode(argc, argv);
+    } else {
+        result = PatchMode(argc, argv);
+    }
+
+    if (result == 2) {
+        goto usage;
+    }
+    return result;
 }
diff --git a/applypatch/utils.c b/applypatch/utils.c
index 912229b..41ff676 100644
--- a/applypatch/utils.c
+++ b/applypatch/utils.c
@@ -38,25 +38,28 @@
   fputc((value >> 56) & 0xff, f);
 }
 
-int Read2(unsigned char* p) {
-  return (int)(((unsigned int)p[1] << 8) |
-               (unsigned int)p[0]);
+int Read2(void* pv) {
+    unsigned char* p = pv;
+    return (int)(((unsigned int)p[1] << 8) |
+                 (unsigned int)p[0]);
 }
 
-int Read4(unsigned char* p) {
-  return (int)(((unsigned int)p[3] << 24) |
-               ((unsigned int)p[2] << 16) |
-               ((unsigned int)p[1] << 8) |
-               (unsigned int)p[0]);
+int Read4(void* pv) {
+    unsigned char* p = pv;
+    return (int)(((unsigned int)p[3] << 24) |
+                 ((unsigned int)p[2] << 16) |
+                 ((unsigned int)p[1] << 8) |
+                 (unsigned int)p[0]);
 }
 
-long long Read8(unsigned char* p) {
-  return (long long)(((unsigned long long)p[7] << 56) |
-                     ((unsigned long long)p[6] << 48) |
-                     ((unsigned long long)p[5] << 40) |
-                     ((unsigned long long)p[4] << 32) |
-                     ((unsigned long long)p[3] << 24) |
-                     ((unsigned long long)p[2] << 16) |
-                     ((unsigned long long)p[1] << 8) |
-                     (unsigned long long)p[0]);
+long long Read8(void* pv) {
+    unsigned char* p = pv;
+    return (long long)(((unsigned long long)p[7] << 56) |
+                       ((unsigned long long)p[6] << 48) |
+                       ((unsigned long long)p[5] << 40) |
+                       ((unsigned long long)p[4] << 32) |
+                       ((unsigned long long)p[3] << 24) |
+                       ((unsigned long long)p[2] << 16) |
+                       ((unsigned long long)p[1] << 8) |
+                       (unsigned long long)p[0]);
 }
diff --git a/applypatch/utils.h b/applypatch/utils.h
index d6d6f1d..bc97f17 100644
--- a/applypatch/utils.h
+++ b/applypatch/utils.h
@@ -23,8 +23,8 @@
 
 void Write4(int value, FILE* f);
 void Write8(long long value, FILE* f);
-int Read2(unsigned char* p);
-int Read4(unsigned char* p);
-long long Read8(unsigned char* p);
+int Read2(void* p);
+int Read4(void* p);
+long long Read8(void* p);
 
 #endif //  _BUILD_TOOLS_APPLYPATCH_UTILS_H