diff --git a/tools/applypatch/Android.mk b/tools/applypatch/Android.mk
index 5796cef..bb1519e 100644
--- a/tools/applypatch/Android.mk
+++ b/tools/applypatch/Android.mk
@@ -17,7 +17,7 @@
 LOCAL_PATH := $(call my-dir)
 include $(CLEAR_VARS)
 
-LOCAL_SRC_FILES := applypatch.c bsdiff.c freecache.c imgpatch.c utils.c
+LOCAL_SRC_FILES := applypatch.c bspatch.c freecache.c imgpatch.c utils.c
 LOCAL_MODULE := libapplypatch
 LOCAL_MODULE_TAGS := eng
 LOCAL_C_INCLUDES += external/bzip2 external/zlib bootable/recovery
@@ -47,12 +47,12 @@
 
 include $(CLEAR_VARS)
 
-LOCAL_SRC_FILES := imgdiff.c utils.c
+LOCAL_SRC_FILES := imgdiff.c utils.c bsdiff.c
 LOCAL_MODULE := imgdiff
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_MODULE_TAGS := eng
 LOCAL_C_INCLUDES += external/zlib
-LOCAL_STATIC_LIBRARIES += libz
+LOCAL_STATIC_LIBRARIES += libz libbz
 
 include $(BUILD_HOST_EXECUTABLE)
 
diff --git a/tools/applypatch/bsdiff.c b/tools/applypatch/bsdiff.c
index d5cd617..b6d342b 100644
--- a/tools/applypatch/bsdiff.c
+++ b/tools/applypatch/bsdiff.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 The Android Open Source Project
+ * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,239 +14,397 @@
  * limitations under the License.
  */
 
-// This file is a nearly line-for-line copy of bspatch.c from the
-// bsdiff-4.3 distribution; the primary differences being how the
-// input and output data are read and the error handling.  Running
-// applypatch with the -l option will display the bsdiff license
-// notice.
+/*
+ * Most of this code comes from bsdiff.c from the bsdiff-4.3
+ * distribution, which is:
+ */
 
-#include <stdio.h>
-#include <sys/stat.h>
-#include <errno.h>
-#include <unistd.h>
-#include <string.h>
+/*-
+ * Copyright 2003-2005 Colin Percival
+ * All rights reserved
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted providing that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
 
 #include <bzlib.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
-#include "mincrypt/sha.h"
-#include "applypatch.h"
+#define MIN(x,y) (((x)<(y)) ? (x) : (y))
 
-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"
-       );
-}
-
-static off_t offtin(u_char *buf)
+static void split(off_t *I,off_t *V,off_t start,off_t len,off_t h)
 {
-  off_t y;
+	off_t i,j,k,x,tmp,jj,kk;
 
-  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(len<16) {
+		for(k=start;k<start+len;k+=j) {
+			j=1;x=V[I[k]+h];
+			for(i=1;k+i<start+len;i++) {
+				if(V[I[k+i]+h]<x) {
+					x=V[I[k+i]+h];
+					j=0;
+				};
+				if(V[I[k+i]+h]==x) {
+					tmp=I[k+j];I[k+j]=I[k+i];I[k+i]=tmp;
+					j++;
+				};
+			};
+			for(i=0;i<j;i++) V[I[k+i]]=k+j-1;
+			if(j==1) I[k]=-1;
+		};
+		return;
+	};
 
-  if(buf[7]&0x80) y=-y;
+	x=V[I[start+len/2]+h];
+	jj=0;kk=0;
+	for(i=start;i<start+len;i++) {
+		if(V[I[i]+h]<x) jj++;
+		if(V[I[i]+h]==x) kk++;
+	};
+	jj+=start;kk+=jj;
 
-  return y;
+	i=start;j=0;k=0;
+	while(i<jj) {
+		if(V[I[i]+h]<x) {
+			i++;
+		} else if(V[I[i]+h]==x) {
+			tmp=I[i];I[i]=I[jj+j];I[jj+j]=tmp;
+			j++;
+		} else {
+			tmp=I[i];I[i]=I[kk+k];I[kk+k]=tmp;
+			k++;
+		};
+	};
+
+	while(jj+j<kk) {
+		if(V[I[jj+j]+h]==x) {
+			j++;
+		} else {
+			tmp=I[jj+j];I[jj+j]=I[kk+k];I[kk+k]=tmp;
+			k++;
+		};
+	};
+
+	if(jj>start) split(I,V,start,jj-start,h);
+
+	for(i=0;i<kk-jj;i++) V[I[jj+i]]=kk-1;
+	if(jj==kk-1) I[jj]=-1;
+
+	if(start+len>kk) split(I,V,kk,start+len-kk,h);
 }
 
+static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize)
+{
+	off_t buckets[256];
+	off_t i,h,len;
 
-int ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size,
-                     const char* patch_filename, ssize_t patch_offset,
-                     SinkFn sink, void* token, SHA_CTX* ctx) {
+	for(i=0;i<256;i++) buckets[i]=0;
+	for(i=0;i<oldsize;i++) buckets[old[i]]++;
+	for(i=1;i<256;i++) buckets[i]+=buckets[i-1];
+	for(i=255;i>0;i--) buckets[i]=buckets[i-1];
+	buckets[0]=0;
 
-  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;
-  }
+	for(i=0;i<oldsize;i++) I[++buckets[old[i]]]=i;
+	I[0]=oldsize;
+	for(i=0;i<oldsize;i++) V[i]=buckets[old[i]];
+	V[oldsize]=0;
+	for(i=1;i<256;i++) if(buckets[i]==buckets[i-1]+1) I[buckets[i]]=-1;
+	I[0]=-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);
+	for(h=1;I[0]!=-(oldsize+1);h+=h) {
+		len=0;
+		for(i=0;i<oldsize+1;) {
+			if(I[i]<0) {
+				len-=I[i];
+				i-=I[i];
+			} else {
+				if(len) I[i-len]=-len;
+				len=V[I[i]]+1-i;
+				split(I,V,i,len,h);
+				i+=len;
+				len=0;
+			};
+		};
+		if(len) I[i-len]=-len;
+	};
 
-  return 0;
+	for(i=0;i<oldsize+1;i++) I[V[i]]=i;
 }
 
-int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size,
-                        const char* patch_filename, ssize_t patch_offset,
-                        unsigned char** new_data, ssize_t* new_size) {
+static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize)
+{
+	off_t i;
 
-  FILE* f;
-  if ((f = fopen(patch_filename, "rb")) == NULL) {
-    fprintf(stderr, "failed to open patch file\n");
-    return 1;
-  }
+	for(i=0;(i<oldsize)&&(i<newsize);i++)
+		if(old[i]!=new[i]) break;
 
-  // 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".
+	return i;
+}
 
-  fseek(f, patch_offset, SEEK_SET);
+static off_t search(off_t *I,u_char *old,off_t oldsize,
+		u_char *new,off_t newsize,off_t st,off_t en,off_t *pos)
+{
+	off_t x,y;
 
-  unsigned char header[32];
-  if (fread(header, 1, 32, f) < 32) {
-    fprintf(stderr, "failed to read patch file header\n");
-    return 1;
-  }
+	if(en-st<2) {
+		x=matchlen(old+I[st],oldsize-I[st],new,newsize);
+		y=matchlen(old+I[en],oldsize-I[en],new,newsize);
 
-  if (memcmp(header, "BSDIFF40", 8) != 0) {
-    fprintf(stderr, "corrupt bsdiff patch file header (magic number)\n");
-    return 1;
-  }
+		if(x>y) {
+			*pos=I[st];
+			return x;
+		} else {
+			*pos=I[en];
+			return y;
+		}
+	};
 
-  ssize_t ctrl_len, data_len;
-  ctrl_len = offtin(header+8);
-  data_len = offtin(header+16);
-  *new_size = offtin(header+24);
+	x=st+(en-st)/2;
+	if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) {
+		return search(I,old,oldsize,new,newsize,x,en,pos);
+	} else {
+		return search(I,old,oldsize,new,newsize,st,x,pos);
+	};
+}
 
-  if (ctrl_len < 0 || data_len < 0 || *new_size < 0) {
-    fprintf(stderr, "corrupt patch file header (data lengths)\n");
-    return 1;
-  }
+static void offtout(off_t x,u_char *buf)
+{
+	off_t y;
 
-  fclose(f);
+	if(x<0) y=-x; else y=x;
 
-  int bzerr;
+		buf[0]=y%256;y-=buf[0];
+	y=y/256;buf[1]=y%256;y-=buf[1];
+	y=y/256;buf[2]=y%256;y-=buf[2];
+	y=y/256;buf[3]=y%256;y-=buf[3];
+	y=y/256;buf[4]=y%256;y-=buf[4];
+	y=y/256;buf[5]=y%256;y-=buf[5];
+	y=y/256;buf[6]=y%256;y-=buf[6];
+	y=y/256;buf[7]=y%256;
 
-#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;                                                            \
-  }
+	if(x<0) buf[7]|=0x80;
+}
 
-  OPEN_AT(cpf, cpfbz2, 32);
-  OPEN_AT(dpf, dpfbz2, 32+ctrl_len);
-  OPEN_AT(epf, epfbz2, 32+ctrl_len+data_len);
+// This is main() from bsdiff.c, with the following changes:
+//
+//    - old, oldsize, new, newsize are arguments; we don't load this
+//      data from files.  old and new are owned by the caller; we
+//      don't free them at the end.
+//
+//    - the "I" block of memory is owned by the caller, who passes a
+//      pointer to *I, which can be NULL.  This way if we call
+//      bsdiff() multiple times with the same 'old' data, we only do
+//      the qsufsort() step the first time.
+//
+int bsdiff(u_char* old, off_t oldsize, off_t** IP, u_char* new, off_t newsize,
+           const char* patch_filename)
+{
+	int fd;
+	off_t *I;
+	off_t scan,pos,len;
+	off_t lastscan,lastpos,lastoffset;
+	off_t oldscore,scsc;
+	off_t s,Sf,lenf,Sb,lenb;
+	off_t overlap,Ss,lens;
+	off_t i;
+	off_t dblen,eblen;
+	u_char *db,*eb;
+	u_char buf[8];
+	u_char header[32];
+	FILE * pf;
+	BZFILE * pfbz2;
+	int bz2err;
 
-#undef OPEN_AT
+        if (*IP == NULL) {
+            off_t* V;
+            *IP = malloc((oldsize+1) * sizeof(off_t));
+            V = malloc((oldsize+1) * sizeof(off_t));
+            qsufsort(*IP, V, old, oldsize);
+            free(V);
+        }
+        I = *IP;
 
-  *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;
-  }
+	if(((db=malloc(newsize+1))==NULL) ||
+		((eb=malloc(newsize+1))==NULL)) err(1,NULL);
+	dblen=0;
+	eblen=0;
 
-  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");
-        return 1;
-      }
-      ctrl[i] = offtin(buf);
-    }
+	/* Create the patch file */
+	if ((pf = fopen(patch_filename, "w")) == NULL)
+              err(1, "%s", patch_filename);
 
-    // Sanity check
-    if (newpos + ctrl[0] > *new_size) {
-      fprintf(stderr, "corrupt patch (new file overrun)\n");
-      return 1;
-    }
+	/* Header is
+		0	8	 "BSDIFF40"
+		8	8	length of bzip2ed ctrl block
+		16	8	length of bzip2ed diff block
+		24	8	length of new file */
+	/* File is
+		0	32	Header
+		32	??	Bzip2ed ctrl block
+		??	??	Bzip2ed diff block
+		??	??	Bzip2ed extra block */
+	memcpy(header,"BSDIFF40",8);
+	offtout(0, header + 8);
+	offtout(0, header + 16);
+	offtout(newsize, header + 24);
+	if (fwrite(header, 32, 1, pf) != 1)
+		err(1, "fwrite(%s)", patch_filename);
 
-    // 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;
-    }
+	/* Compute the differences, writing ctrl as we go */
+	if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
+		errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
+	scan=0;len=0;
+	lastscan=0;lastpos=0;lastoffset=0;
+	while(scan<newsize) {
+		oldscore=0;
 
-    // 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];
-      }
-    }
+		for(scsc=scan+=len;scan<newsize;scan++) {
+			len=search(I,old,oldsize,new+scan,newsize-scan,
+					0,oldsize,&pos);
 
-    // Adjust pointers
-    newpos += ctrl[0];
-    oldpos += ctrl[0];
+			for(;scsc<scan+len;scsc++)
+			if((scsc+lastoffset<oldsize) &&
+				(old[scsc+lastoffset] == new[scsc]))
+				oldscore++;
 
-    // Sanity check
-    if (newpos + ctrl[1] > *new_size) {
-      fprintf(stderr, "corrupt patch (new file overrun)\n");
-      return 1;
-    }
+			if(((len==oldscore) && (len!=0)) ||
+				(len>oldscore+8)) break;
 
-    // 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;
-    }
+			if((scan+lastoffset<oldsize) &&
+				(old[scan+lastoffset] == new[scan]))
+				oldscore--;
+		};
 
-    // Adjust pointers
-    newpos += ctrl[1];
-    oldpos += ctrl[2];
-  }
+		if((len!=oldscore) || (scan==newsize)) {
+			s=0;Sf=0;lenf=0;
+			for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) {
+				if(old[lastpos+i]==new[lastscan+i]) s++;
+				i++;
+				if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; };
+			};
 
-  BZ2_bzReadClose(&bzerr, cpfbz2);
-  BZ2_bzReadClose(&bzerr, dpfbz2);
-  BZ2_bzReadClose(&bzerr, epfbz2);
-  fclose(cpf);
-  fclose(dpf);
-  fclose(epf);
+			lenb=0;
+			if(scan<newsize) {
+				s=0;Sb=0;
+				for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) {
+					if(old[pos-i]==new[scan-i]) s++;
+					if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; };
+				};
+			};
 
-  return 0;
+			if(lastscan+lenf>scan-lenb) {
+				overlap=(lastscan+lenf)-(scan-lenb);
+				s=0;Ss=0;lens=0;
+				for(i=0;i<overlap;i++) {
+					if(new[lastscan+lenf-overlap+i]==
+					   old[lastpos+lenf-overlap+i]) s++;
+					if(new[scan-lenb+i]==
+					   old[pos-lenb+i]) s--;
+					if(s>Ss) { Ss=s; lens=i+1; };
+				};
+
+				lenf+=lens-overlap;
+				lenb-=lens;
+			};
+
+			for(i=0;i<lenf;i++)
+				db[dblen+i]=new[lastscan+i]-old[lastpos+i];
+			for(i=0;i<(scan-lenb)-(lastscan+lenf);i++)
+				eb[eblen+i]=new[lastscan+lenf+i];
+
+			dblen+=lenf;
+			eblen+=(scan-lenb)-(lastscan+lenf);
+
+			offtout(lenf,buf);
+			BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
+			if (bz2err != BZ_OK)
+				errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
+
+			offtout((scan-lenb)-(lastscan+lenf),buf);
+			BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
+			if (bz2err != BZ_OK)
+				errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
+
+			offtout((pos-lenb)-(lastpos+lenf),buf);
+			BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
+			if (bz2err != BZ_OK)
+				errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
+
+			lastscan=scan-lenb;
+			lastpos=pos-lenb;
+			lastoffset=pos-scan;
+		};
+	};
+	BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
+	if (bz2err != BZ_OK)
+		errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
+
+	/* Compute size of compressed ctrl data */
+	if ((len = ftello(pf)) == -1)
+		err(1, "ftello");
+	offtout(len-32, header + 8);
+
+	/* Write compressed diff data */
+	if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
+		errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
+	BZ2_bzWrite(&bz2err, pfbz2, db, dblen);
+	if (bz2err != BZ_OK)
+		errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
+	BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
+	if (bz2err != BZ_OK)
+		errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
+
+	/* Compute size of compressed diff data */
+	if ((newsize = ftello(pf)) == -1)
+		err(1, "ftello");
+	offtout(newsize - len, header + 16);
+
+	/* Write compressed extra data */
+	if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
+		errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
+	BZ2_bzWrite(&bz2err, pfbz2, eb, eblen);
+	if (bz2err != BZ_OK)
+		errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
+	BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
+	if (bz2err != BZ_OK)
+		errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
+
+	/* Seek to the beginning, write the header, and close the file */
+	if (fseeko(pf, 0, SEEK_SET))
+		err(1, "fseeko");
+	if (fwrite(header, 32, 1, pf) != 1)
+		err(1, "fwrite(%s)", patch_filename);
+	if (fclose(pf))
+		err(1, "fclose");
+
+	/* Free the memory we used */
+	free(db);
+	free(eb);
+
+	return 0;
 }
diff --git a/tools/applypatch/bspatch.c b/tools/applypatch/bspatch.c
new file mode 100644
index 0000000..d5cd617
--- /dev/null
+++ b/tools/applypatch/bspatch.c
@@ -0,0 +1,252 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// This file is a nearly line-for-line copy of bspatch.c from the
+// bsdiff-4.3 distribution; the primary differences being how the
+// input and output data are read and the error handling.  Running
+// applypatch with the -l option will display the bsdiff license
+// notice.
+
+#include <stdio.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <bzlib.h>
+
+#include "mincrypt/sha.h"
+#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"
+       );
+}
+
+static off_t offtin(u_char *buf)
+{
+  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];
+
+  if(buf[7]&0x80) y=-y;
+
+  return y;
+}
+
+
+int ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size,
+                     const char* patch_filename, 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;
+  }
+
+  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);
+
+  return 0;
+}
+
+int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size,
+                        const char* patch_filename, ssize_t patch_offset,
+                        unsigned char** new_data, ssize_t* new_size) {
+
+  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");
+        return 1;
+      }
+      ctrl[i] = offtin(buf);
+    }
+
+    // Sanity check
+    if (newpos + ctrl[0] > *new_size) {
+      fprintf(stderr, "corrupt patch (new file overrun)\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;
+    }
+
+    // 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) {
+      fprintf(stderr, "corrupt patch (new file overrun)\n");
+      return 1;
+    }
+
+    // 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;
+    }
+
+    // Adjust pointers
+    newpos += ctrl[1];
+    oldpos += ctrl[2];
+  }
+
+  BZ2_bzReadClose(&bzerr, cpfbz2);
+  BZ2_bzReadClose(&bzerr, dpfbz2);
+  BZ2_bzReadClose(&bzerr, epfbz2);
+  fclose(cpf);
+  fclose(dpf);
+  fclose(epf);
+
+  return 0;
+}
diff --git a/tools/applypatch/imgdiff.c b/tools/applypatch/imgdiff.c
index 5386d9b..38e3c83 100644
--- a/tools/applypatch/imgdiff.c
+++ b/tools/applypatch/imgdiff.c
@@ -134,6 +134,8 @@
   size_t source_start;
   size_t source_len;
 
+  off_t* I;             // used by bsdiff
+
   // --- for CHUNK_DEFLATE chunks only: ---
 
   // original (compressed) deflate data
@@ -167,6 +169,10 @@
   }
 }
 
+// from bsdiff.c
+int bsdiff(u_char* old, off_t oldsize, off_t** IP, u_char* new, off_t newsize,
+           const char* patch_filename);
+
 unsigned char* ReadZip(const char* filename,
                        int* num_chunks, ImageChunk** chunks,
                        int include_pseudo_chunk) {
@@ -278,6 +284,7 @@
     curr->len = st.st_size;
     curr->data = img;
     curr->filename = NULL;
+    curr->I = NULL;
     ++curr;
     ++*num_chunks;
   }
@@ -292,6 +299,7 @@
       curr->deflate_len = temp_entries[nextentry].deflate_len;
       curr->deflate_data = img + pos;
       curr->filename = temp_entries[nextentry].filename;
+      curr->I = NULL;
 
       curr->len = temp_entries[nextentry].uncomp_len;
       curr->data = malloc(curr->len);
@@ -336,6 +344,7 @@
     }
     curr->data = img + pos;
     curr->filename = NULL;
+    curr->I = NULL;
     pos += curr->len;
 
     ++*num_chunks;
@@ -400,6 +409,7 @@
       curr->type = CHUNK_NORMAL;
       curr->len = GZIP_HEADER_LEN;
       curr->data = p;
+      curr->I = NULL;
 
       pos += curr->len;
       p += curr->len;
@@ -407,6 +417,7 @@
 
       curr->type = CHUNK_DEFLATE;
       curr->filename = NULL;
+      curr->I = NULL;
 
       // We must decompress this chunk in order to discover where it
       // ends, and so we can put the uncompressed data and its length
@@ -452,6 +463,7 @@
       curr->start = pos;
       curr->len = GZIP_FOOTER_LEN;
       curr->data = img+pos;
+      curr->I = NULL;
 
       pos += curr->len;
       p += curr->len;
@@ -475,6 +487,7 @@
       *chunks = realloc(*chunks, *num_chunks * sizeof(ImageChunk));
       ImageChunk* curr = *chunks + (*num_chunks-1);
       curr->start = pos;
+      curr->I = NULL;
 
       // 'pos' is not the offset of the start of a gzip chunk, so scan
       // forward until we find a gzip header.
@@ -591,43 +604,12 @@
     }
   }
 
-  char stemp[] = "/tmp/imgdiff-src-XXXXXX";
-  char ttemp[] = "/tmp/imgdiff-tgt-XXXXXX";
   char ptemp[] = "/tmp/imgdiff-patch-XXXXXX";
-  mkstemp(stemp);
-  mkstemp(ttemp);
   mkstemp(ptemp);
 
-  FILE* f = fopen(stemp, "wb");
-  if (f == NULL) {
-    fprintf(stderr, "failed to open src chunk %s: %s\n",
-            stemp, strerror(errno));
-    return NULL;
-  }
-  if (fwrite(src->data, 1, src->len, f) != src->len) {
-    fprintf(stderr, "failed to write src chunk to %s: %s\n",
-            stemp, strerror(errno));
-    return NULL;
-  }
-  fclose(f);
-
-  f = fopen(ttemp, "wb");
-  if (f == NULL) {
-    fprintf(stderr, "failed to open tgt chunk %s: %s\n",
-            ttemp, strerror(errno));
-    return NULL;
-  }
-  if (fwrite(tgt->data, 1, tgt->len, f) != tgt->len) {
-    fprintf(stderr, "failed to write tgt chunk to %s: %s\n",
-            ttemp, strerror(errno));
-    return NULL;
-  }
-  fclose(f);
-
-  char cmd[200];
-  sprintf(cmd, "bsdiff %s %s %s", stemp, ttemp, ptemp);
-  if (system(cmd) != 0) {
-    fprintf(stderr, "failed to run bsdiff: %s\n", strerror(errno));
+  int r = bsdiff(src->data, src->len, &(src->I), tgt->data, tgt->len, ptemp);
+  if (r != 0) {
+    fprintf(stderr, "bsdiff() failed: %d\n", r);
     return NULL;
   }
 
@@ -641,8 +623,6 @@
   unsigned char* data = malloc(st.st_size);
 
   if (tgt->type == CHUNK_NORMAL && tgt->len <= st.st_size) {
-    unlink(stemp);
-    unlink(ttemp);
     unlink(ptemp);
 
     tgt->type = CHUNK_RAW;
@@ -652,7 +632,7 @@
 
   *size = st.st_size;
 
-  f = fopen(ptemp, "rb");
+  FILE* f = fopen(ptemp, "rb");
   if (f == NULL) {
     fprintf(stderr, "failed to open patch %s: %s\n", ptemp, strerror(errno));
     return NULL;
@@ -663,8 +643,6 @@
   }
   fclose(f);
 
-  unlink(stemp);
-  unlink(ttemp);
   unlink(ptemp);
 
   tgt->source_start = src->start;