diff --git a/fastboot/engine.c b/fastboot/engine.c
index 8d46991..4045759 100644
--- a/fastboot/engine.c
+++ b/fastboot/engine.c
@@ -76,6 +76,7 @@
 #define OP_NOTICE     4
 #define OP_FORMAT     5
 #define OP_DOWNLOAD_SPARSE 6
+#define OP_COMMAND_IGNORE_FAIL 7
 
 typedef struct Action Action;
 
@@ -374,6 +375,8 @@
 
     // Following piece of code is similar to fb_queue_flash() but executes
     // actions directly without queuing
+    snprintf(cmd, sizeof(cmd), "preflash:%s", partition);
+    fb_command(usb, cmd);  /* Ignore status */
     fprintf(stderr, "sending '%s' (%lli KB)...\n", partition, image.image_size/1024);
     status = fb_download_data(usb, image.buffer, image.image_size);
     if (status) goto cleanup;
@@ -402,6 +405,8 @@
 {
     Action *a;
 
+    a = queue_action(OP_COMMAND_IGNORE_FAIL, "preflash:%s", ptn);
+    a->msg = mkmsg("prep for '%s' (%d KB)", ptn, sz / 1024);
     a = queue_action(OP_DOWNLOAD, "");
     a->data = data;
     a->size = sz;
@@ -415,6 +420,8 @@
 {
     Action *a;
 
+    a = queue_action(OP_COMMAND_IGNORE_FAIL, "preflash:%s", ptn);
+    a->msg = mkmsg("prep for sparse '%s' (%d KB)", ptn, sz / 1024);
     a = queue_action(OP_DOWNLOAD_SPARSE, "");
     a->data = s;
     a->size = 0;
@@ -575,7 +582,9 @@
 
 void fb_queue_download(const char *name, void *data, unsigned size)
 {
-    Action *a = queue_action(OP_DOWNLOAD, "");
+    Action *a;
+    a = queue_action(OP_COMMAND_IGNORE_FAIL, "preflash:");
+    a = queue_action(OP_DOWNLOAD, "");
     a->data = data;
     a->size = size;
     a->msg = mkmsg("downloading '%s'", name);
@@ -614,6 +623,8 @@
             status = fb_command(usb, a->cmd);
             status = a->func(a, status, status ? fb_get_error() : "");
             if (status) break;
+        } else if (a->op == OP_COMMAND_IGNORE_FAIL) {
+            fb_command(usb, a->cmd);   /* Ignore status */
         } else if (a->op == OP_QUERY) {
             status = fb_command_response(usb, a->cmd, resp);
             status = a->func(a, status, status ? fb_get_error() : resp);
diff --git a/fastboot/fastboot_protocol.txt b/fastboot/fastboot_protocol.txt
index 2248992..eede5d1 100644
--- a/fastboot/fastboot_protocol.txt
+++ b/fastboot/fastboot_protocol.txt
@@ -1,5 +1,5 @@
 
-FastBoot  Version  0.4
+FastBoot  Version  0.4++
 ----------------------
 
 The fastboot protocol is a mechanism for communicating with bootloaders
@@ -67,10 +67,6 @@
 Example Session
 ---------------
 
-Host:    "getvar:version"        request version variable
-
-Client:  "OKAY0.4"               return version "0.4"
-
 Host:    "getvar:nonexistant"    request some undefined variable
 
 Client:  "OKAY"                  return value ""
@@ -123,6 +119,11 @@
   "flash:%s"           Write the previously downloaded image to the
                        named partition (if possible).
 
+  "preflash:%s"        Optionally prepare for a download + flash.
+                       E.g. flash directly during download. To deal with a
+                       failed "flash" followed by a "boot", we send
+                       "preflash:".
+
   "erase:%s"           Erase the indicated partition (clear to 0xFFs)
 
   "boot"               The previously downloaded data is a boot.img
@@ -140,7 +141,9 @@
 
   "powerdown"          Power off the device.
 
-
+* Note about sparse files
+  Large files can be split up using libsparse, and sent to the bootloader
+  as repeated chunks of "download:%08x" + "flash:%s".
 
 Client Variables
 ----------------
@@ -151,9 +154,6 @@
 
 The various currently defined names are:
 
-  version             Version of FastBoot protocol supported.
-                      It should be "0.3" for this document.
-
   version-bootloader  Version string for the Bootloader.
 
   version-baseband    Version string of the Baseband Software