auto import from //depot/cupcake/@135843
diff --git a/fastboot/protocol.c b/fastboot/protocol.c
new file mode 100644
index 0000000..c788a12
--- /dev/null
+++ b/fastboot/protocol.c
@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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
+ * COPYRIGHT OWNER OR CONTRIBUTORS 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "fastboot.h"
+
+static char ERROR[128];
+
+char *fb_get_error(void)
+{
+ return ERROR;
+}
+
+static int check_response(usb_handle *usb, unsigned size,
+ unsigned data_okay, char *response)
+{
+ unsigned char status[65];
+ int r;
+
+ for(;;) {
+ r = usb_read(usb, status, 64);
+ if(r < 0) {
+ sprintf(ERROR, "status read failed (%s)", strerror(errno));
+ usb_close(usb);
+ return -1;
+ }
+ status[r] = 0;
+
+ if(r < 4) {
+ sprintf(ERROR, "status malformed (%d bytes)", r);
+ usb_close(usb);
+ return -1;
+ }
+
+ if(!memcmp(status, "INFO", 4)) {
+ fprintf(stderr,"%s\n", status);
+ continue;
+ }
+
+ if(!memcmp(status, "OKAY", 4)) {
+ if(response) {
+ strcpy(response, (char*) status + 4);
+ }
+ return 0;
+ }
+
+ if(!memcmp(status, "FAIL", 4)) {
+ if(r > 4) {
+ sprintf(ERROR, "remote: %s", status + 4);
+ } else {
+ strcpy(ERROR, "remote failure");
+ }
+ return -1;
+ }
+
+ if(!memcmp(status, "DATA", 4) && data_okay){
+ unsigned dsize = strtoul((char*) status + 4, 0, 16);
+ if(dsize > size) {
+ strcpy(ERROR, "data size too large");
+ usb_close(usb);
+ return -1;
+ }
+ return dsize;
+ }
+
+ strcpy(ERROR,"unknown status code");
+ usb_close(usb);
+ break;
+ }
+
+ return -1;
+}
+
+static int _command_send(usb_handle *usb, const char *cmd,
+ const void *data, unsigned size,
+ char *response)
+{
+ int cmdsize = strlen(cmd);
+ int r;
+
+ if(response) {
+ response[0] = 0;
+ }
+
+ if(cmdsize > 64) {
+ sprintf(ERROR,"command too large");
+ return -1;
+ }
+
+ if(usb_write(usb, cmd, cmdsize) != cmdsize) {
+ sprintf(ERROR,"command write failed (%s)", strerror(errno));
+ usb_close(usb);
+ return -1;
+ }
+
+ if(data == 0) {
+ return check_response(usb, size, 0, response);
+ }
+
+ r = check_response(usb, size, 1, 0);
+ if(r < 0) {
+ return -1;
+ }
+ size = r;
+
+ if(size) {
+ r = usb_write(usb, data, size);
+ if(r < 0) {
+ sprintf(ERROR, "data transfer failure (%s)", strerror(errno));
+ usb_close(usb);
+ return -1;
+ }
+ if(r != ((int) size)) {
+ sprintf(ERROR, "data transfer failure (short transfer)");
+ usb_close(usb);
+ return -1;
+ }
+ }
+
+ r = check_response(usb, 0, 0, 0);
+ if(r < 0) {
+ return -1;
+ } else {
+ return size;
+ }
+}
+
+int fb_command(usb_handle *usb, const char *cmd)
+{
+ return _command_send(usb, cmd, 0, 0, 0);
+}
+
+int fb_command_response(usb_handle *usb, const char *cmd, char *response)
+{
+ return _command_send(usb, cmd, 0, 0, response);
+}
+
+int fb_download_data(usb_handle *usb, const void *data, unsigned size)
+{
+ char cmd[64];
+ int r;
+
+ sprintf(cmd, "download:%08x", size);
+ r = _command_send(usb, cmd, data, size, 0);
+
+ if(r < 0) {
+ return -1;
+ } else {
+ return 0;
+ }
+}
+