Support -i partition:file feature for both read and write.

flash.h

 /*
  * This file is part of the flashrom project.
  *
  * Copyright (C) 2000 Silicon Integrated System Corporation
  * Copyright (C) 2000 Ronald G. Minnich <rminnich@gmail.com>
  * Copyright (C) 2005-2009 coresystems GmbH
  * Copyright (C) 2006-2009 Carl-Daniel Hailfinger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ skipping 236 matching lines @@
 #define msg_cspew(...)  print(MSG_BARF, __VA_ARGS__)    /* chip debug barf  */
 
 /* cli_classic.c */
 int cli_classic(int argc, char *argv[]);
 int cli_mfg(int argc, char *argv[]);
 
 /* layout.c */
 int read_romlayout(char *name);
 int find_romentry(char *name);
 int handle_romentries(struct flashchip *flash, uint8_t *oldcontents, uint8_t *newcontents);
+int handle_partial_read(
+    struct flashchip *flash,
+    uint8_t *buf,
+    int (*read) (struct flashchip *flash, uint8_t *buf, int start, int len));
+    /* RETURN: the number of partitions that have beenpartial read.
+    *         ==0 means no partition is specified.
+    *         < 0 means writing file error. */
 
 /* spi.c */
 struct spi_command {
         unsigned int writecnt;
         unsigned int readcnt;
         const unsigned char *writearr;
         unsigned char *readarr;
 };
 int spi_send_command(unsigned int writecnt, unsigned int readcnt,
                 const unsigned char *writearr, unsigned char *readarr);
 int spi_send_multicommand(struct spi_command *cmds);
 uint32_t spi_get_valid_read_addr(void);
 
 #endif                          /* !__FLASH_H__ */