fastboot/engine.c - platform/system/core - Gitiles

 /*
  * 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 "fastboot.h"
 #include "make_ext4fs.h"

 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <stdbool.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>

 #ifdef USE_MINGW
 #include <fcntl.h>
 #else
 #include <sys/mman.h>
 #endif

 #define ARRAY_SIZE(x)           (sizeof(x)/sizeof(x[0]))

 double now()
 {
     struct timeval tv;
     gettimeofday(&tv, NULL);
     return (double)tv.tv_sec + (double)tv.tv_usec / 1000000;
 }

 char *mkmsg(const char *fmt, ...)
 {
     char buf[256];
     char *s;
     va_list ap;

     va_start(ap, fmt);
     vsprintf(buf, fmt, ap);
     va_end(ap);

     s = strdup(buf);
     if (s == 0) die("out of memory");
     return s;
 }

 #define OP_DOWNLOAD   1
 #define OP_COMMAND    2
 #define OP_QUERY      3
 #define OP_NOTICE     4
 #define OP_FORMAT     5
 #define OP_DOWNLOAD_SPARSE 6

 typedef struct Action Action;

 #define CMD_SIZE 64

 struct Action
 {
     unsigned op;
     Action *next;

     char cmd[CMD_SIZE];
     const char *prod;
     void *data;
     unsigned size;

     const char *msg;
     int (*func)(Action *a, int status, char *resp);

     double start;
 };

 static Action *action_list = 0;
 static Action *action_last = 0;


 struct image_data {
     long long partition_size;
     long long image_size; // real size of image file
     void *buffer;
 };

 void generate_ext4_image(struct image_data *image);
 void cleanup_image(struct image_data *image);

 int fb_getvar(struct usb_handle *usb, char *response, const char *fmt, ...)
 {
     char cmd[CMD_SIZE] = "getvar:";
     int getvar_len = strlen(cmd);
     va_list args;

     response[FB_RESPONSE_SZ] = '\0';
     va_start(args, fmt);
     vsnprintf(cmd + getvar_len, sizeof(cmd) - getvar_len, fmt, args);
     va_end(args);
     cmd[CMD_SIZE - 1] = '\0';
     return fb_command_response(usb, cmd, response);
 }

 struct generator {
     char *fs_type;

     /* generate image and return it as image->buffer.
      * size of the buffer returned as image->image_size.
      *
      * image->partition_size specifies what is the size of the
      * file partition we generate image for.
      */
     void (*generate)(struct image_data *image);

     /* it cleans the buffer allocated during image creation.
      * this function probably does free() or munmap().
      */
     void (*cleanup)(struct image_data *image);
 } generators[] = {
     { "ext4", generate_ext4_image, cleanup_image }
 };

 /* Return true if this partition is supported by the fastboot format command.
  * It is also used to determine if we should first erase a partition before
  * flashing it with an ext4 filesystem.  See needs_erase()
  *
  * Not all devices report the filesystem type, so don't report any errors,
  * just return false.
  */
 int fb_format_supported(usb_handle *usb, const char *partition)
 {
     char response[FB_RESPONSE_SZ+1];
     struct generator *generator = NULL;
     int status;
     unsigned int i;

     status = fb_getvar(usb, response, "partition-type:%s", partition);
     if (status) {
         return 0;
     }

     for (i = 0; i < ARRAY_SIZE(generators); i++) {
         if (!strncmp(generators[i].fs_type, response, FB_RESPONSE_SZ)) {
             generator = &generators[i];
             break;
         }
     }

     if (generator) {
         return 1;
     }

     return 0;
 }

 static int cb_default(Action *a, int status, char *resp)
 {
     if (status) {
         fprintf(stderr,"FAILED (%s)\n", resp);
     } else {
         double split = now();
         fprintf(stderr,"OKAY [%7.3fs]\n", (split - a->start));
         a->start = split;
     }
     return status;
 }

 static Action *queue_action(unsigned op, const char *fmt, ...)
 {
     Action *a;
     va_list ap;
     size_t cmdsize;

     a = calloc(1, sizeof(Action));
     if (a == 0) die("out of memory");

     va_start(ap, fmt);
     cmdsize = vsnprintf(a->cmd, sizeof(a->cmd), fmt, ap);
     va_end(ap);

     if (cmdsize >= sizeof(a->cmd)) {
         free(a);
         die("Command length (%d) exceeds maximum size (%d)", cmdsize, sizeof(a->cmd));
     }

     if (action_last) {
         action_last->next = a;
     } else {
         action_list = a;
     }
     action_last = a;
     a->op = op;
     a->func = cb_default;

     a->start = -1;

     return a;
 }

 void fb_queue_erase(const char *ptn)
 {
     Action *a;
     a = queue_action(OP_COMMAND, "erase:%s", ptn);
     a->msg = mkmsg("erasing '%s'", ptn);
 }

 /* Loads file content into buffer. Returns NULL on error. */
 static void *load_buffer(int fd, off_t size)
 {
     void *buffer;

 #ifdef USE_MINGW
     ssize_t count = 0;

     // mmap is more efficient but mingw does not support it.
     // In this case we read whole image into memory buffer.
     buffer = malloc(size);
     if (!buffer) {
         perror("malloc");
         return NULL;
     }

     lseek(fd, 0, SEEK_SET);
     while(count < size) {
         ssize_t actually_read = read(fd, (char*)buffer+count, size-count);

         if (actually_read == 0) {
             break;
         }
         if (actually_read < 0) {
             if (errno == EINTR) {
                 continue;
             }
             perror("read");
             free(buffer);
             return NULL;
         }

         count += actually_read;
     }
 #else
     buffer = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
     if (buffer == MAP_FAILED) {
         perror("mmap");
         return NULL;
     }
 #endif

     return buffer;
 }

 void cleanup_image(struct image_data *image)
 {
 #ifdef USE_MINGW
     free(image->buffer);
 #else
     munmap(image->buffer, image->image_size);
 #endif
 }

 void generate_ext4_image(struct image_data *image)
 {
     int fd;
     struct stat st;

     fd = fileno(tmpfile());
     make_ext4fs_sparse_fd(fd, image->partition_size, NULL, NULL);

     fstat(fd, &st);
     image->image_size = st.st_size;
     image->buffer = load_buffer(fd, st.st_size);

     close(fd);
 }

 int fb_format(Action *a, usb_handle *usb, int skip_if_not_supported)
 {
     const char *partition = a->cmd;
     char response[FB_RESPONSE_SZ+1];
     int status = 0;
     struct image_data image;
     struct generator *generator = NULL;
     int fd;
     unsigned i;
     char cmd[CMD_SIZE];

     status = fb_getvar(usb, response, "partition-type:%s", partition);
     if (status) {
         if (skip_if_not_supported) {
             fprintf(stderr,
                     "Erase successful, but not automatically formatting.\n");
             fprintf(stderr,
                     "Can't determine partition type.\n");
             return 0;
         }
         fprintf(stderr,"FAILED (%s)\n", fb_get_error());
         return status;
     }

     for (i = 0; i < ARRAY_SIZE(generators); i++) {
         if (!strncmp(generators[i].fs_type, response, FB_RESPONSE_SZ)) {
             generator = &generators[i];
             break;
         }
     }
     if (!generator) {
         if (skip_if_not_supported) {
             fprintf(stderr,
                     "Erase successful, but not automatically formatting.\n");
             fprintf(stderr,
                     "File system type %s not supported.\n", response);
             return 0;
         }
         fprintf(stderr,"Formatting is not supported for filesystem with type '%s'.\n",
                 response);
         return -1;
     }

     status = fb_getvar(usb, response, "partition-size:%s", partition);
     if (status) {
         if (skip_if_not_supported) {
             fprintf(stderr,
                     "Erase successful, but not automatically formatting.\n");
             fprintf(stderr, "Unable to get partition size\n.");
             return 0;
         }
         fprintf(stderr,"FAILED (%s)\n", fb_get_error());
         return status;
     }
     image.partition_size = strtoll(response, (char **)NULL, 16);

     generator->generate(&image);
     if (!image.buffer) {
         fprintf(stderr,"Cannot generate image.\n");
         return -1;
     }

     // Following piece of code is similar to fb_queue_flash() but executes
     // actions directly without queuing
     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;

     fprintf(stderr, "writing '%s'...\n", partition);
     snprintf(cmd, sizeof(cmd), "flash:%s", partition);
     status = fb_command(usb, cmd);
     if (status) goto cleanup;

 cleanup:
     generator->cleanup(&image);

     return status;
 }

 void fb_queue_format(const char *partition, int skip_if_not_supported)
 {
     Action *a;

     a = queue_action(OP_FORMAT, partition);
     a->data = (void*)skip_if_not_supported;
     a->msg = mkmsg("formatting '%s' partition", partition);
 }

 void fb_queue_flash(const char *ptn, void *data, unsigned sz)
 {
     Action *a;

     a = queue_action(OP_DOWNLOAD, "");
     a->data = data;
     a->size = sz;
     a->msg = mkmsg("sending '%s' (%d KB)", ptn, sz / 1024);

     a = queue_action(OP_COMMAND, "flash:%s", ptn);
     a->msg = mkmsg("writing '%s'", ptn);
 }

 void fb_queue_flash_sparse(const char *ptn, struct sparse_file *s, unsigned sz)
 {
     Action *a;

     a = queue_action(OP_DOWNLOAD_SPARSE, "");
     a->data = s;
     a->size = 0;
     a->msg = mkmsg("sending sparse '%s' (%d KB)", ptn, sz / 1024);

     a = queue_action(OP_COMMAND, "flash:%s", ptn);
     a->msg = mkmsg("writing '%s'", ptn);
 }

 static int match(char *str, const char **value, unsigned count)
 {
     const char *val;
     unsigned n;
     int len;

     for (n = 0; n < count; n++) {
         const char *val = value[n];
         int len = strlen(val);
         int match;

         if ((len > 1) && (val[len-1] == '*')) {
             len--;
             match = !strncmp(val, str, len);
         } else {
             match = !strcmp(val, str);
         }

         if (match) return 1;
     }

     return 0;
 }


 static int cb_check(Action *a, int status, char *resp, int invert)
 {
     const char **value = a->data;
     unsigned count = a->size;
     unsigned n;
     int yes;

     if (status) {
         fprintf(stderr,"FAILED (%s)\n", resp);
         return status;
     }

     if (a->prod) {
         if (strcmp(a->prod, cur_product) != 0) {
             double split = now();
             fprintf(stderr,"IGNORE, product is %s required only for %s [%7.3fs]\n",
                     cur_product, a->prod, (split - a->start));
             a->start = split;
             return 0;
         }
     }

     yes = match(resp, value, count);
     if (invert) yes = !yes;

     if (yes) {
         double split = now();
         fprintf(stderr,"OKAY [%7.3fs]\n", (split - a->start));
         a->start = split;
         return 0;
     }

     fprintf(stderr,"FAILED\n\n");
     fprintf(stderr,"Device %s is '%s'.\n", a->cmd + 7, resp);
     fprintf(stderr,"Update %s '%s'",
             invert ? "rejects" : "requires", value[0]);
     for (n = 1; n < count; n++) {
         fprintf(stderr," or '%s'", value[n]);
     }
     fprintf(stderr,".\n\n");
     return -1;
 }

 static int cb_require(Action *a, int status, char *resp)
 {
     return cb_check(a, status, resp, 0);
 }

 static int cb_reject(Action *a, int status, char *resp)
 {
     return cb_check(a, status, resp, 1);
 }

 void fb_queue_require(const char *prod, const char *var,
 		int invert, unsigned nvalues, const char **value)
 {
     Action *a;
     a = queue_action(OP_QUERY, "getvar:%s", var);
     a->prod = prod;
     a->data = value;
     a->size = nvalues;
     a->msg = mkmsg("checking %s", var);
     a->func = invert ? cb_reject : cb_require;
     if (a->data == 0) die("out of memory");
 }

 static int cb_display(Action *a, int status, char *resp)
 {
     if (status) {
         fprintf(stderr, "%s FAILED (%s)\n", a->cmd, resp);
         return status;
     }
     fprintf(stderr, "%s: %s\n", (char*) a->data, resp);
     return 0;
 }

 void fb_queue_display(const char *var, const char *prettyname)
 {
     Action *a;
     a = queue_action(OP_QUERY, "getvar:%s", var);
     a->data = strdup(prettyname);
     if (a->data == 0) die("out of memory");
     a->func = cb_display;
 }

 static int cb_save(Action *a, int status, char *resp)
 {
     if (status) {
         fprintf(stderr, "%s FAILED (%s)\n", a->cmd, resp);
         return status;
     }
     strncpy(a->data, resp, a->size);
     return 0;
 }

 void fb_queue_query_save(const char *var, char *dest, unsigned dest_size)
 {
     Action *a;
     a = queue_action(OP_QUERY, "getvar:%s", var);
     a->data = (void *)dest;
     a->size = dest_size;
     a->func = cb_save;
 }

 static int cb_do_nothing(Action *a, int status, char *resp)
 {
     fprintf(stderr,"\n");
     return 0;
 }

 void fb_queue_reboot(void)
 {
     Action *a = queue_action(OP_COMMAND, "reboot");
     a->func = cb_do_nothing;
     a->msg = "rebooting";
 }

 void fb_queue_command(const char *cmd, const char *msg)
 {
     Action *a = queue_action(OP_COMMAND, cmd);
     a->msg = msg;
 }

 void fb_queue_download(const char *name, void *data, unsigned size)
 {
     Action *a = queue_action(OP_DOWNLOAD, "");
     a->data = data;
     a->size = size;
     a->msg = mkmsg("downloading '%s'", name);
 }

 void fb_queue_notice(const char *notice)
 {
     Action *a = queue_action(OP_NOTICE, "");
     a->data = (void*) notice;
 }

 int fb_execute_queue(usb_handle *usb)
 {
     Action *a;
     char resp[FB_RESPONSE_SZ+1];
     int status = 0;

     a = action_list;
     if (!a)
         return status;
     resp[FB_RESPONSE_SZ] = 0;

     double start = -1;
     for (a = action_list; a; a = a->next) {
         a->start = now();
         if (start < 0) start = a->start;
         if (a->msg) {
             // fprintf(stderr,"%30s... ",a->msg);
             fprintf(stderr,"%s...\n",a->msg);
         }
         if (a->op == OP_DOWNLOAD) {
             status = fb_download_data(usb, a->data, a->size);
             status = a->func(a, status, status ? fb_get_error() : "");
             if (status) break;
         } else if (a->op == OP_COMMAND) {
             status = fb_command(usb, a->cmd);
             status = a->func(a, status, status ? fb_get_error() : "");
             if (status) break;
         } else if (a->op == OP_QUERY) {
             status = fb_command_response(usb, a->cmd, resp);
             status = a->func(a, status, status ? fb_get_error() : resp);
             if (status) break;
         } else if (a->op == OP_NOTICE) {
             fprintf(stderr,"%s\n",(char*)a->data);
         } else if (a->op == OP_FORMAT) {
             status = fb_format(a, usb, (int)a->data);
             status = a->func(a, status, status ? fb_get_error() : "");
             if (status) break;
         } else if (a->op == OP_DOWNLOAD_SPARSE) {
             status = fb_download_data_sparse(usb, a->data);
             status = a->func(a, status, status ? fb_get_error() : "");
             if (status) break;
         } else {
             die("bogus action");
         }
     }

     fprintf(stderr,"finished. total time: %.3fs\n", (now() - start));
     return status;
 }

 int fb_queue_is_empty(void)
 {
     return (action_list == NULL);
 }
	/*
	* 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 "fastboot.h"
	#include "make_ext4fs.h"

	#include <errno.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <stdarg.h>
	#include <stdbool.h>
	#include <string.h>
	#include <sys/stat.h>
	#include <sys/time.h>
	#include <sys/types.h>
	#include <unistd.h>

	#ifdef USE_MINGW
	#include <fcntl.h>
	#else
	#include <sys/mman.h>
	#endif

	#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))

	double now()
	{
	struct timeval tv;
	gettimeofday(&tv, NULL);
	return (double)tv.tv_sec + (double)tv.tv_usec / 1000000;
	}

	char mkmsg(const char fmt, ...)
	{
	char buf[256];
	char *s;
	va_list ap;

	va_start(ap, fmt);
	vsprintf(buf, fmt, ap);
	va_end(ap);

	s = strdup(buf);
	if (s == 0) die("out of memory");
	return s;
	}

	#define OP_DOWNLOAD 1
	#define OP_COMMAND 2
	#define OP_QUERY 3
	#define OP_NOTICE 4
	#define OP_FORMAT 5
	#define OP_DOWNLOAD_SPARSE 6

	typedef struct Action Action;

	#define CMD_SIZE 64

	struct Action
	{
	unsigned op;
	Action *next;

	char cmd[CMD_SIZE];
	const char *prod;
	void *data;
	unsigned size;

	const char *msg;
	int (func)(Action a, int status, char *resp);

	double start;
	};

	static Action *action_list = 0;
	static Action *action_last = 0;


	struct image_data {
	long long partition_size;
	long long image_size; // real size of image file
	void *buffer;
	};

	void generate_ext4_image(struct image_data *image);
	void cleanup_image(struct image_data *image);

	int fb_getvar(struct usb_handle usb, char response, const char *fmt, ...)
	{
	char cmd[CMD_SIZE] = "getvar:";
	int getvar_len = strlen(cmd);
	va_list args;

	response[FB_RESPONSE_SZ] = '\0';
	va_start(args, fmt);
	vsnprintf(cmd + getvar_len, sizeof(cmd) - getvar_len, fmt, args);
	va_end(args);
	cmd[CMD_SIZE - 1] = '\0';
	return fb_command_response(usb, cmd, response);
	}

	struct generator {
	char *fs_type;

	/* generate image and return it as image->buffer.
	* size of the buffer returned as image->image_size.
	*
	* image->partition_size specifies what is the size of the
	* file partition we generate image for.
	*/
	void (generate)(struct image_data image);

	/* it cleans the buffer allocated during image creation.
	* this function probably does free() or munmap().
	*/
	void (cleanup)(struct image_data image);
	} generators[] = {
	{ "ext4", generate_ext4_image, cleanup_image }
	};

	/* Return true if this partition is supported by the fastboot format command.
	* It is also used to determine if we should first erase a partition before
	* flashing it with an ext4 filesystem. See needs_erase()
	*
	* Not all devices report the filesystem type, so don't report any errors,
	* just return false.
	*/
	int fb_format_supported(usb_handle usb, const char partition)
	{
	char response[FB_RESPONSE_SZ+1];
	struct generator *generator = NULL;
	int status;
	unsigned int i;

	status = fb_getvar(usb, response, "partition-type:%s", partition);
	if (status) {
	return 0;
	}

	for (i = 0; i < ARRAY_SIZE(generators); i++) {
	if (!strncmp(generators[i].fs_type, response, FB_RESPONSE_SZ)) {
	generator = &generators[i];
	break;
	}
	}

	if (generator) {
	return 1;
	}

	return 0;
	}

	static int cb_default(Action a, int status, char resp)
	{
	if (status) {
	fprintf(stderr,"FAILED (%s)\n", resp);
	} else {
	double split = now();
	fprintf(stderr,"OKAY [%7.3fs]\n", (split - a->start));
	a->start = split;
	}
	return status;
	}

	static Action queue_action(unsigned op, const char fmt, ...)
	{
	Action *a;
	va_list ap;
	size_t cmdsize;

	a = calloc(1, sizeof(Action));
	if (a == 0) die("out of memory");

	va_start(ap, fmt);
	cmdsize = vsnprintf(a->cmd, sizeof(a->cmd), fmt, ap);
	va_end(ap);

	if (cmdsize >= sizeof(a->cmd)) {
	free(a);
	die("Command length (%d) exceeds maximum size (%d)", cmdsize, sizeof(a->cmd));
	}

	if (action_last) {
	action_last->next = a;
	} else {
	action_list = a;
	}
	action_last = a;
	a->op = op;
	a->func = cb_default;

	a->start = -1;

	return a;
	}

	void fb_queue_erase(const char *ptn)
	{
	Action *a;
	a = queue_action(OP_COMMAND, "erase:%s", ptn);
	a->msg = mkmsg("erasing '%s'", ptn);
	}

	/* Loads file content into buffer. Returns NULL on error. */
	static void *load_buffer(int fd, off_t size)
	{
	void *buffer;

	#ifdef USE_MINGW
	ssize_t count = 0;

	// mmap is more efficient but mingw does not support it.
	// In this case we read whole image into memory buffer.
	buffer = malloc(size);
	if (!buffer) {
	perror("malloc");
	return NULL;
	}

	lseek(fd, 0, SEEK_SET);
	while(count < size) {
	ssize_t actually_read = read(fd, (char*)buffer+count, size-count);

	if (actually_read == 0) {
	break;
	}
	if (actually_read < 0) {
	if (errno == EINTR) {
	continue;
	}
	perror("read");
	free(buffer);
	return NULL;
	}

	count += actually_read;
	}
	#else
	buffer = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
	if (buffer == MAP_FAILED) {
	perror("mmap");
	return NULL;
	}
	#endif

	return buffer;
	}

	void cleanup_image(struct image_data *image)
	{
	#ifdef USE_MINGW
	free(image->buffer);
	#else
	munmap(image->buffer, image->image_size);
	#endif
	}

	void generate_ext4_image(struct image_data *image)
	{
	int fd;
	struct stat st;

	fd = fileno(tmpfile());
	make_ext4fs_sparse_fd(fd, image->partition_size, NULL, NULL);

	fstat(fd, &st);
	image->image_size = st.st_size;
	image->buffer = load_buffer(fd, st.st_size);

	close(fd);
	}

	int fb_format(Action a, usb_handle usb, int skip_if_not_supported)
	{
	const char *partition = a->cmd;
	char response[FB_RESPONSE_SZ+1];
	int status = 0;
	struct image_data image;
	struct generator *generator = NULL;
	int fd;
	unsigned i;
	char cmd[CMD_SIZE];

	status = fb_getvar(usb, response, "partition-type:%s", partition);
	if (status) {
	if (skip_if_not_supported) {
	fprintf(stderr,
	"Erase successful, but not automatically formatting.\n");
	fprintf(stderr,
	"Can't determine partition type.\n");
	return 0;
	}
	fprintf(stderr,"FAILED (%s)\n", fb_get_error());
	return status;
	}

	for (i = 0; i < ARRAY_SIZE(generators); i++) {
	if (!strncmp(generators[i].fs_type, response, FB_RESPONSE_SZ)) {
	generator = &generators[i];
	break;
	}
	}
	if (!generator) {
	if (skip_if_not_supported) {
	fprintf(stderr,
	"Erase successful, but not automatically formatting.\n");
	fprintf(stderr,
	"File system type %s not supported.\n", response);
	return 0;
	}
	fprintf(stderr,"Formatting is not supported for filesystem with type '%s'.\n",
	response);
	return -1;
	}

	status = fb_getvar(usb, response, "partition-size:%s", partition);
	if (status) {
	if (skip_if_not_supported) {
	fprintf(stderr,
	"Erase successful, but not automatically formatting.\n");
	fprintf(stderr, "Unable to get partition size\n.");
	return 0;
	}
	fprintf(stderr,"FAILED (%s)\n", fb_get_error());
	return status;
	}
	image.partition_size = strtoll(response, (char **)NULL, 16);

	generator->generate(&image);
	if (!image.buffer) {
	fprintf(stderr,"Cannot generate image.\n");
	return -1;
	}

	// Following piece of code is similar to fb_queue_flash() but executes
	// actions directly without queuing
	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;

	fprintf(stderr, "writing '%s'...\n", partition);
	snprintf(cmd, sizeof(cmd), "flash:%s", partition);
	status = fb_command(usb, cmd);
	if (status) goto cleanup;

	cleanup:
	generator->cleanup(&image);

	return status;
	}

	void fb_queue_format(const char *partition, int skip_if_not_supported)
	{
	Action *a;

	a = queue_action(OP_FORMAT, partition);
	a->data = (void*)skip_if_not_supported;
	a->msg = mkmsg("formatting '%s' partition", partition);
	}

	void fb_queue_flash(const char ptn, void data, unsigned sz)
	{
	Action *a;

	a = queue_action(OP_DOWNLOAD, "");
	a->data = data;
	a->size = sz;
	a->msg = mkmsg("sending '%s' (%d KB)", ptn, sz / 1024);

	a = queue_action(OP_COMMAND, "flash:%s", ptn);
	a->msg = mkmsg("writing '%s'", ptn);
	}

	void fb_queue_flash_sparse(const char ptn, struct sparse_file s, unsigned sz)
	{
	Action *a;

	a = queue_action(OP_DOWNLOAD_SPARSE, "");
	a->data = s;
	a->size = 0;
	a->msg = mkmsg("sending sparse '%s' (%d KB)", ptn, sz / 1024);

	a = queue_action(OP_COMMAND, "flash:%s", ptn);
	a->msg = mkmsg("writing '%s'", ptn);
	}

	static int match(char str, const char *value, unsigned count)
	{
	const char *val;
	unsigned n;
	int len;

	for (n = 0; n < count; n++) {
	const char *val = value[n];
	int len = strlen(val);
	int match;

	if ((len > 1) && (val[len-1] == '*')) {
	len--;
	match = !strncmp(val, str, len);
	} else {
	match = !strcmp(val, str);
	}

	if (match) return 1;
	}

	return 0;
	}



	static int cb_check(Action a, int status, char resp, int invert)
	{
	const char **value = a->data;
	unsigned count = a->size;
	unsigned n;
	int yes;

	if (status) {
	fprintf(stderr,"FAILED (%s)\n", resp);
	return status;
	}

	if (a->prod) {
	if (strcmp(a->prod, cur_product) != 0) {
	double split = now();
	fprintf(stderr,"IGNORE, product is %s required only for %s [%7.3fs]\n",
	cur_product, a->prod, (split - a->start));
	a->start = split;
	return 0;
	}
	}

	yes = match(resp, value, count);
	if (invert) yes = !yes;

	if (yes) {
	double split = now();
	fprintf(stderr,"OKAY [%7.3fs]\n", (split - a->start));
	a->start = split;
	return 0;
	}

	fprintf(stderr,"FAILED\n\n");
	fprintf(stderr,"Device %s is '%s'.\n", a->cmd + 7, resp);
	fprintf(stderr,"Update %s '%s'",
	invert ? "rejects" : "requires", value[0]);
	for (n = 1; n < count; n++) {
	fprintf(stderr," or '%s'", value[n]);
	}
	fprintf(stderr,".\n\n");
	return -1;
	}

	static int cb_require(Action a, int status, char resp)
	{
	return cb_check(a, status, resp, 0);
	}

	static int cb_reject(Action a, int status, char resp)
	{
	return cb_check(a, status, resp, 1);
	}

	void fb_queue_require(const char prod, const char var,
	int invert, unsigned nvalues, const char **value)
	{
	Action *a;
	a = queue_action(OP_QUERY, "getvar:%s", var);
	a->prod = prod;
	a->data = value;
	a->size = nvalues;
	a->msg = mkmsg("checking %s", var);
	a->func = invert ? cb_reject : cb_require;
	if (a->data == 0) die("out of memory");
	}

	static int cb_display(Action a, int status, char resp)
	{
	if (status) {
	fprintf(stderr, "%s FAILED (%s)\n", a->cmd, resp);
	return status;
	}
	fprintf(stderr, "%s: %s\n", (char*) a->data, resp);
	return 0;
	}

	void fb_queue_display(const char var, const char prettyname)
	{
	Action *a;
	a = queue_action(OP_QUERY, "getvar:%s", var);
	a->data = strdup(prettyname);
	if (a->data == 0) die("out of memory");
	a->func = cb_display;
	}

	static int cb_save(Action a, int status, char resp)
	{
	if (status) {
	fprintf(stderr, "%s FAILED (%s)\n", a->cmd, resp);
	return status;
	}
	strncpy(a->data, resp, a->size);
	return 0;
	}

	void fb_queue_query_save(const char var, char dest, unsigned dest_size)
	{
	Action *a;
	a = queue_action(OP_QUERY, "getvar:%s", var);
	a->data = (void *)dest;
	a->size = dest_size;
	a->func = cb_save;
	}

	static int cb_do_nothing(Action a, int status, char resp)
	{
	fprintf(stderr,"\n");
	return 0;
	}

	void fb_queue_reboot(void)
	{
	Action *a = queue_action(OP_COMMAND, "reboot");
	a->func = cb_do_nothing;
	a->msg = "rebooting";
	}

	void fb_queue_command(const char cmd, const char msg)
	{
	Action *a = queue_action(OP_COMMAND, cmd);
	a->msg = msg;
	}

	void fb_queue_download(const char name, void data, unsigned size)
	{
	Action *a = queue_action(OP_DOWNLOAD, "");
	a->data = data;
	a->size = size;
	a->msg = mkmsg("downloading '%s'", name);
	}

	void fb_queue_notice(const char *notice)
	{
	Action *a = queue_action(OP_NOTICE, "");
	a->data = (void*) notice;
	}

	int fb_execute_queue(usb_handle *usb)
	{
	Action *a;
	char resp[FB_RESPONSE_SZ+1];
	int status = 0;

	a = action_list;
	if (!a)
	return status;
	resp[FB_RESPONSE_SZ] = 0;

	double start = -1;
	for (a = action_list; a; a = a->next) {
	a->start = now();
	if (start < 0) start = a->start;
	if (a->msg) {
	// fprintf(stderr,"%30s... ",a->msg);
	fprintf(stderr,"%s...\n",a->msg);
	}
	if (a->op == OP_DOWNLOAD) {
	status = fb_download_data(usb, a->data, a->size);
	status = a->func(a, status, status ? fb_get_error() : "");
	if (status) break;
	} else if (a->op == OP_COMMAND) {
	status = fb_command(usb, a->cmd);
	status = a->func(a, status, status ? fb_get_error() : "");
	if (status) break;
	} else if (a->op == OP_QUERY) {
	status = fb_command_response(usb, a->cmd, resp);
	status = a->func(a, status, status ? fb_get_error() : resp);
	if (status) break;
	} else if (a->op == OP_NOTICE) {
	fprintf(stderr,"%s\n",(char*)a->data);
	} else if (a->op == OP_FORMAT) {
	status = fb_format(a, usb, (int)a->data);
	status = a->func(a, status, status ? fb_get_error() : "");
	if (status) break;
	} else if (a->op == OP_DOWNLOAD_SPARSE) {
	status = fb_download_data_sparse(usb, a->data);
	status = a->func(a, status, status ? fb_get_error() : "");
	if (status) break;
	} else {
	die("bogus action");
	}
	}

	fprintf(stderr,"finished. total time: %.3fs\n", (now() - start));
	return status;
	}

	int fb_queue_is_empty(void)
	{
	return (action_list == NULL);
	}