Add dumpimage, a tool to extract data from U-Boot images
Given a multi-file image created through the mkimage's -d option:
$ mkimage -A x86 -O linux -T multi -n x86 -d vmlinuz:initrd.img:System.map \
multi.img
Image Name: x86
Created: Thu Jul 25 10:29:13 2013
Image Type: Intel x86 Linux Multi-File Image (gzip compressed)
Data Size: 13722956 Bytes = 13401.32 kB = 13.09 MB
Load Address: 00000000
Entry Point: 00000000
Contents:
Image 0: 4040128 Bytes = 3945.44 kB = 3.85 MB
Image 1: 7991719 Bytes = 7804.41 kB = 7.62 MB
Image 2: 1691092 Bytes = 1651.46 kB = 1.61 MB
It is possible to perform the innverse operation -- extracting any file from
the image -- by using the dumpimage's -i option:
$ dumpimage -i multi.img -p 2 System.map
Although it's feasible to retrieve "data files" from image through scripting,
the requirement to embed tools such 'dd', 'awk' and 'sed' for this sole purpose
is cumbersome and unreliable -- once you must keep track of file sizes inside
the image. Furthermore, extracting data files using "dumpimage" tool is faster
than through scripting.
Signed-off-by: Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/dumpimage.c b/tools/dumpimage.c
new file mode 100644
index 0000000..542ee28
--- /dev/null
+++ b/tools/dumpimage.c
@@ -0,0 +1,305 @@
+/*
+ * Based on mkimage.c.
+ *
+ * Written by Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include "dumpimage.h"
+#include <image.h>
+#include <version.h>
+
+static void usage(void);
+
+/* image_type_params linked list to maintain registered image types supports */
+static struct image_type_params *dumpimage_tparams;
+
+/* parameters initialized by core will be used by the image type code */
+static struct image_tool_params params = {
+ .type = IH_TYPE_KERNEL,
+};
+
+/**
+ * dumpimage_register() - register respective image generation/list support
+ *
+ * the input struct image_type_params is checked and appended to the link
+ * list, if the input structure is already registered, issue an error
+ *
+ * @tparams: Image type parameters
+ */
+static void dumpimage_register(struct image_type_params *tparams)
+{
+ struct image_type_params **tp;
+
+ if (!tparams) {
+ fprintf(stderr, "%s: %s: Null input\n", params.cmdname,
+ __func__);
+ exit(EXIT_FAILURE);
+ }
+
+ /* scan the linked list, check for registry and point the last one */
+ for (tp = &dumpimage_tparams; *tp != NULL; tp = &(*tp)->next) {
+ if (!strcmp((*tp)->name, tparams->name)) {
+ fprintf(stderr, "%s: %s already registered\n",
+ params.cmdname, tparams->name);
+ return;
+ }
+ }
+
+ /* add input struct entry at the end of link list */
+ *tp = tparams;
+ /* mark input entry as last entry in the link list */
+ tparams->next = NULL;
+
+ debug("Registered %s\n", tparams->name);
+}
+
+/**
+ * dumpimage_get_type() - find the image type params for a given image type
+ *
+ * Scan all registered image types and check the input type_id for each
+ * supported image type
+ *
+ * @return respective image_type_params pointer. If the input type is not
+ * supported by any of registered image types, returns NULL
+ */
+static struct image_type_params *dumpimage_get_type(int type)
+{
+ struct image_type_params *curr;
+
+ for (curr = dumpimage_tparams; curr != NULL; curr = curr->next) {
+ if (curr->check_image_type) {
+ if (!curr->check_image_type(type))
+ return curr;
+ }
+ }
+ return NULL;
+}
+
+/*
+ * dumpimage_verify_print_header() - verifies the image header
+ *
+ * Scan registered image types and verify the image_header for each
+ * supported image type. If verification is successful, this prints
+ * the respective header.
+ *
+ * @return 0 on success, negative if input image format does not match with
+ * any of supported image types
+ */
+static int dumpimage_verify_print_header(void *ptr, struct stat *sbuf)
+{
+ int retval = -1;
+ struct image_type_params *curr;
+
+ for (curr = dumpimage_tparams; curr != NULL; curr = curr->next) {
+ if (curr->verify_header) {
+ retval = curr->verify_header((unsigned char *)ptr,
+ sbuf->st_size, ¶ms);
+ if (retval != 0)
+ continue;
+ /*
+ * Print the image information if verify is
+ * successful
+ */
+ if (curr->print_header) {
+ curr->print_header(ptr);
+ } else {
+ fprintf(stderr,
+ "%s: print_header undefined for %s\n",
+ params.cmdname, curr->name);
+ }
+ break;
+ }
+ }
+
+ return retval;
+}
+
+/*
+ * dumpimage_extract_datafile -
+ *
+ * It scans all registered image types,
+ * verifies image_header for each supported image type
+ * if verification is successful, it extracts the desired file,
+ * indexed by pflag, from the image
+ *
+ * returns negative if input image format does not match with any of
+ * supported image types
+ */
+static int dumpimage_extract_datafile(void *ptr, struct stat *sbuf)
+{
+ int retval = -1;
+ struct image_type_params *curr;
+
+ for (curr = dumpimage_tparams; curr != NULL; curr = curr->next) {
+ if (curr->verify_header) {
+ retval = curr->verify_header((unsigned char *)ptr,
+ sbuf->st_size, ¶ms);
+ if (retval != 0)
+ continue;
+ /*
+ * Extract the file from the image
+ * if verify is successful
+ */
+ if (curr->extract_datafile) {
+ curr->extract_datafile(ptr, ¶ms);
+ } else {
+ fprintf(stderr,
+ "%s: extract_datafile undefined for %s\n",
+ params.cmdname, curr->name);
+ break;
+ }
+ }
+ }
+
+ return retval;
+}
+
+int main(int argc, char **argv)
+{
+ int opt;
+ int ifd = -1;
+ struct stat sbuf;
+ char *ptr;
+ int retval = 0;
+ struct image_type_params *tparams = NULL;
+
+ /* Init all image generation/list support */
+ register_image_tool(dumpimage_register);
+
+ params.cmdname = *argv;
+
+ while ((opt = getopt(argc, argv, "li:o:p:V")) != -1) {
+ switch (opt) {
+ case 'l':
+ params.lflag = 1;
+ break;
+ case 'i':
+ params.imagefile = optarg;
+ params.iflag = 1;
+ break;
+ case 'o':
+ params.outfile = optarg;
+ break;
+ case 'p':
+ params.pflag = strtoul(optarg, &ptr, 10);
+ if (*ptr) {
+ fprintf(stderr,
+ "%s: invalid file position %s\n",
+ params.cmdname, *argv);
+ exit(EXIT_FAILURE);
+ }
+ break;
+ case 'V':
+ printf("dumpimage version %s\n", PLAIN_VERSION);
+ exit(EXIT_SUCCESS);
+ default:
+ usage();
+ }
+ }
+
+ if (optind >= argc)
+ usage();
+
+ /* set tparams as per input type_id */
+ tparams = dumpimage_get_type(params.type);
+ if (tparams == NULL) {
+ fprintf(stderr, "%s: unsupported type %s\n",
+ params.cmdname, genimg_get_type_name(params.type));
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * check the passed arguments parameters meets the requirements
+ * as per image type to be generated/listed
+ */
+ if (tparams->check_params) {
+ if (tparams->check_params(¶ms))
+ usage();
+ }
+
+ if (params.iflag)
+ params.datafile = argv[optind];
+ else
+ params.imagefile = argv[optind];
+ if (!params.outfile)
+ params.outfile = params.datafile;
+
+ ifd = open(params.imagefile, O_RDONLY|O_BINARY);
+ if (ifd < 0) {
+ fprintf(stderr, "%s: Can't open \"%s\": %s\n",
+ params.cmdname, params.imagefile,
+ strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ if (params.lflag || params.iflag) {
+ if (fstat(ifd, &sbuf) < 0) {
+ fprintf(stderr, "%s: Can't stat \"%s\": %s\n",
+ params.cmdname, params.imagefile,
+ strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ if ((unsigned)sbuf.st_size < tparams->header_size) {
+ fprintf(stderr,
+ "%s: Bad size: \"%s\" is not valid image\n",
+ params.cmdname, params.imagefile);
+ exit(EXIT_FAILURE);
+ }
+
+ ptr = mmap(0, sbuf.st_size, PROT_READ, MAP_SHARED, ifd, 0);
+ if (ptr == MAP_FAILED) {
+ fprintf(stderr, "%s: Can't read \"%s\": %s\n",
+ params.cmdname, params.imagefile,
+ strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * Both calls bellow scan through dumpimage registry for all
+ * supported image types and verify the input image file
+ * header for match
+ */
+ if (params.iflag) {
+ /*
+ * Extract the data files from within the matched
+ * image type. Returns the error code if not matched
+ */
+ retval = dumpimage_extract_datafile(ptr, &sbuf);
+ } else {
+ /*
+ * Print the image information for matched image type
+ * Returns the error code if not matched
+ */
+ retval = dumpimage_verify_print_header(ptr, &sbuf);
+ }
+
+ (void)munmap((void *)ptr, sbuf.st_size);
+ (void)close(ifd);
+
+ return retval;
+ }
+
+ (void)close(ifd);
+
+ return EXIT_SUCCESS;
+}
+
+static void usage(void)
+{
+ fprintf(stderr, "Usage: %s -l image\n"
+ " -l ==> list image header information\n",
+ params.cmdname);
+ fprintf(stderr,
+ " %s -i image [-p position] [-o outfile] data_file\n"
+ " -i ==> extract from the 'image' a specific 'data_file'"
+ ", indexed by 'position' (starting at 0)\n",
+ params.cmdname);
+ fprintf(stderr,
+ " %s -V ==> print version information and exit\n",
+ params.cmdname);
+
+ exit(EXIT_FAILURE);
+}
