From: Guilherme Maciel Ferreira guilherme.maciel.ferreira@gmail.com
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 ---
Changes in v2: - Add additional -o option for when the file name is not valid - Correct checkpatch problems
Makefile | 1 + README | 9 ++ tools/.gitignore | 1 + tools/Makefile | 26 +++++ tools/default_image.c | 57 ++++++++++ tools/dumpimage.c | 305 ++++++++++++++++++++++++++++++++++++++++++++++++++ tools/dumpimage.h | 33 ++++++ tools/imagetool.h | 12 ++ 8 files changed, 444 insertions(+) create mode 100644 tools/dumpimage.c create mode 100644 tools/dumpimage.h
diff --git a/Makefile b/Makefile index a2fb037..653d3b3 100644 --- a/Makefile +++ b/Makefile @@ -796,6 +796,7 @@ clean: $(obj)tools/envcrc \ $(obj)tools/gdb/{astest,gdbcont,gdbsend} \ $(obj)tools/gen_eth_addr $(obj)tools/img2srec \ + $(obj)tools/dump{env,}image \ $(obj)tools/mk{env,}image $(obj)tools/mpc86x_clk \ $(obj)tools/mk{$(BOARD),}spl \ $(obj)tools/mxsboot \ diff --git a/README b/README index 5def773..5072f08 100644 --- a/README +++ b/README @@ -5193,6 +5193,15 @@ when your kernel is intended to use an initial ramdisk: Load Address: 0x00000000 Entry Point: 0x00000000
+The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" +option performs the converse operation of the mkimage's second form (the "-d" +option). Given an image built by mkimage, the dumpimage extracts a "data file" +from the image: + + tools/dumpimage -i image -p position data_file + -i ==> extract from the 'image' a specific 'data_file', \ + indexed by 'position' +
Installing a Linux Image: ------------------------- diff --git a/tools/.gitignore b/tools/.gitignore index a7fee26..2320fd8 100644 --- a/tools/.gitignore +++ b/tools/.gitignore @@ -3,6 +3,7 @@ /gen_eth_addr /img2srec /kwboot +/dumpimage /mkenvimage /mkimage /mpc86x_clk diff --git a/tools/Makefile b/tools/Makefile index 154eae3..e1264fd 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -50,6 +50,7 @@ BIN_FILES-$(CONFIG_BUILD_ENVCRC) += envcrc$(SFX) BIN_FILES-$(CONFIG_CMD_NET) += gen_eth_addr$(SFX) BIN_FILES-$(CONFIG_CMD_LOADS) += img2srec$(SFX) BIN_FILES-$(CONFIG_XWAY_SWAP_BYTES) += xway-swap-bytes$(SFX) +BIN_FILES-y += dumpimage$(SFX) BIN_FILES-y += mkenvimage$(SFX) BIN_FILES-y += mkimage$(SFX) BIN_FILES-$(CONFIG_EXYNOS5250) += mk$(BOARD)spl$(SFX) @@ -72,6 +73,7 @@ EXT_OBJ_FILES-y += lib/sha1.o # Source files located in the tools directory NOPED_OBJ_FILES-y += aisimage.o NOPED_OBJ_FILES-y += default_image.o +NOPED_OBJ_FILES-y += dumpimage.o NOPED_OBJ_FILES-y += fit_image.o NOPED_OBJ_FILES-y += image-host.o NOPED_OBJ_FILES-y += imximage.o @@ -200,6 +202,30 @@ $(obj)xway-swap-bytes$(SFX): $(obj)xway-swap-bytes.o $(HOSTCC) $(HOSTCFLAGS) $(HOSTLDFLAGS) -o $@ $^ $(HOSTSTRIP) $@
+$(obj)dumpimage$(SFX): $(obj)aisimage.o \ + $(FIT_SIG_OBJS) \ + $(obj)crc32.o \ + $(obj)default_image.o \ + $(obj)fit_image.o \ + $(obj)image-fit.o \ + $(obj)image.o \ + $(obj)image-host.o \ + $(obj)imagetool.o \ + $(obj)imximage.o \ + $(obj)kwbimage.o \ + $(obj)dumpimage.o \ + $(obj)md5.o \ + $(obj)mxsimage.o \ + $(obj)omapimage.o \ + $(obj)os_support.o \ + $(obj)pblimage.o \ + $(obj)sha1.o \ + $(obj)ublimage.o \ + $(LIBFDT_OBJS) \ + $(RSA_OBJS) + $(HOSTCC) $(HOSTCFLAGS) $(HOSTLDFLAGS) -o $@ $^ $(HOSTLIBS) + $(HOSTSTRIP) $@ + $(obj)mkenvimage$(SFX): $(obj)crc32.o $(obj)mkenvimage.o \ $(obj)os_support.o $(HOSTCC) $(HOSTCFLAGS) $(HOSTLDFLAGS) -o $@ $^ diff --git a/tools/default_image.c b/tools/default_image.c index cc790b2..0a0792e 100644 --- a/tools/default_image.c +++ b/tools/default_image.c @@ -117,6 +117,62 @@ static void image_set_header(void *ptr, struct stat *sbuf, int ifd, image_set_hcrc(hdr, checksum); }
+static int image_save_datafile(struct image_tool_params *params, + ulong file_data, ulong file_len) +{ + int dfd; + const char *datafile = params->outfile; + + dfd = open(datafile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, + S_IRUSR | S_IWUSR); + if (dfd < 0) { + fprintf(stderr, "%s: Can't open "%s": %s\n", + params->cmdname, datafile, strerror(errno)); + return -1; + } + + if (write(dfd, (void *)file_data, file_len) != (ssize_t)file_len) { + fprintf(stderr, "%s: Write error on "%s": %s\n", + params->cmdname, datafile, strerror(errno)); + close(dfd); + return -1; + } + + close(dfd); + + return 0; +} + +static int image_extract_datafile(void *ptr, struct image_tool_params *params) +{ + const image_header_t *hdr = (const image_header_t *)ptr; + ulong file_data; + ulong file_len; + + if (image_check_type(hdr, IH_TYPE_MULTI)) { + ulong idx = params->pflag; + ulong count; + + /* get the number of data files present in the image */ + count = image_multi_count(hdr); + + /* retrieve the "data file" at the idx position */ + image_multi_getimg(hdr, idx, &file_data, &file_len); + + if ((file_len == 0) || (idx >= count)) { + fprintf(stderr, "%s: No such data file %ld in "%s"\n", + params->cmdname, idx, params->imagefile); + return -1; + } + } else { + file_data = image_get_data(hdr); + file_len = image_get_size(hdr); + } + + /* save the "data file" into the file system */ + return image_save_datafile(params, file_data, file_len); +} + /* * Default image type parameters definition */ @@ -128,6 +184,7 @@ static struct image_type_params defimage_params = { .verify_header = image_verify_header, .print_header = image_print_contents, .set_header = image_set_header, + .extract_datafile = image_extract_datafile, .check_params = image_check_params, };
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); +} diff --git a/tools/dumpimage.h b/tools/dumpimage.h new file mode 100644 index 0000000..d78523d --- /dev/null +++ b/tools/dumpimage.h @@ -0,0 +1,33 @@ +/* + * Based on mkimage.c. + * + * Written by Guilherme Maciel Ferreira guilherme.maciel.ferreira@gmail.com + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef _DUMPIMAGE_H_ +#define _DUMPIMAGE_H_ + +#include "os_support.h" +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <time.h> +#include <unistd.h> +#include <sha1.h> +#include "fdt_host.h" +#include "imagetool.h" + +#undef DUMPIMAGE_DEBUG + +#ifdef DUMPIMAGE_DEBUG +#define debug(fmt, args...) printf(fmt, ##args) +#else +#define debug(fmt, args...) +#endif /* DUMPIMAGE_DEBUG */ + +#endif /* _DUMPIMAGE_H_ */ diff --git a/tools/imagetool.h b/tools/imagetool.h index b8adb61..c2c9aea 100644 --- a/tools/imagetool.h +++ b/tools/imagetool.h @@ -34,7 +34,9 @@ struct image_tool_params { int dflag; int eflag; int fflag; + int iflag; int lflag; + int pflag; int vflag; int xflag; int skipcpy; @@ -50,6 +52,7 @@ struct image_tool_params { char *datafile; char *imagefile; char *cmdname; + const char *outfile; /* Output filename */ const char *keydir; /* Directory holding private keys */ const char *keydest; /* Destination .dtb for public key */ const char *comment; /* Comment to add to signature node */ @@ -97,6 +100,15 @@ struct image_type_params { void (*set_header) (void *, struct stat *, int, struct image_tool_params *); /* + * This function is used by the command to retrieve a data file from + * the image (i.e. dumpimage -i <image> -p <position> <data_file>). + * Thus the code to extract a file from an image must be put here. + * + * Returns 0 if the file was successfully retrieved from the image, + * or a negative value on error. + */ + int (*extract_datafile) (void *, struct image_tool_params *); + /* * Some image generation support for ex (default image type) supports * more than one type_ids, this callback function is used to check * whether input (-T <image_type>) is supported by registered image