Embedding timestamps in FIT images results in unreproducible builds for targets that generate a fit image, such as dra7xx_evm.

This patch uses the SOURCE_DATE_EPOCH environment variable, when set, to use specified value for the date.

Thanks to HW42 for debugging the issue and providing the patch:

https://lists.alioth.debian.org/pipermail/reproducible-builds/Week-of-Mon-20...

For more information about reproducible builds and the SOURCE_DATE_EPOCH specification:

https://reproducible-builds.org/specs/source-date-epoch/ https://reproducible-builds.org/

Signed-off-by: Vagrant Cascadian vagrant@debian.org ---

tools/default_image.c | 14 +------------- tools/fit_image.c | 6 ++++-- tools/imagetool.c | 20 ++++++++++++++++++++ tools/imagetool.h | 16 ++++++++++++++++ 4 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/tools/default_image.c b/tools/default_image.c index 3ed7014..6e4ae14 100644 --- a/tools/default_image.c +++ b/tools/default_image.c @@ -88,7 +88,6 @@ static void image_set_header(void *ptr, struct stat *sbuf, int ifd, struct image_tool_params *params) { uint32_t checksum; - char *source_date_epoch; time_t time;

image_header_t * hdr = (image_header_t *)ptr; @@ -98,18 +97,7 @@ static void image_set_header(void *ptr, struct stat *sbuf, int ifd, sizeof(image_header_t)), sbuf->st_size - sizeof(image_header_t));

- source_date_epoch = getenv("SOURCE_DATE_EPOCH"); - if (source_date_epoch != NULL) { - time = (time_t) strtol(source_date_epoch, NULL, 10); - - if (gmtime(&time) == NULL) { - fprintf(stderr, "%s: SOURCE_DATE_EPOCH is not valid\n", - __func__); - time = 0; - } - } else { - time = sbuf->st_mtime; - } + time = imagetool_get_source_date(params, sbuf->st_mtime);

/* Build new header */ image_set_magic(hdr, IH_MAGIC); diff --git a/tools/fit_image.c b/tools/fit_image.c index 0551572..23dbce4 100644 --- a/tools/fit_image.c +++ b/tools/fit_image.c @@ -51,8 +51,10 @@ static int fit_add_file_data(struct image_tool_params *params, size_t size_inc, }

/* for first image creation, add a timestamp at offset 0 i.e., root */ - if (params->datafile) - ret = fit_set_timestamp(ptr, 0, sbuf.st_mtime); + if (params->datafile) { + time_t time = imagetool_get_source_date(params, sbuf.st_mtime); + ret = fit_set_timestamp(ptr, 0, time); + }

if (!ret) { ret = fit_add_verification_data(params->keydir, dest_blob, ptr, diff --git a/tools/imagetool.c b/tools/imagetool.c index 08d191d..855a096 100644 --- a/tools/imagetool.c +++ b/tools/imagetool.c @@ -115,3 +115,23 @@ int imagetool_get_filesize(struct image_tool_params *params, const char *fname)

return sbuf.st_size; } + +time_t imagetool_get_source_date( + struct image_tool_params *params, + time_t fallback) +{ + char *source_date_epoch = getenv("SOURCE_DATE_EPOCH"); + + if (source_date_epoch == NULL) + return fallback; + + time_t time = (time_t) strtol(source_date_epoch, NULL, 10); + + if (gmtime(&time) == NULL) { + fprintf(stderr, "%s: SOURCE_DATE_EPOCH is not valid\n", + params->cmdname); + time = 0; + } + + return time; +} diff --git a/tools/imagetool.h b/tools/imagetool.h index a3ed0f4..b422df2 100644 --- a/tools/imagetool.h +++ b/tools/imagetool.h @@ -205,6 +205,22 @@ int imagetool_save_subimage( */ int imagetool_get_filesize(struct image_tool_params *params, const char *fname);

+/** + * imagetool_get_source_date() - Get timestamp for build output. + * + * Gets a timestamp for embedding it in a build output. If set + * SOURCE_DATE_EPOCH is used. Else the given fallback value is returned. Prints + * an error message if SOURCE_DATE_EPOCH contains an invalid value and returns + * 0. + * + * @params: mkimage parameters + * @fallback: timestamp to use if SOURCE_DATE_EPOCH isn't set + * @return timestamp based on SOURCE_DATE_EPOCH + */ +time_t imagetool_get_source_date( + struct image_tool_params *params, + time_t fallback); + /* * There is a c file associated with supported image type low level code * for ex. default_image.c, fit_image.c