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Respect SOURCE_DATE_EPOCH when building FIT images.

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-20160606/005722.html

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>
Reviewed-by: Simon Glass <sjg@chromium.org>
tags/2020-06-01
Vagrant Cascadian 5 years ago
committed by Tom Rini
parent
commit
5847084f6b
4 changed files with 41 additions and 15 deletions
  1. +1
    -13
      tools/default_image.c
  2. +4
    -2
      tools/fit_image.c
  3. +20
    -0
      tools/imagetool.c
  4. +16
    -0
      tools/imagetool.h

+ 1
- 13
tools/default_image.c View File

@@ -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);


+ 4
- 2
tools/fit_image.c View File

@@ -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,


+ 20
- 0
tools/imagetool.c View File

@@ -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;
}

+ 16
- 0
tools/imagetool.h View File

@@ -206,6 +206,22 @@ 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