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
---
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
--
2.1.4
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