build(core): use deterministic git rev-parse

The output may differ in shallow vs. full repo.

[no changelog]

core/embed/projects/firmware/mpconfigport.h

@@ -177,6 +177,10 @@
 
 #define MP_STATE_PORT MP_STATE_VM
 
+// by default contains nearest git tag, which may not be present in shallow
+// repo, breaking reproducibility
+#define MICROPY_BANNER_NAME_AND_VERSION ""
+
 // ============= this ends common config section ===================
 
 

core/embed/projects/unix/mpconfigport.h

@@ -217,6 +217,10 @@ extern const struct _mp_print_t mp_stderr_print;
 
 #define MP_STATE_PORT MP_STATE_VM
 
+// by default contains nearest git tag, which may not be present in shallow
+// repo, breaking reproducibility
+#define MICROPY_BANNER_NAME_AND_VERSION ""
+
 // ============= this ends common config section ===================
 
 // For size_t and ssize_t

core/site_scons/tools.py

@@ -33,9 +33,9 @@ def get_git_revision_hash() -> str:
 
 def get_git_revision_short_hash() -> str:
     return (
-        subprocess.check_output(["git", "rev-parse", "--short", "HEAD"])
+        subprocess.check_output(["git", "rev-parse", "--verify", "HEAD"])
         .decode("ascii")
-        .strip()
+        .strip()[:7]
     )