sys/tiny_strerror: add tiny_strerror_minimal

makefiles/pseudomodules.inc.mk

@@ -477,6 +477,7 @@ PSEUDOMODULES += suit_transport_%
 PSEUDOMODULES += suit_storage_%
 PSEUDOMODULES += sys_bus_%
 PSEUDOMODULES += tiny_strerror_as_strerror
+PSEUDOMODULES += tiny_strerror_minimal
 PSEUDOMODULES += vdd_lc_filter_%
 ## @defgroup pseudomodule_vfs_auto_format vfs_auto_format
 ## @brief Format mount points at startup unless they can be mounted

sys/include/tiny_strerror.h

@@ -24,6 +24,13 @@
  * @note        Using module `tiny_strerror_as_strerror` will replace all calls
  *              to `strerror()` by calls to `tiny_strerror()`, which may safe
  *              a bit of ROM.
+ *
+ * @note        Using module `tiny_strerror_minimal` will just print the error
+ *              code value.
+ *              This will save ~1k of ROM, but won't provide much more information.
+ *
+ * @warning     The module `tiny_strerror_minimal` is not thread-safe.
+ *
  * @{
  *
  *

sys/tiny_strerror/tiny_strerror.c

@@ -18,6 +18,7 @@
  */
 
 #include <errno.h>
+#include <stdio.h>
 #include <string.h>
 
 #include "kernel_defines.h"
@@ -112,6 +113,12 @@ const char *tiny_strerror(int errnum)
     const char *retval = "-unknown";
     unsigned offset = 1;
 
+    if (IS_USED(MODULE_TINY_STRERROR_MINIMAL)) {
+        static char buf[4];
+        snprintf(buf, sizeof(buf), "%d", errnum);
+        return buf;
+    }
+
     if (errnum <= 0) {
         offset = 0;
         errnum = -errnum;