unix/variants: Enable seeding random module on import in dev, coverage.

Signed-off-by: Damien George <damien@micropython.org>

ports/unix/mpconfigport.h

@@ -253,6 +253,17 @@ void mp_unix_mark_exec(void);
 #define MICROPY_FORCE_PLAT_ALLOC_EXEC (1)
 #endif
 
+#ifdef MICROPY_PY_URANDOM_SEED_INIT_FUNC
+// Support for seeding the random module on import.
+#include <stddef.h>
+void mp_hal_get_random(size_t n, void *buf);
+static inline unsigned long mp_urandom_seed_init(void) {
+    unsigned long r;
+    mp_hal_get_random(sizeof(r), &r);
+    return r;
+}
+#endif
+
 #ifdef __linux__
 // Can access physical memory using /dev/mem
 #define MICROPY_PLAT_DEV_MEM  (1)

ports/unix/variants/coverage/mpconfigvariant.h

@@ -31,7 +31,6 @@
 #define MICROPY_CONFIG_ROM_LEVEL (MICROPY_CONFIG_ROM_LEVEL_EXTRA_FEATURES)
 
 // Disable some features that come enabled by default with the feature level.
-#define MICROPY_MODULE_BUILTIN_INIT             (0)
 #define MICROPY_PY_BUILTINS_EXECFILE            (0)
 #define MICROPY_PY_SYS_STDIO_BUFFER             (0)
 #define MICROPY_PY_USELECT                      (0)
@@ -50,6 +49,7 @@
 #define MICROPY_PY_SYS_GETSIZEOF       (1)
 #define MICROPY_PY_SYS_TRACEBACKLIMIT  (1)
 #define MICROPY_PY_IO_BUFFEREDWRITER (1)
+#define MICROPY_PY_URANDOM_SEED_INIT_FUNC (mp_urandom_seed_init())
 #define MICROPY_PY_URE_DEBUG           (1)
 #define MICROPY_PY_URE_MATCH_GROUPS    (1)
 #define MICROPY_PY_URE_MATCH_SPAN_START_END (1)

ports/unix/variants/dev/mpconfigvariant.h

@@ -28,7 +28,6 @@
 #define MICROPY_CONFIG_ROM_LEVEL (MICROPY_CONFIG_ROM_LEVEL_EXTRA_FEATURES)
 
 // Disable some features that come enabled by default with the feature level.
-#define MICROPY_MODULE_BUILTIN_INIT             (0)
 #define MICROPY_PY_BUILTINS_EXECFILE            (0)
 #define MICROPY_PY_SYS_STDIO_BUFFER             (0)
 #define MICROPY_PY_USELECT                      (0)
@@ -37,3 +36,4 @@
 #define MICROPY_REPL_EMACS_WORDS_MOVE           (1)
 #define MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE     (1)
 #define MICROPY_PY_SYS_SETTRACE                 (1)
+#define MICROPY_PY_URANDOM_SEED_INIT_FUNC       (mp_urandom_seed_init())