make time zone work

libsrc/rp6502/ria_tzset.c

@@ -1,9 +0,0 @@
-#include <rp6502.h>
-#include <time.h>
-
-int clock_gettimezone (time_t time, clockid_t clock_id, struct _timezone* tz);
-
-void ria_tzset (unsigned long time)
-{
-    clock_gettimezone (time, CLOCK_REALTIME, &_tz);
-}

libsrc/rp6502/tzset_time.s

@@ -0,0 +1,29 @@
+; tzset_time.s
+;
+; This file is part of
+; cc65 - a freeware C compiler for 6502 based systems
+;
+; https://cc65.github.io
+;
+; See "LICENSE" file for legal information.
+;
+; void __fastcall__ tzset_time (time_t* time);
+;
+
+        .export         _tzset_time
+        .import         _clock_gettimezone, __tz
+        .import         pushax, ldax0sp, ldeaxi, pusheax, pusha, incsp2
+        .include        "time.inc"
+
+
+_tzset_time:
+        jsr     pushax
+        jsr     ldax0sp
+        jsr     ldeaxi
+        jsr     pusheax
+        lda     #CLOCK_REALTIME
+        jsr     pusha
+        lda     #<(__tz)
+        ldx     #>(__tz)
+        jsr     _clock_gettimezone
+        jmp     incsp2