librtc

7 files changed, 468 insertions, 56 deletions

diff --git a/Makefile b/Makefile
index 0864d959f..6175c5cd3 100644
--- a/Makefile
+++ b/Makefile
@@ -62,6 +62,8 @@ include tilesets.mk
 
 $(OBJS): $(CSRCS:src/%.c=genasm/%.s)
 
+genasm/librtc.s: CFLAGS := -mthumb-interwork -Iinclude
+
 # TODO: fix this .syntax hack
 
 genasm/prefix.tmp:
diff --git a/asm/rom.s b/asm/rom.s
index f98d7cd5d..913d13834 100644
--- a/asm/rom.s
+++ b/asm/rom.s
@@ -18378,8 +18378,8 @@ _080090EC: .4byte 0x00000fbc
 _080090F0: .4byte 0x0000efff
 	thumb_func_end sub_8009084
 
-	thumb_func_start GameFreakRTC_ClearIME
-GameFreakRTC_ClearIME: ; 80090F4
+	thumb_func_start GFRTC_DisableInterrupts
+GFRTC_DisableInterrupts: ; 80090F4
 	ldr r2, _08009104
 	ldr r1, _08009108
 	ldrh r0, [r1]
@@ -18390,10 +18390,10 @@ GameFreakRTC_ClearIME: ; 80090F4
 	.align 2
 _08009104: .4byte 0x0300046e
 _08009108: .4byte 0x04000208
-	thumb_func_end GameFreakRTC_ClearIME
+	thumb_func_end GFRTC_DisableInterrupts
 
-	thumb_func_start sub_800910C
-sub_800910C: ; 800910C
+	thumb_func_start GFRTC_RestoreInterrupts
+GFRTC_RestoreInterrupts: ; 800910C
 	ldr r0, _08009118
 	ldr r1, _0800911C
 	ldrh r1, [r1]
@@ -18402,10 +18402,10 @@ sub_800910C: ; 800910C
 	.align 2
 _08009118: .4byte 0x04000208
 _0800911C: .4byte 0x0300046e
-	thumb_func_end sub_800910C
+	thumb_func_end GFRTC_RestoreInterrupts
 
-	thumb_func_start GameFreakRTC_ConvertFromBCD
-GameFreakRTC_ConvertFromBCD: ; 8009120
+	thumb_func_start GFRTC_ConvertBcdToBinary
+GFRTC_ConvertBcdToBinary: ; 8009120
 	push {lr}
 	lsls r0, 24
 	lsrs r2, r0, 24
@@ -18429,10 +18429,10 @@ _08009136:
 _08009144:
 	pop {r1}
 	bx r1
-	thumb_func_end GameFreakRTC_ConvertFromBCD
+	thumb_func_end GFRTC_ConvertBcdToBinary
 
-	thumb_func_start GameFreakRTC_IsLeapYear
-GameFreakRTC_IsLeapYear: ; 8009148
+	thumb_func_start GFRTC_IsLeapYear
+GFRTC_IsLeapYear: ; 8009148
 	push {r4,lr}
 	lsls r0, 24
 	lsrs r1, r0, 24
@@ -18463,10 +18463,10 @@ _0800917A:
 	pop {r4}
 	pop {r1}
 	bx r1
-	thumb_func_end GameFreakRTC_IsLeapYear
+	thumb_func_end GFRTC_IsLeapYear
 
-	thumb_func_start GameFreakRTC_ConvertYearMonthDayToNumDays
-GameFreakRTC_ConvertYearMonthDayToNumDays: ; 8009180
+	thumb_func_start GFRTC_ConvertYmdToDayCount
+GFRTC_ConvertYmdToDayCount: ; 8009180
 	push {r4-r7,lr}
 	mov r7, r8
 	push {r7}
@@ -18488,7 +18488,7 @@ _0800919C:
 	lsrs r5, r0, 16
 	lsls r0, r4, 24
 	lsrs r0, 24
-	bl GameFreakRTC_IsLeapYear
+	bl GFRTC_IsLeapYear
 	lsls r0, 24
 	lsrs r0, 24
 	cmp r0, 0x1
@@ -18518,7 +18518,7 @@ _080091D8:
 	cmp r6, 0x2
 	bls _080091F0
 	adds r0, r7, 0
-	bl GameFreakRTC_IsLeapYear
+	bl GFRTC_IsLeapYear
 	lsls r0, 24
 	lsrs r0, 24
 	cmp r0, 0x1
@@ -18540,36 +18540,36 @@ _080091F0:
 	.align 2
 _08009204: .4byte 0x0000016d
 _08009208: .4byte gUnknown_081E761C
-	thumb_func_end GameFreakRTC_ConvertYearMonthDayToNumDays
+	thumb_func_end GFRTC_ConvertYmdToDayCount
 
-	thumb_func_start GameFreakRTC_GetNumDaysInternal
-GameFreakRTC_GetNumDaysInternal: ; 800920C
+	thumb_func_start GFRTC_GetDayCount
+GFRTC_GetDayCount: ; 800920C
 	push {r4-r6,lr}
 	adds r6, r0, 0
 	ldrb r0, [r6]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r5, r0, 0
 	lsls r5, 24
 	lsrs r5, 24
 	ldrb r0, [r6, 0x1]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r4, r0, 0
 	lsls r4, 24
 	lsrs r4, 24
 	ldrb r0, [r6, 0x2]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r2, r0, 0
 	lsls r2, 24
 	lsrs r2, 24
 	adds r0, r5, 0
 	adds r1, r4, 0
-	bl GameFreakRTC_ConvertYearMonthDayToNumDays
+	bl GFRTC_ConvertYmdToDayCount
 	lsls r0, 16
 	lsrs r0, 16
 	pop {r4-r6}
 	pop {r1}
 	bx r1
-	thumb_func_end GameFreakRTC_GetNumDaysInternal
+	thumb_func_end GFRTC_GetDayCount
 
 	thumb_func_start GameFreakRTC_Init
 GameFreakRTC_Init: ; 8009248
@@ -18577,12 +18577,12 @@ GameFreakRTC_Init: ; 8009248
 	ldr r5, _08009274
 	movs r0, 0
 	strh r0, [r5]
-	bl GameFreakRTC_ClearIME
+	bl GFRTC_DisableInterrupts
 	bl RTC_SetReadWrite
 	bl RTC_Init
 	ldr r4, _08009278
 	strb r0, [r4]
-	bl sub_800910C
+	bl GFRTC_RestoreInterrupts
 	ldrb r4, [r4]
 	movs r0, 0xF
 	ands r0, r4
@@ -18604,9 +18604,9 @@ _08009286:
 	strh r0, [r5]
 	ldr r4, _080092A0
 	adds r0, r4, 0
-	bl GameFreakRTC_GetControlRegAndRTCDateTime
+	bl GFRTC_GetControlRegAndRtcDateTime
 	adds r0, r4, 0
-	bl GameFreakRTC_TestForErrors
+	bl GFRTC_TestForErrors
 	ldr r1, _080092A4
 	strh r0, [r1]
 _0800929A:
@@ -18648,7 +18648,7 @@ _080092D0: .4byte 0x03000458
 _080092D4: .4byte gUnknown_081E7610
 _080092D8:
 	adds r0, r2, 0
-	bl GameFreakRTC_GetControlRegAndRTCDateTime
+	bl GFRTC_GetControlRegAndRtcDateTime
 _080092DE:
 	pop {r4}
 	pop {r0}
@@ -18659,10 +18659,10 @@ _080092DE:
 GameFreakRTC_GetRTCDateTimeInternal: ; 80092E4
 	push {r4,lr}
 	adds r4, r0, 0
-	bl GameFreakRTC_ClearIME
+	bl GFRTC_DisableInterrupts
 	adds r0, r4, 0
 	bl RTC_GetDateTime
-	bl sub_800910C
+	bl GFRTC_RestoreInterrupts
 	pop {r4}
 	pop {r0}
 	bx r0
@@ -18672,17 +18672,17 @@ GameFreakRTC_GetRTCDateTimeInternal: ; 80092E4
 GameFreakRTC_GetControlReg: ; 80092FC
 	push {r4,lr}
 	adds r4, r0, 0
-	bl GameFreakRTC_ClearIME
+	bl GFRTC_DisableInterrupts
 	adds r0, r4, 0
 	bl RTC_GetControlReg
-	bl sub_800910C
+	bl GFRTC_RestoreInterrupts
 	pop {r4}
 	pop {r0}
 	bx r0
 	thumb_func_end GameFreakRTC_GetControlReg
 
-	thumb_func_start GameFreakRTC_GetControlRegAndRTCDateTime
-GameFreakRTC_GetControlRegAndRTCDateTime: ; 8009314
+	thumb_func_start GFRTC_GetControlRegAndRtcDateTime
+GFRTC_GetControlRegAndRtcDateTime: ; 8009314
 	push {r4,lr}
 	adds r4, r0, 0
 	bl GameFreakRTC_GetControlReg
@@ -18691,10 +18691,10 @@ GameFreakRTC_GetControlRegAndRTCDateTime: ; 8009314
 	pop {r4}
 	pop {r0}
 	bx r0
-	thumb_func_end GameFreakRTC_GetControlRegAndRTCDateTime
+	thumb_func_end GFRTC_GetControlRegAndRtcDateTime
 
-	thumb_func_start GameFreakRTC_TestForErrors
-GameFreakRTC_TestForErrors: ; 8009328
+	thumb_func_start GFRTC_TestForErrors
+GFRTC_TestForErrors: ; 8009328
 	push {r4-r7,lr}
 	mov r7, r8
 	push {r7}
@@ -18716,7 +18716,7 @@ GameFreakRTC_TestForErrors: ; 8009328
 	orrs r4, r0
 _0800934E:
 	ldrb r0, [r7]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	mov r8, r0
 	cmp r0, 0xFF
 	bne _08009362
@@ -18726,7 +18726,7 @@ _0800934E:
 	lsrs r4, r0, 16
 _08009362:
 	ldrb r0, [r7, 0x1]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r6, r0, 0
 	cmp r6, 0xFF
 	beq _08009376
@@ -18741,7 +18741,7 @@ _08009376:
 	lsrs r4, r0, 16
 _0800937E:
 	ldrb r0, [r7, 0x2]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r5, r0, 0
 	cmp r5, 0xFF
 	bne _08009396
@@ -18757,7 +18757,7 @@ _08009396:
 	mov r1, r8
 	lsls r0, r1, 24
 	lsrs r0, 24
-	bl GameFreakRTC_IsLeapYear
+	bl GFRTC_IsLeapYear
 	lsls r0, 24
 	lsrs r0, 24
 	ldr r1, _080093B0
@@ -18783,7 +18783,7 @@ _080093BE:
 	lsrs r4, r0, 16
 _080093CE:
 	ldrb r0, [r7, 0x4]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r5, r0, 0
 	cmp r5, 0x18
 	ble _080093E6
@@ -18795,7 +18795,7 @@ _080093CE:
 	lsrs r4, r0, 16
 _080093E6:
 	ldrb r0, [r7, 0x5]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r5, r0, 0
 	cmp r5, 0x3C
 	ble _080093FE
@@ -18807,7 +18807,7 @@ _080093E6:
 	lsrs r4, r0, 16
 _080093FE:
 	ldrb r0, [r7, 0x6]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	adds r5, r0, 0
 	cmp r5, 0x3C
 	ble _08009416
@@ -18826,14 +18826,14 @@ _08009416:
 	bx r1
 	.align 2
 _08009424: .4byte gUnknown_081E761C
-	thumb_func_end GameFreakRTC_TestForErrors
+	thumb_func_end GFRTC_TestForErrors
 
 	thumb_func_start sub_8009428
 sub_8009428: ; 8009428
 	push {lr}
-	bl GameFreakRTC_ClearIME
+	bl GFRTC_DisableInterrupts
 	bl RTC_Reset
-	bl sub_800910C
+	bl GFRTC_RestoreInterrupts
 	pop {r0}
 	bx r0
 	thumb_func_end sub_8009428
@@ -18970,22 +18970,22 @@ GameFreakRTC_GetRTCDelta: ; 8009534
 	adds r5, r0, 0
 	adds r7, r1, 0
 	adds r6, r2, 0
-	bl GameFreakRTC_GetNumDaysInternal
+	bl GFRTC_GetDayCount
 	adds r4, r0, 0
 	lsls r4, 16
 	lsrs r4, 16
 	ldrb r0, [r5, 0x6]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	ldrb r1, [r6, 0x4]
 	subs r0, r1
 	strb r0, [r7, 0x4]
 	ldrb r0, [r5, 0x5]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	ldrb r1, [r6, 0x3]
 	subs r0, r1
 	strb r0, [r7, 0x3]
 	ldrb r0, [r5, 0x4]
-	bl GameFreakRTC_ConvertFromBCD
+	bl GFRTC_ConvertBcdToBinary
 	ldrb r1, [r6, 0x2]
 	subs r0, r1
 	strb r0, [r7, 0x2]
@@ -19154,7 +19154,7 @@ GameFreakRTC_GetNumMinutes: ; 800968C
 	adds r0, r4, 0
 	bl GameFreakRTC_GetRTCDateTime
 	adds r0, r4, 0
-	bl GameFreakRTC_GetNumDaysInternal
+	bl GFRTC_GetDayCount
 	lsls r0, 16
 	lsrs r0, 16
 	lsls r1, r0, 1
@@ -678074,7 +678074,7 @@ _0814AE2C: .4byte gUnknown_0842F6C0
 	.include "asm/libgcnmultiboot.s"
 	.include "asm/libmks4agb.s"
 	.include "asm/libagbbackup.s"
-	.include "asm/librtc.s"
+	.include "genasm/librtc.s"
 	.include "asm/libagbsyscall.s"
 	.include "asm/libgcc.s"
 	.include "data/data2.s"
diff --git a/include/global.h b/include/global.h
index fec0500f7..0c7fef66e 100644
--- a/include/global.h
+++ b/include/global.h
@@ -1,6 +1,8 @@
 #ifndef GUARD_GLOBAL_H
 #define GUARD_GLOBAL_H
 
+#include <stddef.h>
+
 typedef unsigned char  u8;
 typedef unsigned short u16;
 typedef unsigned int   u32;
@@ -22,8 +24,6 @@ typedef u8  bool8;
 typedef u16 bool16;
 typedef u32 bool32;
 
-#define NULL (void *)0
-
 #define TRUE  1
 #define FALSE 0
 
diff --git a/iwram_syms.txt b/iwram_syms.txt
index 96d059ec9..cbcd2de7b 100644
--- a/iwram_syms.txt
+++ b/iwram_syms.txt
@@ -1,3 +1,5 @@
 gPlayTimeCounterState = 0x300057C;
 
+gRtcLocked = 0x3000F36;
+
 gUnknownStringVar = 0x3002900;
diff --git a/ld_script.txt b/ld_script.txt
index 48982d49d..30ef0fa11 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -3,4 +3,5 @@ ENTRY(Start)
 SECTIONS {
     . = 0x8000000;
     .text : { *(.text); }
+    /DISCARD/ : { *(.rodata) }
 }
diff --git a/src/librtc.c b/src/librtc.c
new file mode 100644
index 000000000..a64c5af89
--- /dev/null
+++ b/src/librtc.c
@@ -0,0 +1,406 @@
+#include "global.h"
+
+struct RtcInfo
+{
+    u8 year;
+    u8 month;
+    u8 dayOfMonth;
+    u8 dayOfWeek;
+    u8 hour;
+    u8 minute;
+    u8 second;
+    u8 control;
+    u8 unknown1;
+    u8 unknown2;
+};
+
+#define OFFSET_YEAR         offsetof(struct RtcInfo, year)
+#define OFFSET_MONTH        offsetof(struct RtcInfo, month)
+#define OFFSET_DAY_OF_MONTH offsetof(struct RtcInfo, dayOfMonth)
+#define OFFSET_DAY_OF_WEEK  offsetof(struct RtcInfo, dayOfWeek)
+#define OFFSET_HOUR         offsetof(struct RtcInfo, hour)
+#define OFFSET_MINUTE       offsetof(struct RtcInfo, minute)
+#define OFFSET_SECOND       offsetof(struct RtcInfo, second)
+#define OFFSET_CONTROL      offsetof(struct RtcInfo, control)
+#define OFFSET_UNKNOWN1     offsetof(struct RtcInfo, unknown1)
+#define OFFSET_UNKNOWN2     offsetof(struct RtcInfo, unknown2)
+
+#define RTC_BUF(info, index) (*((u8 *)(info) + (index)))
+
+#define RTC_DATETIME_BUF(info, index) (*((u8 *)(info) + OFFSET_YEAR + (index)))
+#define RTC_DATETIME_BUF_LEN (OFFSET_SECOND - OFFSET_YEAR + 1)
+
+#define RTC_TIME_BUF(info, index) (*((u8 *)(info) + OFFSET_HOUR + (index)))
+#define RTC_TIME_BUF_LEN (OFFSET_SECOND - OFFSET_HOUR + 1)
+
+extern vu16 GPIOPortData;
+extern vu16 GPIOPortDirection;
+extern vu16 GPIOPortReadWrite;
+
+extern bool8 gRtcLocked;
+
+void RTC_SetReadWrite();
+void RTC_SetReadOnly();
+u8 RTC_Init();
+bool8 RTC_Reset();
+bool8 RTC_GetControlReg(struct RtcInfo *rtc);
+bool8 RTC_SetControlReg(struct RtcInfo *rtc);
+bool8 RTC_GetDateTime(struct RtcInfo *rtc);
+bool8 RTC_SetDateTime(struct RtcInfo *rtc);
+bool8 RTC_GetTime(struct RtcInfo *rtc);
+bool8 RTC_SetTime(struct RtcInfo *rtc);
+bool8 RTC_SetUnknownData(struct RtcInfo *rtc);
+s32 RTC_WriteByte(u8 value);
+s32 RTC_WriteByteReversed(u8 value);
+u8 RTC_ReadByte();
+void RTC_SetReadWriteInternal();
+void RTC_SetReadOnlyInternal();
+
+void RTC_SetReadWrite()
+{
+    RTC_SetReadWriteInternal();
+    gRtcLocked = FALSE;
+}
+
+void RTC_SetReadOnly()
+{
+    RTC_SetReadOnlyInternal();
+    gRtcLocked = TRUE;
+}
+
+u8 RTC_Init()
+{
+    u8 v2;
+    struct RtcInfo rtc;
+
+    if (!RTC_GetControlReg(&rtc))
+        return 0;
+
+    v2 = 0;
+
+    if ((rtc.control & 0xC0) == 0x80 || !(rtc.control & 0xC0))
+    {
+        if (!RTC_Reset())
+            return 0;
+
+        v2++;
+    }
+
+    RTC_GetTime(&rtc);
+
+    if (rtc.second & 0x80)
+    {
+        if (!RTC_Reset())
+            return (v2 << 4) & 0xF0;
+
+        v2++;
+    }
+
+    return (v2 << 4) | 1;
+}
+
+bool8 RTC_Reset()
+{
+    u8 result;
+    struct RtcInfo rtc;
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x60);
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    rtc.control = 0x40;
+
+    result = RTC_SetControlReg(&rtc);
+
+    return result;
+}
+
+bool8 RTC_GetControlReg(struct RtcInfo *rtc)
+{
+    u8 controlData;
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x63);
+
+    GPIOPortDirection = 5;
+
+    controlData = RTC_ReadByte();
+
+    rtc->control = (controlData & 0xC0) | ((controlData & 0x20) >> 3) | ((controlData & 8) >> 2) | ((controlData & 2) >> 1);
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    return TRUE;
+}
+
+bool8 RTC_SetControlReg(struct RtcInfo *rtc)
+{
+    u8 controlData;
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    controlData = ((rtc->control & 4) << 3) | (1 << 6) | ((rtc->control & 2) << 2) | ((rtc->control & 1) << 1);
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x62);
+
+    RTC_WriteByteReversed(controlData);
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    return TRUE;
+}
+
+bool8 RTC_GetDateTime(struct RtcInfo *rtc)
+{
+    u8 i;
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x65);
+
+    GPIOPortDirection = 5;
+
+    for (i = 0; i < RTC_DATETIME_BUF_LEN; i++)
+        RTC_DATETIME_BUF(rtc, i) = RTC_ReadByte();
+
+    RTC_BUF(rtc, OFFSET_HOUR) &= 0x7F;
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    return TRUE;
+}
+
+bool8 RTC_SetDateTime(struct RtcInfo *rtc)
+{
+    u8 i;
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x64);
+
+    for (i = 0; i < RTC_DATETIME_BUF_LEN; i++)
+        RTC_WriteByteReversed(RTC_DATETIME_BUF(rtc, i));
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    return TRUE;
+}
+
+bool8 RTC_GetTime(struct RtcInfo *rtc)
+{
+    u8 i;
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x67);
+
+    GPIOPortDirection = 5;
+
+    for (i = 0; i < RTC_TIME_BUF_LEN; i++)
+        RTC_TIME_BUF(rtc, i) = RTC_ReadByte();
+
+    RTC_BUF(rtc, OFFSET_HOUR) &= 0x7F;
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    return TRUE;
+}
+
+bool8 RTC_SetTime(struct RtcInfo *rtc)
+{
+    u8 i;
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x66);
+
+    for (i = 0; i < RTC_TIME_BUF_LEN; i++)
+        RTC_WriteByteReversed(RTC_TIME_BUF(rtc, i));
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    return TRUE;
+}
+
+bool8 RTC_SetUnknownData(struct RtcInfo *rtc)
+{
+    u8 i;
+    u8 a[2];
+
+    if (gRtcLocked == TRUE)
+        return FALSE;
+
+    gRtcLocked = TRUE;
+
+    a[0] = ((rtc->unknown1 & 0xF) + 10 * ((rtc->unknown1 >> 4) & 0xF));
+
+    if (a[0] <= 0xB)
+        a[0] = rtc->unknown1;
+    else
+        a[0] = rtc->unknown1 | 0x80;
+
+    a[1] = rtc->unknown2;
+
+    GPIOPortData = 1;
+    GPIOPortData = 5;
+
+    GPIOPortDirection = 7;
+
+    RTC_WriteByte(0x68);
+
+    for (i = 0; i < 2; i++)
+        RTC_WriteByteReversed(a[i]);
+
+    GPIOPortData = 1;
+    GPIOPortData = 1;
+
+    gRtcLocked = FALSE;
+
+    return TRUE;
+}
+
+s32 RTC_WriteByte(u8 value)
+{
+    u8 i;
+    u8 temp;
+
+    for (i = 0; i < 8; i++)
+    {
+        temp = ((value >> (7 - i)) & 1);
+        GPIOPortData = (temp << 1) | 4;
+        GPIOPortData = (temp << 1) | 4;
+        GPIOPortData = (temp << 1) | 4;
+        GPIOPortData = (temp << 1) | 5;
+    }
+
+    // control reaches end of non-void function
+}
+
+s32 RTC_WriteByteReversed(u8 value)
+{
+    u8 i;
+    u8 temp;
+
+    for (i = 0; i < 8; i++)
+    {
+        temp = ((value >> i) & 1);
+        GPIOPortData = (temp << 1) | 4;
+        GPIOPortData = (temp << 1) | 4;
+        GPIOPortData = (temp << 1) | 4;
+        GPIOPortData = (temp << 1) | 5;
+    }
+
+    // control reaches end of non-void function
+}
+
+u8 RTC_ReadByte()
+{
+    u8 i;
+    u8 temp;
+    u8 value;
+
+    for (i = 0; i < 8; i++)
+    {
+        GPIOPortData = 4;
+        GPIOPortData = 4;
+        GPIOPortData = 4;
+        GPIOPortData = 4;
+        GPIOPortData = 4;
+        GPIOPortData = 5;
+
+        temp = ((GPIOPortData & 2) >> 1);
+        value = (value >> 1) | (temp << 7); // UB: accessing uninitialized var
+    }
+
+    return value;
+}
+
+void RTC_SetReadWriteInternal()
+{
+    GPIOPortReadWrite = 1;
+}
+
+void RTC_SetReadOnlyInternal()
+{
+    GPIOPortReadWrite = 0;
+}
diff --git a/src/play_time.c b/src/play_time.c
index 69633ca48..f950e31a5 100644
--- a/src/play_time.c
+++ b/src/play_time.c
@@ -1,4 +1,5 @@
 #include "global.h"
+#include "play_time.h"
 
 enum
 {