3 files changed, 96 insertions, 0 deletions
diff --git a/arm7/lib/include/OS_tick.h b/arm7/lib/include/OS_tick.h
new file mode 100644
index 00000000..892e0499
--- /dev/null
+++ b/arm7/lib/include/OS_tick.h
@@ -0,0 +1,11 @@
+#ifndef POKEDIAMOND_OS_TICK_H
+#define POKEDIAMOND_OS_TICK_H
+
+#include "OS_timer.h"
+
+void OS_InitTick(void);
+u16 OS_IsTickAvailable(void);
+void OSi_CountUpTick(void);
+u64 OS_GetTick(void);
+
+#endif
diff --git a/arm7/lib/include/OS_timer.h b/arm7/lib/include/OS_timer.h
new file mode 100644
index 00000000..697842fe
--- /dev/null
+++ b/arm7/lib/include/OS_timer.h
@@ -0,0 +1,32 @@
+#ifndef POKEDIAMOND_OS_TIMER_H
+#define POKEDIAMOND_OS_TIMER_H
+
+#include "consts.h"
+
+typedef enum
+{
+    OS_TIMER_PRESCALER_1 = (0UL << REG_OS_TM0CNT_H_PS_SHIFT),
+    OS_TIMER_PRESCALER_64 = (1UL << REG_OS_TM0CNT_H_PS_SHIFT),
+    OS_TIMER_PRESCALER_256 = (2UL << REG_OS_TM0CNT_H_PS_SHIFT),
+    OS_TIMER_PRESCALER_1024 = (3UL << REG_OS_TM0CNT_H_PS_SHIFT)
+} OSTimerPrescaler;
+
+typedef enum
+{
+    OS_TIMER_0 = 0,
+    OS_TIMER_1 = 1,
+    OS_TIMER_2 = 2,
+    OS_TIMER_3 = 3
+} OSTimer;
+
+static inline void OS_SetTimerCount(OSTimer id, u16 count)
+{
+    *((REGType16 *)((u32)&reg_OS_TM0CNT_L + id * 4)) = count;
+}
+
+static inline void OS_SetTimerControl(OSTimer id, u16 control)
+{
+    *((REGType16 *)((u32)&reg_OS_TM0CNT_H + id * 4)) = control;
+}
+
+#endif 
+\ No newline at end of file
diff --git a/arm7/lib/src/OS_tick.c b/arm7/lib/src/OS_tick.c
new file mode 100644
index 00000000..063b05c9
--- /dev/null
+++ b/arm7/lib/src/OS_tick.c
@@ -0,0 +1,53 @@
+#include "OS_interrupt.h"
+#include "OS_system.h"
+#include "OS_tick.h"
+#include "function_target.h"
+
+extern void OSi_SetTimerReserved(u32);
+
+static u16 OSi_UseTick;
+static u64 OSi_TickCounter;
+static BOOL OSi_NeedResetTimer;
+
+ARM_FUNC void OS_InitTick(void) {
+    if (OSi_UseTick == 0) {
+        OSi_UseTick = 1;
+        OSi_SetTimerReserved(0);
+        OSi_TickCounter = 0;
+        OS_SetTimerControl(OS_TIMER_0, 0);
+        OS_SetTimerCount(OS_TIMER_0, 0);
+        OS_SetTimerControl(OS_TIMER_0, 0xc1);
+        OS_SetIrqFunction(8, OSi_CountUpTick);
+        (void)OS_EnableIrqMask(8);
+        OSi_NeedResetTimer = 0;
+    }
+}
+
+ARM_FUNC u16 OS_IsTickAvailable(void) {
+    return OSi_UseTick;
+}
+
+ARM_FUNC void OSi_CountUpTick(void) {
+    OSi_TickCounter++;
+    if (OSi_NeedResetTimer != 0) {
+        OS_SetTimerControl(OS_TIMER_0, 0);
+        OS_SetTimerCount(OS_TIMER_0, 0);
+        OS_SetTimerControl(OS_TIMER_0, 0xc1);
+        OSi_NeedResetTimer = 0;
+    }
+    OSi_EnterTimerCallback(0, (void(*)(void*))OSi_CountUpTick, NULL);
+}
+
+ARM_FUNC u64 OS_GetTick(void) {
+    OSIntrMode prev = OS_DisableInterrupts();
+    vu16 countL = *(REGType16 *)((u32)&reg_OS_TM0CNT_L + OS_TIMER_0 * 4);
+    vu64 countH = OSi_TickCounter & 0xffffffffffffULL;
+
+    if (reg_OS_IF & 8 && !(countL & 0x8000)) {
+        countH++;
+    }
+
+    (void)OS_RestoreInterrupts(prev);
+
+    return (countH << 16) | countL;
+}