Kernel Interrupt Events

KBaseInterruptEvent

Abstract base class for all interrupt events.

Size: 0x4 bytes

Offset	Type	Description
0x0	void **	Pointer to vtable

This abstract base class defines virtual KSchedulableInterruptEvent* handleInterruptAndGetKSchedulableInterruptEvent(u32 interruptID) = 0. It’s actually the function called by the IRQ handler, which returns a KSchedulableInterruptEvent to call the second virtual method of (which signals the object) after a reschedule.

If either NULL or 1 is returned, nothing will be signaled. If NULL is returned, no post-interrupt rescheduling will be done.

KCacheMaintenanceInterruptEvent

Kernel Interrupt Events

class KCacheMaintenanceInterruptEvent extends KBaseInterruptEvent

This object handles data cache (L2C not included) and instruction cache maintainance.

There is only one instance of this object.

Size : 0x4C bytes (N3DS) / 0x34 bytes (O3DS)

Offset	Type	Description
0x0	void **	Pointer to vtable
0x4	u8	Cache operation
0x5	u8	Indicates whether to do the operation asynchronically (this is what is used when processes are running for ranges >= 0x200 bytes)
0x6	s8	Number of cores still doing cache maintenance operations
0x7	u8	Padding
0x8	KThread *	Thread operating on the object
0xC	void *	Start address (when applicable)
0x10	void *	End address (when applicable)
0x14	KThreadLinkedListNode *	Related to KThread+0xA0
0x18	KThreadLinkedList *	KThread+0xA8 of the current thread
0x1C	KAsyncCacheMaintenanceInterruptEvent[number of cores]	Used when the field at offset 0x5 is 1, see below

Possible operations (any other value leads to a kernel panic):

KDebug

Kernel Synchronization Objects, Kernel Interrupt Events

class KDebug extends KSynchronizationObject and KSendableInterruptEvent;

Size : 0xA0 bytes

Offset	Type	Description
0x0	u32	Pointer to vtable
0x4	u32	Reference count
0x8	u32	Count of KThreads that sync with this object - number of nodes in the linked list below
0xC	KLinkedListNode*	Pointer to first KLinkedListNode in node list of KThreads that sync with this object
0x10	KLinkedListNode*	Pointer to last KLinkedListNode in node list of KThreads that sync with this object
0x14	KSendableInterruptEvent	Process termination event
0x1C	u8	Indicates an ATTACH PROCESS event has been signaled to this object
0x1D	u8	Debug string length >> 31, always 0
0x1E	u8	Indicates that a debug event is currently being signaled to this object
0x1F	u8	Indicates that the parent process is paused (using svcBreakDebugProcess). svcContinueDebugEvent will ignore all debug events other than EXIT PROCESS, and some other debug SVCs will return an error.
0x20	DebugEventType	Type of the latest debug event
0x24	u32	Unknown, probably unused
0x28	KThread *	Thread having exclusive access to this object
0x2C	u32	Debug event flags set by svcContinueDebugEvents Bit0: no exception dumps are made if this is set. Bit1 and following: report EXCEPTION (this flag is bypassed for svc 0xFF), SCHEDULE, SYSCALL, MAP debug events, respectively.
0x30	u32	Stop point type that caused the event: 0 = svc 0xFF, 1 = breakpoint, 2 = watchpoint (otherwise it’s not updated).
0x34	u32	Count of KEventInfo object nodes to be fetched with svcGetProcessDebugEvent (associated with this KDebug object)
0x38	KLinkedListNode*	Pointer to first KLinkedListNode in linked list of KEventInfo objects to be fetched with svcGetProcessDebugEvent
0x3C	KLinkedListNode*	Pointer to last KLinkedListNode in linked list of KEventInfo objects to be fetched with svcGetProcessDebugEvent
0x40	u32	Count of KEventInfo object nodes to be fetched with svcContinueDebugEvent (associated with this KDebug object)
0x44	KLinkedListNode*	Pointer to first KLinkedListNode in linked list of KEventInfo objects to be fetched with svcContinueDebugEvent
0x48	KLinkedListNode*	Pointer to last KLinkedListNode in linked list of KEventInfo objects to be fetched with svcContinueDebugEvent
0x4C	KProcess*	Parent process
0x50	KThread*	Current KThread- thread being debugged
0x54	KThread*	Thread using ContinueDebugEvent
0x58	s32	Cpu core of thread using ContinueDebugEvent
0x5C	u32	Count of KDebugThread object nodes associated with this KDebug object
0x60	KLinkedListNode*	Pointer to first KLinkedListNode in linked list of KDebugThread objects
0x64	KLinkedListNode*	Pointer to last KLinkedListNode in linked list of KDebugThread objects
0x68	u32	List size; this KLinkedList of all the KThread instances of the parent process: the currently running threads followed the others, by core then by dynamic priority.
0x6C	KLinkedListNode*	Pointer to first KLinkedListNode in the above list
0x70	KLinkedListNode*	Pointer to last KLinkedListNode in the above list
0x74	KRecursiveLock	Recursive lock
0x7C	KThread*	Current KThread- used in svcBreak
0x80	u8	Cleared when an EXCEPTION debug event was (attempted to be) signaled (i.e. even when bit2 of the debug flag is clear)
0x81	u8	Indicates that an EXCEPTION debug event was signaled
0x82	u8	Indicates that all threads should be unlocked
0x83	u8	Indicates that an EXCEPTION debug event different from USER_BREAK was continued, while the process was paused
0x84	u8	Indicates that a USER_BREAK debug event was continued while the process was paused
0x85	u8	Indicates that the KProcess instance it belongs to has exited (normally ?)
0x86	u8	Indicates that the KProcess instance it belongs to has been terminated
0x87	u8	Indicates that svcBreak was used and not yet handled by svcContinueDebugEvent, with type != (UN)LOAD_RO
0x88	u32 *	Register dump
0x8C	u32	Exception type
0x90	u16	Number of “EXCEPTION” events encountered (0 or 1)
0x92	u16	ID of the invalid SVC that was attempted
0x94	u16	Total number of debug events associated with this object awaiting svcContinueDebugEvent
0x96	u16	Number of EXIT PROCESS debug events associated with this object awaiting svcContinueDebugEvent
0x98	const char *	Debug string
0x9C	u32	Debug string length

Category:Kernel synchronization objects Category:Kernel interrupt events

KEvent

Kernel Synchronization Objects, Kernel Interrupt Events

class KEvent extends KSynchronizationObject and KUserBindableInterruptEvent;

Size : 0x28 bytes

Offset	Type	Description
0x0	u32	Pointer to vtable
0x4	u32	Reference count
0x8	u32	Count of KThreads that sync with this object - number of nodes in the linked list below
0xC	KLinkedListNode*	Pointer to first KLinkedListNode in node list of KThreads that sync with this object
0x10	KLinkedListNode*	Pointer to last KLinkedListNode in node list of KThreads that sync with this object
0x14	KUserBindableInterruptEvent	Interrupt event (*this)
0x20	bool	Event is signaled
0x21	bool	Manual clear
0x22	u8	Reset type
0x23	u8	Unused, alignment
0x24	KProcess *	Owner

Category:Kernel synchronization objects Category:Kernel interrupt events

KFIQInterruptEvent

Kernel Interrupt Events

class KFIQInterruptEvent extends KSynchronizationInterruptEvent

Size : 0x10 bytes

Interrupt event object associated with SGI #15, which is the only private interrupt that can be bound using svcBindInterrupt.

Although that SGI #15 is sent to both core0 and core1, there’s only one instance of KFIQInterruptEvent for all cores, the fields of which are set by svcBindInterrupt. If it has been bound on one core, it can’t be bound on the others (0xD8A007FC, “already exists”, is returned). It is usually bound by the dmnt or the debugger sysmodules.

KProcess

Kernel Synchronization Objects, Kernel Interrupt Events

class KProcess extends KSynchronizationObject and KSendableInterruptEvent;

Size : 0x270 (N3DS) / 0x268 bytes (O3DS post 8.x) / 0x260 bytes (O3DS pre 8.x). 0x4D8 bytes on ARM9. The only field that changed is the KProcessHwInfo member instance. The definition of KProcess remain identical in all cases.

The listed offsets are N3DS-only.

Offset	Type	Description
0x0	void**	Pointer to vtable
0x4	u32	Reference count
0x8	u32	Count of KThreads that sync with this object - number of nodes in the linked list below
0xC	KLinkedListNode*	Pointer to first KLinkedListNode in node list of KThreads that sync with this object
0x10	KLinkedListNode*	Pointer to last KLinkedListNode in node list of KThreads that sync with this object
0x14	KSendableInterruptEvent	Interrupt event (*this) sent to terminate the process
0x1C	KProcessHwInfo	Process hardware/context info. Used to manage segmentation, etc.
0x68	u32	Total size of all Thread Context pages owned by threads that belong to this process
0x6C	u32	Number of KThreadLocalPages used by this KProcess
0x70	KLinkedListNode*	Pointer to first KLinkedListNode in the list of KThreadLocalPages
0x74	KLinkedListNode*	Pointer to last KLinkedListNode in the list of KThreadLocalPages
0x78	u32	Unknown
0x7C	s32	Ideal processor for this process
0x80	KDebug*	KDebug object created from svc 0x60 to debug the process
0x84	KResourceLimit*	Pointer to resource limits for process.
0x88	u8	Normally 1 to indicate process is open/available. Set to 2 to indicate process is exiting/closing and 3 to indicate exited/closed.
0x89	u8	Process affinity mask
0x8A	u16	Unused, alignment
0x8C	s16	Number of threads which belong to this process.
0x8E	s16	Max number of threads which can belong to this process. This is always 0.
0x90	0x10-bytes	SVC access control mask from the exheader kernel descriptors. This is copied to the Thread Context area when creating threads, which is the actual data the SVC-handler checks for SVC-access-control.
0xA0	u32[4]	Interrupt flags- 32 interrupts per word, 4 words, 0x80 interrupts total divided evenly across 4 words
0xB0	u32	Kernel flags from the exheader kernel descriptors.
0xB4	u16	Handle table size from the exheader kernel descriptors. When this is 0, handle table is stored in WRAM.
0xB6	u16	Kernel release version field, from the exheader kernel descriptors.
0xB8	KCodeSet*	Pointer to KCodeSet instance
0xBC	u32	Process id, this always begins at 0x0 for the first process.
0xC0	s64	Process creation time as tick count
0xC8	KThread*	Pointer to the process’s main thread.
0xCC	u32[4]	Interrupt enabled flags- 32 interrupts per word, 4 words, 0x80 interrupts total divided evenly across 4 words
0xDC	KProcessHandleTable	This is the data for tracking and using all of the KProcess’s handles.
0x234	u32	Unused (From here up, everything is set to 0 on creation, has 0 written to it again during process creation, and is never used again.)
0x238	u64	Unused
0x240	u64	Unused
0x248	u64	Unused
0x250	u64	Unused
0x258	u64	Unused
0x260	u64	Unused
0x268	u64	Unused

KProcessHandleTable #

Offset	Type	Description
0x0	HandleDescriptor*	Pointer to the process’s handle table.
0x4	s16	The max number of handles that can be open at once - usually 0x200.
0x6	s16	The highest count of handles that have been open at once
0x8	HandleDescriptor*	Pointer to the next open HandleDescriptor entry in the handle table.
0xC	s16	Total handles used by this KProcess.
0xE	s16	The current number of handles in use.
0x10	KObjectMutex	Mutex
0x18	HandleDescriptor[0x28]	This small handle data table, internal to the KProcess, is only used in certain processes that don’t have an external handle descriptor table in FCRAM. It is all zeros in most processes.

HandleDescriptor #

Offset	Type	Description
0x0	u32	Handle info
0x4	u32	Pointer to the kernel object that the handle references.

The handle info u32 works as such:

KSchedulableInterruptEvent

Kernel Interrupt Events

class KSchedulableInterruptEvent extends KSynchronizationInterruptEvent

Size : 0x8 bytes

Abstract class used as base for KScheduler, KFIQInterruptEvent, KUserBindableInterruptEvent, KThread, etc.

The virtual interrupt function of this class returns an instance to this (as KSchedulableInterruptEvent). After being added to the KSchedulableInterruptEventLinkedList instance of the current core and picked up by its kernel thread, the second virtual function is executed. The instances of the subclasses that also inherit from KSynchronizationObject are signaled as well.

KScheduler

Kernel Interrupt Events

class KScheduler extends KSchedulableInterruptEvent;

Size : 0x228 bytes

Offset	Type	Description
0x0	void **	Pointer to vtable
0x4	KSynchronizationObject *	Inherited field. Unused.
0x8	u32	Count for thread switch attempts - this is only added to if a context switch function runs but exits because the scheduler is locked by another thread.
0xC	bool	Context switch needed
0xD	bool	Context switch started during interrupt
0xE	bool	Trigger CPU cross-core interrupt (interrupt 8)
0xF	bool	Post-interrupt rescheduling needed
0x10	s16	Scheduler core number
0x12	s16	Count of threads currently being managed by this scheduler object
0x14	u32	Bit field for high priority threads in KScheduler(0-31)
0x18	u32	Bit field for low priority threads in KScheduler(32-63)
0x1C	KThread*	Scheduler’s idle thread (runs when no other runnable thread is available)
0x20	KThreadLinkedList	Linked list of threads managed by this KScheduler instance
0x28	ThreadSchedulePrioList[64]	List of KThread pair structs by priority

There is 1 KScheduler object per core.

KSemaphore

Kernel Synchronization Objects, Kernel Interrupt Events

class KSemaphore extends KSynchronizationObject and KUserBindableInterruptEvent;

Size : 0x2C bytes

Offset	Type	Description
0x0	u32	Pointer to vtable
0x4	u32	Reference count
0x8	u32	Count of KThreads that sync with this object - number of nodes in the linked list below
0xC	KLinkedListNode*	Pointer to first KLinkedListNode in list of KThreads that sync with this semaphore
0x10	KLinkedListNode*	Pointer to last KLinkedListNode in list of KThreads that sync with this semaphore
0x14	KUserBindableInterruptEvent	Interrupt event (*this)
0x20	u32	Count
0x24	u32	Max count
0x28	KProcess*	Owner

Category:Kernel synchronization objects Category:Kernel interrupt events

KSendableInterruptEvent

Kernel Interrupt Events

class KSendableInterruptEvent extends KSynchronizationInterruptEvent;

Size : 0x8 bytes

Abstract class used as base for KProcess, KThread and some DMA-related object. Used with KInterruptEventMailbox

Offset	Type	Description
0x0	void **	Pointer to vtable
0x4	KSynchronizationInterruptEvent *	Next interrupt event (associated with the current one), of type KSendableInterruptEvent

Category:Kernel interrupt events

KSynchronizationInterruptEvent

Kernel Interrupt Events

class KSynchronizationInterruptEvent extends KBaseInterruptEvent

Size : 0x8 bytes

This this the abstract base class for all interrupt events related to synchronization objects: KSchedulableInterruptEvent, KTimeableInterruptEvent and KSendableInterruptEvent

There’s no new virtual function defined by this class.

Offset	Type	Description
0x0	void **	Pointer to vtable
0x4	KSynchronizationInterruptEvent *	Next interrupt event (associated with the current one). The linked list represented by this attribute can contain cycles

Category:Kernel interrupt events

KThread

Kernel Synchronization Objects, Kernel Interrupt Events

class KThread extends KSynchronizationObject, KTimeableInterruptEvent, KSendableInterruptEvent and KSchedulableInterruptEvent;

Size : 0xB0 bytes

Offset	Type	Description
0x0	u32	Pointer to vtable
0x4	u32	Reference count
0x8	u32	Count of KThreads that sync with this object - number of nodes in the linked list below
0xC	KLinkedListNode*	Pointer to first KLinkedListNode in node list of KThreads that sync with this object
0x10	KLinkedListNode*	Pointer to last KLinkedListNode in node list of KThreads that sync with this object
0x14	KTimeableInterruptEvent	Used to suspend threads (*this)
0x24	KSendableInterruptEvent	Interrupt event (*this) sent to terminate a thread, except in the case just below
0x2C	KSchedulableInterruptEvent	Interrupt event (this) scheduled by the IRQ handler when the thread should terminate (this)
0x34	u8	Scheduling mask
0x35	u8	Set to 1 when a thread is woken up from a svcSendSyncRequest call due to the ServerSession endpoint closing down
0x36	s8	Indicates that the thread shall terminate
0x37	u8	Indicates there was an error translating the parameters in the command buffer during an IPC call
0x38	KDebugThread*	Pointer to KDebugThread object used with the current KThread
0x3C	u32	Base thread priority
0x40	u32	Pointer to object the KThread is waiting on- can be a timer, event, session, etc.
0x44	Result	Status for object above
0x48	KObjectMutex*	Locking kernel mutex
0x4C	u32	Arbitration address
0x50	KLinkedListNode*	Pointer to first KLinkedListNode in node list of objects this thread is waiting on
0x54	KLinkedListNode*	Pointer to last KLinkedListNode in node list of objects this thread is
0x5C	KMutexLinkedList *	Set in some very specific circumstances
0x60	u32	Count of KMutex objects this thread is using
0x64	KLinkedListNode*	Pointer to first KLinkedListNode in node list of KMutex objects this thread is using
0x68	KLinkedListNode*	Pointer to last KLinkedListNode in node list of KMutex objects this thread is using
0x6C	s32	Dynamic thread priority
0x70	s32	Processor that created the thread (in the sense of “first ran”) ; processor the thread is running in
0x74	KPreemptionTimer *	Points to KResourceLimit+0x60, which among other things holds the amount of CPU time available in ticks, or NULL
0x7C	u8	Thread is alive
0x7D	u8	Thread has been terminated
0x7E	u8	Thread affinity mask - set differently depending on whether the thread is created via svc call or from inside the kernel
0x80	KProcess*	Process the thread belongs to (virtual address)
0x84	u32	Thread id
0x88	u32*	Ptr to svc mode register storage for KThread inside the thread context.
0x8C	u32*	End-address of the page for this thread context allocated in the 0xFF4XX000 region. Thus, if the beginning of this mapped page is 0xFF401000, this ptr would be 0xFF402000. Thread context page - used for thread svc stack, preserving svc mode registers and VFP exception register for thread.
0x90	s32	Ideal processor (processorid value from svcCreateThread)
0x94	void*	Ptr to Thread Local Storage
0x98	void*	Ptr to Thread Local Storage in FCRAM via kernel vmem
0xA0	KThreadLinkedListNode	Previous and next scheduled threads
0xA8	KThreadLinkedList *	Pointer to linked list of scheduled threads that has stolen it, or 0 if in normal list
0xAC	s32	Priority to restore after sleep if suspended, otherwise -1

With the following declarations: struct KThreadLinkedList { KThread *first, *last; }; and struct KThreadLinkedListNode { KThread *prev, *next; };.

KTimeableInterruptEvent

Kernel Interrupt Events

class KTimeableInterruptEvent extends KSynchronizationInterruptEvent

Size : 0x10 bytes

Abstract class used as base for KThread, KTimer, and the dummy subclass of the attribute at offset 0x10 of KTimerAndWDTManager. Instances of these classes are kept track of by the KTimerAndWDTManager.

As of 11.3.0-36, a second virtual method was added to decide whether to remove an object from the list of objects tracked by the KTimerAndWDTManager instance, see changelog.

Offset	Type	Description
0x0	void **	Pointer to vtable
0x4	KSynchronizationInterruptEvent *	Next interrupt event (associated with the current one). The linked list represented by this attribute can contain cycles. For KThread instances, this is usually a KTimer, and vice-versa
0x8	s64	Desired time point (relative to the CPU power-on) in CPU ticks for KTimerAndWDTManager when it’s handling its list of KTimeableInterruptEvent instances

Category:Kernel interrupt events

KTimer

Kernel Synchronization Objects, Kernel Interrupt Events

class KTimer extends KSynchronizationObject and KTimeableInterruptEvent;

Size : 0x3C bytes

Offset	Type	Description
0x0	u32	Pointer to vtable
0x4	u32	Reference count
0x8	u32	Count of KThreads that sync with this object - number of nodes in the linked list below
0xC	KLinkedListNode*	Pointer to first KLinkedListNode in node list of KThreads that sync with this object
0x10	KLinkedListNode*	Pointer to last KLinkedListNode in node list of KThreads that sync with this object
0x14	KTimeableInterruptEvent	Interrupt event (*this) to be used with KTimerAndWDTManager holding its desired time point (relative to the CPU power-on) in CPU ticks (when handling its list of KTimableInterruptEvent instances). Gets incremented at each interval
0x24	u8	Timer is signaled
0x25	u8	Timer reset type (one shot, sticky, pulse)
0x26	u16	Starting from 11.3.0-36: set to 0 prior to removing the timer from the KTimerAndWDTManager queue, set to 1 just after that.
0x28	s64	Interval in nanoseconds
0x30	s64	Current value in nanoseconds: current system uptime + user-specified time offset, updated at each interval
0x38	KProcess*	Owner

Negative intervals and time offsets are considered null.

KTimerAndWDTManager

Kernel Interrupt Events

class KTimerAndWDTManager extends KSchedulableInterruptEvent

Size : 0x28 bytes

This is the interrupt event object associated with SGIs #29 and #30 (timer and watchdog timer interrupts). It keeps tracks of the system uptime and manages KTimeableInterruptEvent instances.

The interrupt handler of this object updates its counter attributes and returns 0 if it was called with interuptID = 31 (or any invalid interruptID value) (Watchdog timer underflow), otherwise it does nothing and returns the object itself (timer interrupt).

KTLBOperationsInterruptEvent

Kernel Interrupt Events

class KTLBOperationsInterruptEvent extends KBaseInterruptEvent

There is one instance of this object per core.

Size : 0x10 bytes

Offset	Type	Description
0x0	void **	Pointer to vtable
0x4	KProcessHwInfo*	Context info (for operation 1)
0x8	void *	Virtual address (for operation 2)
0xC	u32	Current operation

Possible operations (any other value leads to a kernel panic):

Operation	Description
0	No operation (when an operation is completed, the interrupt handler sets this value)
1	Invalidate unified TLB entries on context ID match
2	Invalidate entire unified TLB
3	Invalidate unified TLB entries on VA match
4	Reset context: sets the context ID to 0 and TTB0 to

Category:Kernel interrupt events

KUserBindableInterruptEvent

Kernel Interrupt Events

class KUserBindableInterruptEvent extends KSchedulableInterruptEvent

Size : 0xC bytes

Abstract class which is a base class for KEvent and KSemaphore, to be used with svcBindInterrupt.

Semaphores cannot be bound to level high (“rising edge”) active interrupts.

For public interrupts (i.e. anything else than SGI #15 in this case), svcBindInterrupt sets the flag that indicates that the interrupt shall be disabled after each time the interrupt is received.

The second virtual function reenables the interrupt (using the interrupt ID) and signals the object (as synchronization object). In the case of KSemaphore this also increments the semaphore’s count.