SVC

System calls

Id	Name	In	Out
0x1	#svcSetHeapSize	W1=size	W0=result, X1=outaddr
0x2	#svcSetMemoryPermission	X0=addr, X1=size, W2=prot	W0=result
0x3	#svcSetMemoryAttribute	X0=addr, X1=size, W2=state0, W3=state1	W0=result
0x4	#svcMapMemory	X0=dstaddr, X1=srcaddr, X2=size	W0=result
0x5	#svcUnmapMemory	X0=dstaddr, X1=srcaddr, X2=size	W0=result
0x6	#svcQueryMemory	X0=MemoryInfo*, X2=addr	W0=result, W1=PageInfo
0x7	#svcExitProcess	None
0x8	#svcCreateThread	X1=entry, X2=thread_context, X3=stacktop, W4=prio, W5=processor_id	W0=result, W1=handle
0x9	#svcStartThread	W0=thread_handle	W0=result
0xA	#svcExitThread	None
0xB	#svcSleepThread	X0=nano	W0=result
0xC	#svcGetThreadPriority	W1=thread_handle	W0=result, W1=prio
0xD	#svcSetThreadPriority	W0=thread_handle, W1=prio	W0=result
0xE	#svcGetThreadCoreMask	W2=thread_handle	W0=result, W1=out, X2=out
0xF	#svcSetThreadCoreMask	W0=thread_handle, W1=in, X2=in2	W0=result
0x10	#svcGetCurrentProcessorNumber	None	W0/X0=cpuid
0x11	svcSignalEvent	W0=wevent_handle	W0=result
0x12	svcClearEvent	W0=wevent_or_revent_handle	W0=result
0x13	#svcMapSharedMemory	W0=shmem_handle, X1=addr, X2=size, W3=perm	W0=result
0x14	svcUnmapSharedMemory	W0=shmem_handle, X1=addr, X2=size	W0=result
0x15	#svcCreateTransferMemory	X1=addr, X2=size, W3=perm	W0=result, W1=tmem_handle
0x16	svcCloseHandle	W0=handle	W0=result
0x17	svcResetSignal	W0=revent_or_process_handle	W0=result
0x18	#svcWaitSynchronization	X1=handles_ptr, W2=num_handles. X3=timeout	W0=result, W1=handle_idx
0x19	svcCancelSynchronization	W0=thread_handle	W0=result
0x1A	svcArbitrateLock	W0=cur_thread_handle, X1=ptr, W2=req_thread_handle
0x1B	svcArbitrateUnlock	X0=ptr
0x1C	svcWaitProcessWideKeyAtomic	X0=ptr0, X1=ptr, W2=thread_handle, X3=timeout	W0=result
0x1D	svcSignalProcessWideKey	X0=ptr, W1=value	W0=result
0x1E	#svcGetSystemTick	None	X0={value of cntpct_el0}
0x1F	svcConnectToNamedPort	X1=port_name_str	W0=result, W1=handle
0x20	svcSendSyncRequestLight	W0=light_session_handle, X1=?	W0=result
0x21	svcSendSyncRequest	X0=normal_session_handle	W0=result
0x22	#svcSendSyncRequestWithUserBuffer	X0=cmdbufptr, X1=size, X2=handle	W0=result
0x23	svcSendAsyncRequestWithUserBuffer	X1=cmdbufptr, X2=size, X3=handle	W0=result, W1=revent_handle
0x24	svcGetProcessId	W1=thread_or_process_or_debug_handle	W0=result, X1=pid
0x25	svcGetThreadId	W1=thread_handle	W0=result, X1=out
0x26	#svcBreak	X0=break_reason,X1,X2=info	?
0x27	svcOutputDebugString	X0=str, X1=size	W0=result
0x28	svcReturnFromException	X0=result
0x29	#svcGetInfo	X1=info_id, X2=handle, X3=info_sub_id	W0=result, X1=out
0x2A	svcFlushEntireDataCache	None	None
0x2B	svcFlushDataCache	X0=addr, X1=size	W0=result
0x2C	[3.0.0+] #svcMapPhysicalMemory	X0=addr, X1=size	W0=result
0x2D	[3.0.0+] svcUnmapPhysicalMemory	X0=addr, X1=size	W0=result
0x2E	[5.0.0+] svcGetFutureThreadInfo	X3=timeout	W0=result, bunch of crap
0x2F	svcGetLastThreadInfo	None	W0=result, W1,W2,W3,W4=unk, W5=truncated_u64, W6=bool
0x30	svcGetResourceLimitLimitValue	W1=reslimit_handle, W2=#LimitableResource	W0=result, X1=value
0x31	svcGetResourceLimitCurrentValue	W1=reslimit_handle, W2=#LimitableResource	W0=result, X1=value
0x32	svcSetThreadActivity	W0=thread_handle, W1=bool	W0=result
0x33	svcGetThreadContext3	X0=#ThreadContext*, W1=thread_handle	W0=result
0x34	[4.0.0+] svcWaitForAddress	X0=ptr, W1=#ArbitrationType, X2=value X3=timeout
0x35	[4.0.0+] svcSignalToAddress	X0=ptr, W1=#SignalType, X2=value W3=num_to_signal
0x3C	#svcDumpInfo
0x3D	[4.0.0+] svcDumpInfoNew
0x40	svcCreateSession	W2=is_light, X3=?	W0=result, W1=server_handle, W2=client_handle
0x41	#svcAcceptSession	W1=port_handle	W0=result, W1=session_handle
0x42	svcReplyAndReceiveLight	W0=light_session_handle	W0=result, W1,W2,W3,W4,W5,W6,W7=out
0x43	#svcReplyAndReceive	X1=ptr_handles, W2=num_handles, X3=replytarget_handle(0=none), X4=timeout	W0=result, W1=handle_idx
0x44	svcReplyAndReceiveWithUserBuffer	X1=buf, X2=sz, X3=ptr_handles, W4=num_handles, X5=replytarget_handle(0=none), X6=timeout	W0=result, W1=handle_idx
0x45	svcCreateEvent	None	W0=result, W1=wevent_handle, W2=revent_handle
0x48	[5.0.0+] #svcMapPhysicalMemoryUnsafe	X0=addr, X1=size	W0=result
0x49	[5.0.0+] svcUnmapPhysicalMemoryUnsafe	X0=addr, X1=size	W0=result
0x4A	[5.0.0+] svcSetUnsafeLimit	X0=size	W0=result
0x4B	[4.0.0+] #svcCreateCodeMemory	X1=addr, X2=size	W0=result, W1=code_memory_handle
0x4C	[4.0.0+] #svcControlCodeMemory	W0=code_memory_handle, W1=#CodeMemoryOperation, X2=dstaddr, X3=size, W4=perm	W0=result
0x4D	svcSleepSystem	None	None
0x4E	#svcReadWriteRegister	X1=reg_addr, W2=rw_mask, W3=in_val	W0=result, W1=out_val
0x4F	svcSetProcessActivity	W0=process_handle, W1=bool	W0=result
0x50	#svcCreateSharedMemory	W1=size, W2=myperm, W3=otherperm	W0=result, W1=shmem_handle
0x51	#svcMapTransferMemory	X0=tmem_handle, X1=addr, X2=size, W3=perm	W0=result
0x52	#svcUnmapTransferMemory	W0=tmemhandle, X1=addr, X2=size	W0=result
0x53	svcCreateInterruptEvent	X1=irq_num, W2=flag	W0=result, W1=handle
0x54	#svcQueryPhysicalAddress	X1=addr	W0=result, X1=physaddr, X2=kerneladdr, X3=size
0x55	#svcQueryIoMapping	X1=physaddr, X2=size	W0=result, X1=virtaddr
0x56	#svcCreateDeviceAddressSpace	X1=dev_as_start_addr, X2=dev_as_end_addr	W0=result, W1=dev_as_handle
0x57	#svcAttachDeviceAddressSpace	W0=device, X1=dev_as_handle	W0=result
0x58	#svcDetachDeviceAddressSpace	W0=device, X1=dev_as_handle	W0=result
0x59	#svcMapDeviceAddressSpaceByForce	W0=dev_as_handle, W1=proc_handle, X2=dev_map_addr, X3=dev_as_size, X4=dev_as_addr, W5=perm	W0=result
0x5A	#svcMapDeviceAddressSpaceAligned	W0=dev_as_handle, W1=proc_handle, X2=dev_map_addr, X3=dev_as_size, X4=dev_as_addr, W5=perm	W0=result
0x5B	svcMapDeviceAddressSpace
0x5C	#svcUnmapDeviceAddressSpace	W0=dev_as_handle, W1=proc_handle, X2=dev_map_addr, X3=dev_as_size, X4=dev_as_addr	W0=result
0x5D	svcInvalidateProcessDataCache	W0=process_handle, X1=addr, X2=size	W0=size
0x5E	svcStoreProcessDataCache	W0=process_handle, X1=addr, X2=size	W0=size
0x5F	svcFlushProcessDataCache	W0=process_handle, X1=addr, X2=size	W0=size
0x60	svcDebugActiveProcess	X1=pid	W0=result, W1=debug_handle
0x61	svcBreakDebugProcess	W0=debug_handle	W0=result
0x62	svcTerminateDebugProcess	W0=debug_handle	W0=result
0x63	svcGetDebugEvent	X0=#DebugEventInfo*, W1=debug_handle	W0=result
0x64	svcContinueDebugEvent	[Until 3.0.0] W0=debug_handle, W1=#ContinueDebugFlagsOld, X2=thread_id [3.0.0 +] W0=debug_handle, W1=#ContinueDebugFlags, X2=thread_id_list(u64 *), W3=num_tids (max 64, 0 means "all threads")	W0=result
0x65	svcGetProcessList	X1=pids_out_ptr, W2=max_out	W0=result, W1=num_out
0x66	svcGetThreadList	X1=tids_out_ptr, W2=max_out, W3=debug_handle_or_zero	W0=result, X1=num_out
0x67	svcGetDebugThreadContext	X0=ThreadContext*, X1=debug_handle, X2=thread_id, W3=#ThreadContextFlags	W0=result
0x68	svcSetDebugThreadContext	W0=debug_handle, W1=#ThreadContextFlags, X2=ThreadContext*, X3=thread_id	W0=result
0x69	svcQueryDebugProcessMemory	X0=#MemoryInfo*, X2=debug_handle, X3=addr	W0=result, W1=PageInfo
0x6A	svcReadDebugProcessMemory	X0=buffer*, X1=debug_handle, X2=src_addr, X3=size	W0=result
0x6B	svcWriteDebugProcessMemory	X0=debug_handle, X1=buffer*, X2=dst_addr, X3=size	W0=result
0x6C	#svcSetHardwareBreakPoint	W0=HardwareBreakpointId, X1=watchpoint_flags/breakpoint_flags, X2=watchpoint_value/debug_handle
0x6D	svcGetDebugThreadParam	X2=debug_handle, X3=thread_id, W4=#DebugThreadParam	W0=result, X1=out0, W2=out1
0x6F	[5.0.0+] #svcGetSystemInfo	X1=info_id, X2=handle, X3=info_sub_id	W0=result, X1=out
0x70	svcCreatePort	W2=max_sessions, W3=unk_bool, X4=name_ptr	W0=result, W1=clientport_handle, W2=serverport_handle
0x71	svcManageNamedPort	X1=name_ptr, W2=max_sessions	W0=result, W1=serverport_handle
0x72	svcConnectToPort	W1=clientport_handle	W0=result, W1=session_handle
0x73	#svcSetProcessMemoryPermission	W0=process_handle, X1=addr, X2=size, W3=perm	W0=result
0x74	#svcMapProcessMemory	X0=dstaddr, W1=process_handle, X2=srcaddr, X3=size	W0=result
0x75	#svcUnmapProcessMemory	X0=dstaddr, W1=process_handle, X2=srcaddr, X3=size	W0=result
0x76	#svcQueryProcessMemory	X0=meminfo_ptr, W2=process_handle, X3=addr	W0=result, W1=pageinfo
0x77	#svcMapProcessCodeMemory	W0=process_handle, X1=dstaddr, X2=srcaddr, X3=size	W0=result
0x78	#svcUnmapProcessCodeMemory	W0=process_handle, X1=dstaddr, X2=srcaddr, X3=size	W0=result
0x79	#svcCreateProcess	X1=procinfo_ptr, X2=caps_ptr, W3=cap_num	W0=result, W1=process_handle
0x7A	svcStartProcess	W0=process_handle, W1=main_thread_prio, W2=default_cpuid, W3=main_thread_stacksz	W0=result
0x7B	svcTerminateProcess	W0=process_handle	W0=result
0x7C	#svcGetProcessInfo	W0=process_handle	W0=result, X1=#ProcessState
0x7D	svcCreateResourceLimit	None	W0=result, W1=reslimit_handle
0x7E	svcSetResourceLimitLimitValue	W0=reslimit_handle, W1=#LimitableResource, X2=value	W0=result
0x7F	svcCallSecureMonitor	X0=smc_sub_id, X1,X2,X3,X4,X5,X6,X7=smc_args	X0,X1,X2,X3,X4,X5,X6,X7=result

svcSetHeapSize

Argument	Type	Name
(In) W1	u64	Size
(Out) W0	#Result	Ret
(Out) X1	u64	OutAddr

Description: Set the process heap to a given Size. It can both extend and shrink the heap.

Size must be a multiple of 0x200000.

On success, the heap base-address (which is fixed by kernel, aslr'd) is written to OutAddr.

Uses current process pool partition.

[2.0.0+] Size must be less than 0x18000000.

svcSetMemoryPermission

Argument	Type	Name
(In) X0	void*	Addr
(In) X1	u64	Size
(In) W2	#Permission	Prot
(Out) W0	#Result	Ret

Description: Change permission of page-aligned memory region.

Bit2 of permission (exec) is not allowed. Setting write-only is not allowed either (bit1).

This can be used to move back and forth between ---, r-- and rw-.

svcSetMemoryAttribute

Argument	Type	Name
(In) X0	void*	Addr
(In) X1	u64	Size
(In) W2	u32	State0
(In) W3	u32	State1
(Out) W0	#Result	Ret

Description: Change attribute of page-aligned memory region.

This is used to turn on/off caching for a given memory area. Useful when talking to devices such as the GPU.

What happens "under the hood" is the "Memory Attribute Indirection Register" index is changed from 2 to 3 in the MMU descriptor.

State0	State1	Action
0	0	Clear bit3 in #MemoryAttribute.
8	0	Clear bit3 in #MemoryAttribute.
8	8	Set bit3 in #MemoryAttribute.

svcMapMemory

Argument	Type	Name
(In) X0	void*	DstAddr
(In) X1	void*	SrcAddr
(In) X2	u64	Size
(Out) W0	#Result	Ret

Description: Maps a memory range into a different range.

Mainly used for adding guard pages around stack.

Source range gets reprotected to --- (it can no longer be accessed), and bit0 is set in the source #MemoryAttribute.

If dstaddr >= LowerTreshold, the dst-range is enforced to be within the process' "MapRegion". Code can get the range of this region from #svcGetInfo id0=2,3.

In this case, the mapped memory will have state 0x5C3C0B.

As long as (dstaddr+size) < LowerThreshold, then you can map anywhere but the mapped memory will have state 0x482907 instead.

LowerTreshold is 0x80000000 for 36-bit address spaces, and 0x40000000 for 32-bit ones.

[2.0.0+] Support for the 0x482907 mappings outside the "MapRegion" were removed.

svcUnmapMemory

Argument	Type	Name
(In) X0	void*	DstAddr
(In) X1	void*	SrcAddr
(In) X2	u64	Size
(Out) W0	#Result	Ret

Description: Unmaps a region that was previously mapped with #svcMapMemory.

It's possible to unmap ranges partially, you don't need to unmap the entire range "in one go".

The srcaddr/dstaddr must match what was given when the pages were originally mapped.

svcQueryMemory

Argument	Type	Name
(In) X0	#MemoryInfo*	MemInfo
(In) X2	void*	Addr
(Out) W0	#Result	Ret
(Out) W1	PageInfo	PageInfo

Description: Query information about an address. Will always fetch the lowest page-aligned mapping that contains the provided address.

Outputs a #MemoryInfo struct.

svcExitProcess

Argument	Type	Name
(In) None
(Out) None

Description: Exits the current process.

svcCreateThread

Argument	Type	Name
(In) X1	void(*)(void*)	Entry
(In) X2	void*	ThreadContext
(In) X3	void*	StackTop
(In) W4	u32	Priority
(In) W5	u32	ProcessorId
(Out) W0	#Result	Ret
(Out) W1	Handle<Thread>	Handle

Description: Create a thread in the current process.

Processor_id must be 0,1,2,3 or -2, where -2 uses the default cpuid for process.

svcStartThread

Argument	Type	Name
(In) W0	Handle<Thread>	Handle
(Out) None

Description: Starts the thread for the provided handle.

svcExitThread

Argument	Type	Name
(In) None
(Out) None

Description: Exits the current thread.

svcSleepThread

Argument	Type	Name
(In) X0	u64	Nano
(Out) W0	#Result	Ret

Description: Sleep for a specified amount of time, or yield thread.

Setting nano=0 means "yield thread".

svcGetThreadPriority

Argument	Type	Name
(In) W1	Handle<Thread>	Handle
(Out) W0	#Result	Ret
(Out) W1	u64	Priority

Description: Get priority of provided thread handle.

svcSetThreadPriority

Argument	Type	Name
(In) W0	Handle<Thread>	Handle
(In) W1	u32	Priority
(Out) W0	#Result	Ret

Description: Set priority of provided thread handle.

Priority is a number 0-0x3F. Lower value means higher priority.

svcGetThreadCoreMask

Argument	Type	Name
(In) W2	Handle<Thread>	Handle
(Out) W0	#Result	Ret
(Out) W1	u32	Out0
(Out) X2	u64	Out1

Description: Get affinity mask of provided thread handle.

svcSetThreadCoreMask

Argument	Type	Name
(In) W0	Handle<Thread>	Handle
(In) W1	u32	In0
(In) X2	u64	In1
(Out) W0	#Result	Ret

Description: Set affinity mask of provided thread handle.

svcGetCurrentProcessorNumber

Argument	Type	Name
(In) None
(Out) W0/X0	u64	CpuId

Description: Get which cpu is executing the current thread.

Cpu-id is an integer in the range 0-3.

svcMapSharedMemory

Argument	Type	Name
(In) W0	Handle<SharedMemory>	MemHandle
(In) X1	void*	Addr
(In) X2	u64	Size
(In) W3	#Permission	Permissions
(Out) W0	#Result	Ret

Maps the block supplied by the handle. The required permissions are different for the process that created the handle and all other processes.

Increases reference count for the KSharedMemory object. Thus in order to release the memory associated with the object, all handles to it must be closed and all mappings must be unmapped.

svcCreateTransferMemory

Argument	Type	Name
(In) X1	void*	Addr
(In) X2	u64	Size
(In) W3	#Permission	Permissions
(Out) W0	#Result	Ret
(Out) W1	Handle<TransferMemory>	Handle

This one reprotects the src block with perms you give it. It also sets bit0 into #MemoryAttribute.

Executable bit perm not allowed.

Closing all handles automatically causes the bit0 in #MemoryAttribute to clear, and the permission to reset.

svcWaitSynchronization

Argument	Type	Name
(In) X1	Handle*	HandlesPtr
(In) W2	u64	HandlesNum
(In) X3	u64	Timeout
(Out) W0	#Result	Ret
(Out) W1	u64	HandleIndex

Works with num_handles <= 0x40, error on num_handles == 0.

Does not accept 0xFFFF8001 or 0xFFFF8000 as handles.

Object types

Port: signals when there is an incoming connection waiting to be accepted.

Session (server-side): signals when there is an incoming message waiting to be received or the pipe is closed.

Result codes

0x0: Success. One of the objects was signalled before the timeout expired. Handle index is updated to indicate which object signalled.

0xe401: Invalid handle. Returned when one of the handles passed is invalid. Handle index is not updated.

0xea01: Timeout. Returned when no objects have been signalled within the timeout. Handle index is not updated.

svcGetSystemTick

Argument	Type	Name
(Out) X0	u64	Ticks

Returns the value of cntpct_el0.

The frequency is 19200000 Hz (constant from official sw).

Official sw reads cntpct_el0 directly from usermode without using this SVC. sdk-nso has this SVC, but it's not known to be called anywhere.

svcSendSyncRequestWithUserBuffer

Argument	Type	Name
(In) X0	void*	CmdPtr
(In) X1	u64	Size
(In) W2	Handle<Session>	Handle
(Out) W0	#Result	Ret

Size must be 0x1000-aligned.

svcBreak

Argument	Type	Name
(In) X0	u64	Break Reason
(In) X1	u64
(In) X2	u64	Info
(Out) ?	?	?

When used on retail where inx0 bit31 is clear, the system will throw a fatal-error. Otherwise when bit31 is set, it will return 0 and notify the debugger?

svcGetInfo

Argument	Type	Name
(In) X1	u64	InfoId
(In) W2	Handle	Handle
(In) X3	u64	InfoSubId
(Out) W0	#Result	Ret
(Out) X1	u64	Out

Handle type	Id0	Id1	Description
Process	0	0	AllowedCpuIdBitmask
Process	1	0	AllowedThreadPrioBitmask
Process	2	0	MapRegionBaseAddr
Process	3	0	MapRegionSize
Process	4	0	HeapRegionBaseAddr
Process	5	0	HeapRegionSize
Process	6	0	TotalMemoryAvailable. Total memory available(free+used).
Process	7	0	TotalMemoryUsage. Total used size of codebin memory + main-thread stack + allocated heap.
Zero	8	0	IsCurrentProcessBeingDebugged
Zero	9	0	Returns ResourceLimit handle for current process. Used by PM.
Zero	10	-1, {current coreid}	IdleTickCount
Zero	11	0-3	RandomEntropy from current process. TRNG. Used to seed usermode PRNGs.
Process	12	0	[2.0.0+] AddressSpaceBaseAddr
Process	13	0	[2.0.0+] AddressSpaceSize
Process	14	0	[2.0.0+] NewMapRegionBaseAddr
Process	15	0	[2.0.0+] NewMapRegionSize
Process	16	0	[3.0.0+] PersonalMmHeapSize
Process	17	0	[3.0.0+] PersonalMmHeapUsage
Process	18	0	[3.0.0+] TitleId
Zero	19	0	[4.0.0-4.1.0] PrivilegedProcessId_LowerBound
Zero	19	1	[4.0.0-4.1.0] PrivilegedProcessId_UpperBound
Process	20	0	[5.0.0+] UserExceptionContextAddr
Thread	0xF0000002	0	Performance counter related.

svcMapPhysicalMemory

This is like svcSetHeapSize except you can allocate heap at any address you'd like.

Uses current process pool partition.

svcDumpInfo

Argument	Type	Name
(In) None
(Out) None

Does nothing, just returns with registers set to all-zero.

svcAcceptSession

Argument	Type	Name
(In) W1	Handle<Port>	Port
(Out) W0	#Result	Result
(Out) W1	Handle<ServerSession>	Session

Result codes

0xf201: No session waiting to be accepted

svcReplyAndReceive

Argument	Type	Name
(In) W1	*Handle<Port or ServerSession>	Handles
(In) W2	u32	NumHandles
(In) W3	Handle<ServerSession>	ReplyTarget
(In) X4	u64 (nanoseconds)	Timeout
(Out) W0	#Result	Result
(Out) W1	u32	HandleIndex

If ReplyTarget is not zero, a reply from the TLS will be sent to that session. Then it will wait until either of the passed sessions has an incoming message, is closed, a passed port has an incoming connection, or the timeout expires. If there is an incoming message, it is copied to the TLS.

After being validated, passed handles will be enumerated in order; even if a session has been closed, if one that appears earlier in the list has an incoming message, it will take priority and a result code of 0x0 will be returned.

Result codes

0x0: Success. Either a session has an incoming message or a port has an incoming connection. HandleIndex is set appropriately.

0xea01: Timeout. No handles were signalled before the timeout expired. HandleIndex is not updated.

0xf601: Port remote dead. One of the sessions has been closed. HandleIndex is set appropriately.

svcMapPhysicalMemoryUnsafe

Same as #svcMapPhysicalMemory except it always uses pool partition 0.

svcCreateCodeMemory

Takes an address range with backing memory to create the code memory object.

The memory is initially memset to 0xFF after being locked.

svcControlCodeMemory

Maps the backing memory for a Code memory object into the current process.

For CodeMemoryOperation_MapOwner, memory permission must be RW-.

For CodeMemoryOperation_MapSlave, memory permission must be R-- or R-X.

Operations CodeMemoryOperation_UnmapOwner/CodeMemoryOperation_UnmapSlave unmap memory that was previously mapped this way.

This allows one "secure JIT" process to map the code memory as RW-, and the other "slave" process to map it R-X.

[5.0.0+] Error 0xE401 is now returned when the process owner of the Code memory object is the same as the current process.

svcReadWriteRegister

Argument	Type	Name
(In) X1	u64	RegAddr
(In) W2	u64	RwMask
(In) W3	u64	InValue
(Out) W0	#Result	Ret
(Out) W1	u64	OutValue

Read/write IO registers with a hardcoded whitelist. Input address is physical-address and must be aligned to 4.

rw_mask is 0 for reading and 0xffffffff for writing. You can also write individual bits by using a mask value.

You can only write to registers inside physical pages 0x70019000 (MC), 0x7001C000 (MC0), 0x7001D000 (MC1), and they all share the same whitelist.

The whitelist is same for writing as for reading.

The whitelist is:

0x054, 0x090, 0x094, 0x098, 0x09c, 0x0a0, 0x0a4, 0x0a8, 0x0ac, 0x0b0, 0x0b4, 0x0b8, 0x0bc, 0x0c0, 0x0c4, 0x0c8, 0x0d0, 0x0d4, 0x0d8, 0x0dc, 0x0e0, 0x100, 0x108, 0x10c, 0x118, 0x11c, 0x124, 0x128, 0x12c, 0x130, 0x134, 0x138, 0x13c, 0x158, 0x15c, 0x164, 0x168, 0x16c, 0x170, 0x174, 0x178, 0x17c, 0x200, 0x204, 0x2e4, 0x2e8, 0x2ec, 0x2f4, 0x2f8, 0x310, 0x314, 0x320, 0x328, 0x344, 0x348, 0x370, 0x374, 0x37c, 0x380, 0x390, 0x394, 0x398, 0x3ac, 0x3b8, 0x3bc, 0x3c0, 0x3c4, 0x3d8, 0x3e8, 0x41c, 0x420, 0x424, 0x428, 0x42c, 0x430, 0x44c, 0x47c, 0x480, 0x484, 0x50c, 0x554, 0x558, 0x55c, 0x670, 0x674, 0x690, 0x694, 0x698, 0x69c, 0x6a0, 0x6a4, 0x6c0, 0x6c4, 0x6f0, 0x6f4, 0x960, 0x970, 0x974, 0xa20, 0xa24, 0xb88, 0xb8c, 0xbc4, 0xbc8, 0xbcc, 0xbd0, 0xbd4, 0xbd8, 0xbdc, 0xbe0, 0xbe4, 0xbe8, 0xbec, 0xc00, 0xc5c, 0xcac

[2.0.0+] Whitelist was extended with 0x4c4, 0x4c8, 0x4cc, 0x584, 0x588, 0x58c.

[2.0.0+] The IO registers in range 0x7000E400 (PMC) size 0xC00 skip the whitelist, and do a TrustZone call using SMC Id1 0xC3000008(ReadWriteRegister).

[4.0.0+] Access to the Memory Controller (0x70019000) also uses smcReadWriteRegister.

Here is the whitelist imposed by that SMC, relative to the start of the PMC registers:

0x000, 0x00c, 0x010, 0x014, 0x01c, 0x020, 0x02c, 0x030, 0x034, 0x038, 0x03c, 0x040, 0x044, 0x048, 0x0dc, 0x0e0, 0x0e4, 0x160, 0x164, 0x168, 0x170, 0x1a8, 0x1b8, 0x1bc, 0x1c0, 0x1c4, 0x1c8, 0x2b4, 0x2d4, 0x440, 0x4d8

Here is the whitelist imposed by smcReadWriteRegister (checked in addition to the whitelist in svcReadWriteRegister), relative to the start of the MC registers:

0x000, 0x004, 0x008, 0x00C, 0x010, 0x01C, 0x020, 0x030, 0x034, 0x050, 0x054, 0x090, 0x094, 0x098, 0x09C, 0x0A0, 0x0A4, 0x0A8, 0x0AC, 0x0B0, 0x0B4, 0x0B8, 0x0BC, 0x0C0, 0x0C4, 0x0C8, 0x0D0, 0x0D4, 0x0D8, 0x0DC, 0x0E0, 0x100, 0x108, 0x10C, 0x118, 0x11C, 0x124, 0x128, 0x12C, 0x130, 0x134, 0x138, 0x13C, 0x158, 0x15C, 0x164, 0x168, 0x16C, 0x170, 0x174, 0x178, 0x17C, 0x200, 0x204, 0x238, 0x240, 0x244, 0x250, 0x254, 0x258, 0x264, 0x268, 0x26C, 0x270, 0x274, 0x280, 0x284, 0x288, 0x28C, 0x294, 0x2E4, 0x2E8, 0x2EC, 0x2F4, 0x2F8, 0x310, 0x314, 0x320, 0x328, 0x344, 0x348, 0x370, 0x374, 0x37C, 0x380, 0x390, 0x394, 0x398, 0x3AC, 0x3B8, 0x3BC, 0x3C0, 0x3C4, 0x3D8, 0x3E8, 0x41C, 0x420, 0x424, 0x428, 0x42C, 0x430, 0x44C, 0x47C, 0x480, 0x484, 0x4C4, 0x4C8, 0x4CC, 0x50C, 0x554, 0x558, 0x55C, 0x584, 0x588, 0x58C, 0x670, 0x674, 0x690, 0x694, 0x698, 0x69C, 0x6A0, 0x6A4, 0x6C0, 0x6C4, 0x6F0, 0x6F4, 0x960, 0x970, 0x974, 0x9B8, 0xA20, 0xA24, 0xA88, 0xA94, 0xA98, 0xA9C, 0xAA0, 0xAA4, 0xAA8, 0xAAC, 0xAB0, 0xAB4, 0xAB8, 0xABC, 0xAC0, 0xAC4, 0xAC8, 0xACC, 0xAD0, 0xAD4, 0xAD8, 0xADC, 0xAE0, 0xB88, 0xB8C, 0xBC4, 0xBC8, 0xBCC, 0xBD0, 0xBD4, 0xBD8, 0xBDC, 0xBE0, 0xBE4, 0xBE8, 0xBEC, 0xC00, 0xC5C, 0xCAC

svcCreateSharedMemory

Argument	Type	Name
(In) W1	u64	Size
(In) W2	#Permission	LocalPerm
(In) W3	#Permission	RemotePerm
(Out) W0	#Result	Ret
(Out) W1	Handle<SharedMemory>	MemHandle

Other perm can be used to enforce permission 1, 3, or 0x10000000 if don't care.

Allocates memory from the current process' pool partition.

svcMapTransferMemory

Argument	Type	Name
(In) X0	Handle<TransferMemory>	MemHandle
(In) X1	void*	Addr
(In) X2	u64	Size
(In) W3	#Permission	Permissions
(Out) W0	#Result	Ret

The newly mapped pages will have #MemoryState type 0xE.

You must pass same size and permissions as given in svcCreateMemoryMirror, otherwise error.

svcUnmapTransferMemory

Argument	Type	Name
(In) X0	Handle<TransferMemory>	MemHandle
(In) X1	void*	Addr
(In) X2	u64	Size
(Out) W0	#Result	Ret

Size must match size given in map syscall, otherwise there's an invalid-size error.

svcQueryPhysicalAddress

Argument	Type	Name
(In) X1	u64	Addr
(Out) W0	#Result	Ret
(Out) X1	u64	PhysAddr
(Out) X2	u64	KernelAddr
(Out) X3	u64	Size

svcQueryIoMapping

Argument	Type	Name
(In) X1	u64	PhysAddr
(In) X2	u64	Size
(Out) W0	#Result	Ret
(Out) X1	void*	VirtAddr

Description: Returns a virtual address mapped to a given IO range.

svcCreateDeviceAddressSpace

Argument	Type	Name
(In) X1	u64	StartAddr
(In) X2	u64	EndAddr
(Out) W0	#Result	Ret
(Out) W1	Handle<DeviceAddressSpace>	AddressSpaceHandle

Description: Creates a virtual address space for binding device address spaces and returns a handle.

dev_as_start_addr is normally set to 0 and dev_as_end_addr is normally set to 0xFFFFFFFF.

svcAttachDeviceAddressSpace

Argument	Type	Name
(In) W0	#DeviceName	DeviceId
(In) X1	Handle<DeviceAddressSpace>	DeviceAsHandle
(Out) W0	#Result	Ret

Description: Attaches a device address space to a device.

svcDetachDeviceAddressSpace

Argument	Type	Name
(In) W0	#DeviceName	DeviceId
(In) X1	Handle<DeviceAddressSpace>	DeviceAsHandle
(Out) W0	#Result	Ret

Description: Detaches a device address space from a device.

svcMapDeviceAddressSpaceByForce

Argument	Type	Name
(In) W0	Handle<DeviceAddressSpace>	DeviceAsHandle
(In) W1	Handle<Process>	ProcessHandle
(In) X2	void*	SrcAddr
(In) X3	u64	DeviceAsSize
(In) X4	u64	DeviceAsAddr
(In) W5	#Permission	Permissions
(Out) W0	#Result	Ret

Description: Maps an attached device address space to an userspace address.

dev_map_addr is the userspace destination address, while dev_as_addr is the source address between dev_as_start_addr and dev_as_end_addr (passed to #svcCreateDeviceAddressSpace).

The userspace destination address must have the MapDeviceAllowed bit set. Bit IsDeviceMapped will be set after mapping.

svcMapDeviceAddressSpaceAligned

Argument	Type	Name
(In) W0	Handle<DeviceAddressSpace>	DeviceAsHandle
(In) W1	Handle<Process>	ProcessHandle
(In) X2	void*	SrcAddr
(In) X3	u64	DeviceAsSize
(In) X4	u64	DeviceAsAddr
(In) W5	#Permission	Permissions
(Out) W0	#Result	Ret

Description: Maps an attached device address space to an userspace address.

Same as #svcMapDeviceAddressSpaceByForce, but the userspace destination address must have the MapDeviceAlignedAllowed bit set instead.

svcUnmapDeviceAddressSpace

Argument	Type	Name
(In) W0	Handle<DeviceAddressSpace>	DeviceAsHandle
(In) W1	Handle<Process>	ProcessHandle
(In) X2	void*	SrcAddr
(In) X3	u64	DeviceAsSize
(In) X4	u64	DeviceAsAddr
(Out) W0	#Result	Ret

Description: Unmaps an attached device address space from an userspace address.

svcGetSystemInfo

Argument	Type	Name
(In) X1	u64	InfoId
(In) W2	Handle	Handle
(In) X3	u64	InfoSubId
(Out) W0	#Result	Ret
(Out) X1	u64	Out

Handle type	Id0	Id1	Description
Zero	0	0	TotalMemorySize_Application
Zero	0	1	TotalMemorySize_Applet
Zero	0	2	TotalMemorySize_System
Zero	0	3	TotalMemorySize_SystemUnsafe
Zero	1	0	CurrentMemorySize_Application
Zero	1	1	CurrentMemorySize_Applet
Zero	1	2	CurrentMemorySize_System
Zero	1	3	CurrentMemorySize_SystemUnsafe
Zero	2	0	PrivilegedProcessId_LowerBound
Zero	2	1	PrivilegedProcessId_UpperBound

svcSetProcessMemoryPermission

Argument	Type	Name
(In) W0	Handle<Process>	ProcessHandle
(In) X1	u64	Addr
(In) X2	u64	Size
(In) W3	void*	Perm
(Out) W0	#Result	Ret

This sets the memory permissions for the specified memory with the supplied process handle.

This throws an error(0xD801) when the input perm is >0x5, hence -WX and RWX are not allowed.

svcMapProcessMemory

Argument	Type	Name
(In) X0	u64	DstAddr
(In) W1	Handle<Process>	ProcessHandle
(In) X2	void*	SrcAddr
(In) X3	u64	Size
(Out) W0	#Result	Ret

Maps the src address from the supplied process handle into the current process.

This allows mapping code and rodata with RW- permission.

svcUnmapProcessMemory

Argument	Type	Name
(In) X0	void*	DstAddr
(In) W1	Handle<Process>	ProcessHandle
(In) X2	u64	SrcAddr
(In) X3	u64	Size
(Out) W0	#Result	Ret

Unmaps what was mapped by #svcMapProcessMemory.

svcQueryProcessMemory

Argument	Type	Name
(In) X0	#MemoryInfo*	MemInfoPtr
(In) W2	Handle<Process>	ProcessHandle
(In) X3	u64	Addr
(Out) W0	#Result	Ret
(Out) W1	PageInfo	PageInfo

Equivalent to #svcQueryMemory except takes a process handle.

svcMapProcessCodeMemory

Argument	Type	Name
(In) W0	Handle<Process>	ProcessHandle
(In) X1	u64	DstAddr
(In) X2	u64	SrcAddr
(In) X3	u64	Size
(Out) W0	#Result	Ret

Takes a process handle, and maps normal heap in that process as executable code in that process. Used when loading NROs. This does not support using the current-process handle alias.

svcUnmapProcessCodeMemory

Argument	Type	Name
(In) W0	Handle<Process>	ProcessHandle
(In) X1	u64	DstAddr
(In) X2	u64	SrcAddr
(In) X3	u64	Size
(Out) W0	#Result	Ret

Unmaps what was mapped by #svcMapProcessCodeMemory.

svcCreateProcess

Argument	Type	Name
(In) X1	#CreateProcessInfo*	InfoPtr
(In) X2	u64	CapabilitiesPtr
(In) X3	u64	CapabilitiesNum
(Out) W0	#Result	Ret
(Out) W1	Handle<Process>	ProcessHandle

Takes a #CreateProcessInfo as input.

svcGetProcessInfo

Argument	Type	Name
(In) W0	Handle<Process>	ProcessHandle
(Out) W0	#Result	Ret
(Out) W1	#ProcessState	State

Returns an enum with value 0-7.

Debugging

[2.0.0+] Exactly 6 debug SVCs require that IsDebugMode is non-zero. Error 0x4201 is returned otherwise.

• svcBreakDebugProcess
• svcContinueDebugEvent
• svcWriteDebugProcessMemory
• svcSetDebugThreadContext
• svcTerminateDebugProcess
• svcSetHardwareBreakPoint

svcDebugActiveProcess stops execution of the target process, the normal method for resuming it requires svcContinueDebugEvent(see above). Closing the debug handle also results in execution being resumed.

svcSetHardwareBreakPoint

Argument	Type	Name
(In) W0	u32	hardware_breakpoint_id
(In) W1	u64	flags
(In) W2	u64	value
(Out) W0	#Result	Ret

Sets one of the AArch64 hardware breakpoints. The nintendo switch has 6 hardware breakpoints, and 4 hardware watchpoints. The syscall has two behaviors depending on the value of hardware_breakpoint_id:

If hardware_breakpoint_id < 0x10, then it sets one of the AArch64 hardware breakpoints. Flags will go to DBGBCRn_EL1, and value to DBGBVRn_EL1. The only flags the user is allowed to set are those in the bitmask 0x7F01E1. Furthermore, the kernel will or it with 0x4004, in order to set various security flags to guarantee the watchpoints only triggers for code in EL0. If the user asks for a Breakpoint Type of ContextIDR match, the kernel shall use the given debug_handle to set DBGBVRn_EL1 to the ContextID of the debugged process.

If hardware_breakpoint_id is between 0x10 and 0x20 (exclusive), then it sets one of the AArch64 hardware watchpoints. Flags will go to DBGWCRn_EL1, and the value to DBGWVRn_EL1. The only flags the user is allowed to set are those in the bitmask 0xFF0F1FF9. Furthermore, the kernel will or it with 0x104004. This will set various security flags, and set the watchpoint type to be a Linked Watchpoint. This means that you need to link it to a Linked ContextIDR breakpoint. Check the ARM documentation for more information.

Note that hardware_breakpoint_id 0 to 4 match only to Virtual Address, while hardware_breakpoint_id 5 and 6 match against either Virtual Address, ContextID, or VMID. As such, if you are configuring a breakpoint to link for a watchpoint, make sure you use hardware_breakpoint_id 5 or 6.

For more documentation for hardware breakpoints, check out the AArch64 documentation for the DBGBCRn_EL1 register and the DBGWCRn_EL1 register

Enum/Structures

ThreadContextRequestFlags

Bitfield of one of more of these:

Bit	Bitmask	Name
0	1	NormalContext
1	2
2	4
3	8

DeviceName

Value	Name
0	DeviceName_AFI
1	DeviceName_AVPC
2	DeviceName_DC
3	DeviceName_DCB
4	DeviceName_HC
5	DeviceName_HDA
6	DeviceName_ISP2
7	DeviceName_MSENCNVENC
8	DeviceName_NV
9	DeviceName_NV2
10	DeviceName_PPCS
11	DeviceName_SATA
12	DeviceName_VI
13	DeviceName_VIC
14	DeviceName_XUSB_HOST
15	DeviceName_XUSB_DEV
16	DeviceName_TSEC
17	DeviceName_PPCS1
18	DeviceName_DC1
19	DeviceName_SDMMC1A
20	DeviceName_SDMMC2A
21	DeviceName_SDMMC3A
22	DeviceName_SDMMC4A
23	DeviceName_ISP2B
24	DeviceName_GPU
25	DeviceName_GPUB
26	DeviceName_PPCS2
27	DeviceName_NVDEC
28	DeviceName_APE
29	DeviceName_SE
30	DeviceName_NVJPG
31	DeviceName_HC1
32	DeviceName_SE1
33	DeviceName_AXIAP
34	DeviceName_ETR
35	DeviceName_TSECB
36	DeviceName_TSEC1
37	DeviceName_TSECB1
38	DeviceName_NVDEC1

CodeMemoryOperation

Value	Name
0	CodeMemoryOperation_MapOwner
1	CodeMemoryOperation_MapSlave
2	CodeMemoryOperation_UnmapOwner
3	CodeMemoryOperation_UnmapSlave

LimitableResource

Value	Name
0	LimitableResource_Memory
1	LimitableResource_Threads
2	LimitableResource_Events
3	LimitableResource_TransferMemories
4	LimitableResource_Sessions

ProcessEvent

Value	Name	Notes
0	ProcessEvent_Created
1	ProcessEvent_DebugAttached
2	ProcessEvent_DebugDetached
3	ProcessEvent_Crashed	Processes will not enter this state unless they were created with EnableDebug.
4	ProcessEvent_Running
5	ProcessEvent_Exiting
6	ProcessEvent_Exited
7	ProcessEvent_DebugSuspended

DebugThreadParam

Value	Name
0	DebugThreadParam_DynamicPriority
1	DebugThreadParam_SchedulingStatus
2	DebugThreadParam_PreferredCpuCore
3	DebugThreadParam_CurrentCpuCore
4	DebugThreadParam_AffinityMask

Dynamic priority: output in out2

Scheduling status: out1 contains bit0: is debug-suspended, bit1: is user-suspended (svcSetThreadActivity 1 or svcSetProcessActivity 1). Out2 contains {suspended, idle, running, terminating} => {5, 0, 1, 4}

DebugThreadParam_PreferredCpuCore: output in out2

DebugThreadParam_CurrentCpuCore: output in out2

DebugThreadParam_AffinityMask: output in out1

CreateProcessInfo

Offset	Length	Bits	Description
0	12		ProcessName (doesn't have to be null-terminated)
0	4		ProcessCategory (0: regular title, 1: kernel built-in)
0x10	8		TitleId
0x18	8		CodeAddr
0x20	4		CodeNumPages
0x24	4		MmuFlags
		Bit0	IsAarch64
		Bit3-1	#AddressSpaceType
		Bit4	[2.0.0+] EnableDebug
		Bit5	EnableAslr
		Bit6	UseSystemMemBlocks
		Bit7	[4.0.0] ?
		Bit10-7	[5.0.0+] PoolPartition (0=Application, 1=Applet, 2=Sysmodule, 3=Nvservices)
0x28	4		ResourceLimitHandle
0x2C	4		[3.0.0+] PersonalMmHeapNumPages

On [1.0.0] there's only one pool.

On [2.0.0-4.0.0] PoolPartition is 1 for built-ins and 0 for rest.

On [5.0.0] PoolPartition is specified in CreateProcessArgs. There are now 4 pool partitions.

AddressSpaceType

Type	Name	Width	Description
0	Normal_32Bit	32
1	Normal_36Bit	36
2	WithoutMap_32Bit	32	Appears to be missing map region [?]
3	[2.0.0+] Normal_39Bit	39

MemoryInfo

Offset	Length	Description
0	8	BaseAddress
8	8	Size
0x10	4	MemoryType: lower 8 bits of #MemoryState
0x14	4	#MemoryAttribute
0x18	4	Permission (bit0: R, bit1: W, bit2: X)
0x1C	4	IpcRefCount
0x20	4	DeviceRefCount
0x24	4	Padding: always zero

MemoryAttribute

Bits	Description
0	IsBorrowed
1	IsIpcMapped: when IpcRefCount > 0.
2	IsDeviceMapped: when DeviceRefCount > 0.
3	IsUncached

MemoryState

Bits	Description
7-0	Type
8	PermissionChangeAllowed
9	ForceReadWritableByDebugSyscalls
10	IpcSendAllowed_Type0
11	IpcSendAllowed_Type3
12	IpcSendAllowed_Type1
14	ProcessPermissionChangeAllowed
15	MapAllowed
16	UnmapProcessCodeMemoryAllowed
17	TransferMemoryAllowed
18	QueryPhysicalAddressAllowed
19	MapDeviceAllowed (#svcMapDeviceAddressSpace and #svcMapDeviceAddressSpaceByForce)
20	MapDeviceAlignedAllowed
21	IpcBufferAllowed
22	IsPoolAllocated/IsReferenceCounted
23	MapProcessAllowed
24	AttributeChangeAllowed
25	[4.0.0+] CodeMemoryAllowed

Value	Type	Meaning
0x00000000	MemoryType_Unmapped
0x00002001	MemoryType_Io	Mapped by kernel capability parsing in #svcCreateProcess.
0x00042002	MemoryType_Normal	Mapped by kernel capability parsing in #svcCreateProcess.
0x00DC7E03	MemoryType_CodeStatic	Mapped during #svcCreateProcess.
[1.0.0+] 0x01FEBD04 [4.0.0+] 0x03FEBD04	MemoryType_CodeMutable	Transition from 0xDC7E03 performed by #svcSetProcessMemoryPermission.
[1.0.0+] 0x017EBD05 [4.0.0+] 0x037EBD05	MemoryType_Heap	Mapped using #svcSetHeapSize.
0x00402006	MemoryType_SharedMemory	Mapped using #svcMapSharedMemory.
0x00482907	[1.0.0] MemoryType_WeirdMappedMemory	Mapped using #svcMapMemory.
0x00DD7E08	MemoryType_ModuleCodeStatic	Mapped using #svcMapProcessCodeMemory.
[1.0.0+] 0x01FFBD09 [4.0.0+] 0x03FFBD09	MemoryType_ModuleCodeMutable	Transition from 0xDD7E08 performed by #svcSetProcessMemoryPermission.
0x005C3C0A	MemoryType_IpcBuffer0	IPC buffers with descriptor flags=0.
0x005C3C0B	MemoryType_MappedMemory	Mapped using #svcMapMemory.
0x0040200C	MemoryType_ThreadLocal	Mapped during #svcCreateThread.
0x015C3C0D	MemoryType_TransferMemoryIsolated	Mapped using #svcMapTransferMemory when the owning process has perm=0.
0x005C380E	MemoryType_TransferMemory	Mapped using #svcMapTransferMemory when the owning process has perm!=0.
0x0040380F	MemoryType_ProcessMemory	Mapped using #svcMapProcessMemory.
0x00000010	MemoryType_Reserved
0x005C3811	MemoryType_IpcBuffer1	IPC buffers with descriptor flags=1.
0x004C2812	MemoryType_IpcBuffer3	IPC buffers with descriptor flags=3.
0x00002013	MemoryType_KernelStack	Mapped in kernel during #svcCreateThread.
0x00402214	[4.0.0+] MemoryType_CodeReadOnly	Mapped in kernel during #svcControlCodeMemory.
0x00402015	[4.0.0+] MemoryType_CodeWritable	Mapped in kernel during #svcControlCodeMemory.

ArbitrationType

Value	Type
0x0	WaitIfLessThan
0x1	DecrementAndWaitIfLessThan
0x2	WaitIfEqual

SignalType

Value	Type
0x0	Signal
0x1	SignalAndIncrementIfEqual
0x2	SignalAndModifyBasedOnWaitingThreadCountIfEqual

ContinueDebugFlagsOld

Until 3.0.0:

Bit	Bitmask	Description
0	1	IgnoreException (note: ResumeAllThreads or debug-suspended-thread-id needed)
1	2	SwallowException
2	4	ResumeAllThreads

ContinueDebugFlags

Starting from 3.0.0:

Bit	Bitmask	Description
0	1	IgnoreException (note: doesn't need to be set in the same call than Resume)
1	2	SwallowException
2	4	Resume
3	8	IgnoreExceptionInverted

IgnoreExceptionInverted is like CancelSynchronization but acts on all threads that aren't in the input list.

If the input number of threads is 0, this means "all threads".

DebugEventInfo

Size: 0x40

Offset	Length	Description
0	u32	EventType
4	u32	Flags (bit0: NeedsContinue)
8	u64	ThreadId
0x10		PerTypeSpecifics

AttachProcess specific:

Offset	Length	Description
0x10	u64	TitleId
0x18	u64	ProcessId
0x20	char[12]	ProcessName
0x2C	u32	MmuFlags
0x30	u64	[5.0.0+] UserExceptionContextAddr

AttachThread specific:

Offset	Length	Description
0x10	u64	ThreadId
0x18	u64	TlsPtr
0x20	u64	Entrypoint

Exit specific:

Offset	Length	Description
0x10	u32	Type (0=PausedThread, 1=RunningThread, 2=TerminatedProcess)

Exception specific:

Offset	Length	Description
0x10	u32	ExceptionType
0x18	u64	FaultRegister
0x20		PerExceptionSpecifics

DebugEventType

Value	Name
0	DebugEvent_AttachProcess
1	DebugEvent_AttachThread
2
3	DebugEvent_Exit
4	DebugEvent_Exception

DebugExceptionType

Value	Name
0	Exception_UndefinedInstruction
1	Exception_InstructionAbort
2	Exception_DataAbortMisc
3	Exception_PcSpAlignmentFault
4	Exception_DebuggerAttached
5	Exception_BreakPoint
6	Exception_UserBreak
7	Exception_DebuggerBreak
8	Exception_BadSvcId
9	[?] Exception_SError

UndefinedInstruction specifics:

Offset	Length	Description
0x20	u32	Opcode

BreakPoint specifics:

Offset	Length	Description
0x20	u32	IsWatchpoint

UserBreak specifics:

Offset	Length	Description
0x20	u32	Info0
0x28	u64	Info1
0x30	u64	Info2

BadSvcId specifics:

Offset	Length	Description
0x20	u32	SvcId

Exception handling

There is userland code for handling exceptions, however this doesn't seem to be executed on retail mode.

When a usermode exception occurs, it jumps to the main code binary entrypoint (main_binary_address + 0 == _start).

During normal boot _start is invoked with X0=0 and X1=main_thread_handle (triggering normal crt0 setup). During an usermode exception _start is invoked with X0=exception_info0_ptr and X1=exception_info1_ptr instead.

The _start method determines whether to boot normally or handle an exception if X0 is set to 0 or not.