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 R0=prio, R1=entry, R2=thread_context, R3=stacktop, R4=processor_id	W0=result, W1=handle
0x9	#svcStartThread	W0=thread_handle	W0=result
0xA	#svcExitThread	None
0xB	#svcSleepThread	X0=nano R0=nano_lower32, R1=lower_upper32
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=out0, X2=out1 R0=result, R1=out0, R2=out1_lower32, R3=out1_upper32
0xF	#svcSetThreadCoreMask	W0=thread_handle, W1=in, X2=in2 R0=thread_handle, R1=in, R2=in2_lower32, R3=in2_upper32	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 R0=timeout_lower32, R1=handles_ptr, R2=num_handles, R3=timeout_upper32	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 R0=ptr0, R1=ptr, R2=thread_handle, R3=timeout_lower32, R4=timeout_upper32	W0=result
0x1D	svcSignalProcessWideKey	X0=ptr, W1=value	W0=result
0x1E	#svcGetSystemTick	None	X0={value of cntpct_el0} R0=cntpct_el0_lower32, R1=cntpct_el0_upper32
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 R0=result, R1=pid_lower32, R2=pid_upper32
0x25	svcGetThreadId	W1=thread_handle	W0=result, X1=out R0=result, R1=out_lower32, R2=out_upper32
0x26	#svcBreak	X0=break_reason,X1,X2=info	W0=result = 0
0x27	svcOutputDebugString	X0=str, X1=size	W0=result
0x28	svcReturnFromException	X0=result
0x29	#svcGetInfo	W1=info_id, X2=handle, X3=info_sub_id R0=info_sub_id_lower32, R1=info_id, R2=handle, R3=info_sub_id_upper32	W0=result, X1=out R0=result, R1=out_lower32, R2=out_upper32
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 R0=timeout_lower32, R1=timeout_upper32	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 R0=result, R1=value_lower32, R2=value_upper32
0x31	svcGetResourceLimitCurrentValue	W1=reslimit_handle, W2=#LimitableResource	W0=result, X1=value R0=result, R1=value_lower32, R2=value_upper32
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 R0=ptr, R1=#ArbitrationType, R2=value, R3=timeout_lower32, R4=timeout_upper32
0x35	[4.0.0+] svcSignalToAddress	X0=ptr, W1=#SignalType, X2=value, W3=num_to_signal
0x36	[8.0.0+] svcSynchronizePreemptionState	None	W0=result
0x3C	#svcDumpInfo
0x3D	[4.0.0+] svcDumpInfoNew
0x40	svcCreateSession	W2=is_light, X3=name_ptr	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 R0=timeout_lower32, R1=ptr_handles, R2=num_handles, R3=replytarget_handle(0=none), R4=timeout_upper32	W0=result, W1=handle_idx
0x44	svcReplyAndReceiveWithUserBuffer	X1=buf, X2=sz, X3=ptr_handles, W4=num_handles, X5=replytarget_handle(0=none), X6=timeout R0=num_handles, R1=buf, R2=sz, R3=ptr_handles, R4=replytarget_handle(0=none), R5=timeout_lower32, R6=timeout_upper32	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 R0=code_memory_handle, R1=#CodeMemoryOperation, R2=dstaddr_lower32, R3=dstaddr_upper32, R4=size_lower32, R5=size_upper32, R6=perm	W0=result
0x4D	svcSleepSystem	None	None
0x4E	#svcReadWriteRegister	X1=reg_addr, W2=rw_mask, W3=in_val R0=rw_mask, R1=in_val, R2=reg_addr_lower32, R3=reg_addr_upper32	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=baseaddr, X3=size
0x55	#svcQueryIoMapping	X1=physaddr, X2=size R0=size, R2=physaddr_lower32, R3=physaddr_upper32	W0=result, X1=virtaddr
0x56	#svcCreateDeviceAddressSpace	X1=dev_as_start_addr, X2=dev_as_end_addr R0=dev_as_end_addr_lower32, R1=dev_as_end_addr_upper32, R2=dev_as_start_addr_lower32, R3=dev_as_start_addr_upper32	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 R0=dev_as_handle, R1=proc_handle, R2=dev_map_addr_lower32, R3=dev_map_addr_upper32, R4=rev_as_size, R5=dev_as_addr_lower32, R6=dev_as_addr_upper32, R7=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 R0=dev_as_handle, R1=proc_handle, R2=dev_map_addr_lower32, R3=dev_map_addr_upper32, R4=rev_as_size, R5=dev_as_addr_lower32, R6=dev_as_addr_upper32, R7=perm	W0=result
0x5B	svcMapDeviceAddressSpace	W1=dev_as_handle, W2=proc_handle, X3=dev_map_addr, X4=dev_as_size, X5=dev_as_addr, W6=perm R0=dev_map_addr_lower32, R1=dev_as_handle, R2=proc_handle, R3=dev_map_addr_upper32, R4=dev_as_size, R5=dev_as_addr_lower32, R6=dev_as_addr_upper32, R7=perm	W0=result, X1=mapped_size R0=result, R1=mapped_size
0x5C	#svcUnmapDeviceAddressSpace	W0=dev_as_handle, W1=proc_handle, X2=dev_map_addr, X3=dev_as_size, X4=dev_as_addr R0=dev_as_handle, R1=proc_handle, R2=dev_map_addr_lower32, R3=dev_map_addr_upper32, R4=dev_as_size, R5=dev_as_addr_lower32, R6=dev_as_addr_upper32	W0=result
0x5D	svcInvalidateProcessDataCache	W0=process_handle, X1=addr, X2=size R0=process_handle, R1=size_lower32, R2=addr_lower32, R3=addr_upper32, R4=size_upper32	W0=size
0x5E	svcStoreProcessDataCache	W0=process_handle, X1=addr, X2=size R0=process_handle, R1=size_lower32, R2=addr_lower32, R3=addr_upper32, R4=size_upper32	W0=size
0x5F	svcFlushProcessDataCache	W0=process_handle, X1=addr, X2=size R0=process_handle, R1=size_lower32, R2=addr_lower32, R3=addr_upper32, R4=size_upper32	W0=size
0x60	svcDebugActiveProcess	X1=pid R2=pid_lower32, R3=pid_upper32	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	[1.0.0-2.3.0] W0=debug_handle, W1=#ContinueDebugFlagsOld, X2=thread_id R0=debug_handle, R1=#ContinueDebugFlagsOld, R2=thread_id_lower32, R3=thread_id_upper32 [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 R0=ThreadContext*, R1=debug_handle, R2=thread_id_lower32, R3=thread_id_upper32, R4=#ThreadContextFlags	W0=result
0x68	svcSetDebugThreadContext	W0=debug_handle, X1=thread_id, X2=ThreadContext*, W3=#ThreadContextFlags R0=debug_handle, R1=ThreadContext*, R2=thread_id_lower32, R3=thread_id_upper32, R4=#ThreadContextFlags	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 R0=HardwareBreakpointId, R1=value_lower32, R2=flags_lower32, R3=flags_upper32, R4=value_upper32	W0=result
0x6D	svcGetDebugThreadParam	X2=debug_handle, X3=thread_id, W4=#DebugThreadParam R0=thread_id_lower32, R1=thread_id_upper32, R2=debug_handle, R3=#DebugThreadParam	W0=result, X1=out0, W2=out1 R0=result, R1=out0_lower32, R2=out0_upper32, R3=out1
0x6F	[5.0.0+] #svcGetSystemInfo	X1=info_id, X2=handle, X3=info_sub_id R1=info_sub_id_lower32, R2=info_id, R3=handle, R4=info_sub_id_upper32	W0=result, X1=out R0=result, R1=out_lower32, R2=out_upper32
0x70	svcCreatePort	W2=max_sessions, W3=is_light, X4=name_ptr R0=name_ptr, R2=max_sessions, R3=is_light	W0=result, W1=serverport_handle, W2=clientport_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 R0=process_handle, R1=size_lower32, R2=addr_lower32, R3=addr_upper32, R4=size_upper32, R5=perm	W0=result
0x74	#svcMapProcessMemory	X0=dstaddr, W1=process_handle, X2=srcaddr, X3=size R0=dstaddr, R1=process_handle, R2=srcaddr_lower32, R3=srcaddr_upper32, R4=size	W0=result
0x75	#svcUnmapProcessMemory	X0=dstaddr, W1=process_handle, X2=srcaddr, X3=size R0=dstaddr, R1=process_handle, R2=srcaddr_lower32, R3=srcaddr_upper32, R4=size	W0=result
0x76	#svcQueryProcessMemory	X0=meminfo_ptr, W2=process_handle, X3=addr R0=meminfo_ptr, R1=addr_lower32, R2=process_handle, R3=addr_upper32	W0=result, W1=pageinfo
0x77	#svcMapProcessCodeMemory	W0=process_handle, X1=dstaddr, X2=srcaddr, X3=size R0=process_handle, R1=srcaddr_lower32, R2=dstaddr_lower32, R3=dstaddr_upper32, R4=srcaddr_lower32, R5=size_lower32, R6=size_upper32	W0=result
0x78	#svcUnmapProcessCodeMemory	W0=process_handle, X1=dstaddr, X2=srcaddr, X3=size R0=process_handle, R1=srcaddr_lower32, R2=dstaddr_lower32, R3=dstaddr_upper32, R4=srcaddr_lower32, R5=size_lower32, R6=size_upper32	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 R0=process_handle, R1=main_thread_prio, R2=default_cpuid, R3=main_thread_stacksz_lower32, R4=main_thread_stacksz_upper32	W0=result
0x7B	svcTerminateProcess	W0=process_handle	W0=result
0x7C	#svcGetProcessInfo	W0=process_handle, W1=#ProcessInfoType R1=process_handle, R2=#ProcessInfoType	W0=result, X1=#ProcessState R0=result, R1=#ProcessState_lower32, R2=#ProcessState_upper32
0x7D	svcCreateResourceLimit	None	W0=result, W1=reslimit_handle
0x7E	svcSetResourceLimitLimitValue	W0=reslimit_handle, W1=#LimitableResource, X2=value R0=reslimit_handle, R1=#LimitableResource, R2=value_lower32, R3=value_upper32	W0=result
0x7F	#svcCallSecureMonitor	X0=smc_sub_id, X1,X2,X3,X4,X5,X6,X7=smc_args R0=smc_sub_id, R1, R2, R3=smc_args	X0,X1,X2,X3,X4,X5,X6,X7=result R0,R1,R2,R3=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 (2MB).

On success, the heap base-address (which is fixed by kernel, aslr'd, and always in the Heap memory region) is written to OutAddr.

Uses current process pool partition. The memory allocated counts towards the caller's process Memory ResourceLimit.

[2.0.0+] Size must be less than or equal to 4GB.

Result codes

0x0: Success.

0xCA01: Invalid size passed. It's either bigger than 4GB, or misaligned.

0xD001: Size is bigger than the Heap Region size.

0xCE01: KMemoryBlockAllocator slab allocator exhausted.

0xD401: The memory region is in an invalid state. Likely because a mapping was made in the heap region.

0x10801: Memory resource limit reached.

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-.

Result codes

0x0: Success. The memory region was reprotected.

0xCC01: Unaligned address specified.

0xCA01: Unaligned or zero size specified.

0xD401: The provided memory region does not fall within the userland address space.

0xD801: Invalid permission specified. Valid permissions are ---, r-- and rw-.

0xD401: The provided memory region was in an invalid state. The region must have the PermissionChangeAllowed bit set in its #MemoryState, and must not have the IsBorrowed or IsUncached #MemoryAttribute.

0xCE01: Kernel resource exhausted.

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.

[1.0.0] This could be used to map into either the Alias Region or the Stack region.

[2.0.0+] This can only be used to map into the Stack region.

Code can get the range of the Alias region from #svcGetInfo id0=2,3, and on 2.0.0+ the range of the Stack region via #svcGetInfo id0=14, 15 (on 1.0.0, the Stack region had hardcoded limits).

When mapped into the Alias region, the mapped memory will have state 0x482907.

When mapped into the Stack region, the mapped memory will have state 0x5C3C0B.

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

Argument64	Argument32	Type	Name
(In) X1	R1	void(*)(void*)	Entry
(In) X2	R2	void*	ThreadContext
(In) X3	R3	void*	StackTop
(In) W4	R0	u32	Priority
(In) W5	R4	u32	ProcessorId
(Out) W0	R0	#Result	Ret
(Out) W1	R1	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

Argument64	Argument32	Type	Name
(In) X0	R0, R1	s64	Nanoseconds

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

Setting nanoseconds to 0, -1, or -2 indicates a yielding type.

Value	Type
0	Yielding without core migration
-1	Yielding with core migration
-2	Yielding to any other 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

Argument64	Argument32	Type	Name
(In) W2	R2	Handle<Thread>	Handle
(Out) W0	R0	#Result	Ret
(Out) W1	R1	u32	Out0
(Out) X2	R2, R3	u64	Out1

Description: Get affinity mask of provided thread handle.

svcSetThreadCoreMask

Argument64	Argument32	Type	Name
(In) W0	R0	Handle<Thread>	Handle
(In) W1	R1	u32	In0
(In) X2	R2, R3	u64	In1
(Out) W0	R0	#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.

svcSignalEvent

Argument	Type	Name
(In) W0	Handle<WritableEvent>	Event
(Out) X0	#Result	Result

Description: Puts the given event in the signaled state.

Will wake up any thread currently waiting on this event. Can potentially trigger a reschedule.

Any calls to #svcWaitSynchronization on this handle will return immediately, until the event's signaled state is reset.

Result codes

0x0: Success. Event is now in signaled state.

0xE401: Invalid handle. The handle either does not exist, or is not a WritableEvent.

svcClearEvent

Argument	Type	Name
(In) W0	Handle<WritableEvent or ReadableEvent>	Event
(Out) X0	#Result	Result

Description: Takes the given event out of the signaled state.

Result codes

0x0: Success, the event is now in the not-signaled state.

0xE401: Invalid handle. The handle either does not exist, or is not a ReadableEvent nor a WritableEvent.

0xFA01: The handle was not in a signaled state.

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.

svcResetSignal

Argument	Type	Name
(In) W0	Handle<ReadableEvent> or Handle<Process>	Handle
(Out) W0	#Result	Ret

Resets the signal on the given handle, ensuring future calls to #svcWaitSynchronization on this handle will sleep until the handle is signaled again. If the handle is a ReadableEvent, this is equivalent to calling svcClearEvent() on the handle.

If the handle is a Process, it will clear the signaled state (which is set when the process changes #ProcessState. Once the process enters the Exited state, calling svcResetSignal on the process will no longer have an effect (the process is permanently signaled), and the syscall will return 0xFA01.

Result codes

0x0: Success. The signal was reset.

0xE401: The handle is invalid or of the wrong type.

0xFA01: The handle was not signaled, or the process is in exited state, causing it to be permanently signaled.

svcWaitSynchronization

Argument64	Argument32	Type	Name
(In) X1	R1	Handle*	HandlesPtr
(In) W2	R2	u64	HandlesNum
(In) X3	R0, R3	u64	Timeout
(Out) W0	R0	#Result	Ret
(Out) W1	R1	u64	HandleIndex

Works with num_handles <= 0x40.

When zero handles are passed, this will wait forever until either timeout or cancellation occurs.

Does not accept 0xFFFF8001 or 0xFFFF8000 as handles.

Object types

KDebug: signals when there is a new DebugEvent (retrievable via #svcGetDebugEvent).

KClientPort: signals when the number of sessions is less than the maximum allowed.

KProcess: signals when the process undergoes a state change (retrievable via #svcGetProcessInfo).

KReadableEvent: signals when the event's corresponding KWritableEvent has been signaled via svcSignalEvent.

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

KServerSession: signals when there is an incoming message waiting to be received or the pipe is closed.

KThread: signals when the thread has exited.

Result codes

0x0: Success. One of the objects was signaled before the timeout expired, or one of the objects is a Session with a closed remote. Handle index is updated to indicate which object signaled.

0x7601: Thread termination requested. Handle index is not updated.

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

0xe601: Invalid address. Returned when the handles pointer is not a readable address. Handle index is not updated.

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

0xec01: Interrupted. Returned when another thread uses #svcCancelSynchronization to cancel this thread. Handle index is not updated.

0xee01: Too many handles. Returned when the number of handles passed is > 0x40.

svcCancelSynchronization

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

If the referenced thread is currently in a synchronization call (#svcWaitSynchronization, #svcReplyAndReceive or #svcReplyAndReceiveLight), that call will be interrupted and return 0xec01. If that thread is not currently executing such a synchronization call, the next call to a synchronization call will return 0xec01.

This doesn't take force-pause (activity/debug pause) into account.

Result codes

0x0: Success. The thread was either interrupted or has had its flag set.

0xe401: Invalid handle. The handle given was either invalid or not a thread handle.

svcGetSystemTick

Argument64	Argument32	Type	Name
(Out) X0	R0, R1	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 and CmdPtr must be 0x1000-aligned.

Result codes

0x0: Success.

0xcc01: CmdPtr is not 0x1000-aligned.

0xca01: Size is not 0x1000-aligned.

0xce01: KSessionRequest allocation failed (unlikely) or pointer buffer size exceeded.

0xe401: Handles does not exist, or handle is not an instance of KClientSession.

svcBreak

Argument	Type	Name
(In) X0	u64	Break Reason
(In) X1	u64
(In) X2	u64	Info
(Out) W0	Result	0 (Success)

If the process is attached, report the Break event. Then, if svcContinueDebugEvent didn't apply IgnoreException on the thread: if TPIDR_EL0 is 0, adjust ELR_EL1 to retry to svc instruction (and set TPIDR_EL0 to 1).

Otherwise, if bit31 in reason isn't set, perform crash reporting (see Exception Handling section below), if it doesn't terminate the process adjust ELR_EL1 as well.

Otherwise just return 0.

svcGetInfo

Argument	Type	Name
(In) W1	u32	InfoId
(In) W2	Handle	Handle
(In) X3	u64	InfoSubId
(Out) W0	#Result	Ret
(Out) X1	u64	Out

Argument	Type	Name
(In) R0	u32	InfoSubIdLower32
(In) R1	u32	InfoId
(In) R2	Handle	Handle
(In) R3	u32	InfoSubIdUpper32
(Out) R0	#Result	Ret
(Out) R1	u32	OutLower32
(Out) R2	u32	OutUpper32

Handle type	Id0	Id1	Description
Process	0	0	AllowedCpuIdBitmask
Process	1	0	AllowedThreadPrioBitmask
Process	2	0	AliasRegionBaseAddr
Process	3	0	AliasRegionSize
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+] StackRegionBaseAddr
Process	15	0	[2.0.0+] StackRegionSize
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
Process	21	0	[6.0.0+] TotalMemoryAvailableWithoutMmHeap
Process	22	0	[6.0.0+] TotalMemoryUsedWithoutMmHeap
Process	23	0	[9.0.0+] IsApplication
Thread	0xF0000002	0-3, -1	Thread Ticks. When 0-3 are passed, gets specific core CPU ticks spent on thread. When -1 is passed, gets total CPU ticks spent on thread.

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

Argument64	Argument32	Type	Name
(In) W1	R1	*Handle<Port or ServerSession>	Handles
(In) W2	R2	u32	NumHandles
(In) W3	R3	Handle<ServerSession>	ReplyTarget
(In) X4	R0, R4	u64 (nanoseconds)	Timeout
(Out) W0	R0	#Result	Result
(Out) W1	R1	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.

If ReplyTarget is zero, the TLS should contain a blank message. If this message has a C descriptor, the buffer it points to will be used as the pointer buffer. See IPC_Marshalling#IPC_buffers. Note that a pointer buffer cannot be specified if ReplyTarget is not zero.

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

Argument64	Argument32	Type	Name
(In) X1	R2, R3	u64	RegAddr
(In) W2	R0	u64	RwMask
(In) W3	R1	u64	InValue
(Out) W0	R0	#Result	Ret
(Out) W1	R1	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.

svcCreateInterruptEvent

Argument	Type	Name
(In) X1	u64	IrqNum
(In) W2	bool	Flags
(Out) W0	#Result	Ret
(Out) W1	Handle<ReadableEvent>	ReadableEventHandle

Create an event handle for the given IRQ number. Waiting on this handle will wait until the IRQ is triggered. The flags argument configures the triggering. If it is false, the IRQ is active HIGH level sensitive, if it is true it is rising-edge sensitive.

Result codes

0x0: Success.

0xF001: Flags was > 1

0xF201: IRQ above 0x3FF or outside the IRQ access mask was given.

0xCE01: A SlabHeap was exhausted (too many interrupts created).

0xF401: IRQ already has an event registered.

0xD201: The handle table is full. Try closing some handles.

svcQueryPhysicalAddress

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

Description: Query the physical address of a virtual address. Will always fetch the lowest page-aligned mapping that contains the provided physical address.

The returned BaseAddr is the virtual address of that page-aligned mapping, while PhysAddr is the physical address of that page. Size is the amount of continuous physical memory in that mapping.

svcQueryIoMapping

Argument64	Argument32	Type	Name
(In) X1	R2, R3	u64	PhysAddr
(In) X2	R0	u64	Size
(Out) W0	R0	#Result	Ret
(Out) X1	R1	void*	VirtAddr

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

svcCreateDeviceAddressSpace

Argument64	Argument32	Type	Name
(In) X1	R2, R3	u64	StartAddr
(In) X2	R0, R1	u64	EndAddr
(Out) W0	R0	#Result	Ret
(Out) W1	R1	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

Argument64	Argument32	Type	Name
(In) W0	R0	Handle<DeviceAddressSpace>	DeviceAsHandle
(In) W1	R1	Handle<Process>	ProcessHandle
(In) X2	R2, R3	void*	SrcAddr
(In) X3	R4	u64	DeviceAsSize
(In) X4	R5, R6	u64	DeviceAsAddr
(In) W5	R7	#Permission	Permissions
(Out) W0	R0	#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

Argument64	Argument32	Type	Name
(In) W0	R0	Handle<DeviceAddressSpace>	DeviceAsHandle
(In) W1	R1	Handle<Process>	ProcessHandle
(In) X2	R2, R3	void*	SrcAddr
(In) X3	R4	u64	DeviceAsSize
(In) X4	R5, R6	u64	DeviceAsAddr
(In) W5	R7	#Permission	Permissions
(Out) W0	R0	#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

Argument64	Argument32	Type	Name
(In) W0	R0	Handle<DeviceAddressSpace>	DeviceAsHandle
(In) W1	R1	Handle<Process>	ProcessHandle
(In) X2	R2, R3	void*	SrcAddr
(In) X3	R4	u64	DeviceAsSize
(In) X4	R5, R6	u64	DeviceAsAddr
(Out) W0	R0	#Result	Ret

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

svcContinueDebugEvent

[1.0.0-2.3.0] Argument64	Argument32	Type	Name
(In) W0	R0	Handle<Debug>	DebugHandle
(In) W1	R1	#ContinueDebugFlagsOld	DebugFlags
(In) X2	R2, R3	u64	ThreadId
(Out) W0	R0	#Result	Ret

[3.0.0+] Argument64	Argument32	Type	Name
(In) W0	R0	Handle<Debug>	DebugHandle
(In) W1	R1	#ContinueDebugFlags	DebugFlags
(In) X2	R2	u64*	ThreadIdList
(In) X3	R3	size_t	NumTids (max 64 - 0 means "all threads")
(Out) W0	R0	#Result	Ret

Result codes

0x0: Success. The process has been resumed.

0xe401: Invalid debug handle.

0xf401: Process has debug events queued or is already running.

svcGetProcessList

Argument64	Argument32	Type	Name
(In) X1	R1	u64*	PidBuffer
(In) X2	R2	size_t	PidBufferSize
(Out) X0	R0	#Result	Ret
(Out) X1	R1	size_t	NumProcesses

Description: Fills the provided array with the pids of currently living processes. A process "lives" so long as it is currently running or a handle to it still exists.

It returns the total number of processes currently alive. If this number is bigger than the size of PidBuffer, the user won't have all the pids.

Result codes

0x0: Success.

0xd401: The provided buffer is outside the process address space.

0xe601: copyToUser failed. The provided buffer is not user-accessible.

0xee01: The provided buffer size is too big. Max value is 0xFFFFFFF.

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

Argument64	Argument32	Type	Name
(In) W0	R0	Handle<Process>	ProcessHandle
(In) X1	R2, R3	u64	Addr
(In) X2	R1, R4	u64	Size
(In) W3	R5	void*	Perm
(Out) W0	R0	#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

Argument64	Argument32	Type	Name
(In) X0	R0	u64	DstAddr
(In) W1	R1	Handle<Process>	ProcessHandle
(In) X2	R2, R3	void*	SrcAddr
(In) X3	R4	u64	Size
(Out) W0	R0	#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

Argument64	Argument32	Type	Name
(In) X0	R0	void*	DstAddr
(In) W1	R1	Handle<Process>	ProcessHandle
(In) X2	R2, R3	u64	SrcAddr
(In) X3	R4	u64	Size
(Out) W0	R0	#Result	Ret

Unmaps what was mapped by #svcMapProcessMemory.

svcQueryProcessMemory

Argument64	Argument32	Type	Name
(In) X0	R0	#MemoryInfo*	MemInfoPtr
(In) W2	R2	Handle<Process>	ProcessHandle
(In) X3	R1, R3	u64	Addr
(Out) W0	R0	#Result	Ret
(Out) W1	R1	PageInfo	PageInfo

Equivalent to #svcQueryMemory except takes a process handle.

svcMapProcessCodeMemory

Argument64	Argument32	Type	Name
(In) W0	R0	Handle<Process>	ProcessHandle
(In) X1	R2, R3	u64	DstAddr
(In) X2	R1, R4	u64	SrcAddr
(In) X3	R5, R6	u64	Size
(Out) W0	R0	#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

Argument64	Argument32	Type	Name
(In) W0	R0	Handle<Process>	ProcessHandle
(In) X1	R2, R3	u64	DstAddr
(In) X2	R1, R4	u64	SrcAddr
(In) X3	R5, R6	u64	Size
(Out) W0	R0	#Result	Ret

Unmaps what was mapped by #svcMapProcessCodeMemory.

svcCreateProcess

Argument	Type	Name
(In) X1	#CreateProcessInfo*	InfoPtr
(In) X2	u32*	CapabilitiesPtr
(In) X3	u64	CapabilitiesNum
(Out) W0	#Result	Ret
(Out) W1	Handle<Process>	ProcessHandle

Takes a #CreateProcessInfo as input. CapabilitiesPtr points to an array of kernel capabilities. CapabilitiesNum is a number of capabilities in the CapabilitiesPtr array (number of element, not number of bytes).

Result codes

0x0: Success.

0xCA01: Attempted to map more code pages than available in address space.

0xCC01: Provided CodeAddr is invalid (make sure it's in range?)

0xE401: The resource handle passed is invalid.

0xE601: Attempt to copy procinfo from user-supplied pointer failed. Attempt to copy capabilities_num from user-supplied pointer failed.

0xE801: Attempted to create a 32-bit process with a 36-bit address space.

0xF001: Unused bits are set in mmuflags. Unknown address space type used.

svcGetProcessInfo

Argument64	Argument32	Type	Name
(In) W0	R1	Handle<Process>	ProcessHandle
(In) W1	R2	#ProcessInfoType	InfoType
(Out) W0	R0	#Result	Ret
(Out) X1	R1, R2	#ProcessState	State

Returns an enum with value 0-7.

svcCallSecureMonitor

Argument64	Argument32	Type	Name
(In) X0	R0	u64	Function ID
(In) X1-X7	R1-R3	u64	SMC sub-arguments
(Out) X0	R0	SMC Result	Result of SMC
(Out) X1-X7	R1-R3	u64	SMC sub-output

Takes in a SMC function ID in X0, and arguments for that SMC function in X1-X7.

Passing an invalid SMC function ID or calling from a core other than core 3 will result in a secure monitor panic.

The kernel parses bits 9-15 in the passed SMC function ID (per the ARM SMC calling convention), and when set uses as an indicator to translate a pointer in the associated register (X1-X7) to a physical address. The kernel will translate any address mapped as R-W, other addresses (R--, R-X, or invalid pointers) will be translated as 0/NULL.

Output is returned raw from the Secure Monitor; X0 will be the untranslated SMC result and X1-X7 will contain other SMC output (or be unchanged, depending on the SMC).

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

Argument64	Argument32	Type	Name
(In) W0	R0	u32	hardware_breakpoint_id
(In) X1	R2, R3	u64	flags
(In) X2	R1, R4	u64	value
(Out) W0	R0	#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

ThreadContextFlags

Bitfield of one of more of these:

Bit	Bitmask	Name	Description
0	1	General-purpose registers	If in 64-bit mode, GPRs 0–28 will be read/written. If in 32-bit mode, GPRs 0–12 will be read/written.
1	2	Control registers	Reads/writes the FP, LR, PC, SP, PSTATE, and TPIDR registers.
2	4	Floating-point registers	Reads/writes the floating-point vector registers.
3	8	Floating-point control registers	Reads/writes the FPCR and FPSR registers.

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	Note
0	LimitableResource_Memory	Bytes of memory a process may allocate.
1	LimitableResource_Threads	Amount of threads a process can create.
2	LimitableResource_Events	Amount of events a process can create through svcCreateEvent or svcSendAsyncRequestWithUserBuffer.
3	LimitableResource_TransferMemories	Amount of TransferMemory a process can create through svcCreateTransferMemory.
4	LimitableResource_Sessions	Amount of session a process can create through svcCreateSession, svcConnectToPort or svcConnectToNamedPort.

ProcessInfoType

Value	Name
0	ProcessInfoType_ProcessState

ProcessState

Value	Name	Notes
0	ProcessState_Created
1	ProcessState_CreatedAttached
2	ProcessState_Started
3	ProcessState_Crashed	Processes will not enter this state unless they were created with EnableDebug.
4	ProcessState_StartedAttached
5	ProcessState_Exiting
6	ProcessState_Exited
7	ProcessState_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)
0x0C	4		ProcessCategory (0: regular title, 1: kernel built-in)
0x10	8		TitleId
0x18	8		CodeAddr
0x20	4		CodeNumPages
0x24	4		Flags
		Bit0	IsAarch64
		Bit3-1	#AddressSpaceType
		Bit4	[2.0.0+] EnableDebug
		Bit5	EnableAslr
		Bit6	IsApplication
		Bit7	[4.0.0] UseSecureMemory
		Bit10-7	[5.0.0+] PoolPartition (0=Application, 1=Applet, 2=Sysmodule, 3=Nvservices)
		Bit11	[7.0.0+] OptimizeMemoryAllocation (Only allowed in combination with IsApplication).
0x28	4		ResourceLimitHandle or zero
0x2C	4		[3.0.0+] SystemResourceNumPages

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.

On [5.0.0] (maybe lower?) a zero ResourceLimitHandle defaults to sysmodule limits and 0x12300000 bytes of memory.

The PersonalMmHeap are allocated as follows:

• For the application, normal insecure pool is used. Carveout 5 is used to provide protection.
• For the applet, a pre-allocated secure pool segment of size 0x400000 is used.
• For sysmodules, secure pool is allocated.

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	Name	Description
0	IsBorrowed	Used by MapMemory, as an async IPC user buffer,
1	IsIpcLocked	True when IpcRefCount > 0
2	IsDeviceShared	True when DeviceRefCount > 0
3	IsUncached

MemoryState

Bits	Description	Meaning
7-0	Type
8	PermissionChangeAllowed
9	ForceReadWritableByDebugSyscalls	Allows using #svcWriteDebugProcessMemory on segments mapped read-only.
10	IpcSendAllowed	Allows sending this region as an IPC A/B/W buffer with flags=0.
11	NonDeviceIpcSendAllowed	Allows sending this region as an IPC A/B/W buffer with flags=1.
12	NonSecureIpcSendAllowed	Allows sending this region as an IPC A/B/W buffer with flags=3.
14	ProcessPermissionChangeAllowed
15	MapAllowed
16	UnmapProcessCodeMemoryAllowed
17	TransferMemoryAllowed
18	QueryPhysicalAddressAllowed
19	MapDeviceAllowed (#svcMapDeviceAddressSpace and #svcMapDeviceAddressSpaceByForce)
20	MapDeviceAlignedAllowed
21	IpcBufferAllowed
22	IsPoolAllocated/IsReferenceCounted	The physical memory blocks backing this region are refcounted.
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_Alias	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_Ipc	IPC buffers with descriptor flags=0.
0x005C3C0B	MemoryType_Stack	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_NonSecureIpc	IPC buffers with descriptor flags=1.
0x004C2812	MemoryType_NonDeviceIpc	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

[1.0.0-2.3.0]

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

ContinueDebugFlags

[3.0.0+]

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

IgnoreExceptionsOfOthers is like IgnoreException but acts on all threads that aren't in the input list. The affected threads are resumed.

Only one of of Resume and IgnoreOtherThreadsExceptions can be set at a time.

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

DebugEventInfo

The below table is for the Aarch64 version of the system call. For A32, all u64 fields but title/process/thread id are actually u32, making the structure 0x28-byte-big (0x40 for a64).

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=ExitedProcess, 3=TerminatedProcess)

Exception specific:

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

DebugEventType

Value	Name
0	DebugEvent_AttachProcess
1	DebugEvent_AttachThread
2	DebugEvent_ExitProcess
3	DebugEvent_ExitThread
4	DebugEvent_Exception

DebugExceptionType

Value	Name
0	Exception_Trap (*)
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 [not in 1.0.0]

* Undefined instructions, software breakpoints, some other traps.

** Data aborts, FP traps, and everything else that doesn't belong to any of the above.

Trap 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

First of all, a function that might be called by synchronous exception handler and that is called by the SError handler fetches the exception info, adjusts PC, panics on exceptions taken from EL1, then dispatches the exception.

The dispatcher has two mutually exclusive exception reporting methods:

• by storing information at the start of the process's TLS memregion (TPIDRRO_EL0) and jumping back to the crt0
• by using KDebug

KDebug dispatching is used when at least one of the following conditions are met:

• SMC ConfigItem KernelMemConfig bit 1 is NOT set (it isn't on retail), unless: this is a software or hardware breakpoint, or a watchpoint, or [4.0.0+?] the process is attached and this is a Google PNaCl trap instruction (see LLVM source)
• FAR doesn't point to a valid address in mapped-readable CodeStatic memory (i.e. this is the case for NRO and JIT memory) or this is one of the following exceptions (it particular, that doesn't include FP exceptions occurring in CodeStatic memory):
  • Uncategorized
  • IllegalState
  • SupervisorCallA32
  • SupervisorCallA64
  • PCAlignment
  • SPAlignment
  • SError
  • BreakpointLowerEl
  • SoftwareStepLowerEl (note: no way set single-step flag; not parsed)
  • WatchpointLowerEl
  • SoftwareBreakpointA32 (note: not parsed)
  • SoftwareBreakpointA64 (note: not parsed)

In all other cases the userland-handled exception path is taken.

KDebug path:

If the process is attached, the exception is reported to the KDebug. If the thread was continued using flag IgnoreExceptions, it returns from the exception as if nothing happened.

If the latter is not the case, or if the process isn't attached, proceed to [2.0.0+] crash reporting (or in [1.0.0] just terminate the process): if EnableDebug is set, and depending on the process state (more than one crash per process isn't permitted) it may signal itself with ProcessState_Crashed so that PM asks NS to start creport so that creport attaches to it and reports the crashes. Otherwise, just terminate.

Userland reporting path and svcReturnFromException:

TLS region start (A64):

Offset	Length	Description
0x0	0x148	Exception stack
0x148	0x78	ExceptionFrameA64

ExceptionFrameA64:

Offset	Length	Description
0x0	0x48 (8*9)	GPRs 0..8.
0x48	0x8	lr
0x50	0x8	sp
0x58	0x8	pc (elr_el1)
0x60	0x4	pstate & 0xFF0FFE20
0x64	0x4	afsr0
0x68	0x4	afsr1
0x6C	0x4	esr
0x70	0x8	far

TLS region start (A32):

Offset	Length	Description
0x0	0x178	Exception stack
0x148	0x44	ExceptionFrameA32

ExceptionFrameA32:

Offset	Length	Description
0x0	0x20 (8*4)	GPRs 0..7.
0x20	0x4	sp
0x24	0x4	lr
0x28	0x4	pc (elr_el1)
0x2C	0x4	tpidr_el0 = 1
0x30	0x4	cpsr & 0xFF0FFE20
0x34	0x4	afsr0
0x38	0x4	afsr1
0x3C	0x4	esr
0x40	0x4	far

In that case, after storing the regs in the TLS, the exception handler returns to the application's crt0 (entrypoint), with X0=<error description code> (see below) and X1=SP=frame=<stack top> (see above)

Desc. code	Meaning
0x100	Instruction abort
0x102	Misaligned PC
0x103	Misaligned SP
0x106	SError [not in 1.0.0?]
0x301	Bad SVC
0x104	Uncategorized, CP15RTTrap, CP15RRTTrap, CP14RTTrap, CP14RRTTrap, IllegalState, SystemRegisterTrap
0x101	None of the above, EC <= 0x34 and not a breakpoint

(During normal app boot the process is invoked with X0=0 and X1=main_thread_handle. The crt0 of retail apps determines whether to boot normally or handle an exception if X0 is set to 0 or not)

The application is supposed to promptly update the contents of elr_el1 to a user handler (and any other regs it sees fit) and call svcReturnFromException (error code) to call that handler. The latter is then expected to promptly abort the program.

svcReturnFromException updates the contents of the kernel stack frame with what the user provided in the TLS structure, sets TPIDR_EL0 to 1, then:

• if the provided error code is 0, gracefully pivots and returns from exception
• if it is not, replays the exception and pass it to the KDebug (see above). One can pass 0x10001 to prevent process termination. If the process is attached, this also prevents crash-collection/termination (different from the exception handler behavior)

If an exception occurs from the above user handler, the entire exception handling process will repeat with the new exception.

Note that if a thread that wasn't faulting calls svcReturnFromException, it signals an "invalid syscall" exception

Note that IsDebugMode is not used during exception-handling, except for enabling printing a message to UART-A. This UART code causes a system-hang on retail (likely due to a loop that doesn't exit). This printing doesn't seem to run when the process is attached for debugging?