Kernel ABI

Calling Convention

Seems to be AAPCS-based (with modifications)

Overview

Inputs

• r0–r3 : Argument / Scratch registers (caller-saved), inherited from AAPCS. If an input is to be placed on the stack, it will instead use the next free register starting from r0.

Outputs

• r0-r1 : Result, inherited from AAPCS. If multiple outputs are returned (e.g., ControlMemory), they are placed in consecutive registers starting from r0.

Example

Result ControlMemory(uintptr_t* out, uintptr_t addr0, uintptr_t addr1, size_t size, MemoryOperation operation, MemoryPermission permissions)

Inputs

Following standard AAPCS register selection:

r1 -> addr0

r2 -> addr1

r3 -> size

As there are still have more arguments, the next free registers are selected starting from r0

r0 -> operation

r4 -> permissions

Outputs

r0 -> Result

r1 -> uintptr_t out

System calls

ID	Name	Inputs	Outputs
0x01	ControlMemory	r0: MemoryOperation operation r1: u32/void* addr0 r2: u32/void* addr1 r3: u32 size r4: MemoryPermission permissions	r0: Result r1: u32/void* addr_out
0x02	QueryMemory	r2?: u32/void* addr	r0: Result r1: u32 base_process_virtual_address r2: u32 size r3: MemoryPermission permission r4: MemoryState state r5: PageFlags page_flags
0x03	ExitProcess	None	None, doesn't return
0x04	GetProcessAffinityMask	r0: [out] u8* affinitymask r1: Handle<KProcess> process r2: s32 processorcount	r0: Result
0x05	SetProcessAffinityMask	r0: Handle<KProcess> process r1: [in] const u8* affinitymask r2: s32 processorcount	r0: Result
0x06	GetProcessIdealProcessor	r1?: Handle<KProcess> process	r0: Result r1: s32 processorid r2: Clobbered?
0x07	SetProcessIdealProcessor	r0: Handle<KProcess> process r1: s32 processorid	r0: Result
0x08	CreateThread	r0: s32 thread_priority r1: ThreadFunc entrypoint r2: u32 arg r3: u32/void* stack_top r4: s32 processor_id	r0: Result r1: Handle<KThread> thread_handle
0x09	ExitThread	None	None, doesn't return
0x0A	SleepThread	r0-r1: s64 nanoseconds	None
0x0B	GetThreadPriority	r0: Ignored? r1: Handle thread_handle	r0: Result r1: s32 thread_priority r2: Clobbered?
0x0C	SetThreadPriority	r0: Handle<KThread> thread_handle r1: s32 thread_priority	r0: Result
0x0D	GetThreadAffinityMask	r0: [out] u8* affinitymask r1: Handle<KThread> thread_handle r2: s32 processorcount	r0: Result
0x0E	SetThreadAffinityMask	r0: Handle<KThread> thread_handle r1: [in] const u8* affinitymask r2: s32 processorcount	r0: Result
0x0F	GetThreadIdealProcessor	r0: Ignored? r1: Handle<KThread> thread_handle	r0: Result r1: s32 processorid
0x10	SetThreadIdealProcessor	r0: Handle<KThread> thread_handle r1: s32 processorid	r0: Result
0x11	GetProcessorID	None	r0: s32 processorid
0x24	WaitSynchronization1	r0: Handle<KSynchronizationObject> handle r2-r3: s64 timeout	r0: Result
0x1B	SetTimer	Timer handle, initial_low, interval_low, initial_high, interval_high	Result
0x28	GetSystemTick	None	r0: Low 32 bits of the tick count r1: High 32 bits of the tick count
0x2D	ConnectToPort	?? r1: pointer to port name	r0: Result r1: handle to KClientSession
0x32	SendSyncRequest	r0: handle to KClientSession	r0: Result