Re: [seL4] seL4 IPC fastpath question

Hi,

1. IPC fastpath can apply in seL4_Call and seL4_Reply_Recv, is it right?

seL4_Send, seL4_Recv can't apply IPC fastpath.

Yes. We could add fastpaths for other paths if required but they do not currently exist.

2. IPC_fastpath can only send message that message's length is 0, is it right?

No. The IPC fastpath can only send messages that fit into registers. The constant `seL4_FastMessageRegisters` defines this value for all platforms (usually 4, except for ia32).

3. In seL4 IPC mechanism, IPC only use registers not memory?

No. IPC messages > seL4_FastMessageRegisters is transferred via the IPC buffer in memory.

?Cheers, Anna.