  RISC/os also had maybe the most inflated syscall interface as can be seen in this header file defining the [http://www.linux-mips.org/git?p=linux.git;a=blob;h=0d0eb00000eb0a0e00a0000c00000b0d00000dbc;hb=f000000cb0e00000f0c0dd0f00000f0c00000d0a;f=include/asm-mips/riscos-syscall.h RISC/os syscalls]. The basic structure is:  