Basic ABI: SysV i386

Out-of-Process Method Invocation:
   Caller:
      eax: pointer to parameter info block (PIB)

      Call 0x7fff0000 to invoke the method.
      
      Upon return:
      ebx, esi, edi, ebp, esp: preserved
      eax: pointer to exception, or NULL if none
           If there is an exception, the user part of the syscall
           function will search for an exception handling function
           that covers the calling address.  If none is found,
           it will assume that it is a language without exception
           handling, an5Ad return the exception to the caller in eax.
      edx: length of exception segment, if any
      ecx: may be clobbered
      
   Callee:
      eax: pointer to PIB
      edx: pointer to caller information struct, or NULL if not
           requested
      esp: NULL.

      Jump to 0x7fff0080 to return.
      
      Upon return:
      eax: pointer to exception, or NULL if none
      edx: length of exception segment, if any
      ebx, ecx, esi, edi, ebp, esp: may be clobbered

Other system calls:
	eax, edx, ecx: syscall arguments.
	
	Call 0x7fff0000 + 0x80 * syscallnum

	eax: return value
	edx, ecx: may be clobbered