@@ -52,22 +52,35 @@
 		%assign i i+1
 	%endrep
 
 	; valency >= 7. this is not valid, so
-	; we set our return value to 0 and the
+	; we set our return value to -1 and the
 	; error number to its maximum value in
 	; order to indicate that the syscall
 	; was invalid
-	mov qword [rbx], 0
+	mov qword [rbx], -1
 	mov qword [r12], -1
 	ret
 
 	; we have a valency match - perform the
 	; requested syscall already store in rax
 	.perform_call: sys.call
+
+	; check for an error - on x86, error is
+	; returned as a negative value in %rax
+	test sys.reg.ret, sys.reg.ret
+	js .error ; jump if sign flag set
 	
 	; move our return values into place and
 	; return to the caller (which should
 	; always be k_platform_syscall, btw)
-	mov [rbx], sys.reg.ret
-	mov [r12], sys.reg.err
+	mov       [rbx], sys.reg.ret
+	mov qword [r12], 0 ; no error
 	ret
+
+	; an error was returned - we need to set
+	; the errno to its positive equivalent,
+	; and store -1 in the return variable
+	.error: neg sys.reg.ret
+	        mov qword [rbx], -1
+			mov       [r12], sys.reg.ret
+			ret