From 9667351422dec0ca40a784a08dec7ce128482aba Mon Sep 17 00:00:00 2001 From: Thomas Schwinge Date: Wed, 10 Jul 2013 23:39:29 +0200 Subject: IRC. --- system_call.mdwn | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'system_call.mdwn') diff --git a/system_call.mdwn b/system_call.mdwn index f180a79b..16d706c7 100644 --- a/system_call.mdwn +++ b/system_call.mdwn @@ -18,3 +18,18 @@ See [[GNU Mach's system calls|microkernel/mach/gnumach/interface/syscall]]. In the [[GNU Hurd|hurd]], a lot of what is traditionlly considered to be a UNIX system call is implemented (primarily by means of [[RPC]]) inside [[glibc]]. + + +# IRC, freenode, #hurd, 2013-06-15 + + true system calls are always implemented the same way, by the + kernel, using traps or specialized instructions that enable crossing from + user to kernel space + glibc simply translates function calls to system calls by packing + arguments appropriately and using that trap or syscall instruction + on microkernel based systems however, true system calls are + normally used only for IPC + so we also use the term syscall to refer to those RPCs that + provide system services + e.G. open() is a call to a file system server (and maybe several + actually) -- cgit v1.2.3