Where is the source to the system calls?

[Kurt J. Lidl]

On Sun, Nov 07, 2004 at 04:29:42PM -0800, Dan Strick wrote:
> Does anyone know where the system calls are really defined?
> I followed open() to _open() to __sys_open() which seems
> to be part of something called libc_r before I ran into a
> blank wall.  I grepped all of the regular files in /usr/src
> and /usr/include and turned up nothing.  I even tried
> grepping for open in the output of "nm -g /usr/lib/libc.a".
> There is no __sys_open() in libc.  Am I dealing with
> C-compiler magic?  Secret macro instructions invoking
> undocumented gnu C-compiler asm() features?  A CIA plot?
> 
> Is any of this low level structure documented anywhere?

Grok the following:
	/usr/src/lib/libc/sys/Makefile.inc
	/usr/src/sys/sys/syscall.mk
	
-Kurt