From 88dd1da188f37a9132230967883ba38c645c6dd9 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Sun, 29 Dec 2013 16:29:02 -0500
Subject: ia64: syscall: add some helpful documentation

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 ports/sysdeps/unix/sysv/linux/ia64/syscall.S | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'ports/sysdeps')

diff --git a/ports/sysdeps/unix/sysv/linux/ia64/syscall.S b/ports/sysdeps/unix/sysv/linux/ia64/syscall.S
index 8bb77d255c..4cd75b8d4c 100644
--- a/ports/sysdeps/unix/sysv/linux/ia64/syscall.S
+++ b/ports/sysdeps/unix/sysv/linux/ia64/syscall.S
@@ -19,6 +19,10 @@
 #include <sysdep.h>
 
 ENTRY(syscall)
+	/* We are called like so:
+	   {out0,out1,...,out6} registers -> {NR, arg1, ..., arg6}
+	   Shift the register window so that {out1...out6} are available
+	   in {out0...out5} like the kernel syscall handler expects.  */
 	alloc r2=ar.pfs,1,0,8,0
 	mov r15=r32		/* syscall number */
 	break __BREAK_SYSCALL
-- 
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