to avoid compatability issues, just define nsec as _nsec.  nsec
is still a bad idea

Reference: /n/atom/patch/applied/sys_nsec
Date: Thu Jun 12 15:19:26 CES 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/libc/9syscall/mkfile	Thu Jun 12 15:19:07 2014
+++ /sys/src/libc/9syscall/mkfile	Thu Jun 12 15:19:08 2014
@@ -3,6 +3,7 @@
 
 install:V:
 	SYS=`{sed '/^#define._X[123]/d; s/#define.([A-Z0-9_]*).*/\1/' sys.h}
+	vlongret=()
 	for(I in $SYS) {
 		i=`{echo $I|tr A-Z a-z}
 		n=`{sed -n '/[ 	]'$I'[ 	]/s/.*	//p' sys.h}
@@ -18,7 +19,7 @@
 			echo MOVW R1, '0(FP)'
 			echo MOVW '$'$n, R1
 			echo SYSCALL
-			if(~ $i seek) {
+			if(~ $i seek _nsec) {
 				echo 'MOVW $-1,R5
 				BNE R1,R5,4(PC)
 				MOVW a+0(FP),R5
@@ -41,7 +42,7 @@
 			echo ADD '$4',R29
 			echo SYSCALL
 			echo ADD '$-4',R29
-			if(~ $i seek) {		# untested so far - geoff
+			if(~ $i seek _nsec) {		# untested so far - geoff
 				echo 'MOVW $-1,R5
 				BNE R1,R5,4(PC)
 				MOVW a+0(FP),R5
@@ -53,7 +54,7 @@
 			echo TEXT $i'(SB)', 1, '$0'
 			echo MOVL '$'$n, AX
 			echo INT '$'64
-			if(~ $i seek) {
+			if(~ $i seek _nsec) {
 				echo 'CMPL AX,$-1
 				JNE 4(PC)
 				MOVL a+0(FP),CX
@@ -66,7 +67,13 @@
 				echo TEXT _seek'(SB)', 1, '$0'
 			if not
 				echo TEXT $i'(SB)', 1, '$0'
-			echo MOVQ RARG, 'a0+0(FP)'
+			#
+			# For architectures which pass the first argument
+			# in a register, if the system call takes no arguments
+			# there will be no 'a0+0(FP)' reserved on the stack.
+			#
+			if(! ~ $i _nsec)
+				echo MOVQ RARG, 'a0+0(FP)'
 			echo MOVQ '$'$n, RARG
 			echo SYSCALL
 			echo RET
@@ -75,7 +82,7 @@
 			echo MOVW R7, '0(FP)'
 			echo MOVW '$'$n, R7
 			echo TA R0
-			if(~ $i seek) {
+			if(~ $i seek _nsec) {
 				echo 'CMP R7,$-1
 				BNE 4(PC)
 				MOVW a+0(FP),R8
@@ -100,7 +107,7 @@
 			echo MOVW R0, '0(FP)'
 			echo MOVW '$'$n, R0
 			echo SWI 0
-			if(~ $i seek) {
+			if(~ $i seek _nsec) {
 				echo 'CMP $-1,R0
 				BNE 4(PC)
 				MOVW a+0(FP),R1
@@ -113,7 +120,7 @@
 			echo MOVW R3, '0(FP)'
 			echo MOVW '$'$n, R3
 			echo SYSCALL
-			if(~ $i seek) {
+			if(~ $i seek _nsec) {
 				echo 'CMP R3,$-1
 				BNE 4(PC)
 				MOVW a+0(FP),R8
--- /sys/src/libc/9syscall/sys.h	Thu Jun 12 15:19:08 2014
+++ /sys/src/libc/9syscall/sys.h	Thu Jun 12 15:19:09 2014
@@ -49,3 +49,4 @@
 #define	PREAD		50
 #define	PWRITE		51
 #define	TSEMACQUIRE	52
+#define	_NSEC		53