Initial Spring 2016 commit.

userland/lib/libc/syscalls/gensyscalls.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+#
+# gensyscalls.sh
+# Usage: ./gensyscalls.sh < syscalls.h
+#
+# Parses the kernel's syscalls.h into the body of syscalls.S
+#
+
+# tabs to spaces, just in case
+tr '\t' ' ' |\
+awk '
+    # Do not read the parts of the file that are not between the markers.
+    /^\/\*CALLBEGIN\*\// { look=1; }
+    /^\/\*CALLEND\*\// { look=0; }
+
+    # And, do not read lines that do not match the approximate right pattern.
+    look && /^#define SYS_/ && NF==3 {
+	sub("^SYS_", "", $2);
+	# print the name of the call and the number.
+	print $2, $3;
+    }
+' | awk '{
+	# output something simple that will work in syscalls.S.
+	printf "SYSCALL(%s, %s)\n", $1, $2;
+}'