Index: src/syscall/mkall.sh
--- src/syscall/mkall.sh.orig
+++ src/syscall/mkall.sh
@@ -337,15 +337,28 @@ openbsd_arm64)
 	mkasm="go run mkasm.go"
 	;;
 openbsd_mips64)
-	GOOSARCH_in="syscall_openbsd1.go syscall_openbsd_$GOARCH.go"
+	GOOSARCH_in="syscall_openbsd_libc.go syscall_openbsd_$GOARCH.go"
 	mkerrors="$mkerrors -m64"
-	mksyscall="./mksyscall.pl -openbsd"
+	mksyscall="./mksyscall.pl -openbsd -libc"
 	mksysctl="./mksysctl_openbsd.pl"
 	zsysctl="zsysctl_openbsd.go"
 	mksysnum="curl -s 'http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_openbsd.pl"
 	# Let the type of C char be signed to make the bare syscall
 	# API consistent between platforms.
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs -- -fsigned-char"
+	mkasm="go run mkasm.go"
+	;;
+openbsd_riscv64)
+	GOOSARCH_in="syscall_openbsd_libc.go syscall_openbsd_$GOARCH.go"
+	mkerrors="$mkerrors -m64"
+	mksyscall="./mksyscall.pl -openbsd -libc"
+	mksysctl="./mksysctl_openbsd.pl"
+	zsysctl="zsysctl_openbsd.go"
+	mksysnum="curl -s 'http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_openbsd.pl"
+	# Let the type of C char be signed to make the bare syscall
+	# API consistent between platforms.
+	mktypes="GOARCH=$GOARCH go tool cgo -godefs -- -fsigned-char"
+	mkasm="go run mkasm.go"
 	;;
 plan9_386)
 	mkerrors=
