Index: src/runtime/os_openbsd_syscall.go
--- src/runtime/os_openbsd_syscall.go.orig
+++ src/runtime/os_openbsd_syscall.go
@@ -1,47 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build openbsd && mips64
-
-package runtime
-
-import (
-	"internal/abi"
-	"internal/goarch"
-	"unsafe"
-)
-
-//go:noescape
-func tfork(param *tforkt, psize uintptr, mm *m, gg *g, fn uintptr) int32
-
-// May run with m.p==nil, so write barriers are not allowed.
-//
-//go:nowritebarrier
-func newosproc(mp *m) {
-	stk := unsafe.Pointer(mp.g0.stack.hi)
-	if false {
-		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
-	}
-
-	// Stack pointer must point inside stack area (as marked with MAP_STACK),
-	// rather than at the top of it.
-	param := tforkt{
-		tf_tcb:   unsafe.Pointer(&mp.tls[0]),
-		tf_tid:   nil, // minit will record tid
-		tf_stack: uintptr(stk) - goarch.PtrSize,
-	}
-
-	var oset sigset
-	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
-	ret := tfork(&param, unsafe.Sizeof(param), mp, mp.g0, abi.FuncPCABI0(mstart))
-	sigprocmask(_SIG_SETMASK, &oset, nil)
-
-	if ret < 0 {
-		print("runtime: failed to create new OS thread (have ", mcount()-1, " already; errno=", -ret, ")\n")
-		if ret == -_EAGAIN {
-			println("runtime: may need to increase max user processes (ulimit -p)")
-		}
-		throw("runtime.newosproc")
-	}
-}
