nios2: Add usermode binaries emulation

Add missing bits for qemu-user required for emulating Altera Nios2
userspace binaries.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Jeff Da Silva <jdasilva@altera.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Sandra Loosemore <sandra@codesourcery.com>
Cc: Yves Vandervennet <yvanderv@altera.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Message-Id: <20170118220146.489-4-marex@denx.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>

linux-user/nios2/target_cpu.h

@@ -0,0 +1,39 @@
+/*
+ * Nios2 specific CPU ABI and functions for linux-user
+ *
+ * Copyright (c) 2016 Marek Vasut <marex@denx.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TARGET_CPU_H
+#define TARGET_CPU_H
+
+static inline void cpu_clone_regs(CPUNios2State *env, target_ulong newsp)
+{
+    if (newsp) {
+        env->regs[R_SP] = newsp;
+    }
+    env->regs[R_RET0] = 0;
+}
+
+static inline void cpu_set_tls(CPUNios2State *env, target_ulong newtls)
+{
+    /*
+     * Linux kernel 3.10 does not pay any attention to CLONE_SETTLS
+     * in copy_thread(), so QEMU need not do so either.
+     */
+}
+
+#endif