S/390 CPU fake emulation

Because Qemu currently requires a TCG target to exist and there are quite some
useful helpers here to lay the groundwork for out KVM target, let's create a
stub TCG emulation target for S390X CPUs.

This is required to make tcg happy. The emulation target itself won't work
though.

Signed-off-by: Alexander Graf <[email protected]>
Signed-off-by: Aurelien Jarno <[email protected]>
diff --git a/target-s390x/helper.c b/target-s390x/helper.c
new file mode 100644
index 0000000..4a198ae
--- /dev/null
+++ b/target-s390x/helper.c
@@ -0,0 +1,62 @@
+/*
+ *  S/390 helpers
+ *
+ *  Copyright (c) 2009 Ulrich Hecht
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "cpu.h"
+#include "exec-all.h"
+#include "gdbstub.h"
+#include "qemu-common.h"
+
+CPUS390XState *cpu_s390x_init(const char *cpu_model)
+{
+    CPUS390XState *env;
+    static int inited = 0;
+
+    env = qemu_mallocz(sizeof(CPUS390XState));
+    cpu_exec_init(env);
+    if (!inited) {
+        inited = 1;
+    }
+
+    env->cpu_model_str = cpu_model;
+    cpu_reset(env);
+    qemu_init_vcpu(env);
+    return env;
+}
+
+target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
+{
+    return addr;
+}
+
+void cpu_reset(CPUS390XState *env)
+{
+    if (qemu_loglevel_mask(CPU_LOG_RESET)) {
+        qemu_log("CPU Reset (CPU %d)\n", env->cpu_index);
+        log_cpu_state(env, 0);
+    }
+
+    memset(env, 0, offsetof(CPUS390XState, breakpoints));
+    /* FIXME: reset vector? */
+    tlb_flush(env, 1);
+}