linux-user: Add AArch64 support

This patch adds support for AArch64 in all the small corners of
linux-user (primarily in image loading and startup code).

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: John Rigby <john.rigby@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1378235544-22290-22-git-send-email-peter.maydell@linaro.org
Message-id: 1368505980-17151-11-git-send-email-john.rigby@linaro.org
[PMM:
 * removed some unnecessary #defines from syscall.h
 * catch attempts to use a 32 bit only cpu with aarch64-linux-user
 * termios stuff moved into its own patch
 * we specify our minimum uname version here now
]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/linux-user/main.c b/linux-user/main.c
index 8838305..01e3cd4 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3968,6 +3968,22 @@
     cpu_x86_load_seg(env, R_FS, 0);
     cpu_x86_load_seg(env, R_GS, 0);
 #endif
+#elif defined(TARGET_AARCH64)
+    {
+        int i;
+
+        if (!(arm_feature(env, ARM_FEATURE_AARCH64))) {
+            fprintf(stderr,
+                    "The selected ARM CPU does not support 64 bit mode\n");
+            exit(1);
+        }
+
+        for (i = 0; i < 31; i++) {
+            env->xregs[i] = regs->regs[i];
+        }
+        env->pc = regs->pc;
+        env->xregs[31] = regs->sp;
+    }
 #elif defined(TARGET_ARM)
     {
         int i;