diff mbox

[3/7] nios2: Add usermode binaries emulation

Message ID 1465844745-5412-3-git-send-email-marex@denx.de (mailing list archive)
State New, archived
Headers show

Commit Message

Marek Vasut June 13, 2016, 7:05 p.m. UTC
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>
---
 include/elf.h                     |   2 +
 linux-user/elfload.c              |  58 +++++++
 linux-user/main.c                 | 136 +++++++++++++++-
 linux-user/nios2/syscall_nr.h     | 330 ++++++++++++++++++++++++++++++++++++++
 linux-user/nios2/target_cpu.h     |  38 +++++
 linux-user/nios2/target_signal.h  |  26 +++
 linux-user/nios2/target_structs.h |  58 +++++++
 linux-user/nios2/target_syscall.h |  37 +++++
 linux-user/nios2/termbits.h       | 220 +++++++++++++++++++++++++
 linux-user/signal.c               | 238 ++++++++++++++++++++++++++-
 linux-user/syscall_defs.h         |   7 +-
 11 files changed, 1143 insertions(+), 7 deletions(-)
 create mode 100644 linux-user/nios2/syscall_nr.h
 create mode 100644 linux-user/nios2/target_cpu.h
 create mode 100644 linux-user/nios2/target_signal.h
 create mode 100644 linux-user/nios2/target_structs.h
 create mode 100644 linux-user/nios2/target_syscall.h
 create mode 100644 linux-user/nios2/termbits.h
diff mbox

Patch

diff --git a/include/elf.h b/include/elf.h
index 28d448b..557fbfa 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -125,6 +125,8 @@  typedef int64_t  Elf64_Sxword;
  */
 #define EM_S390_OLD     0xA390
 
+#define EM_ALTERA_NIOS2 113     /* Altera Nios II soft-core processor */
+
 #define EM_MICROBLAZE      189
 #define EM_MICROBLAZE_OLD  0xBAAB
 
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index bb2558f..1c693ec 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -964,6 +964,64 @@  static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUMBState *env
 
 #endif /* TARGET_MICROBLAZE */
 
+#ifdef TARGET_NIOS2
+
+#define ELF_START_MMAP 0x80000000
+
+#define elf_check_arch(x) ((x) == EM_ALTERA_NIOS2)
+
+#define ELF_CLASS   ELFCLASS32
+#define ELF_ARCH    EM_ALTERA_NIOS2
+
+static inline void init_thread(struct target_pt_regs *regs,
+                               struct image_info *infop)
+{
+    regs->ea = infop->entry;
+    regs->sp = infop->start_stack;
+    regs->estatus = 0x3;
+}
+
+#define ELF_EXEC_PAGESIZE        4096
+
+#define USE_ELF_CORE_DUMP
+#define ELF_NREG 49
+typedef target_elf_greg_t target_elf_gregset_t[ELF_NREG];
+
+/* See linux kernel: arch/mips/kernel/process.c:elf_dump_regs.  */
+static void elf_core_copy_regs(target_elf_gregset_t *regs,
+			       const CPUNios2State *env)
+{
+    int i;
+
+    (*regs)[0] = -1;
+    for (i = 1; i < 8; i++)	/* r0-r7 */
+        (*regs)[i] = tswapreg(env->regs[i + 7]);
+
+    for (i = 8; i < 16; i++)	/* r8-r15 */
+        (*regs)[i] = tswapreg(env->regs[i - 8]);
+
+    for (i = 16; i < 24; i++)	/* r16-r23 */
+        (*regs)[i] = tswapreg(env->regs[i + 7]);
+    (*regs)[24] = -1;	/* R_ET */
+    (*regs)[25] = -1;	/* R_BT */
+    (*regs)[26] = tswapreg(env->regs[R_GP]);
+    (*regs)[27] = tswapreg(env->regs[R_SP]);
+    (*regs)[28] = tswapreg(env->regs[R_FP]);
+    (*regs)[29] = tswapreg(env->regs[R_EA]);
+    (*regs)[30] = -1;	/* R_SSTATUS */
+    (*regs)[31] = tswapreg(env->regs[R_RA]);
+
+    (*regs)[32] = tswapreg(env->regs[R_PC]);
+
+    (*regs)[33] = -1; /* R_STATUS */
+    (*regs)[34] = tswapreg(env->regs[CR_ESTATUS]);
+
+    for (i = 35; i < 49; i++)	/* ... */
+	    (*regs)[i] = -1;
+}
+
+#endif /* TARGET_NIOS2 */
+
 #ifdef TARGET_OPENRISC
 
 #define ELF_START_MMAP 0x08000000
diff --git a/linux-user/main.c b/linux-user/main.c
index f8a8764..5ec5ccc 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -65,8 +65,11 @@  do {                                                                    \
  * This way we will never overlap with our own libraries or binaries or stack
  * or anything else that QEMU maps.
  */
-# ifdef TARGET_MIPS
-/* MIPS only supports 31 bits of virtual address space for user space */
+# if defined(TARGET_MIPS) || defined(TARGET_NIOS2)
+/*
+ * MIPS only supports 31 bits of virtual address space for user space.
+ * Nios2 also only supports 31 bits.
+ */
 unsigned long reserved_va = 0x77000000;
 # else
 unsigned long reserved_va = 0xf7000000;
@@ -2719,6 +2722,105 @@  error:
 }
 #endif
 
+#ifdef TARGET_NIOS2
+
+void cpu_loop(CPUNios2State *env)
+{
+    CPUState *cs = ENV_GET_CPU(env);
+    target_siginfo_t info;
+    int trapnr, gdbsig, ret;
+
+    for (;;) {
+        cpu_exec_start(cs);
+        trapnr = cpu_nios2_exec(cs);
+        cpu_exec_end(cs);
+        gdbsig = 0;
+
+        switch (trapnr) {
+        case EXCP_INTERRUPT:
+            /* just indicate that signals should be handled asap */
+            break;
+        case EXCP_TRAP:
+            if (env->regs[R_AT] == 0) {
+                abi_long ret;
+                qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
+
+                ret = do_syscall(env, env->regs[2],
+                                 env->regs[4], env->regs[5], env->regs[6],
+                                 env->regs[7], env->regs[8], env->regs[9],
+                                 0, 0);
+
+		if (env->regs[2] == 0)	/* FIXME: syscall 0 workaround */
+			ret = 0;
+
+                env->regs[2] = abs(ret);
+		/* Return value is 0..4096 */
+                env->regs[7] = (ret > 0xfffffffffffff000ULL);
+                env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
+                env->regs[CR_STATUS] &= ~0x3;
+                env->regs[R_EA] = env->regs[R_PC] + 4;
+                env->regs[R_PC] += 4;
+		break;
+            } else {
+                qemu_log_mask(CPU_LOG_INT, "\nTrap\n");
+
+                env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
+                env->regs[CR_STATUS] &= ~0x3;
+                env->regs[R_EA] = env->regs[R_PC] + 4;
+                env->regs[R_PC] = env->exception_addr;
+
+                gdbsig = TARGET_SIGTRAP;
+                break;
+            }
+        case 0xaa:
+            switch (env->regs[R_PC]) {
+                //case 0x1000:	/* __kuser_helper_version */
+		case 0x1004:	/* __kuser_cmpxchg */
+                    start_exclusive();
+		    if (env->regs[4] & 0x3)
+		        goto kuser_fail;
+                    ret = get_user_u32(env->regs[2], env->regs[4]);
+                    if (ret) {
+                        end_exclusive();
+                        goto kuser_fail;
+                    }
+                    env->regs[2] -= env->regs[5];
+                    if (env->regs[2] == 0) {
+                        put_user_u32(env->regs[6], env->regs[4]);
+                    }
+                    end_exclusive();
+                    env->regs[R_PC] = env->regs[R_RA];
+                    break;
+                    //case 0x1040:	/* __kuser_sigtramp */
+kuser_fail:
+                default:
+                    info.si_signo = TARGET_SIGSEGV;
+                    info.si_errno = 0;
+                    /* XXX: check env->error_code */
+                    info.si_code = TARGET_SEGV_MAPERR;
+                    info._sifields._sigfault._addr = env->regs[R_PC];
+                    queue_signal(env, info.si_signo, &info);
+            }
+	    break;
+        default:
+            EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
+                     trapnr);
+            gdbsig = TARGET_SIGILL;
+            break;
+        }
+        if (gdbsig) {
+            gdb_handlesig(cs, gdbsig);
+            if (gdbsig != TARGET_SIGTRAP) {
+                exit(EXIT_FAILURE);
+            }
+        }
+
+        process_pending_signals(env);
+    }
+}
+
+#endif /* TARGET_NIOS2 */
+
 #ifdef TARGET_OPENRISC
 
 void cpu_loop(CPUOpenRISCState *env)
@@ -4687,6 +4789,36 @@  int main(int argc, char **argv, char **envp)
             env->hflags |= MIPS_HFLAG_M16;
         }
     }
+#elif defined(TARGET_NIOS2)
+    {
+	env->regs[0] = 0;
+	env->regs[1] = regs->r1;
+	env->regs[2] = regs->r2;
+	env->regs[3] = regs->r3;
+	env->regs[4] = regs->r4;
+	env->regs[5] = regs->r5;
+	env->regs[6] = regs->r6;
+	env->regs[7] = regs->r7;
+	env->regs[8] = regs->r8;
+	env->regs[9] = regs->r9;
+	env->regs[10] = regs->r10;
+	env->regs[11] = regs->r11;
+	env->regs[12] = regs->r12;
+	env->regs[13] = regs->r13;
+	env->regs[14] = regs->r14;
+	env->regs[15] = regs->r15;
+	// unsigned long  orig_r2;
+	env->regs[R_RA] = regs->ra;
+	env->regs[R_FP] = regs->fp;
+	env->regs[R_SP] = regs->sp;
+	env->regs[R_GP] = regs->gp;
+	env->regs[CR_ESTATUS] = regs->estatus;
+	env->regs[R_EA] = regs->ea;
+	// unsigned long  orig_r7;
+
+	/* Emulate eret when starting thread. */
+	env->regs[R_PC] = regs->ea;
+    }
 #elif defined(TARGET_OPENRISC)
     {
         int i;
diff --git a/linux-user/nios2/syscall_nr.h b/linux-user/nios2/syscall_nr.h
new file mode 100644
index 0000000..0939d43
--- /dev/null
+++ b/linux-user/nios2/syscall_nr.h
@@ -0,0 +1,330 @@ 
+#define TARGET_NR_io_setup			0
+#define TARGET_NR_io_destroy			1
+#define TARGET_NR_io_submit			2
+#define TARGET_NR_io_cancel			3
+#define TARGET_NR_io_getevents			4
+#define TARGET_NR_setxattr			5
+#define TARGET_NR_lsetxattr			6
+#define TARGET_NR_fsetxattr			7
+#define TARGET_NR_getxattr			8
+#define TARGET_NR_lgetxattr			9
+#define TARGET_NR_fgetxattr			10
+#define TARGET_NR_listxattr			11
+#define TARGET_NR_llistxattr			12
+#define TARGET_NR_flistxattr			13
+#define TARGET_NR_removexattr			14
+#define TARGET_NR_lremovexattr			15
+#define TARGET_NR_fremovexattr			16
+#define TARGET_NR_getcwd			17
+#define TARGET_NR_lookup_dcookie		18
+#define TARGET_NR_eventfd2			19
+#define TARGET_NR_epoll_create1			20
+#define TARGET_NR_epoll_ctl			21
+#define TARGET_NR_epoll_pwait			22
+#define TARGET_NR_dup				23
+#define TARGET_NR_dup3				24
+#define TARGET_NR_fcntl64			25
+#define TARGET_NR_inotify_init1			26
+#define TARGET_NR_inotify_add_watch		27
+#define TARGET_NR_inotify_rm_watch		28
+#define TARGET_NR_ioctl				29
+#define TARGET_NR_ioprio_set			30
+#define TARGET_NR_ioprio_get			31
+#define TARGET_NR_flock				32
+#define TARGET_NR_mknodat			33
+#define TARGET_NR_mkdirat			34
+#define TARGET_NR_unlinkat			35
+#define TARGET_NR_symlinkat			36
+#define TARGET_NR_linkat			37
+#define TARGET_NR_renameat			38
+#define TARGET_NR_umount2			39
+#define TARGET_NR_mount				40
+#define TARGET_NR_pivot_root			41
+#define TARGET_NR_nfsservctl			42
+#define TARGET_NR_statfs64			43
+#define TARGET_NR_fstatfs64			44
+#define TARGET_NR_truncate64			45
+#define TARGET_NR_ftruncate64			46
+#define TARGET_NR_fallocate			47
+#define TARGET_NR_faccessat			48
+#define TARGET_NR_chdir				49
+#define TARGET_NR_fchdir			50
+#define TARGET_NR_chroot			51
+#define TARGET_NR_fchmod			52
+#define TARGET_NR_fchmodat			53
+#define TARGET_NR_fchownat			54
+#define TARGET_NR_fchown			55
+#define TARGET_NR_openat			56
+#define TARGET_NR_close				57
+#define TARGET_NR_vhangup			58
+#define TARGET_NR_pipe2				59
+#define TARGET_NR_quotactl			60
+#define TARGET_NR_getdents64			61
+#define TARGET_NR_read				63
+#define TARGET_NR_write				64
+#define TARGET_NR_readv				65
+#define TARGET_NR_writev			66
+#define TARGET_NR_pread64			67
+#define TARGET_NR_pwrite64			68
+#define TARGET_NR_preadv			69
+#define TARGET_NR_pwritev			70
+#define TARGET_NR_sendfile64			71
+#define TARGET_NR_pselect6			72
+#define TARGET_NR_ppoll				73
+#define TARGET_NR_signalfd4			74
+#define TARGET_NR_vmsplice			75
+#define TARGET_NR_splice			76
+#define TARGET_NR_tee				77
+#define TARGET_NR_readlinkat			78
+#define TARGET_NR_fstatat64			79
+#define TARGET_NR_fstat64			80
+#define TARGET_NR_sync				81
+#define TARGET_NR_fsync				82
+#define TARGET_NR_fdatasync			83
+#define TARGET_NR_sync_file_range		84
+#define TARGET_NR_timerfd_create		85
+#define TARGET_NR_timerfd_settime		86
+#define TARGET_NR_timerfd_gettime		87
+#define TARGET_NR_utimensat			88
+#define TARGET_NR_acct				89
+#define TARGET_NR_capget			90
+#define TARGET_NR_capset			91
+#define TARGET_NR_personality			92
+#define TARGET_NR_exit				93
+#define TARGET_NR_exit_group			94
+#define TARGET_NR_waitid			95
+#define TARGET_NR_set_tid_address		96
+#define TARGET_NR_unshare			97
+#define TARGET_NR_futex				98
+#define TARGET_NR_set_robust_list		99
+#define TARGET_NR_get_robust_list		100
+#define TARGET_NR_nanosleep			101
+#define TARGET_NR_getitimer			102
+#define TARGET_NR_setitimer			103
+#define TARGET_NR_kexec_load			104
+#define TARGET_NR_init_module			105
+#define TARGET_NR_delete_module			106
+#define TARGET_NR_timer_create			107
+#define TARGET_NR_timer_gettime			108
+#define TARGET_NR_timer_getoverrun		109
+#define TARGET_NR_timer_settime			110
+#define TARGET_NR_timer_delete			111
+#define TARGET_NR_clock_settime			112
+#define TARGET_NR_clock_gettime			113
+#define TARGET_NR_clock_getres			114
+#define TARGET_NR_clock_nanosleep		115
+#define TARGET_NR_syslog			116
+#define TARGET_NR_ptrace			117
+#define TARGET_NR_sched_setparam		118
+#define TARGET_NR_sched_setscheduler		119
+#define TARGET_NR_sched_getscheduler		120
+#define TARGET_NR_sched_getparam		121
+#define TARGET_NR_sched_setaffinity		122
+#define TARGET_NR_sched_getaffinity		123
+#define TARGET_NR_sched_yield			124
+#define TARGET_NR_sched_get_priority_max	125
+#define TARGET_NR_sched_get_priority_min	126
+#define TARGET_NR_sched_rr_get_interval		127
+#define TARGET_NR_restart_syscall		128
+#define TARGET_NR_kill				129
+#define TARGET_NR_tkill				130
+#define TARGET_NR_tgkill			131
+#define TARGET_NR_sigaltstack			132
+#define TARGET_NR_rt_sigsuspend			133
+#define TARGET_NR_rt_sigaction			134
+#define TARGET_NR_rt_sigprocmask		135
+#define TARGET_NR_rt_sigpending			136
+#define TARGET_NR_rt_sigtimedwait		137
+#define TARGET_NR_rt_sigqueueinfo		138
+#define TARGET_NR_rt_sigreturn			139
+#define TARGET_NR_setpriority			140
+#define TARGET_NR_getpriority			141
+#define TARGET_NR_reboot			142
+#define TARGET_NR_setregid			143
+#define TARGET_NR_setgid			144
+#define TARGET_NR_setreuid			145
+#define TARGET_NR_setuid			146
+#define TARGET_NR_setresuid			147
+#define TARGET_NR_getresuid			148
+#define TARGET_NR_setresgid			149
+#define TARGET_NR_getresgid			150
+#define TARGET_NR_setfsuid			151
+#define TARGET_NR_setfsgid			152
+#define TARGET_NR_times				153
+#define TARGET_NR_setpgid			154
+#define TARGET_NR_getpgid			155
+#define TARGET_NR_getsid			156
+#define TARGET_NR_setsid			157
+#define TARGET_NR_getgroups			158
+#define TARGET_NR_setgroups			159
+#define TARGET_NR_uname				160
+#define TARGET_NR_sethostname			161
+#define TARGET_NR_setdomainname			162
+#define TARGET_NR_getrlimit			163
+#define TARGET_NR_setrlimit			164
+#define TARGET_NR_getrusage			165
+#define TARGET_NR_umask				166
+#define TARGET_NR_prctl				167
+#define TARGET_NR_getcpu			168
+#define TARGET_NR_gettimeofday			169
+#define TARGET_NR_settimeofday			170
+#define TARGET_NR_adjtimex			171
+#define TARGET_NR_getpid			172
+#define TARGET_NR_getppid			173
+#define TARGET_NR_getuid			174
+#define TARGET_NR_geteuid			175
+#define TARGET_NR_getgid			176
+#define TARGET_NR_getegid			177
+#define TARGET_NR_gettid			178
+#define TARGET_NR_sysinfo			179
+#define TARGET_NR_mq_open			180
+#define TARGET_NR_mq_unlink			181
+#define TARGET_NR_mq_timedsend			182
+#define TARGET_NR_mq_timedreceive		183
+#define TARGET_NR_mq_notify			184
+#define TARGET_NR_mq_getsetattr			185
+#define TARGET_NR_msgget			186
+#define TARGET_NR_msgctl			187
+#define TARGET_NR_msgrcv			188
+#define TARGET_NR_msgsnd			189
+#define TARGET_NR_semget			190
+#define TARGET_NR_semctl			191
+#define TARGET_NR_semtimedop			192
+#define TARGET_NR_semop				193
+#define TARGET_NR_shmget			194
+#define TARGET_NR_shmctl			195
+#define TARGET_NR_shmat				196
+#define TARGET_NR_shmdt				197
+#define TARGET_NR_socket			198
+#define TARGET_NR_socketpair			199
+#define TARGET_NR_bind				200
+#define TARGET_NR_listen			201
+#define TARGET_NR_accept			202
+#define TARGET_NR_connect			203
+#define TARGET_NR_getsockname			204
+#define TARGET_NR_getpeername			205
+#define TARGET_NR_sendto			206
+#define TARGET_NR_recvfrom			207
+#define TARGET_NR_setsockopt			208
+#define TARGET_NR_getsockopt			209
+#define TARGET_NR_shutdown			210
+#define TARGET_NR_sendmsg			211
+#define TARGET_NR_recvmsg			212
+#define TARGET_NR_readahead			213
+#define TARGET_NR_brk				214
+#define TARGET_NR_munmap			215
+#define TARGET_NR_mremap			216
+#define TARGET_NR_add_key			217
+#define TARGET_NR_request_key			218
+#define TARGET_NR_keyctl			219
+#define TARGET_NR_clone				220
+#define TARGET_NR_execve			221
+#define TARGET_NR_mmap2				222
+#define TARGET_NR_fadvise64_64			223
+#define TARGET_NR_swapon			224
+#define TARGET_NR_swapoff			225
+#define TARGET_NR_mprotect			226
+#define TARGET_NR_msync				227
+#define TARGET_NR_mlock				228
+#define TARGET_NR_munlock			229
+#define TARGET_NR_mlockall			230
+#define TARGET_NR_munlockall			231
+#define TARGET_NR_mincore			232
+#define TARGET_NR_madvise			233
+#define TARGET_NR_remap_file_pages		234
+#define TARGET_NR_mbind				235
+#define TARGET_NR_get_mempolicy			236
+#define TARGET_NR_set_mempolicy			237
+#define TARGET_NR_migrate_pages			238
+#define TARGET_NR_move_pages			239
+#define TARGET_NR_rt_tgsigqueueinfo		240
+#define TARGET_NR_perf_event_open		241
+#define TARGET_NR_accept4			242
+#define TARGET_NR_recvmmsg			243
+#define TARGET_NR_cacheflush			244
+#define TARGET_NR_arch_specific_syscall		244
+#define TARGET_NR_wait4				260
+#define TARGET_NR_prlimit64			261
+#define TARGET_NR_fanotify_init			262
+#define TARGET_NR_fanotify_mark			263
+#define TARGET_NR_name_to_handle_at		264
+#define TARGET_NR_open_by_handle_at		265
+#define TARGET_NR_clock_adjtime			266
+#define TARGET_NR_syncfs			267
+#define TARGET_NR_setns				268
+#define TARGET_NR_sendmmsg			269
+#define TARGET_NR_process_vm_readv		270
+#define TARGET_NR_process_vm_writev		271
+#define TARGET_NR_kcmp				272
+#define TARGET_NR_finit_module			273
+#define TARGET_NR_sched_setattr			274
+#define TARGET_NR_sched_getattr			275
+#define TARGET_NR_renameat2			276
+#define TARGET_NR_seccomp			277
+#define TARGET_NR_getrandom			278
+#define TARGET_NR_memfd_create			279
+#define TARGET_NR_bpf				280
+#define TARGET_NR_execveat			281
+#define TARGET_NR_userfaultfd			282
+#define TARGET_NR_membarrier			283
+#define TARGET_NR_mlock2			284
+#define TARGET_NR_copy_file_range		285
+#define TARGET_NR_preadv2			286
+#define TARGET_NR_pwritev2			287
+/* FIXME */
+#define TARGET_NR_open 1024
+#define TARGET_NR_link 1025
+#define TARGET_NR_unlink 1026
+#define TARGET_NR_mknod 1027
+#define TARGET_NR_chmod 1028
+#define TARGET_NR_chown 1029
+#define TARGET_NR_mkdir 1030
+#define TARGET_NR_rmdir 1031
+#define TARGET_NR_lchown 1032
+#define TARGET_NR_access 1033
+#define TARGET_NR_rename 1034
+#define TARGET_NR_readlink 1035
+#define TARGET_NR_symlink 1036
+#define TARGET_NR_utimes 1037
+#define TARGET_NR_3264_stat 1038
+#define TARGET_NR_3264_lstat 1039
+#define TARGET_NR_pipe 1040
+#define TARGET_NR_dup2 1041
+#define TARGET_NR_epoll_create 1042
+#define TARGET_NR_inotify_init 1043
+#define TARGET_NR_eventfd 1044
+#define TARGET_NR_signalfd 1045
+#define TARGET_NR_sendfile 1046
+#define TARGET_NR_ftruncate 1047
+#define TARGET_NR_truncate 1048
+#define TARGET_NR_stat 1049
+#define TARGET_NR_lstat 1050
+#define TARGET_NR_fstat 1051
+#define TARGET_NR_fcntl 1052
+#define TARGET_NR_fadvise64 1053
+#define TARGET_NR_newfstatat 1054
+#define TARGET_NR_fstatfs 1055
+#define TARGET_NR_statfs 1056
+#define TARGET_NR_lseek 1057
+#define TARGET_NR_mmap 1058
+#define TARGET_NR_alarm 1059
+#define TARGET_NR_getpgrp 1060
+#define TARGET_NR_pause 1061
+#define TARGET_NR_time 1062
+#define TARGET_NR_utime 1063
+#define TARGET_NR_creat 1064
+#define TARGET_NR_getdents 1065
+#define TARGET_NR_futimesat 1066
+#define TARGET_NR_select 1067
+#define TARGET_NR_poll 1068
+#define TARGET_NR_epoll_wait 1069
+#define TARGET_NR_ustat 1070
+#define TARGET_NR_vfork 1071
+#define TARGET_NR_oldwait4 1072
+#define TARGET_NR_recv 1073
+#define TARGET_NR_send 1074
+#define TARGET_NR_bdflush 1075
+#define TARGET_NR_umount 1076
+#define TARGET_NR_uselib 1077
+#define TARGET_NR__sysctl 1078
+#define TARGET_NR_fork 1079
diff --git a/linux-user/nios2/target_cpu.h b/linux-user/nios2/target_cpu.h
new file mode 100644
index 0000000..5b1e195
--- /dev/null
+++ b/linux-user/nios2/target_cpu.h
@@ -0,0 +1,38 @@ 
+/*
+ * 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
diff --git a/linux-user/nios2/target_signal.h b/linux-user/nios2/target_signal.h
new file mode 100644
index 0000000..23a8267
--- /dev/null
+++ b/linux-user/nios2/target_signal.h
@@ -0,0 +1,26 @@ 
+#ifndef TARGET_SIGNAL_H
+#define TARGET_SIGNAL_H
+
+#include "cpu.h"
+
+/* this struct defines a stack used during syscall handling */
+
+typedef struct target_sigaltstack {
+    abi_long ss_sp;
+    abi_ulong ss_size;
+    abi_long ss_flags;
+} target_stack_t;
+
+/* sigaltstack controls  */
+#define TARGET_SS_ONSTACK     1
+#define TARGET_SS_DISABLE     2
+
+#define TARGET_MINSIGSTKSZ    2048
+#define TARGET_SIGSTKSZ       8192
+
+static inline abi_ulong get_sp_from_cpustate(CPUNios2State *state)
+{
+    return state->regs[R_SP];
+}
+
+#endif /* TARGET_SIGNAL_H */
diff --git a/linux-user/nios2/target_structs.h b/linux-user/nios2/target_structs.h
new file mode 100644
index 0000000..8713772
--- /dev/null
+++ b/linux-user/nios2/target_structs.h
@@ -0,0 +1,58 @@ 
+/*
+ * Nios2 specific structures 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_STRUCTS_H
+#define TARGET_STRUCTS_H
+
+struct target_ipc_perm {
+    abi_int __key;                      /* Key.  */
+    abi_uint uid;                       /* Owner's user ID.  */
+    abi_uint gid;                       /* Owner's group ID.  */
+    abi_uint cuid;                      /* Creator's user ID.  */
+    abi_uint cgid;                      /* Creator's group ID.  */
+    abi_ushort mode;                    /* Read/write permission.  */
+    abi_ushort __pad1;
+    abi_ushort __seq;                   /* Sequence number.  */
+    abi_ushort __pad2;
+    abi_ulong __unused1;
+    abi_ulong __unused2;
+};
+
+struct target_shmid_ds {
+    struct target_ipc_perm shm_perm;    /* operation permission struct */
+    abi_long shm_segsz;                 /* size of segment in bytes */
+    abi_ulong shm_atime;                /* time of last shmat() */
+#if TARGET_ABI_BITS == 32
+    abi_ulong __unused1;
+#endif
+    abi_ulong shm_dtime;                /* time of last shmdt() */
+#if TARGET_ABI_BITS == 32
+    abi_ulong __unused2;
+#endif
+    abi_ulong shm_ctime;                /* time of last change by shmctl() */
+#if TARGET_ABI_BITS == 32
+    abi_ulong __unused3;
+#endif
+    abi_int shm_cpid;                   /* pid of creator */
+    abi_int shm_lpid;                   /* pid of last shmop */
+    abi_ulong shm_nattch;               /* number of current attaches */
+    abi_ulong __unused4;
+    abi_ulong __unused5;
+};
+
+#endif
diff --git a/linux-user/nios2/target_syscall.h b/linux-user/nios2/target_syscall.h
new file mode 100644
index 0000000..23da0d6
--- /dev/null
+++ b/linux-user/nios2/target_syscall.h
@@ -0,0 +1,37 @@ 
+#ifndef TARGET_SYSCALL_H
+#define TARGET_SYSCALL_H
+
+#define UNAME_MACHINE "nios2"
+#define UNAME_MINIMUM_RELEASE "3.19.0"
+
+struct target_pt_regs {
+	unsigned long  r8;	/* r8-r15 Caller-saved GP registers */
+	unsigned long  r9;
+	unsigned long  r10;
+	unsigned long  r11;
+	unsigned long  r12;
+	unsigned long  r13;
+	unsigned long  r14;
+	unsigned long  r15;
+	unsigned long  r1;	/* Assembler temporary */
+	unsigned long  r2;	/* Retval LS 32bits */
+	unsigned long  r3;	/* Retval MS 32bits */
+	unsigned long  r4;	/* r4-r7 Register arguments */
+	unsigned long  r5;
+	unsigned long  r6;
+	unsigned long  r7;
+	unsigned long  orig_r2;	/* Copy of r2 ?? */
+	unsigned long  ra;	/* Return address */
+	unsigned long  fp;	/* Frame pointer */
+	unsigned long  sp;	/* Stack pointer */
+	unsigned long  gp;	/* Global pointer */
+	unsigned long  estatus;
+	unsigned long  ea;	/* Exception return address (pc) */
+	unsigned long  orig_r7;
+};
+
+#define TARGET_MINSIGSTKSZ 2048
+#define TARGET_MLOCKALL_MCL_CURRENT 1
+#define TARGET_MLOCKALL_MCL_FUTURE  2
+
+#endif  /* TARGET_SYSCALL_H */
diff --git a/linux-user/nios2/termbits.h b/linux-user/nios2/termbits.h
new file mode 100644
index 0000000..b64ba97
--- /dev/null
+++ b/linux-user/nios2/termbits.h
@@ -0,0 +1,220 @@ 
+/* from asm/termbits.h */
+/* NOTE: exactly the same as i386 */
+
+#define TARGET_NCCS 19
+
+struct target_termios {
+    unsigned int c_iflag;               /* input mode flags */
+    unsigned int c_oflag;               /* output mode flags */
+    unsigned int c_cflag;               /* control mode flags */
+    unsigned int c_lflag;               /* local mode flags */
+    unsigned char c_line;                    /* line discipline */
+    unsigned char c_cc[TARGET_NCCS];                /* control characters */
+};
+
+/* c_iflag bits */
+#define TARGET_IGNBRK  0000001
+#define TARGET_BRKINT  0000002
+#define TARGET_IGNPAR  0000004
+#define TARGET_PARMRK  0000010
+#define TARGET_INPCK   0000020
+#define TARGET_ISTRIP  0000040
+#define TARGET_INLCR   0000100
+#define TARGET_IGNCR   0000200
+#define TARGET_ICRNL   0000400
+#define TARGET_IUCLC   0001000
+#define TARGET_IXON    0002000
+#define TARGET_IXANY   0004000
+#define TARGET_IXOFF   0010000
+#define TARGET_IMAXBEL 0020000
+#define TARGET_IUTF8   0040000
+
+/* c_oflag bits */
+#define TARGET_OPOST   0000001
+#define TARGET_OLCUC   0000002
+#define TARGET_ONLCR   0000004
+#define TARGET_OCRNL   0000010
+#define TARGET_ONOCR   0000020
+#define TARGET_ONLRET  0000040
+#define TARGET_OFILL   0000100
+#define TARGET_OFDEL   0000200
+#define TARGET_NLDLY   0000400
+#define   TARGET_NL0   0000000
+#define   TARGET_NL1   0000400
+#define TARGET_CRDLY   0003000
+#define   TARGET_CR0   0000000
+#define   TARGET_CR1   0001000
+#define   TARGET_CR2   0002000
+#define   TARGET_CR3   0003000
+#define TARGET_TABDLY  0014000
+#define   TARGET_TAB0  0000000
+#define   TARGET_TAB1  0004000
+#define   TARGET_TAB2  0010000
+#define   TARGET_TAB3  0014000
+#define   TARGET_XTABS 0014000
+#define TARGET_BSDLY   0020000
+#define   TARGET_BS0   0000000
+#define   TARGET_BS1   0020000
+#define TARGET_VTDLY   0040000
+#define   TARGET_VT0   0000000
+#define   TARGET_VT1   0040000
+#define TARGET_FFDLY   0100000
+#define   TARGET_FF0   0000000
+#define   TARGET_FF1   0100000
+
+/* c_cflag bit meaning */
+#define TARGET_CBAUD   0010017
+#define  TARGET_B0     0000000         /* hang up */
+#define  TARGET_B50    0000001
+#define  TARGET_B75    0000002
+#define  TARGET_B110   0000003
+#define  TARGET_B134   0000004
+#define  TARGET_B150   0000005
+#define  TARGET_B200   0000006
+#define  TARGET_B300   0000007
+#define  TARGET_B600   0000010
+#define  TARGET_B1200  0000011
+#define  TARGET_B1800  0000012
+#define  TARGET_B2400  0000013
+#define  TARGET_B4800  0000014
+#define  TARGET_B9600  0000015
+#define  TARGET_B19200 0000016
+#define  TARGET_B38400 0000017
+#define TARGET_EXTA B19200
+#define TARGET_EXTB B38400
+#define TARGET_CSIZE   0000060
+#define   TARGET_CS5   0000000
+#define   TARGET_CS6   0000020
+#define   TARGET_CS7   0000040
+#define   TARGET_CS8   0000060
+#define TARGET_CSTOPB  0000100
+#define TARGET_CREAD   0000200
+#define TARGET_PARENB  0000400
+#define TARGET_PARODD  0001000
+#define TARGET_HUPCL   0002000
+#define TARGET_CLOCAL  0004000
+#define TARGET_CBAUDEX 0010000
+#define  TARGET_B57600  0010001
+#define  TARGET_B115200 0010002
+#define  TARGET_B230400 0010003
+#define  TARGET_B460800 0010004
+#define TARGET_CIBAUD    002003600000  /* input baud rate (not used) */
+#define TARGET_CMSPAR    010000000000  /* mark or space (stick) parity */
+#define TARGET_CRTSCTS   020000000000  /* flow control */
+
+/* c_lflag bits */
+#define TARGET_ISIG    0000001
+#define TARGET_ICANON  0000002
+#define TARGET_XCASE   0000004
+#define TARGET_ECHO    0000010
+#define TARGET_ECHOE   0000020
+#define TARGET_ECHOK   0000040
+#define TARGET_ECHONL  0000100
+#define TARGET_NOFLSH  0000200
+#define TARGET_TOSTOP  0000400
+#define TARGET_ECHOCTL 0001000
+#define TARGET_ECHOPRT 0002000
+#define TARGET_ECHOKE  0004000
+#define TARGET_FLUSHO  0010000
+#define TARGET_PENDIN  0040000
+#define TARGET_IEXTEN  0100000
+
+/* c_cc character offsets */
+#define TARGET_VINTR    0
+#define TARGET_VQUIT    1
+#define TARGET_VERASE   2
+#define TARGET_VKILL    3
+#define TARGET_VEOF     4
+#define TARGET_VTIME    5
+#define TARGET_VMIN     6
+#define TARGET_VSWTC    7
+#define TARGET_VSTART   8
+#define TARGET_VSTOP    9
+#define TARGET_VSUSP    10
+#define TARGET_VEOL     11
+#define TARGET_VREPRINT 12
+#define TARGET_VDISCARD 13
+#define TARGET_VWERASE  14
+#define TARGET_VLNEXT   15
+#define TARGET_VEOL2    16
+
+/* ioctls */
+
+#define TARGET_TCGETS           0x5401
+#define TARGET_TCSETS           0x5402
+#define TARGET_TCSETSW          0x5403
+#define TARGET_TCSETSF          0x5404
+#define TARGET_TCGETA           0x5405
+#define TARGET_TCSETA           0x5406
+#define TARGET_TCSETAW          0x5407
+#define TARGET_TCSETAF          0x5408
+#define TARGET_TCSBRK           0x5409
+#define TARGET_TCXONC           0x540A
+#define TARGET_TCFLSH           0x540B
+
+#define TARGET_TIOCEXCL         0x540C
+#define TARGET_TIOCNXCL         0x540D
+#define TARGET_TIOCSCTTY        0x540E
+#define TARGET_TIOCGPGRP        0x540F
+#define TARGET_TIOCSPGRP        0x5410
+#define TARGET_TIOCOUTQ         0x5411
+#define TARGET_TIOCSTI          0x5412
+#define TARGET_TIOCGWINSZ       0x5413
+#define TARGET_TIOCSWINSZ       0x5414
+#define TARGET_TIOCMGET         0x5415
+#define TARGET_TIOCMBIS         0x5416
+#define TARGET_TIOCMBIC         0x5417
+#define TARGET_TIOCMSET         0x5418
+#define TARGET_TIOCGSOFTCAR     0x5419
+#define TARGET_TIOCSSOFTCAR     0x541A
+#define TARGET_FIONREAD         0x541B
+#define TARGET_TIOCINQ          TARGET_FIONREAD
+#define TARGET_TIOCLINUX        0x541C
+#define TARGET_TIOCCONS         0x541D
+#define TARGET_TIOCGSERIAL      0x541E
+#define TARGET_TIOCSSERIAL      0x541F
+#define TARGET_TIOCPKT          0x5420
+#define TARGET_FIONBIO          0x5421
+#define TARGET_TIOCNOTTY        0x5422
+#define TARGET_TIOCSETD         0x5423
+#define TARGET_TIOCGETD         0x5424
+#define TARGET_TCSBRKP          0x5425 /* Needed for POSIX tcsendbreak() */
+#define TARGET_TIOCTTYGSTRUCT   0x5426 /* For debugging only */
+#define TARGET_TIOCSBRK         0x5427 /* BSD compatibility */
+#define TARGET_TIOCCBRK         0x5428 /* BSD compatibility */
+#define TARGET_TIOCGSID         0x5429 /* Return the session ID of FD */
+#define TARGET_TIOCGPTN         TARGET_IOR('T', 0x30, unsigned int)
+        /* Get Pty Number (of pty-mux device) */
+#define TARGET_TIOCSPTLCK       TARGET_IOW('T', 0x31, int)
+        /* Lock/unlock Pty */
+
+#define TARGET_FIONCLEX         0x5450  /* these numbers need to be adjusted. */
+#define TARGET_FIOCLEX          0x5451
+#define TARGET_FIOASYNC         0x5452
+#define TARGET_TIOCSERCONFIG    0x5453
+#define TARGET_TIOCSERGWILD     0x5454
+#define TARGET_TIOCSERSWILD     0x5455
+#define TARGET_TIOCGLCKTRMIOS   0x5456
+#define TARGET_TIOCSLCKTRMIOS   0x5457
+#define TARGET_TIOCSERGSTRUCT   0x5458 /* For debugging only */
+#define TARGET_TIOCSERGETLSR    0x5459 /* Get line status register */
+#define TARGET_TIOCSERGETMULTI  0x545A /* Get multiport config  */
+#define TARGET_TIOCSERSETMULTI  0x545B /* Set multiport config */
+
+#define TARGET_TIOCMIWAIT      0x545C
+        /* wait for a change on serial input line(s) */
+#define TARGET_TIOCGICOUNT     0x545D
+        /* read serial port inline interrupt counts */
+#define TARGET_TIOCGHAYESESP   0x545E  /* Get Hayes ESP configuration */
+#define TARGET_TIOCSHAYESESP   0x545F  /* Set Hayes ESP configuration */
+
+/* Used for packet mode */
+#define TARGET_TIOCPKT_DATA              0
+#define TARGET_TIOCPKT_FLUSHREAD         1
+#define TARGET_TIOCPKT_FLUSHWRITE        2
+#define TARGET_TIOCPKT_STOP              4
+#define TARGET_TIOCPKT_START             8
+#define TARGET_TIOCPKT_NOSTOP           16
+#define TARGET_TIOCPKT_DOSTOP           32
+
+#define TARGET_TIOCSER_TEMT    0x01 /* Transmitter physically empty */
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 61c1145..54036dd 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -257,7 +257,7 @@  int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset)
 }
 
 #if !defined(TARGET_OPENRISC) && !defined(TARGET_UNICORE32) && \
-    !defined(TARGET_X86_64)
+    !defined(TARGET_X86_64) && !defined(TARGET_NIOS2)
 /* Just set the guest's signal mask to the specified value; the
  * caller is assumed to have called block_signals() already.
  */
@@ -3859,6 +3859,239 @@  long do_rt_sigreturn(CPUCRISState *env)
     return -TARGET_ENOSYS;
 }
 
+#elif defined(TARGET_NIOS2)
+
+#define MCONTEXT_VERSION 2
+
+struct target_sigcontext {
+    int version;
+    unsigned long gregs[32];
+};
+
+struct target_ucontext {
+    abi_ulong tuc_flags;
+    abi_ulong tuc_link;
+    target_stack_t tuc_stack;
+    struct target_sigcontext tuc_mcontext;
+    target_sigset_t tuc_sigmask;   /* mask last for extensibility */
+};
+
+struct target_rt_sigframe {
+    struct target_siginfo info;
+    struct target_ucontext uc;
+};
+
+static inline unsigned long sigsp(unsigned long sp, struct target_sigaction *ka)
+{
+    if (unlikely((ka->sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
+#ifdef CONFIG_STACK_GROWSUP
+        return target_sigaltstack_used.ss_sp;
+
+#else
+        return target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
+#endif
+    return sp;
+}
+
+static int rt_setup_ucontext(struct target_ucontext *uc, CPUNios2State *env)
+{
+    unsigned long *gregs = uc->tuc_mcontext.gregs;
+
+    __put_user(MCONTEXT_VERSION, &uc->tuc_mcontext.version);
+    __put_user(env->regs[1], &gregs[0]);
+    __put_user(env->regs[2], &gregs[1]);
+    __put_user(env->regs[3], &gregs[2]);
+    __put_user(env->regs[4], &gregs[3]);
+    __put_user(env->regs[5], &gregs[4]);
+    __put_user(env->regs[6], &gregs[5]);
+    __put_user(env->regs[7], &gregs[6]);
+    __put_user(env->regs[8], &gregs[7]);
+    __put_user(env->regs[9], &gregs[8]);
+    __put_user(env->regs[10], &gregs[9]);
+    __put_user(env->regs[11], &gregs[10]);
+    __put_user(env->regs[12], &gregs[11]);
+    __put_user(env->regs[13], &gregs[12]);
+    __put_user(env->regs[14], &gregs[13]);
+    __put_user(env->regs[15], &gregs[14]);
+    __put_user(env->regs[16], &gregs[15]);
+    __put_user(env->regs[17], &gregs[16]);
+    __put_user(env->regs[18], &gregs[17]);
+    __put_user(env->regs[19], &gregs[18]);
+    __put_user(env->regs[20], &gregs[19]);
+    __put_user(env->regs[21], &gregs[20]);
+    __put_user(env->regs[22], &gregs[21]);
+    __put_user(env->regs[23], &gregs[22]);
+    __put_user(env->regs[R_RA], &gregs[23]);
+    __put_user(env->regs[R_FP], &gregs[24]);
+    __put_user(env->regs[R_GP], &gregs[25]);
+    __put_user(env->regs[R_EA], &gregs[27]);
+    __put_user(env->regs[R_SP], &gregs[28]);
+
+    return 0;
+}
+
+static int rt_restore_ucontext(CPUNios2State *env, struct target_ucontext *uc,
+                               int *pr2)
+{
+    int temp;
+    abi_ulong frame_addr = env->regs[R_SP];
+    unsigned long *gregs = uc->tuc_mcontext.gregs;
+    int err;
+
+    /* Always make any pending restarted system calls return -EINTR */
+    //current->restart_block.fn = do_no_restart_syscall;
+
+    __get_user(temp, &uc->tuc_mcontext.version);
+    if (temp != MCONTEXT_VERSION)
+        goto badframe;
+
+    /* restore passed registers */
+    __get_user(env->regs[1], &gregs[0]);
+    __get_user(env->regs[2], &gregs[1]);
+    __get_user(env->regs[3], &gregs[2]);
+    __get_user(env->regs[4], &gregs[3]);
+    __get_user(env->regs[5], &gregs[4]);
+    __get_user(env->regs[6], &gregs[5]);
+    __get_user(env->regs[7], &gregs[6]);
+    __get_user(env->regs[8], &gregs[7]);
+    __get_user(env->regs[9], &gregs[8]);
+    __get_user(env->regs[10], &gregs[9]);
+    __get_user(env->regs[11], &gregs[10]);
+    __get_user(env->regs[12], &gregs[11]);
+    __get_user(env->regs[13], &gregs[12]);
+    __get_user(env->regs[14], &gregs[13]);
+    __get_user(env->regs[15], &gregs[14]);
+    __get_user(env->regs[16], &gregs[15]);
+    __get_user(env->regs[17], &gregs[16]);
+    __get_user(env->regs[18], &gregs[17]);
+    __get_user(env->regs[19], &gregs[18]);
+    __get_user(env->regs[20], &gregs[19]);
+    __get_user(env->regs[21], &gregs[20]);
+    __get_user(env->regs[22], &gregs[21]);
+    __get_user(env->regs[23], &gregs[22]);
+    /* gregs[23] is handled below */
+    __get_user(env->regs[R_FP], &gregs[24]);  /* Verify, should this be
+                            settable */
+    __get_user(env->regs[R_GP], &gregs[25]);  /* Verify, should this be
+                            settable */
+
+    __get_user(temp, &gregs[26]);  /* Not really necessary no user
+                            settable bits */
+    __get_user(env->regs[R_EA], &gregs[27]);
+
+    __get_user(env->regs[R_RA], &gregs[23]);
+    __get_user(env->regs[R_SP], &gregs[28]);
+
+    if (do_sigaltstack(frame_addr + offsetof(struct target_rt_sigframe, uc.tuc_stack), 0,
+                       get_sp_from_cpustate(env)) == -EFAULT) {
+        goto badframe;
+    }
+
+    *pr2 = env->regs[2];
+    return err;
+
+badframe:
+    return 1;
+}
+
+static void *get_sigframe(struct target_sigaction *ka, CPUNios2State *env,
+			  size_t frame_size)
+{
+    unsigned long usp;
+
+    /* Default to using normal stack.  */
+    usp = env->regs[R_SP];
+
+    /* This is the X/Open sanctioned signal stack switching.  */
+    usp = sigsp(usp, ka);
+
+    /* Verify, is it 32 or 64 bit aligned */
+    return (void *)((usp - frame_size) & -8UL);
+}
+
+static void setup_rt_frame(int sig, struct target_sigaction *ka,
+                           target_siginfo_t *info,
+                           target_sigset_t *set,
+			   CPUNios2State *env)
+{
+    struct target_rt_sigframe *frame;
+    int i, err = 0;
+
+    frame = get_sigframe(ka, env, sizeof(*frame));
+
+    if (ka->sa_flags & SA_SIGINFO)
+            tswap_siginfo(&frame->info, info);
+
+    /* Create the ucontext.  */
+    __put_user(0, &frame->uc.tuc_flags);
+    __put_user(0, &frame->uc.tuc_link);
+    __put_user(target_sigaltstack_used.ss_sp, &frame->uc.tuc_stack.ss_sp);
+    __put_user(sas_ss_flags(env->regs[R_SP]), &frame->uc.tuc_stack.ss_flags);
+    __put_user(target_sigaltstack_used.ss_size, &frame->uc.tuc_stack.ss_size);
+    err |= rt_setup_ucontext(&frame->uc, env);
+    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
+        __put_user((abi_ulong)set->sig[i],
+            (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
+    }
+
+    if (err)
+        goto give_sigsegv;
+
+    /* Set up to return from userspace; jump to fixed address sigreturn
+       trampoline on kuser page.  */
+    env->regs[R_RA] = (unsigned long) (0x1044);
+
+    /* Set up registers for signal handler */
+    env->regs[R_SP] = (unsigned long) frame;
+    env->regs[4] = (unsigned long) sig;
+    env->regs[5] = (unsigned long) &frame->info;
+    env->regs[6] = (unsigned long) &frame->uc;
+    env->regs[R_EA] = (unsigned long) ka->_sa_handler;
+    return;
+
+give_sigsegv:
+    if (sig == TARGET_SIGSEGV) {
+        ka->_sa_handler = TARGET_SIG_DFL;
+    }
+    force_sig(TARGET_SIGSEGV);
+    return;
+}
+
+long do_sigreturn(CPUNios2State *env)
+{
+    trace_user_do_sigreturn(env, 0);
+    fprintf(stderr, "do_sigreturn: not implemented\n");
+    return -TARGET_ENOSYS;
+}
+
+long do_rt_sigreturn(CPUNios2State *env)
+{
+    /* Verify, can we follow the stack back */
+    abi_ulong frame_addr = env->regs[R_SP];
+    struct target_rt_sigframe *frame;
+    sigset_t set;
+    int rval;
+
+    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
+        goto badframe;
+    }
+
+    target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
+    do_sigprocmask(SIG_SETMASK, &set, NULL);
+
+    if (rt_restore_ucontext(env, &frame->uc, &rval))
+        goto badframe;
+
+    unlock_user_struct(frame, frame_addr, 0);
+    return rval;
+
+badframe:
+    unlock_user_struct(frame, frame_addr, 0);
+    force_sig(TARGET_SIGSEGV);
+    return 0;
+}
+/* TARGET_NIOS2 */
+
 #elif defined(TARGET_OPENRISC)
 
 struct target_sigcontext {
@@ -5883,7 +6116,8 @@  static void handle_pending_signal(CPUArchState *cpu_env, int sig)
 #endif
         /* prepare the stack frame of the virtual CPU */
 #if defined(TARGET_ABI_MIPSN32) || defined(TARGET_ABI_MIPSN64) \
-    || defined(TARGET_OPENRISC) || defined(TARGET_TILEGX)
+    || defined(TARGET_OPENRISC) || defined(TARGET_TILEGX) \
+    || defined(TARGET_NIOS2)
         /* These targets do not have traditional signals.  */
         setup_rt_frame(sig, sa, &k->info, &target_old_set, cpu_env);
 #else
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 6ee9251..f5c9259 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -69,7 +69,8 @@ 
 #if defined(TARGET_I386) || defined(TARGET_ARM) || defined(TARGET_SH4) \
     || defined(TARGET_M68K) || defined(TARGET_CRIS) \
     || defined(TARGET_UNICORE32) || defined(TARGET_S390X) \
-    || defined(TARGET_OPENRISC) || defined(TARGET_TILEGX)
+    || defined(TARGET_OPENRISC) || defined(TARGET_TILEGX) \
+    || defined(TARGET_NIOS2)
 
 #define TARGET_IOC_SIZEBITS	14
 #define TARGET_IOC_DIRBITS	2
@@ -374,7 +375,7 @@  int do_sigaction(int sig, const struct target_sigaction *act,
     || defined(TARGET_M68K) || defined(TARGET_ALPHA) || defined(TARGET_CRIS) \
     || defined(TARGET_MICROBLAZE) || defined(TARGET_UNICORE32) \
     || defined(TARGET_S390X) || defined(TARGET_OPENRISC) \
-    || defined(TARGET_TILEGX)
+    || defined(TARGET_TILEGX) || defined(TARGET_NIOS2)
 
 #if defined(TARGET_SPARC)
 #define TARGET_SA_NOCLDSTOP    8u
@@ -1906,7 +1907,7 @@  struct target_stat {
     abi_ulong  target_st_ctime_nsec;
     unsigned int __unused[2];
 };
-#elif defined(TARGET_OPENRISC) || defined(TARGET_TILEGX)
+#elif defined(TARGET_OPENRISC) || defined(TARGET_TILEGX) || defined(TARGET_NIOS2)
 
 /* These are the asm-generic versions of the stat and stat64 structures */