Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

12 files changed, 922 insertions, 0 deletions

diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c
new file mode 100644
index 000000000..34290fb3b
--- /dev/null
+++ b/linux-user/nios2/cpu_loop.c
@@ -0,0 +1,155 @@
+/*
+ *  qemu user cpu loop
+ *
+ *  Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu.h"
+#include "user-internals.h"
+#include "cpu_loop-common.h"
+#include "signal-common.h"
+
+void cpu_loop(CPUNios2State *env)
+{
+    CPUState *cs = env_cpu(env);
+    Nios2CPU *cpu = NIOS2_CPU(cs);
+    target_siginfo_t info;
+    int trapnr, ret;
+
+    for (;;) {
+        cpu_exec_start(cs);
+        trapnr = cpu_exec(cs);
+        cpu_exec_end(cs);
+
+        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] = cpu->exception_addr;
+
+                info.si_signo = TARGET_SIGTRAP;
+                info.si_errno = 0;
+                info.si_code = TARGET_TRAP_BRKPT;
+                queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+                break;
+            }
+        case EXCP_DEBUG:
+            info.si_signo = TARGET_SIGTRAP;
+            info.si_errno = 0;
+            info.si_code = TARGET_TRAP_BRKPT;
+            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+            break;
+        case 0xaa:
+            switch (env->regs[R_PC]) {
+            /*case 0x1000:*/  /* TODO:__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:*/  /* TODO:__kuser_sigtramp */
+            default:
+                ;
+kuser_fail:
+                info.si_signo = TARGET_SIGSEGV;
+                info.si_errno = 0;
+                /* TODO: check env->error_code */
+                info.si_code = TARGET_SEGV_MAPERR;
+                info._sifields._sigfault._addr = env->regs[R_PC];
+                queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+            }
+            break;
+        default:
+            EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
+                     trapnr);
+            abort();
+        }
+
+        process_pending_signals(env);
+    }
+}
+
+void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
+{
+    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;
+    /* TODO: 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;
+    /* TODO: unsigned long  orig_r7; */
+
+    /* Emulate eret when starting thread. */
+    env->regs[R_PC] = regs->ea;
+}
diff --git a/linux-user/nios2/signal.c b/linux-user/nios2/signal.c
new file mode 100644
index 000000000..a77e8a40f
--- /dev/null
+++ b/linux-user/nios2/signal.c
@@ -0,0 +1,231 @@
+/*
+ *  Emulation of Linux signals
+ *
+ *  Copyright (c) 2003 Fabrice Bellard
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+#include "qemu/osdep.h"
+#include "qemu.h"
+#include "user-internals.h"
+#include "signal-common.h"
+#include "linux-user/trace.h"
+
+#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 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;
+    unsigned long *gregs = uc->tuc_mcontext.gregs;
+
+    /* 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) {
+        return 1;
+    }
+
+    /* 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 */
+    /* Verify, should this be settable */
+    __get_user(env->regs[R_FP], &gregs[24]);
+    /* Verify, should this be settable */
+    __get_user(env->regs[R_GP], &gregs[25]);
+    /* Not really necessary no user settable bits */
+    __get_user(temp, &gregs[26]);
+    __get_user(env->regs[R_EA], &gregs[27]);
+
+    __get_user(env->regs[R_RA], &gregs[23]);
+    __get_user(env->regs[R_SP], &gregs[28]);
+
+    target_restore_altstack(&uc->tuc_stack, env);
+
+    *pr2 = env->regs[2];
+    return 0;
+}
+
+static void *get_sigframe(struct target_sigaction *ka, CPUNios2State *env,
+                          size_t frame_size)
+{
+    unsigned long usp;
+
+    /* This is the X/Open sanctioned signal stack switching.  */
+    usp = target_sigsp(get_sp_from_cpustate(env), ka);
+
+    /* Verify, is it 32 or 64 bit aligned */
+    return (void *)((usp - frame_size) & -8UL);
+}
+
+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);
+    target_save_altstack(&frame->uc.tuc_stack, env);
+    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_sigsegv(sig);
+    return;
+}
+
+long do_sigreturn(CPUNios2State *env)
+{
+    trace_user_do_sigreturn(env, 0);
+    qemu_log_mask(LOG_UNIMP, "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;
+}
diff --git a/linux-user/nios2/sockbits.h b/linux-user/nios2/sockbits.h
new file mode 100644
index 000000000..0e4c8f012
--- /dev/null
+++ b/linux-user/nios2/sockbits.h
@@ -0,0 +1 @@
+#include "../generic/sockbits.h"
diff --git a/linux-user/nios2/syscall_nr.h b/linux-user/nios2/syscall_nr.h
new file mode 100644
index 000000000..11a37b32e
--- /dev/null
+++ b/linux-user/nios2/syscall_nr.h
@@ -0,0 +1,333 @@
+/*
+ * This file contains the system call numbers.
+ * Do not modify.
+ * This file is generated by scripts/gensyscalls.sh
+ */
+#ifndef LINUX_USER_NIOS2_SYSCALL_NR_H
+#define LINUX_USER_NIOS2_SYSCALL_NR_H
+
+#define TARGET_NR_cacheflush (TARGET_NR_arch_specific_syscall)
+#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_llseek 62
+#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_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
+#define TARGET_NR_pkey_mprotect 288
+#define TARGET_NR_pkey_alloc 289
+#define TARGET_NR_pkey_free 290
+#define TARGET_NR_statx 291
+#define TARGET_NR_io_pgetevents 292
+#define TARGET_NR_rseq 293
+#define TARGET_NR_kexec_file_load 294
+#define TARGET_NR_clock_gettime64 403
+#define TARGET_NR_clock_settime64 404
+#define TARGET_NR_clock_adjtime64 405
+#define TARGET_NR_clock_getres_time64 406
+#define TARGET_NR_clock_nanosleep_time64 407
+#define TARGET_NR_timer_gettime64 408
+#define TARGET_NR_timer_settime64 409
+#define TARGET_NR_timerfd_gettime64 410
+#define TARGET_NR_timerfd_settime64 411
+#define TARGET_NR_utimensat_time64 412
+#define TARGET_NR_pselect6_time64 413
+#define TARGET_NR_ppoll_time64 414
+#define TARGET_NR_io_pgetevents_time64 416
+#define TARGET_NR_recvmmsg_time64 417
+#define TARGET_NR_mq_timedsend_time64 418
+#define TARGET_NR_mq_timedreceive_time64 419
+#define TARGET_NR_semtimedop_time64 420
+#define TARGET_NR_rt_sigtimedwait_time64 421
+#define TARGET_NR_futex_time64 422
+#define TARGET_NR_sched_rr_get_interval_time64 423
+#define TARGET_NR_pidfd_send_signal 424
+#define TARGET_NR_io_uring_setup 425
+#define TARGET_NR_io_uring_enter 426
+#define TARGET_NR_io_uring_register 427
+#define TARGET_NR_open_tree 428
+#define TARGET_NR_move_mount 429
+#define TARGET_NR_fsopen 430
+#define TARGET_NR_fsconfig 431
+#define TARGET_NR_fsmount 432
+#define TARGET_NR_fspick 433
+#define TARGET_NR_pidfd_open 434
+#define TARGET_NR_close_range 436
+#define TARGET_NR_openat2 437
+#define TARGET_NR_pidfd_getfd 438
+#define TARGET_NR_faccessat2 439
+#define TARGET_NR_process_madvise 440
+#define TARGET_NR_epoll_pwait2 441
+#define TARGET_NR_mount_setattr 442
+#define TARGET_NR_landlock_create_ruleset 444
+#define TARGET_NR_landlock_add_rule 445
+#define TARGET_NR_landlock_restrict_self 446
+#define TARGET_NR_syscalls 447
+
+#endif /* LINUX_USER_NIOS2_SYSCALL_NR_H */
diff --git a/linux-user/nios2/target_cpu.h b/linux-user/nios2/target_cpu.h
new file mode 100644
index 000000000..2d2008f00
--- /dev/null
+++ b/linux-user/nios2/target_cpu.h
@@ -0,0 +1,48 @@
+/*
+ * 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 2.1 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 NIOS2_TARGET_CPU_H
+#define NIOS2_TARGET_CPU_H
+
+static inline void cpu_clone_regs_child(CPUNios2State *env, target_ulong newsp,
+                                        unsigned flags)
+{
+    if (newsp) {
+        env->regs[R_SP] = newsp;
+    }
+    env->regs[R_RET0] = 0;
+}
+
+static inline void cpu_clone_regs_parent(CPUNios2State *env, unsigned flags)
+{
+}
+
+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.
+     */
+}
+
+static inline abi_ulong get_sp_from_cpustate(CPUNios2State *state)
+{
+    return state->regs[R_SP];
+}
+#endif
diff --git a/linux-user/nios2/target_elf.h b/linux-user/nios2/target_elf.h
new file mode 100644
index 000000000..801e20afa
--- /dev/null
+++ b/linux-user/nios2/target_elf.h
@@ -0,0 +1,14 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation, or (at your option) any
+ * later version. See the COPYING file in the top-level directory.
+ */
+
+#ifndef NIOS2_TARGET_ELF_H
+#define NIOS2_TARGET_ELF_H
+static inline const char *cpu_get_model(uint32_t eflags)
+{
+    return "any";
+}
+#endif
diff --git a/linux-user/nios2/target_errno_defs.h b/linux-user/nios2/target_errno_defs.h
new file mode 100644
index 000000000..28120013e
--- /dev/null
+++ b/linux-user/nios2/target_errno_defs.h
@@ -0,0 +1,7 @@
+#ifndef NIOS2_TARGET_ERRNO_DEFS_H
+#define NIOS2_TARGET_ERRNO_DEFS_H
+
+/* Target uses generic errno */
+#include "../generic/target_errno_defs.h"
+
+#endif
diff --git a/linux-user/nios2/target_fcntl.h b/linux-user/nios2/target_fcntl.h
new file mode 100644
index 000000000..714583215
--- /dev/null
+++ b/linux-user/nios2/target_fcntl.h
@@ -0,0 +1,11 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation, or (at your option) any
+ * later version. See the COPYING file in the top-level directory.
+ */
+
+#ifndef NIOS2_TARGET_FCNTL_H
+#define NIOS2_TARGET_FCNTL_H
+#include "../generic/fcntl.h"
+#endif
diff --git a/linux-user/nios2/target_signal.h b/linux-user/nios2/target_signal.h
new file mode 100644
index 000000000..fe266c4c5
--- /dev/null
+++ b/linux-user/nios2/target_signal.h
@@ -0,0 +1,25 @@
+#ifndef NIOS2_TARGET_SIGNAL_H
+#define NIOS2_TARGET_SIGNAL_H
+
+/* this struct defines a stack used during syscall handling */
+
+typedef struct target_sigaltstack {
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
+} target_stack_t;
+
+
+/* sigaltstack controls  */
+#define TARGET_SS_ONSTACK     1
+#define TARGET_SS_DISABLE     2
+
+#define TARGET_MINSIGSTKSZ    2048
+#define TARGET_SIGSTKSZ       8192
+
+#include "../generic/signal.h"
+
+/* Nios2 uses a fixed address on the kuser page for sigreturn. */
+#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0
+
+#endif /* NIOS2_TARGET_SIGNAL_H */
diff --git a/linux-user/nios2/target_structs.h b/linux-user/nios2/target_structs.h
new file mode 100644
index 000000000..daa2886f9
--- /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 2.1 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 NIOS2_TARGET_STRUCTS_H
+#define NIOS2_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 000000000..78006c24d
--- /dev/null
+++ b/linux-user/nios2/target_syscall.h
@@ -0,0 +1,38 @@
+#ifndef NIOS2_TARGET_SYSCALL_H
+#define NIOS2_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_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
+
+#endif /* NIOS2_TARGET_SYSCALL_H */
diff --git a/linux-user/nios2/termbits.h b/linux-user/nios2/termbits.h
new file mode 100644
index 000000000..b1d4f4fed
--- /dev/null
+++ b/linux-user/nios2/termbits.h
@@ -0,0 +1 @@
+#include "../generic/termbits.h"