semihosting: Create semihost_sys_gettimeofday

This syscall will be used by m68k and nios2 semihosting.

Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/semihosting/syscalls.h

@@ -66,4 +66,7 @@ void semihost_sys_rename(CPUState *cs, gdb_syscall_complete_cb complete,
 void semihost_sys_system(CPUState *cs, gdb_syscall_complete_cb complete,
                          target_ulong cmd, target_ulong cmd_len);
 
+void semihost_sys_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
+                               target_ulong tv_addr, target_ulong tz_addr);
+
 #endif /* SEMIHOSTING_SYSCALLS_H */

semihosting/syscalls.c

@@ -236,6 +236,12 @@ static void gdb_system(CPUState *cs, gdb_syscall_complete_cb complete,
     gdb_do_syscall(complete, "system,%s", cmd, len);
 }
 
+static void gdb_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
+                             target_ulong tv_addr, target_ulong tz_addr)
+{
+    gdb_do_syscall(complete, "gettimeofday,%x,%x", tv_addr, tz_addr);
+}
+
 /*
  * Host semihosting syscall implementations.
  */
@@ -487,6 +493,32 @@ static void host_system(CPUState *cs, gdb_syscall_complete_cb complete,
     unlock_user(p, cmd, 0);
 }
 
+static void host_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
+                              target_ulong tv_addr, target_ulong tz_addr)
+{
+    CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+    struct gdb_timeval *p;
+    int64_t rt;
+
+    /* GDB fails on non-null TZ, so be consistent. */
+    if (tz_addr != 0) {
+        complete(cs, -1, EINVAL);
+        return;
+    }
+
+    p = lock_user(VERIFY_WRITE, tv_addr, sizeof(struct gdb_timeval), 0);
+    if (!p) {
+        complete(cs, -1, EFAULT);
+        return;
+    }
+
+    /* TODO: Like stat, gdb always produces big-endian results; match it. */
+    rt = g_get_real_time();
+    p->tv_sec = cpu_to_be32(rt / G_USEC_PER_SEC);
+    p->tv_usec = cpu_to_be64(rt % G_USEC_PER_SEC);
+    unlock_user(p, tv_addr, sizeof(struct gdb_timeval));
+}
+
 /*
  * Static file semihosting syscall implementations.
  */
@@ -796,3 +828,13 @@ void semihost_sys_system(CPUState *cs, gdb_syscall_complete_cb complete,
         host_system(cs, complete, cmd, cmd_len);
     }
 }
+
+void semihost_sys_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
+                               target_ulong tv_addr, target_ulong tz_addr)
+{
+    if (use_gdb_syscalls()) {
+        gdb_gettimeofday(cs, complete, tv_addr, tz_addr);
+    } else {
+        host_gettimeofday(cs, complete, tv_addr, tz_addr);
+    }
+}