Add BSP and semihosting library for nios2-generic-nommu QEMU emulation.

libgloss/nios2/io-lseek.c

@@ -0,0 +1,52 @@
+/*
+ * io-lseek.c -- 
+ *
+ * Copyright (c) 2006 CodeSourcery Inc
+ * Copyright (c) 2018 Mentor Graphics
+ *
+ * The authors hereby grant permission to use, copy, modify, distribute,
+ * and license this software and its documentation for any purpose, provided
+ * that existing copyright notices are retained in all copies and that this
+ * notice is included verbatim in any distributions. No written agreement,
+ * license, or royalty fee is required for any of the authorized uses.
+ * Modifications to this software may be copyrighted by their authors
+ * and need not follow the licensing terms described here, provided that
+ * the new terms are clearly indicated on the first page of each file where
+ * they apply.
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#define IO lseek
+#include "io.h"
+
+/*
+ * lseek -- reposition a file descriptor
+ * input parameters:
+ *   0 : file descriptor
+ *   1 : high word of offset
+ *   2 : low word of offset
+ *   3 : seek flag
+ * output parameters:
+ *   0 : high word of result
+ *   1 : low word of result
+ *   2 : errno
+ */
+
+off_t lseek (int fd, off_t offset, int whence)
+{
+#if HOSTED
+  gdb_parambuf_t parameters;
+  parameters[0] = (uint32_t) fd;
+  parameters[1] = (uint32_t) ((offset >> 32) & 0xffffffff);
+  parameters[2] = (uint32_t) (offset & 0xffffffff);
+  parameters[3] = __hosted_to_gdb_lseek_flags (whence);
+  __io_hosted (HOSTED_LSEEK, parameters);
+  errno = __hosted_from_gdb_errno (parameters[2]);
+  return ((uint64_t)parameters[0] << 32) | ((uint64_t)parameters[1]);
+#else
+  errno = ENOSYS;
+  return -1;
+#endif
+}