Function rpmsgblk_write

drivers/misc/rpmsgblk.c:326–416

 ****************************************************************************/

static ssize_t rpmsgblk_write(FAR struct inode *inode,
                              FAR const unsigned char *buffer,
                              blkcnt_t start_sector, unsigned int nsectors)
{
  FAR struct rpmsgblk_s *priv = inode->i_private;
  FAR struct rpmsgblk_write_s *msg;
  struct rpmsgblk_cookie_s cookie;
  uint32_t sectorsize;
  uint32_t space;
  size_t written = 0;
  int ret;

  if (buffer == NULL)
    {
      return -EINVAL;
    }

  /* Sanity checks */

  DEBUGASSERT(priv != NULL);

  ret = rpmsgblk_geometry(inode, &priv->geo);
  if (ret < 0)
    {
      ferr("Get geometry failed, ret=%d\n", ret);
      return ret;
    }

  /* Perform the rpmsg write */

  memset(&cookie, 0, sizeof(cookie));
  nxsem_init(&cookie.sem, 0, 0);

  sectorsize = priv->geo.geo_sectorsize;
  while (written < nsectors)
    {
      msg = rpmsgblk_get_tx_payload_buffer(priv, &space);
      if (msg == NULL)
        {
          ret = -ENOMEM;
          goto out;
        }

      DEBUGASSERT(sizeof(*msg) - 1 + sectorsize <= space);

      msg->nsectors = (space - sizeof(*msg) + 1) / sectorsize;
      if (msg->nsectors >= nsectors - written)
        {
          /* Send complete, set cookie is valid, need ack */

          msg->nsectors = nsectors - written;
          msg->header.cookie = (uintptr_t)&cookie;
        }
      else
        {
          /* Not send complete, set cookie invalid, do not need ack */

          msg->header.cookie = 0;