+int drv_attach(uint8_t unit, const char *filename, drv_opt_t options)
+{
+ int res;
+
+ drv = unit;
+ if (drv >= CONFIG_CPM_MAX_DRIVE)
+ return EATRANGE;
+
+ struct cpm_drive_s *p = &drv_table[drv];
+
+ if (options & DRV_OPT_REATTATCH) {
+ if (filename) {
+ return EUNEXPARG;
+ }
+
+ if (!p->img_name) {
+ return EATNOT;
+ }
+
+ /* change options */
+ if ((p->opt ^ options) & DRV_OPT_RO) {
+ f_close(&p->fd);
+ res = f_open(&p->fd, p->img_name,
+ FA_READ | (options&DRV_OPT_RO ? 0 : FA_WRITE));
+ }
+
+ p->opt = options & ~DRV_OPT_REATTATCH;
+
+ } else {
+
+ if (p->img_name)
+ return EATALRDY;
+ if (drv_find_file_attached(filename) >= 0)
+ return EATOTHER;
+
+ p->opt = options;
+
+ /* new attachment */
+
+ if ((p->img_name = strdup(filename)) == NULL)
+ return ENOMEM;
+
+ res = f_open(&p->fd, p->img_name,
+ FA_READ | (options&DRV_OPT_RO ? 0 : FA_WRITE));
+
+ if (!res && f_size(&p->fd) < CONFIG_CPM_DISKSIZE) {
+#if 0
+ unsigned int bw;
+ debug_cpmsd(" expanding image file from %ld to %ld\n",
+ f_size(&p->fd), CONFIG_CPM_DISKSIZE);
+
+ res = f_lseek(&p->fd, CONFIG_CPM_DISKSIZE-CONFIG_CPM_BLOCK_SIZE);
+ if (!res) {
+ memset(disk_buffer, 0xe5, CONFIG_CPM_BLOCK_SIZE);
+ res = f_write(&p->fd, disk_buffer, CONFIG_CPM_BLOCK_SIZE, &bw);
+ if (res || bw < CONFIG_CPM_BLOCK_SIZE) {
+ debug_cpmsd(" failed! res: %d, bytes written: %u\n", res, bw);
+ }
+ p->flags |= DRV_FLG_DIRTY;
+ bg_setstat(handle_cpm_drv_to, 1);
+ }
+#else
+ drv_debug(SINGLE, PSTR("wrong image file size: %ld, should be %ld"),
+ f_size(&p->fd), CONFIG_CPM_DISKSIZE);
+ res = 64;
+#endif
+ }
+ if (res) {
+ drv_detach(drv);
+ return EATOPEN;
+ }