extmod/fsusermount: Support mounting of multiple block devices.

This patch adds support to fsusermount for multiple block devices
(instead of just one).  The maximum allowed is fixed at compile time by
the size of the fs_user_mount array accessed via MP_STATE_PORT, which
in turn is set by MICROPY_FATFS_VOLUMES.

With this patch, stmhal (which is still tightly coupled to fsusermount)
is also modified to support mounting multiple devices   And the flash and
SD card are now just two block devices that are mounted at start up if
they exist (and they have special native code to make them more
efficient).

1 files changed, 25 insertions, 27 deletions

diff --git a/stmhal/moduos.c b/stmhal/moduos.c
index cb2a73c11..293fbabaf 100644
--- a/stmhal/moduos.c
+++ b/stmhal/moduos.c
@@ -58,15 +58,6 @@
 static char lfn[_MAX_LFN + 1];   /* Buffer to store the LFN */
 #endif
 
-STATIC bool sd_in_root(void) {
-#if MICROPY_HW_HAS_SDCARD
-    // TODO this is not the correct logic to check for /sd
-    return sdcard_is_present();
-#else
-    return false;
-#endif
-}
-
 STATIC const qstr os_uname_info_fields[] = {
     MP_QSTR_sysname, MP_QSTR_nodename,
     MP_QSTR_release, MP_QSTR_version, MP_QSTR_machine
@@ -144,12 +135,11 @@ STATIC mp_obj_t os_listdir(mp_uint_t n_args, const mp_obj_t *args) {
     // "hack" to list root directory
     if (path[0] == '/' && path[1] == '\0') {
         mp_obj_t dir_list = mp_obj_new_list(0, NULL);
-        mp_obj_list_append(dir_list, MP_OBJ_NEW_QSTR(MP_QSTR_flash));
-        if (sd_in_root()) {
-            mp_obj_list_append(dir_list, MP_OBJ_NEW_QSTR(MP_QSTR_sd));
-        }
-        if (MP_STATE_PORT(fs_user_mount) != NULL) {
-            mp_obj_list_append(dir_list, mp_obj_new_str(MP_STATE_PORT(fs_user_mount)->str + 1, MP_STATE_PORT(fs_user_mount)->len - 1, false));
+        for (size_t i = 0; i < MP_ARRAY_SIZE(MP_STATE_PORT(fs_user_mount)); ++i) {
+            fs_user_mount_t *vfs = MP_STATE_PORT(fs_user_mount)[i];
+            if (vfs != NULL) {
+                mp_obj_list_append(dir_list, mp_obj_new_str(vfs->str + 1, vfs->len - 1, false));
+            }
         }
         return dir_list;
     }
@@ -298,21 +288,32 @@ STATIC mp_obj_t os_stat(mp_obj_t path_in) {
 #endif
 
     FRESULT res;
-    if (path_equal(path, "/") || path_equal(path, "/flash") || path_equal(path, "/sd")) {
-        // stat built-in directory
-        if (path[1] == 's' && !sd_in_root()) {
-            // no /sd directory
-            res = FR_NO_PATH;
-            goto error;
-        }
+    if (path_equal(path, "/")) {
+        // stat root directory
 	fno.fsize = 0;
 	fno.fdate = 0;
 	fno.ftime = 0;
 	fno.fattrib = AM_DIR;
     } else {
-        res = f_stat(path, &fno);
+        res = FR_NO_PATH;
+        for (size_t i = 0; i < MP_ARRAY_SIZE(MP_STATE_PORT(fs_user_mount)); ++i) {
+            fs_user_mount_t *vfs = MP_STATE_PORT(fs_user_mount)[i];
+            if (vfs != NULL && path_equal(path, vfs->str)) {
+                // stat mounted device directory
+                fno.fsize = 0;
+                fno.fdate = 0;
+                fno.ftime = 0;
+                fno.fattrib = AM_DIR;
+                res = FR_OK;
+            }
+        }
+        if (res == FR_NO_PATH) {
+            // stat normal file
+            res = f_stat(path, &fno);
+        }
         if (res != FR_OK) {
-            goto error;
+            nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError,
+                MP_OBJ_NEW_SMALL_INT(fresult_to_errno_table[res])));
         }
     }
 
@@ -343,9 +344,6 @@ STATIC mp_obj_t os_stat(mp_obj_t path_in) {
     t->items[9] = MP_OBJ_NEW_SMALL_INT(seconds); // st_ctime
 
     return t;
-
-error:
-    nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(fresult_to_errno_table[res])));
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(os_stat_obj, os_stat);