SD/MMC/FAT partition mouting with esp:mount/4 and umount

CHANGELOG.md

@@ -39,6 +39,8 @@ also non string parameters (e.g. `Enum.join([1, 2], ",")`
 - ESP32: add support for `esp_adc` ADC driver, with Erlang and Elixir examples
 - Add handler for ESP32 network driver STA mode `beacon_timeout` (event: 21), see issue
 [#1100](https://github.com/atomvm/AtomVM/issues/1100)
+- Support for mounting/unmounting storage on ESP32 (such as SD or internal flash) using
+`esp:mount/4` and `esp:umount/1`
 
 ### Changed
 

libs/eavmlib/src/esp.erl

@@ -38,6 +38,8 @@
     sleep_enable_ulp_wakeup/0,
     deep_sleep/0,
     deep_sleep/1,
+    mount/4,
+    umount/1,
     nvs_fetch_binary/2,
     nvs_get_binary/1, nvs_get_binary/2, nvs_get_binary/3,
     nvs_set_binary/2, nvs_set_binary/3,
@@ -118,6 +120,8 @@
 }.
 -opaque task_wdt_user_handle() :: binary().
 
+-opaque mounted_fs() :: binary().
+
 -export_type(
     [
         esp_reset_reason/0,
@@ -128,6 +132,7 @@
         esp_partition_address/0,
         esp_partition_size/0,
         esp_partition_props/0,
+        mounted_fs/0,
         task_wdt_config/0,
         task_wdt_user_handle/0
     ]
@@ -279,6 +284,34 @@ deep_sleep() ->
 deep_sleep(_SleepMS) ->
     erlang:nif_error(undefined).
 
+%%-----------------------------------------------------------------------------
+%% @param   Source the device that will be mounted
+%% @param   Target the path where the filesystem will be mounted
+%% @param   FS the filesystem, only fat is supported now
+%% @param   Opts
+%% @returns either a tuple having `ok' and the mounted fs resource, or an error tuple
+%% @doc     Mount a filesystem, and return a resource that can be used later for unmounting it
+%% @end
+%%-----------------------------------------------------------------------------
+-spec mount(
+    Source :: unicode:chardata(),
+    Target :: unicode:chardata(),
+    FS :: fat,
+    Opts :: proplists:proplist() | #{atom() => term()}
+) -> {ok, mounted_fs()} | {error, term()}.
+mount(_Source, _Target, _FS, _Opts) ->
+    erlang:nif_error(undefined).
+
+%%-----------------------------------------------------------------------------
+%% @param   The mounted filesystem resource that should be unmounted
+%% @returns either `ok' or an error tuple
+%% @doc     Unmounts filesystem located at given path
+%% @end
+%%-----------------------------------------------------------------------------
+-spec umount(mounted_fs()) -> ok | {error, term()}.
+umount(_Target) ->
+    erlang:nif_error(undefined).
+
 %%-----------------------------------------------------------------------------
 %% @param   Namespace NVS namespace
 %% @param   Key NVS key

libs/estdlib/src/proplists.erl

@@ -43,7 +43,10 @@
     to_map/1
 ]).
 
+-export_type([property/0, proplist/0]).
+
 -type property() :: atom() | {term(), term()}.
+-type proplist() :: [property()].
 
 % Taken from `otp/blob/master/lib/stdlib/src/proplists.erl`
 %%-----------------------------------------------------------------------------

src/platforms/esp32/components/avm_builtins/CMakeLists.txt

@@ -27,6 +27,7 @@ set(AVM_BUILTIN_COMPONENT_SRCS
     "rtc_slow_nif.c"
     "socket_driver.c"
     "spi_driver.c"
+    "storage_nif.c"
     "uart_driver.c"
     "otp_crypto_platform.c"
     "otp_net_platform.c"
@@ -56,7 +57,7 @@ endif()
 idf_component_register(
     SRCS ${AVM_BUILTIN_COMPONENT_SRCS}
     INCLUDE_DIRS "include"
-    PRIV_REQUIRES "libatomvm" "avm_sys" "nvs_flash" "driver" "esp_event" "esp_wifi" ${ADDITIONAL_PRIV_REQUIRES}
+    PRIV_REQUIRES "libatomvm" "avm_sys" "nvs_flash" "driver" "esp_event" "esp_wifi" "fatfs" ${ADDITIONAL_PRIV_REQUIRES}
     ${OPTIONAL_WHOLE_ARCHIVE}
 )
 

src/platforms/esp32/components/avm_builtins/Kconfig

@@ -72,6 +72,10 @@ config AVM_RTC_SLOW_MAX_SIZE
     # 4KB is a reasonable default
     default 4096
 
+config AVM_ENABLE_STORAGE_NIFS
+    bool "Enable Storage NIFs"
+    default y
+
 config AVM_ENABLE_GPIO_PORT_DRIVER
     bool "Enable GPIO port driver"
     default y