fixup! esp32: Add low level SD card block device NIFs

Signed-off-by: Davide Bettio <davide@uninstall.it>

Author: bettio

src/platforms/esp32/test/main/test_erl_sources/test_sdcard.erl

@@ -45,18 +45,31 @@ test_read(SDCard) ->
     ok.
 
 %% Read the last sector, overwrite it with a known pattern, read it back and
-%% finally restore the original contents so the card is left unchanged.
+%% restore the original contents, so that the card is left unchanged even when
+%% an assertion fails part way through.
 test_write_roundtrip(SDCard) ->
     {ok, #{sector_size := SectorSize, sector_count := SectorCount}} = esp:sdcard_info(SDCard),
     LastSector = SectorCount - 1,
     {ok, Original} = esp:sdcard_read(SDCard, LastSector),
     Pattern = make_pattern(SectorSize),
-    ok = esp:sdcard_write(SDCard, LastSector, Pattern),
-    {ok, Pattern} = esp:sdcard_read(SDCard, LastSector),
-    ok = esp:sdcard_write(SDCard, LastSector, Original),
+    try
+        ok = esp:sdcard_write(SDCard, LastSector, Pattern),
+        {ok, Pattern} = esp:sdcard_read(SDCard, LastSector)
+    after
+        restore_sector(SDCard, LastSector, Original)
+    end,
     {ok, Original} = esp:sdcard_read(SDCard, LastSector),
     ok.
 
+%% Best effort, so that a failing restore does not replace the original error.
+%% The caller asserts separately that the original contents came back.
+restore_sector(SDCard, Sector, Data) ->
+    try
+        esp:sdcard_write(SDCard, Sector, Data)
+    catch
+        _:_ -> ok
+    end.
+
 test_bad_args(SDCard) ->
     {ok, #{sector_size := SectorSize, sector_count := SectorCount}} = esp:sdcard_info(SDCard),
     %% Data that is not exactly one sector long is rejected.