make flash filesystem work on NRF52

docs/software/nrf52-TODO.md

@@ -21,7 +21,6 @@ Needed to be fully functional at least at the same level of the ESP32 boards. At
 
 - DONE get serial API working
 - get full BLE api working
-- make a file system implementation (preferably one that can see the files the bootloader also sees) - preferably https://github.com/adafruit/Adafruit_nRF52_Arduino/blob/master/libraries/InternalFileSytem/examples/Internal_ReadWrite/Internal_ReadWrite.ino else use https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/lib_fds_usage.html?cp=7_5_0_3_55_3
 - make power management/sleep work properly
 - make a settimeofday implementation
 - DONE increase preamble length? - will break other clients? so all devices must update
@@ -125,6 +124,7 @@ Nice ideas worth considering someday...
 - DONE use SX126x::startReceiveDutyCycleAuto to save power by sleeping and briefly waking to check for preamble bits. Change xmit rules to have more preamble bits.
 - scheduleOSCallback doesn't work yet - it is way too fast (causes rapid polling of busyTx, high power draw etc...)
 - find out why we reboot while debugging - it was bluetooth/softdevice
+- make a file system implementation (preferably one that can see the files the bootloader also sees) - preferably https://github.com/adafruit/Adafruit_nRF52_Arduino/blob/master/libraries/InternalFileSytem/examples/Internal_ReadWrite/Internal_ReadWrite.ino else use https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/lib_fds_usage.html?cp=7_5_0_3_55_3
 
 ```
 

src/mesh/NodeDB.cpp

@@ -33,6 +33,14 @@ DeviceState versions used to be defined in the .proto file but really only this
 
 #ifndef NO_ESP32
 #define FS SPIFFS
+#define FSBegin() FS.begin(true)
+#define FILE_O_WRITE "w"
+#define FILE_O_READ "r"
+#else
+#include "InternalFileSystem.h"
+#define FS InternalFS
+#define FSBegin() FS.begin()
+using namespace Adafruit_LittleFS_Namespace;
 #endif
 
 // FIXME - move this somewhere else
@@ -135,8 +143,15 @@ void NodeDB::init()
     info->user = owner;
     info->has_user = true;
 
+    if (!FSBegin()) // FIXME - do this in main?
+    {
+        DEBUG_MSG("ERROR filesystem mount Failed\n");
+        // FIXME - report failure to phone
+    }
+
     // saveToDisk();
     loadFromDisk();
+    // saveToDisk();
 
     // We set these _after_ loading from disk - because they come from the build and are more trusted than
     // what is stored in flash
@@ -180,13 +195,7 @@ void NodeDB::loadFromDisk()
 #ifdef FS
     static DeviceState scratch;
 
-    if (!FS.begin(true)) // FIXME - do this in main?
-    {
-        DEBUG_MSG("ERROR SPIFFS Mount Failed\n");
-        // FIXME - report failure to phone
-    }
-
-    File f = FS.open(preffile);
+    auto f = FS.open(preffile);
     if (f) {
         DEBUG_MSG("Loading saved preferences\n");
         pb_istream_t stream = {&readcb, &f, DeviceState_size};
@@ -220,7 +229,7 @@ void NodeDB::loadFromDisk()
 void NodeDB::saveToDisk()
 {
 #ifdef FS
-    File f = FS.open(preftmp, "w");
+    auto f = FS.open(preftmp, FILE_O_WRITE);
     if (f) {
         DEBUG_MSG("Writing preferences\n");
 

src/mesh/mesh-pb-constants.cpp

@@ -6,6 +6,11 @@
 #include <pb_decode.h>
 #include <pb_encode.h>
 
+#ifdef NO_ESP32
+#include "Adafruit_LittleFS.h"
+using namespace Adafruit_LittleFS_Namespace; // To get File type
+#endif 
+
 /// helper function for encoding a record as a protobuf, any failures to encode are fatal and we will panic
 /// returns the encoded packet size
 size_t pb_encode_to_bytes(uint8_t *destbuf, size_t destbufsize, const pb_msgdesc_t *fields, const void *src_struct)
@@ -36,7 +41,6 @@ bool pb_decode_from_bytes(const uint8_t *srcbuf, size_t srcbufsize, const pb_msg
 bool readcb(pb_istream_t *stream, uint8_t *buf, size_t count)
 {
     bool status = false;
-#ifndef NO_ESP32
     File *file = (File *)stream->state;
 
     if (buf == NULL) {
@@ -45,24 +49,20 @@ bool readcb(pb_istream_t *stream, uint8_t *buf, size_t count)
         return count == 0;
     }
 
-    status = (file->read(buf, count) == count);
+    status = (file->read(buf, count) == (int) count);
 
     if (file->available() == 0)
         stream->bytes_left = 0;
-#endif
+
     return status;
 }
 
 /// Write to an arduino file
 bool writecb(pb_ostream_t *stream, const uint8_t *buf, size_t count)
 {
-#ifndef NO_ESP32
     File *file = (File *)stream->state;
     // DEBUG_MSG("writing %d bytes to protobuf file\n", count);
     return file->write(buf, count) == count;
-#else
-    return false;
-#endif
 }
 
 bool is_in_helper(uint32_t n, const uint32_t *array, pb_size_t count)