Three files were changed. MassStorage.cpp, USBHost_t36.h and msc.h. These changes only allow for MSC to recognize and claim an EXT4 formatted USB storage device. It does not start or mount a EXT4 formatted partition. That can be done at the sketch level with these changes. If the file system is not recognized a new error code is returned to indicate this. This has been tested thoroughly without issue.
Three files were changed. MassStorage.cpp, USBHost_t36.h and msc.h. These changes only allow for MSC to recognize and claim an EXT4 formatted USB storage device. It does not start or mount a EXT4 formatted partition. That can be done at the sketch level with these changes. If the file system is not recognized a new error code is returned to indicate this. This has been tested thoroughly without issue.