EEPROM storage allocated even though it is not used

[sslupsky]

I noticed the following two declarations in EEPROM.cpp

FlashStorage/src/FlashAsEEPROM.cpp

Line 24 in 18c0212

FlashStorage(eeprom_storage, EEPROM_EMULATION);

FlashStorage/src/FlashAsEEPROM.cpp

Line 74 in 18c0212

EEPROMClass EEPROM;

This allocates quite a bit of RAM (1K) when you are not using the EEPROM emulation.

Would it be advantageous to have an initialization method (ie: EEPROM:begin() ) that is called to allocate the storage?

[sslupsky]

There is already an EEPROM::init() method. Perhaps the allocation could be done there?

The way the FlashStorage define works and the FlashStorageClass is templated, it is not obvious how to move the allocation into a class. I was trying do so using my own class and encountered compiler error. The declaration of the _data array is declared as static storage class and this causes problems with the FlashStorageClass template.

Is there a way to instantiate the FlashStorageClass object from within a class? I have two different types of storage that I would like to create two different FlashStorageClass objects for.

[sslupsky]

I defined EEPROM_EMULATION_SIZE 0 as follows:

#define BOOT_STATUS_FILE_MAX_RECORDS 16
#include <FlashStorage.h>

but for some reason that does not appear to prevent the allocation of the memory. Here are the relevant allocations from nm:

20000d6c 00000403 B EEPROM
00017800 00000500 t _dataeeprom_storage

There is 1K of RAM and 1.2K of FLASH allocated to the EEPROM storage.

Note that I do not include FlashAsEEPROM.h. So, it appears to me that FlashAsEEPROM.cpp is being compiled and linked regardless of its inclusion. Does this imply that FlashAsEEPROM.* need to be in their own separate library or is there a way to prevent them from being compiled when not used?

[tuxedo0801]

interesting question...