Added Basic code for LittleFS integration as well as basic FLASH driver code

[Saksham-P]

This code should be the basic code for LittleFS integration into a FLASH memory module, and should include all the basic functions for the FLASH memory module.

Changes Made from pervious branch

All files

• Used DEBUG_ instead of debug_

littlefs_driver.h

• Added function name uint8_t LFS_get_chip_number(lfs_block_t block_num);

littlefs_helper.h

• Commented out #include <stdint.h> as it wasn't required since the data type was available through #include "littlefs/flash_driver.h"
• Renamed LFS_read_file_data to LFS_read_file to keep with naming convention
• Added function name int8_t LFS_list_directory(char *root_directory);+ 2 more

flash_driver.h

• Commented out #include <stdint.h> as it wasn't required since the data type was available through #include "main.h"
• Added #define FLASH_CHIP_BLOCK_SIZE_BYTES 262144 and #define FLASH_CHIP_PAGE_SIZE_BYTES 512

littlefs_driver.c

• Commented out #include "main.h" as it wasn't required
• Implemented uint8_t LFS_get_chip_number(lfs_block_t block_num); using for-loop, although it would be better readable using if-statements. Willing to change it if needed.
• Minor changes to comments

littlefs_helper.c

• Commented out #include <stdint.h> as it wasn't required, not exactly sure how it's able to access data types
• Changed the size of read and program buffers to FLASH_CHIP_PAGE_SIZE_BYTES
• Used the flash_driver.h defines to configure LittleFS
• Implemented LFS_list_directory, LFS_delete_file, LFS_make_directory
• Minor changes to comments

flash_driver.c

• Commented out #include "main.h" as it wasn't required
• // TODO: check if this is how we want to access the FRAM chips ~ Not sure if we want to do this as it wouldn't work well if we wanted to access FLASH and FRAM together or closely together
• Uncommented Line 310 FLASH_deactivate_chip_select(); as I am not quite sure why it was commented with the comment // NOTE: The following line is now commented out. It was previously here though, weird. I could be missing something, so I am willing to change this back
• Minor changes to comments

debug_uart.h, debug_uart.c

• Added DEBUG_uart_print_array_hex

Up Next

There are // FIXME: and // TODO: still around the code I will try and cover, but alongside I aim to create unit tests able to cover the basic FLASH driver code to check if user has the ability to write/read/erase without LittleFS

[DeflateAwning]

Changes from this PR/branch are pulled into PR #45 semi-manually/outside of git.