SDMMC SD Card Drivers

[lekangwang]

Description

What was completed, changed, or updated?

• Added FATFS third party libraries
• Enabled and configure SDMMC to 4-bit data mode
• Update CMakeList.txt to compile FATFS files
• Added low level drivers that calls HAL functions to interact with SD card via SDMMC board peripheral
• Created 2 thread-safe high level functions to read/write to SD card, (file names are limited to 8.3 format)

Why was this done (if applicable)?

• For logging purposes (i.e. crash report)

Testing

What manual tests were used to validate the code?

Tested on 16 and 32 GB card

• Can write the same message 100 times to a file
  

• Reading the first line, data matches as expected
  

• Multithreaded write to same file is handled correctly
  

What unit tests were used to validate the code?

• Low level drivers passes unit tests written by the FATFS author (http://elm-chan.org/fsw/ff/res/app4.c)

Documentation

Milestone number and name: M2

Link to Asana task: https://app.asana.com/0/1203458353737758/1204645027312218/f

Link to Confluence documentation: https://uwarg-docs.atlassian.net/wiki/spaces/ZP/pages/2251620424/SDMMC+SD+Card

Reminders

• Add reviewers to the PR

• Mention the PR in the appropriate discord channel

[antholuo]

Changes mostly look good, especially if tested working.

I'm curious to see how it plays with freertos task scheduling and if that might cause problems with data stalling or weird interrupt issues. Might be worth trying to schedule two threads and having one thread write to the SD card while the other one does busy work?

[HardyYu]

Wow! Having DMA and thread guard implemented is really cool. Very impressive! This pr is kinda large and couldn't finish reviewing it today. I will leave my approvement here since this code was tested to be working. Good work!