Discussion
Continuing my study of SdFat, though other side of the frontend is not just using existing filesystems but initializing new ones.
For this the format() method branches over the SD card's capacity to choose sector quantity per cluster, defers to one of 2 methods whilst outputting results to the console. Both of which shares a method for initializing the root directory by zeroing out the 1st several sectors with log messages, & fills both FATs with all 1s except their 1st byte (hex-F8).
1/3?
They also share a method for initializing "PBS" metadata, whatever PBS standards for in this context. As well as another method for "MBR" metadata, which I seem to recall standards for Master Boot Record.
For FAT16 it iterates over sectors to count them (ignoring a boot partition), validates sector count & derives some metadata from it, writes the MBR, followed by PBR if successful, populates & writes some additional metadata, & creates the root directory.
2/3?
For FAT32 it uses some extremely similar logic, to the point where my synopsis would be exactly the same.
2.1/2.1 Fin! Seems like that covers it...
Tomorrow: Briefly synopsize ExFat support & some support code.
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