Internals
Description of technical choices.
Conventions
API symbols start with
lftl_orLFTL_prefix.“size” is in bytes, “width” is in bits.
Coding style
Tabs are spaces, and they are 2 characters wide.
Error reporting
All user functions directly call the error call back when they detect an error, this ensures
all errors are treated.
This does not force the user to use set_jump:
the error handler can also just wait for reset or trigger an internal reset.
Expansion of variables to full write units
The helper macro LFTL_ARRAY expand each array item to the width of a write unit.
This wastes storage area but that allows to update each variable independantly without any
buffer in RAM.
If the user desire to optimize storage footprint, the way to go is to use LFTL_COMPACT_ARRAY
and use a buffer in RAM to group write operations as demonstrated in the single_area example.
Memory layout
The diagram below present the structure of an LFTL area.
The area contains ns slots, each containing np pages.
The data size supported by the area is np pages minus the size of the meta-data.
