Save 6952 bytes of RAM #2881
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Save 6952 bytes of RAM #2881
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Will make future changes cleaner
This will make the transition to using const values where possible much easier and cleaner.
Use a global array in cms.c to keep track of the dirty elements that need redrawing. This lets us avoid modifying the entry flags to keep track of it, so they can now be completely read only. This in turn lets us also move all the menus to the text section. This commit saves 6112 bytes of RAM in F3, so we have some room to play again without resorting to disabling features.
Instead, change the OSD configuration directly. This saves 2 bytes per OSD element now and for all the future ones, which translates to -80 bytes from BSS in this commit.
Add support for direct pointers to readonly values rather than using intermediate OSD_XXX_t types. Use direct pointers on all readonly values. Make sure all intermediate value/step holders are in flash rather than ram, since they're never modified. This saves another 352 bytes of RAM (mostly on data, a few on bss).
Make sure all of them are declared as const, since they hold a pointer to the actual value as well as the min/max/step, hence they are never changed. This saves another 408 bytes of ram, by moving them to text
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Just checked how much VTX control takes with these changes. Now it takes ~8K of flash and ~500 bytes of RAM, which are way more palatable values. The VTX control CMS code could still be optimised a bit more by avoiding duplication of a bunch of values in BSS (~30 bytes or so), but since I don't have any SA VTX to test and the remaining potential savings aren't that big I'm not touching it anymore for now. |
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Make CMS use a separate static array for keeping track of the items that need redrawing rather than modifying each OSD_Entry_t item. This lets us move all items and most menus to flash (the SA menu uses dynamic entries, so it needs to stay in ram). Note that text increases by 6728 bytes due to these changes, but even F3 still has ~31K free.
Also, a bunch of macros have been added to CMS to make both the code cleaner and changes like this one easier. Please, try to use them in the future when adding new menus.
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