* Get UBL Mesh Generation, Mesh Save & Mesh Load working with 32-Bit platforms
* clean up read_data() and write_data() for non-LPC1768 HAL's
* Get read_data() and write_data() return codes consistent
All HAL's read_data() and write_data() return false if they succeed.
* Get read_data() and write_data() return codes to be consistent
Make read_data() and write_data() return true if an error happens.
* Say UBL is now checked out on machine types in default Configuration.h file.
- fix broken `M421` due to less-than-careful optimization
- add HOME_AFTER_DEACTIVATE define to advanced config so not everyone has to rehome after steppers are deactivated
- misc. cleanups (remove unused label, unused variables)
- Add crc16 utility function
- Implement CRC16 for config store, remove old checksum, increment layout version
- Move UBL mesh store/load to MarlinSettings; increment UBL_VERSION
- Begin to lay out MAT structure, prototype functions, etc.
- Rename ubl.state.eeprom_storage_slot to .storage_slot
- Misc. optimization
- Cleanup/standardize/improve some messages
This is a work in progress!
* M421 Mesh Point Offset and misc. UBL clean up
Allow M421 to accept an offset as well as absolute value for a specified
mesh point.
And misc. UBL clean up to reduce redundent code.
* Better error checking for M421
* Fix M421 Y index bug
I just noticed.... We've had a Y index bug for who knows how long?