The uninitted RAM macro would fail because the OTA code would clear out the
first 50KB or so of RAM to copy its code and global values.
Move all global values to the end of RAM in OTA, and then align any uninitted
vars to a 16KB unit to ensure it won't appear in the 1st part of RAM that is
still needed to copy the OTA executable.
In the normal case, without any uninit_ram vars, no additional space is used.
When uninit_ram is used, up to 16KB of space may be lost to get that alignment,
but it will work properly.
Fixes#1188
Adds a 12K OTA stub 3rd stage bootloader, which reads new firmware
from the LittleFS filesystem and flashes on reboot.
By storing the OTA commands in a file in flash, it is possible to
recover from a power failure during OTA programming. On power
resume, the OTA block will simply re-program from the beginning.
Support cryptographic signed OTA updates, if desired. Includes
host-side signing logic via openssl.
Add PicoOTA library which encapsulates the file format for
the updater, including CRC32 checking.
Add LEAmDNS support to allow Arduino IDE discovery
Add ArduinoOTA class for IDE uploads
Add MD5Builder class
Add Updater class which supports writing and validating
cryptographically signed binaries from any source (http,
Ethernet, WiFi, Serial, etc.)
Add documentation and readmes.
