Arduino Crypto library: compilation problem with MegaTinyCore 2.6.8 (IDE 1.8.19, Win10)

[XFer012]

Hi,
I'm trying to build an Arduino Crypto Library example ("TestEd25519") for ATTiny 3224, latest MegaTinyCore 2.6.8 and Arduino IDE 1.8.19.

I get the following errors (mostly about RNG.cpp):

Arduino: 1.8.19 (Windows 10), TD: 1.57, Board: "ATtiny3224/1624/1614/1604/824/814/804/424/414/404/214/204, ATtiny3224, 10 MHz internal, 1.8V (5 MHz or less), Disabled/Disabled, EEPROM retained, Enabled (default timer), 8ms, Master or Slave (saves flash and RAM), Default (doesn't print floats, 1.4k flash use), PB0-2, PA3-5 (default), On all pins, with new implementation., Disabled (recommended), No delay before window "opens""

In file included from C:\Users\Fernando\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.8\cores\megatinycore/Arduino.h:37:0,

                 from L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:27:

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp: In function 'void WDT_vect()':

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:228:5: warning: 'WDT_vect' appears to be a misspelled 'signal' handler, missing '__vector' prefix [-Wmisspelled-isr]

 ISR(WDT_vect)

     ^

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:239:27: error: 'TCNT0' was not declared in this scope

     unsigned char value = TCNT0;

                           ^~~~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:239:27: note: suggested alternative: 'TCA0'

     unsigned char value = TCNT0;

                           ^~~~~

                           TCA0

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp: In destructor 'RNGClass::~RNGClass()':

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:288:5: error: 'MCUSR' was not declared in this scope

     MCUSR &= ~(1 << WDRF);

     ^~~~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:288:21: error: 'WDRF' was not declared in this scope

     MCUSR &= ~(1 << WDRF);

                     ^~~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:288:21: note: suggested alternative: 'WDT'

     MCUSR &= ~(1 << WDRF);

                     ^~~~

                     WDT

In file included from L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:37:0:

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:291:30: error: 'WDCE' was not declared in this scope

     _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);

                              ^

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:291:30: note: suggested alternative: 'ADC0'

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:291:54: error: 'WDE' was not declared in this scope

     _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);

                                                      ^~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:291:54: note: suggested alternative: 'WDT'

     _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);

                                                      ^~~

                                                      WDT

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:292:23: error: no match for 'operator=' (operand types are 'WDT_t {aka WDT_struct}' and 'int')

     _WD_CONTROL_REG = 0;

                       ^

In file included from c:\users\fernando\appdata\local\arduino15\packages\dxcore\tools\avr-gcc\7.3.0-atmel3.6.1-azduino6\avr\include\avr\io.h:733:0,

                 from c:\users\fernando\appdata\local\arduino15\packages\dxcore\tools\avr-gcc\7.3.0-atmel3.6.1-azduino6\avr\include\avr\pgmspace.h:90,

                 from C:\Users\Fernando\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.8\cores\megatinycore/api/String.h:30,

                 from C:\Users\Fernando\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.8\cores\megatinycore/api/Print.h:24,

                 from C:\Users\Fernando\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.8\cores\megatinycore/api/Stream.h:25,

                 from C:\Users\Fernando\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.8\cores\megatinycore/api/Client.h:22,

                 from C:\Users\Fernando\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.8\cores\megatinycore/api/ArduinoAPI.h:29,

                 from C:\Users\Fernando\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.8\cores\megatinycore/Arduino.h:26,

                 from L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:27:

c:\users\fernando\appdata\local\arduino15\packages\dxcore\tools\avr-gcc\7.3.0-atmel3.6.1-azduino6\avr\include\avr\iotn3224.h:2040:16: note: candidate: constexpr WDT_struct& WDT_struct::operator=(const WDT_struct&)

 typedef struct WDT_struct

                ^~~~~~~~~~

c:\users\fernando\appdata\local\arduino15\packages\dxcore\tools\avr-gcc\7.3.0-atmel3.6.1-azduino6\avr\include\avr\iotn3224.h:2040:16: note:   no known conversion for argument 1 from 'int' to 'const WDT_struct&'

c:\users\fernando\appdata\local\arduino15\packages\dxcore\tools\avr-gcc\7.3.0-atmel3.6.1-azduino6\avr\include\avr\iotn3224.h:2040:16: note: candidate: constexpr WDT_struct& WDT_struct::operator=(WDT_struct&&)

c:\users\fernando\appdata\local\arduino15\packages\dxcore\tools\avr-gcc\7.3.0-atmel3.6.1-azduino6\avr\include\avr\iotn3224.h:2040:16: note:   no known conversion for argument 1 from 'int' to 'WDT_struct&&'

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp: In member function 'void RNGClass::begin(const char*)':

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:485:5: error: 'MCUSR' was not declared in this scope

     MCUSR &= ~(1 << WDRF);

     ^~~~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:485:21: error: 'WDRF' was not declared in this scope

     MCUSR &= ~(1 << WDRF);

                     ^~~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:485:21: note: suggested alternative: 'WDT'

     MCUSR &= ~(1 << WDRF);

                     ^~~~

                     WDT

In file included from L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:37:0:

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:489:30: error: 'WDCE' was not declared in this scope

     _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);

                              ^

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:489:30: note: suggested alternative: 'ADC0'

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:489:54: error: 'WDE' was not declared in this scope

     _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);

                                                      ^~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:489:54: note: suggested alternative: 'WDT'

     _WD_CONTROL_REG |= (1 << _WD_CHANGE_BIT) | (1 << WDE);

                                                      ^~~

                                                      WDT

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:490:29: error: 'WDIE' was not declared in this scope

     _WD_CONTROL_REG = (1 << WDIE);

                             ^~~~

L:\Progetti\Arduino\libraries\Crypto\src\RNG.cpp:490:29: note: suggested alternative: 'WDT'

     _WD_CONTROL_REG = (1 << WDIE);

                             ^~~~

                             WDT

exit status 1

Error compiling for board ATtiny3224/1624/1614/1604/824/814/804/424/414/404/214/204.

I had to disable Verbose Compilation because the message body was too large (> 65535 chars).

I reckon is more a problem with Crypto library assuming things than with MegaTinyCore; still, in case there's a reasonably simple fix it would be nice to have Crypto compatible with the newer ATTinys. :)

Update: same problem with current DxCore 1.5.8 (tested with AVR64DD14).

[SpenceKonde]

#924

This guy fixed it - it can only be dealt with at the library level as the library needs to use a different means to gather entropy (on classic they used the beat of the poorly controlled, asynchronous WDT oscillator against the system clock to generate entropy; on the new parts, there turns out to be a better way that generates more entropy faster (though an analogous method using the RTC is also possible, but in that thread, I got the impression that my CCL hack was faster and - besides that I suspect it's a better source of randomness, since Microchip isn't even trying control the timing of a CCL inverting itself.