Simulation stuck at __bcc_con_outbyte routine

NOEL-V
1

Hello,
I’m simulating the NOEL-V (RV32) using the tiny configuration in the noelv-generic design. The code has been compiled using the NCC toolchain provided here (linux).
The program gets stuck in a loop in __bcc_con_outbyte, apparently waiting for the UART. The rest of the program works as expected as I can successfully run programs that do not print any value.

Do you have any idea of what could be the issue and how can I resolve it? I include a screenshot with the system information and one with the simulation disassembly with the mentioned situation.

Thanks for your help!

noelvinfo
noelvinfo794×900 46.7 KB

imatge_2021-08-26_155921
imatge_2021-08-26_1559211237×526 27.7 KB

2

Hi MarcSB,

Only considering you problem description (no deep analysis of the problem) I would say it could be that the UART is not enabled. You could try including the following function when compiling you main C code to enabling the UART:

void __bcc_init70(void){
  unsigned int * apbuart_ctrl = (unsigned int*)0xfc001008;

  // enable UART
  *apbuart_ctrl = 0x3;
}

int main() {
...
}

Please note: this should be ok for simulation, but when running the application on hardware using GRMON you may need to preserve some debug bits in the UART control register.

Regards,
Nils

3

Hi Nils,
Including the function has solved the issue.
Thank you!

Regards,
Marc