NIOS II - FW doesn't work with compiler optimization turned on

New Contributor

1 year ago

Hi,

I am sorry for the delayed response. I have been out of the office for the last few days.

Thanks for the link, I tried the #pragma directive to disable GCC optimization for one or more functions and it works.

With this technique I was able to isolate the source of the problem: the function that causes it is flash_read_flag_status_register.

It is implemented in this way:

alt_u32 flash_read_flag_status_register(T_flash_state *st)

{

IOWR(st->csr_base, FLASH_CSR_FL_CMD_SET, 0x00001870);

IOWR(st->csr_base, FLASH_CSR_FL_CMD_CTRL, 0x1);

return IORD(st->csr_base, FLASH_CSR_FL_CMD_RD0);

}

and is used to check if the write operation is finished and then checks for errors:

// check for errors
do {

flag_status = flash_read_flag_status_register(st);

} while (!(flag_status & FLASH_FSR_READY));

flash_clear_flag_status_register(st);
if (flag_status & FLASH_FSR_PROTECTION_ERR)
{

ret_flag = FLASH_SECTOR_PROTECTED;
break;

}
if ((flag_status & FLASH_FSR_ERASE_ERR) || (flag_status & FLASH_FSR_PROGRAM_ERR))
{

ret_flag = FLASH_ERROR;
break;

}

To avoid using #pragma I tried setting the flag_status variable as volatile, but it doesn't work.

Do you know why if I use volatile for flag_status it doesn't work?

Can you suggest other attentions I can have to avoid other problems with GCC optimization?

Thanks.

Best Regards,

naand

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