porting nRF52 project from IAR to ARMGCC

[iprogramplus]

Hi. I have a working IAR project based on the nrf52 SDK \nordic\examples\ble_peripheral\ble_app_uart. i am attempting to port the project to ARMGCC using VSCode. I am at a stage in the port where all the files compile and link and I am at the main() stepping in and out of functions using the GDB. i come across a function "localtime" and have a HARDFAULT. I verified the input parameters are valid.

thanks in advance.

Barry

[AMarch01]

You don't specify what version of the library you are using. Also, this stuff gets deep rather quickly and difficult to file without every configuration. 
Is it possible to single step INTO the function? 

My quick guess is that something inside the function went from a heap/stack type variable to a flash variable and something is trying to write to it. I saw something like this happen between 2.7.0 and 2.91 - there was a nice little macro that made a variable for me, but someone added a "const" to it inside the SDK and my code wrote to this generated variable. CRASH
A M 

[iprogramplus]

hello 

i debugged my code in IAR when reaching the statement:  struct tm *t = localtime(&hitless_ptr()->rtc_var.m_time), I looked for the declaration of localtime and IAR took me to C:\Program Files (x86)\IAR Systems\Embedded Workbench 8.3\arm\inc\c, file time32.h. In ARMGCC, compilation and linking go without error or warning, but while debugging in GDB and stepping over localtime, I get the hardfault.

Thanks in advance.

[iprogramplus]

hi Simon,

No, I don't get a HARDFAULT when stepping through the code until I reach the LOCALTIME() function. Then I got a HARDFAULT; I forced a restart and began working again until I reached the LOCALTIME() function.

i am noticing that all the time function while building without errors; Intellisense is complaining.

Thanks in advance.

Barry

[Susheel Nuguru]

I have seen this before. This most likely happens when you use incompatible lib that defines this localtime. Are you using newlibc or something else. Check if the library you linked is compatible with the compiler you are using.

[iprogramplus]

i attached two files with Chat

Fullscreen time_utils.c Download

#include <string.h>  // for strcmp
#include <stdio.h>   // for snprintf
#include "time_utils.h"

static struct my_tm _tm_result;

static const int days_in_month[] = {
    31, 28, 31, 30, 31, 30,
    31, 31, 30, 31, 30, 31
};

static int is_leap(int year) {
    year += 1900;
    return ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0));
}

time_t my_mktime(const struct my_tm *t) {
    time_t days = 0;
    for (int y = 70; y < t->tm_year; y++) {
        days += (is_leap(y) ? 366 : 365);
    }

    for (int m = 0; m < t->tm_mon; m++) {
        days += days_in_month[m];
        if (m == 1 && is_leap(t->tm_year)) {
            days += 1; // Leap year February
        }
    }

    days += t->tm_mday - 1;

    return ((days * 24 + t->tm_hour) * 60 + t->tm_min) * 60 + t->tm_sec;
}

struct my_tm *my_localtime(const time_t *timep) {
    time_t seconds = *timep;
    int days = seconds / 86400;
    int rem = seconds % 86400;

    _tm_result.tm_hour = rem / 3600;
    rem %= 3600;
    _tm_result.tm_min = rem / 60;
    _tm_result.tm_sec = rem % 60;

    int year = 70;
    while (1) {
        int ydays = is_leap(year) ? 366 : 365;
        if (days >= ydays) {
            days -= ydays;
            year++;
        } else break;
    }
    _tm_result.tm_year = year;

    _tm_result.tm_yday = days;

    int month;
    for (month = 0; month < 12; month++) {
        int dim = days_in_month[month];
        if (month == 1 && is_leap(year)) dim += 1;
        if (days >= dim) {
            days -= dim;
        } else break;
    }
    _tm_result.tm_mon = month;
    _tm_result.tm_mday = days + 1;

    // Optional: you can calculate tm_wday here if needed
    _tm_result.tm_isdst = 0;

    return &_tm_result;
}

int my_strftime(char *buf, size_t max, const char *fmt, const struct my_tm *t)
{
    // Only supports this format: " %d/%m/%y %H:%M:%S"
    // Adjust accordingly if needed.
    if (strcmp(fmt, " %d/%m/%y %H:%M:%S") != 0 || max < 20)
        return 0; // unsupported format or buffer too small

    return snprintf(buf, max, " %02d/%02d/%02d %02d:%02d:%02d",
                    t->tm_mday,
                    t->tm_mon + 1,
                    (t->tm_year + 1900) % 100,
                    t->tm_hour,
                    t->tm_min,
                    t->tm_sec);
}

time_utils.h that implement the missing meat in the ARMGCC library.

thanks,

[Susheel Nuguru]

I used your code in nrf5sdk v17 in uart peripheral sample and it works fine without any crash or hardfault.

Attaching my project just for your reference.

8468.uart.zip

Compiler version details here

[iprogramplus]

Cheers!