// D1 regression for the crt0Gno BSS-clear heartbeat bug: a large zero-init
// BSS array pushes __bss_end past the old ~0xB100 corruption threshold.
// crt0Gno no longer clears BSS (the loader fills the embedded zeros), so
// the program must run to the end AND read the array back as all-zero.
#include <stdint.h>

// ~5.75 KB.  With the current GNO libc the runtime BSS base already sits at
// ~0xD000 (well above the old ~0xB100 heartbeat threshold), so this array's job
// is to keep __bss_end large (near the bank-0 top) while still fitting bank 0.
static volatile uint8_t bigBss[0x1700];

int main(void) {
    *(volatile uint16_t *)0x025010UL = 0xBEEF;
    uint16_t zeroed = 1;
    unsigned i;
    for (i = 0; i < 0x1700; i++) {
        if (bigBss[i] != 0) {
            zeroed = 0;
            break;
        }
    }
    *(volatile uint16_t *)0x025012UL = zeroed ? 0x0001 : 0xDEAD;
    bigBss[0]      = 1;                                  // retain
    bigBss[0x16FF] = 2;
    *(volatile uint16_t *)0x025000UL = 0xC0DE;
    for (volatile unsigned long j = 0; j < 600000UL; j++) {
    }
    return 0;
}