Cannot print array using PlatformIO with RISC-V Rev B

Question

I'm trying to print arrays with 256 integers.

I used PlatformIO IDE(VSCode extension), and TeraTerm to print. Selected Board is HiFive1 Rev B(SiFive), and used Freedom E SDK framework.(Of course, I've connected Rev B board to my PC.)

Here is the structure of the array.

typedef struct {
    int32_t coeffs[N];
} poly;

where N is 256.

Then I made a simple C code below to test the structure.

int main() {
    
    poly a, b;
    printf("init poly...\n");
    for(int i = 0; i < N; i++){
        a.coeffs[i] = 0x01;
        b.coeffs[i] = 0x02;
        printf("%d: %08lX  %08lX\n", i, a.coeffs[i], b.coeffs[i]);
    }
    printf("init END...\n");

    printf("for start...\n");
    for(int j = 0; j < N; j++){
        printf("%08lX  %08lX\n", a.coeffs[j], b.coeffs[j]);
        if (j % 16 == 15) {
            printf("\n");
        }
    }
}

Here, N is 256 again.

Build and Upload have done successfully, but I got weird outputs from the code.

Here is the output printed at TeraTerm.

init poly...
0: 00000001  00000002
1: 00000001  00000002
2: 00000001  00000002
...(skipped)
188: 00000001  00000002
189: 00000001  00000002
190: 00000001  00000002
191: 00000001  00000002

As you can see, the expected output after printf("init END...\n"); did not appear. Also, the first for loop looks like 'stopped' after i=192.

I don't think the stack size cause this issue. Because I modified platformio.ini file like below.

[env:hifive1-revb]
platform = sifive
framework = freedom-e-sdk
board = hifive1-revb
monitor_speed = 115200
; Configure stack size
board_build.freedom-e-sdk.heap_size = 0x3000

So I can use 99.4% of the RAM size(used 16288 bytes from 16384 bytes).

But when I use variable a only in the main(deleting variable b), then I can get the expected outputs.

How can I solve this problem? Can't I check the outputs from several arrays with 256 entries?