mtest.c

#include <stdio.h>
#include <stdlib.h>

#define MBYTE 1048576

int main(int argc, char** argv) {
    if (argc != 2) {
        fprintf(stderr, "usage: mtest SIZE_IN_MBYTES\n");
        return 0;
    }
    char* end;
    size_t size_mb = strtoul(argv[1], &end, 10);
    printf("test memory for %d Mbytes\n", size_mb);
    size_t size = size_mb * MBYTE;
    char* mem = malloc(size);
    if (mem == NULL) {
        fprintf(stderr, "memory allocation failed\n");
        return 0;
    }
    srand(42);
    for (size_t i = 0; i < size; ++i) {
        if ((i % MBYTE) == 0)
            printf("write %dM\n", i / MBYTE);
        mem[i] = rand() % 256;
    }
    printf("fill memory success\n");
    srand(42);
    for (size_t i = 0; i < size; ++i) {
        if (mem[i] != (rand() % 256)) {
            fprintf(stderr, "memory content not match\n");
            return 1;
        }
        if ((i % MBYTE) == 0)
            printf("verify %dM\n", i / MBYTE);
    }
    printf("test success\n");
    return 0;
}

Build command:
gcc -O2 -static -Wall -Wextra -pedantic mtest.c -o mtest

armhf binary - https://drive.google.com/file/d/153oHN84rXl00vUYPQrdvilcuchb66TWw/view?usp=sharing