how to download more ram

main.c

/*
 * if you need more memory, add some to your program with this cool trick
 */

#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stddef.h>
#include <stdio.h>
#include <sys/mman.h>

int main() {
  // have to open a partition on the disk, not the disk itself. so do one big disk-sized file?
  int fd = open("/dev/nvme1n1", O_RDWR);
  printf("fd: %d\n", fd);
  void* ptr = mmap(NULL, 0x1000000, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, fd, 0);
  printf("ptr: %p\n", ptr);
  int* intptr = (int*)ptr;
  printf("before: %x%x%x\n", intptr[0], intptr[1], intptr[2]);
  intptr[0] = 0x12345678;
  intptr[1] = 0xcafebabe;
  intptr[2] = intptr[2] += 1;
  printf("after:  %x%x%x\n", intptr[0], intptr[1], intptr[2]);
}