#include "ch32fun.h"
#include "lwip/def.h"
#include "systick.h"

typedef uint32_t sys_prot_t;
static unsigned long next = 1;

int rand(void) {
  next = next * 1103515245 + 12345;
  return (unsigned int)(next / 65536) % 32768;
}

void srand(unsigned int seed) { next = seed; }

uint32_t sys_now(void) { return millis(); }

sys_prot_t sys_arch_protect(void) {
  unsigned int old_mstatus;
  __asm__ volatile("csrrci %0, mstatus, 8" : "=r"(old_mstatus));
  return old_mstatus;
}

void sys_arch_unprotect(sys_prot_t pval) {
  __asm__ volatile("csrw mstatus, %0" : : "r"(pval));
}