#define PMC_BASE 0x7000e400
#define PMC_SCRATCH0 (PMC_BASE + 0x50)
#define PMC_SCRATCH1 (PMC_BASE + 0x54)
#define PMC_CNTRL (PMC_BASE + 0x0)

void _start() {
  __asm__ volatile("mrs r0, cpsr\n"
                   "bic r0, r0, #0x1f\n"
                   "orr r0, r0, #0x13\n"
                   "msr cpsr, r0\n");

  unsigned int *target =
      (unsigned int *)(*(volatile unsigned int *)PMC_SCRATCH1);

  if ((unsigned int)target < 0x40000000 || (unsigned int)target > 0xFFF10000) {
    target = (unsigned int *)0x40000000;
  }

  unsigned int val = *target;

  *(volatile unsigned int *)PMC_SCRATCH0 = val;
  *(volatile unsigned int *)PMC_SCRATCH1 = (unsigned int)target + 4;

  __asm__ volatile("mcr p15, 0, r0, c7, c10, 4\n");

  *(volatile unsigned int *)PMC_CNTRL |= (1 << 4);

  while (1)
    ;
}