Explore the new system architecture of Apple silicon Macs

9:42 - Set up DMA transfer in a PCIe driver

// Get the IOMapper for the device
IOMapper *mapper = IOMapper::copyMapperForDevice(device);

// Use an IODMACommand; pass the mapper when initializing
IODMACommand *dmaCommand = IODMACommand::withSpecification(
   outSegFunc, numAddressBits, maxSegmentSize, mappingOptions,
   maxTransferSize, alignment, mapper, refCon);

// Keep the IODMACommand prepared for the duration of the i/o

14:31 - Check if running in Rosetta

// Use "sysctl.proc_translated" to check if running in Rosetta

// Returns 1 if running in Rosetta
int processIsTranslated() {
   int ret = 0;
   size_t size = sizeof(ret);

   // Call the sysctl and if successful return the result
   if (sysctlbyname("sysctl.proc_translated", &ret, &size, NULL, 0) != -1) 
      return ret;

   // If "sysctl.proc_translated" is not present then must be native
   if (errno == ENOENT)
      return 0;

   return -1;
}