Simple usage of the IOKit framework for macOS in Swift. Note: IOKit is not compatible with App Sandbox and is not suitable for the App Store.

IOKit Discovery.swift

//
//  IOKit Discovery.swift
//
//  Created by Andrew Worth Carson on 7/13/21.
//

import Foundation
import IOKit

enum CFType {
    case bool
    case string
    case any
}


func convertCFUnmanaged(_ unmanaged: Unmanaged<AnyObject>, _ type: CFType) -> Any? {
    switch type {
    case .bool:
        return convertCFUnmanagedToAny(unmanaged) as? Bool
    case .string:
        return convertCFUnmanagedToAny(unmanaged) as? String
    default:
        return convertCFUnmanagedToAny(unmanaged)
    }
}

func convertCFUnmanagedToAny(_ unmanaged: Unmanaged<AnyObject>!) -> Any {
    let value = Unmanaged<AnyObject>.fromOpaque(unmanaged.toOpaque()).takeUnretainedValue() as Any
    return value
}

func registryEntry(platform: mach_port_t, service: String, key: String, type: CFType) -> Any? {
    let ioPlatform = IOServiceGetMatchingService(0, IOServiceMatching(service))
    guard ioPlatform > 0 else {
        return nil
    }
    
    guard let ioData = IORegistryEntryCreateCFProperty(ioPlatform, key as CFString, kCFAllocatorDefault, 0) else {
        IOObjectRelease(ioPlatform)
        return nil
    }
    
    IOObjectRelease(ioPlatform)
    return convertCFUnmanaged(ioData, type)
}

func getSerialNumber() -> String {
    return registryEntry(platform: kIOMasterPortDefault, service: "IOPlatformExpertDevice", key: kIOPlatformSerialNumberKey, type: .string) as! String
}

func isSolidState() -> Bool {
    return registryEntry(platform: kIOMasterPortDefault, service: "X86PlatformPlugin", key: "BootDriveIsInternalSolidState", type: .bool) as! Bool
}

print("Serial number: \(getSerialNumber())")
print("Solid state: \(isSolidState())")