@frozen
public struct ExceptionContext {
    public var x0: UInt64
    public var x1: UInt64
    public var x2: UInt64
    public var x3: UInt64
    public var x4: UInt64
    public var x5: UInt64
    public var x6: UInt64
    public var x7: UInt64
    public var x8: UInt64 
    public var x9: UInt64
    public var x10: UInt64
    public var x11: UInt64
    public var x12: UInt64
    public var x13: UInt64
    public var x14: UInt64
    public var x15: UInt64
    public var x16: UInt64
    public var x17: UInt64
    public var x18: UInt64
    public var x19: UInt64
    public var x20: UInt64
    public var x21: UInt64
    public var x22: UInt64
    public var x23: UInt64
    public var x24: UInt64
    public var x25: UInt64
    public var x26: UInt64
    public var x27: UInt64
    public var x28: UInt64
    public var x29: UInt64 // fp
    public var x30: UInt64 // lr
    public var elr_el1: UInt64 // pc
    public var spsr_el1: UInt64 // cpu status 
    public var esr_el1: UInt64 // error reason
}

@frozen
public enum ExceptionType: UInt64 {
    // curr el with sp0 (EL1t)
    // usually dont happen cuz we switch to sp_el1, but just in case
    case syncEL1t = 0
    case irqEL1t = 1
    case fiqEL1t = 2
    case seErrorEL1t = 3

    // curr el with sp1 (EL1h)
    // exception in kernel space
    case syncEL1h = 4
    case irqEL1h = 5
    case fiqEL1h = 6
    case seErrorEL1h = 7

    // lower EL 64-bit from userspace
    case syncEL0_64 = 8
    case irqEL0_64 = 9
    case fiqEL0_64 = 10
    case seErrorEL0_64 = 11

    // lower EL 32-bit from userspace
    case syncEL0_32 = 12
    case irqEL0_32 = 13
    case fiqEL0_32 = 14
    case seErrorEL0_32 = 15
}

@_cdecl("swift_trap_handler")
public func trapHandler(context: UnsafeMutableRawPointer, rawType: UInt64) {
    let context = context.assumingMemoryBound(to: ExceptionContext.self)
    let type = ExceptionType(rawValue: rawType)!

    panic(context: context.pointee)
}