fix(dt_fixup): correctly patch arm-io/sep/iop-sep-nub/InvalidateHmac

This adds support for pre-SPTM macOS, tested on Macmini9,1 25G70.

dt_fixup was inadvertently not patching InvalidateHmac, as
InvalidateHmac is a node, not a prop. We need to patch InvalidateHmac to
to pass invalidate_hmac in com.apple.kec.InvalidateHmac; this is
required for booting pre-SPTM macOS.

Introduce __contains__ method on ADTNode to check for the existence of
child nodes and properly handle InvalidateHmac.

Author: jprx

README.md

@@ -99,13 +99,10 @@ If you've ever compiled Linux + busybox and booted in qemu (with `-kernel` and
 | M4 Mac Mini    | `Mac16,10`   | `t8132`  | ✅                | ✅         |
 | M3 Macbook Air | `Mac15,13`   | `t8122`  | ✅                | ✅         |
 | M2 Mac Mini    | `Mac14,3`    | `t8112`  | ✅                | ✅         |
-| M1 Mac Mini    | `Macmini9,1` | `t8103`  | ✅                | ❌         |
-
+| M1 Mac Mini    | `Macmini9,1` | `t8103`  | ✅                | ✅         |
 
 ✅ = boots to root shell and can run commands
 
-❌ = panics before `launchd` / shell
-
 Notes:
 - If you don't need MIE, use something without it, as emulating MIE can be slow.
 - Occasionally the system can randomly crash during early boot; if you see a
@@ -364,7 +361,7 @@ with `darwin-vm` too.
 To boot a `development` kernel, we need to create a new kernelcache combining
 the kernel we want to use plus all the kexts for the system we're targeting.
 
-### 1. Select a Mac and macOS version. You need to know
+### 1. Select a Mac and macOS version. You need to know:
 
 - The device name of the Mac you want to use (eg. `Mac16,10` is an M4 Mac Mini).
 - The exact macOS version number to target (eg. `25G70`).

dt_fixup.py

@@ -22,6 +22,9 @@ def __getitem__(self, key):
         return c
     raise ValueError(f"key {key} not present in node {self.props['name']}")
 
+  def __contains__(self, key):
+    return any(c.props['name'] == key for c in self.children)
+
   def remove_child(self, child_name):
     for c in self.children:
       if c.props['name'] == child_name:
@@ -191,7 +194,7 @@ def fixup(d, nvram_file):
   d['chosen'].props['nvram-total-size'] = f"u32:{len(d['chosen'].props['nvram-proxy-data'])}"
   d['chosen'].props['nvram-bank-size']  = f"u32:{len(d['chosen'].props['nvram-proxy-data'])}"
 
-  if 'InvalidateHmac' in d['arm-io']['sep']['iop-sep-nub'].props:
+  if 'InvalidateHmac' in d['arm-io']['sep']['iop-sep-nub']:
     d['arm-io']['sep']['iop-sep-nub']['InvalidateHmac'].props['config'] = "u32:1"
     d['arm-io']['sep']['iop-sep-nub']['InvalidateHmac'].props['sio-hmac1-offset'] = "u64:0"
     d['arm-io']['sep']['iop-sep-nub']['InvalidateHmac'].props['sio-hmac1-disable-mask'] = "u64:0xffffffffffffffff"