From 262d6af519c1f5bffcbe6c0e0952ce6367667ea4 Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Mon, 1 Apr 2019 17:24:15 -0700
Subject: [PATCH] bis_protect: guard against autorcm on rcm-patched units

---
 exosphere/src/fuse.c                                  |  5 +++++
 .../ams_mitm/source/fs_mitm/fsmitm_boot0storage.cpp   | 11 ++++++++++-
 stratosphere/libstratosphere                          |  2 +-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/exosphere/src/fuse.c b/exosphere/src/fuse.c
index 36ac6991f..e591cd249 100644
--- a/exosphere/src/fuse.c
+++ b/exosphere/src/fuse.c
@@ -40,6 +40,11 @@ void fuse_init(void)
     fuse_make_regs_visible();
     fuse_secondary_private_key_disable();
     fuse_disable_programming();
+    
+    /* TODO: Should we allow this to be done later? */
+    if (!g_has_checked_for_rcm_bug_patch) {
+        (void)(fuse_has_rcm_bug_patch());
+    }
 
     /* TODO: Overrides (iROM patches) and various reads happen here */
 }
diff --git a/stratosphere/ams_mitm/source/fs_mitm/fsmitm_boot0storage.cpp b/stratosphere/ams_mitm/source/fs_mitm/fsmitm_boot0storage.cpp
index f0ad46dfc..d1853fd92 100644
--- a/stratosphere/ams_mitm/source/fs_mitm/fsmitm_boot0storage.cpp
+++ b/stratosphere/ams_mitm/source/fs_mitm/fsmitm_boot0storage.cpp
@@ -24,7 +24,16 @@ static HosMutex g_boot0_mutex;
 static u8 g_boot0_bct_buffer[Boot0Storage::BctEndOffset];
 
 bool Boot0Storage::CanModifyBctPubks() {
-    return this->title_id != TitleId_Ns;
+    if (IsRcmBugPatched()) {
+        /* RCM bug patched. */
+        /* Only allow NS to update the BCT pubks. */
+        /* AutoRCM on a patched unit will cause a brick, so homebrew should NOT be allowed to write. */
+        return this->title_id == TitleId_Ns;
+    } else {
+        /* RCM bug unpatched. */
+        /* Allow homebrew but not NS to update the BCT pubks. */
+        return this->title_id != TitleId_Ns;
+    }
 }
 
 Result Boot0Storage::Read(void *_buffer, size_t size, u64 offset) {
diff --git a/stratosphere/libstratosphere b/stratosphere/libstratosphere
index 37b74c7d7..b6ca2d89a 160000
--- a/stratosphere/libstratosphere
+++ b/stratosphere/libstratosphere
@@ -1 +1 @@
-Subproject commit 37b74c7d754c6e6e73278864264940cba4f651db
+Subproject commit b6ca2d89ae5106ea21454f332f07076159ad2e92