fix: disable BTI (fixes #22) (#31)

Author: jprx

README.md

@@ -50,9 +50,6 @@ Currently `MACHINE_CONFIG=T8103` is not correctly building for at least `14.3`
 > [!NOTE]
 > When attempting to boot try adding the boot-arg: `sudo nvram boot-args="-unsafe_kernel_text"`
 
-> [!WARNING]
-> Booting VMAPPLE kernels in VMs only works on Apple M1s [see issue](https://github.com/blacktop/darwin-xnu-build/issues/22)
-
 ## Why? 🤔
 
 I'm hoping to patch and build the xnu source in interesting ways to aid in research and development of macOS/iOS security research tools as well as generate [CodeQL](https://securitylab.github.com/tools/codeql) databases for the community to use.

patches/15.0/disable_bti.patch

@@ -0,0 +1,16 @@
+diff --git a/pexpert/pexpert/arm64/apple_arm64_common.h b/pexpert/pexpert/arm64/apple_arm64_common.h
+index 56caa9556..460c4c4cc 100644
+--- a/pexpert/pexpert/arm64/apple_arm64_common.h
++++ b/pexpert/pexpert/arm64/apple_arm64_common.h
+@@ -89,11 +89,4 @@
+ #define CPU_VERSION_C0                       0x20
+ #define CPU_VERSION_UNKNOWN                  0xff
+ 
+-
+-/*
+- * Conservatively assume that BTI will be enforced.
+- * Individual SoCs and kernel configurations may have different behavior.
+- */
+-#define BTI_ENFORCED 1
+-
+ #endif /* !_PEXPERT_ARM64_APPLE_ARM64_COMMON_H */