xnu-4570.1.46.tar.gz

[apple/xnu.git] / bsd / dev / arm / kern_machdep.c

diff --git a/bsd/dev/arm/kern_machdep.c b/bsd/dev/arm/kern_machdep.c
new file mode 100644 (file)
index 0000000..312952a
--- /dev/null
+++ b/bsd/dev/arm/kern_machdep.c
@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
+ */
+/*
+ *     Copyright (C) 1990,  NeXT, Inc.
+ *
+ *     File:   next/kern_machdep.c
+ *     Author: John Seamons
+ *
+ *     Machine-specific kernel routines.
+ */
+
+#include       <sys/types.h>
+#include       <mach/machine.h>
+#include       <kern/cpu_number.h>
+#include       <machine/exec.h>
+
+#if __arm64__
+extern int bootarg_no64exec;   /* bsd_init.c */
+static cpu_subtype_t cpu_subtype32(void);
+#endif /* __arm64__ */
+
+#if __arm64__
+/*
+ * When an arm64 CPU is executing an arm32 binary, we need to map from the
+ * host's 64-bit subtype to the appropriate 32-bit subtype.
+ */
+static cpu_subtype_t
+cpu_subtype32()
+{
+       switch (cpu_subtype()) {
+       case CPU_SUBTYPE_ARM64_V8:
+               return CPU_SUBTYPE_ARM_V8;
+       default:
+               return 0;
+       }
+}
+#endif /* __arm64__*/
+
+/**********************************************************************
+ * Routine:    grade_binary()
+ *
+ * Function:   Return a relative preference for exectypes and
+ *             execsubtypes in fat executable files.  The higher the
+ *             grade, the higher the preference.  A grade of 0 means
+ *             not acceptable.
+ **********************************************************************/
+int
+grade_binary(cpu_type_t exectype, cpu_subtype_t execsubtype)
+{
+#if __arm64__
+       cpu_subtype_t hostsubtype = (exectype & CPU_ARCH_ABI64) ? cpu_subtype() : cpu_subtype32();
+#else
+       cpu_subtype_t hostsubtype = cpu_subtype();
+#endif /* __arm64__ */
+
+       switch (exectype) {
+#if __arm64__
+       case CPU_TYPE_ARM64:
+               if (bootarg_no64exec) return 0;
+
+               switch (hostsubtype) {
+               case CPU_SUBTYPE_ARM64_V8:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM64_V8:
+                               return 9;
+                       case CPU_SUBTYPE_ARM64_ALL:
+                               return 8;
+                       }
+                       break;
+
+
+               break;
+#else /* __arm64__ */
+
+       case CPU_TYPE_ARM:
+               switch (hostsubtype) {
+               /*
+                * For 32-bit ARMv8, try the ARMv8 slice before falling back to Swift.
+                */
+               case CPU_SUBTYPE_ARM_V8:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V8:
+                               return 7;
+                       }
+                       goto v7s;
+
+               /*
+                * For Swift and later, we prefer to run a swift slice, but fall back
+                * to v7 as Cortex A9 errata should not apply
+                */
+v7s:
+               case CPU_SUBTYPE_ARM_V7S:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V7S:
+                               return 6;
+                       }
+                       goto v7;
+
+               /*
+                * For Cortex A7, accept v7k only due to differing ABI
+                */
+               case CPU_SUBTYPE_ARM_V7K:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V7K:
+                               return 6;
+                       }
+                       break;  
+
+               /*
+                * For Cortex A9, we prefer the A9 slice, but will run v7 albeit
+                * under the risk of hitting the NEON load/store errata
+                */
+               case CPU_SUBTYPE_ARM_V7F:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V7F:
+                               return 6;
+                       }
+                       goto v7;
+
+v7:
+               case CPU_SUBTYPE_ARM_V7:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V7:
+                               return 5;
+                       }
+                       // fall through...
+
+               case CPU_SUBTYPE_ARM_V6:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V6:
+                               return 4;
+                       }
+                       // fall through...
+
+               case CPU_SUBTYPE_ARM_V5TEJ:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V5TEJ:
+                               return 3;
+                       }
+                       // fall through
+
+               case CPU_SUBTYPE_ARM_V4T:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V4T:
+                               return 2;
+                       case CPU_SUBTYPE_ARM_ALL:
+                               return 1;
+                       }
+                       break;
+
+               case CPU_SUBTYPE_ARM_XSCALE:
+                       switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_XSCALE:
+                               return 4;
+                       case CPU_SUBTYPE_ARM_V5TEJ:
+                               return 3;
+                       case CPU_SUBTYPE_ARM_V4T:
+                               return 2;
+                       case CPU_SUBTYPE_ARM_ALL:
+                               return 1;
+                       }
+                       break;
+               }
+#endif /* __arm64__ */
+       }
+
+       return 0;
+}
+
+boolean_t
+pie_required(cpu_type_t exectype, cpu_subtype_t execsubtype)
+{
+       switch (exectype) {
+#if __arm64__
+       case CPU_TYPE_ARM64:
+               return TRUE;
+#endif /* __arm64__ */
+
+       case CPU_TYPE_ARM:
+               switch (execsubtype) {
+                       case CPU_SUBTYPE_ARM_V7K:
+                               return TRUE;
+                       }
+               break;
+       }
+       return FALSE;
+}