]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/i386/i386_init.c
xnu-7195.101.1.tar.gz
[apple/xnu.git] / osfmk / i386 / i386_init.c
index 45034034c8cc9b15cbdccce61b58b56f2adf1a83..ad1f15c1f8d08cc3199a1835ed6ec0daae68b770 100644 (file)
@@ -1,68 +1,64 @@
 /*
- * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2003-2019 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
- * 
- * This file contains Original Code and/or Modifications of Original Code 
- * as defined in and that are subject to the Apple Public Source License 
- * Version 2.0 (the 'License'). You may not use this file except in 
- * compliance with the License.  The rights granted to you under the 
- * License may not be used to create, or enable the creation or 
- * redistribution of, unlawful or unlicensed copies of an Apple operating 
- * system, or to circumvent, violate, or enable the circumvention or 
- * violation of, any terms of an Apple operating system software license 
- * agreement.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
- * Please obtain a copy of the License at 
- * http://www.opensource.apple.com/apsl/ and read it before using this 
- * file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  *
- * The Original Code and all software distributed under the License are 
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
- * Please see the License for the specific language governing rights and 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
  * limitations under the License.
  *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_COPYRIGHT@
  */
-/* 
+/*
  * Mach Operating System
  * Copyright (c) 1991,1990,1989, 1988 Carnegie Mellon University
  * All Rights Reserved.
- * 
+ *
  * Permission to use, copy, modify and distribute this software and its
  * documentation is hereby granted, provided that both the copyright
  * notice and this permission notice appear in all copies of the
  * software, derivative works or modified versions, and any portions
  * thereof, and that both notices appear in supporting documentation.
- * 
+ *
  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- * 
+ *
  * Carnegie Mellon requests users of this software to return to
- * 
+ *
  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  *  School of Computer Science
  *  Carnegie Mellon University
  *  Pittsburgh PA 15213-3890
- * 
+ *
  * any improvements or extensions that they make and grant Carnegie Mellon
  * the rights to redistribute these changes.
  */
 
-#include <platforms.h>
-#include <mach_kdb.h>
-#include <himem.h>
 
 #include <mach/i386/vm_param.h>
 
 #include <string.h>
+#include <stdint.h>
 #include <mach/vm_param.h>
 #include <mach/vm_prot.h>
 #include <mach/machine.h>
 #include <kern/misc_protos.h>
 #include <kern/startup.h>
 #include <kern/clock.h>
-#include <kern/xpr.h>
+#include <kern/pms.h>
 #include <kern/cpu_data.h>
 #include <kern/processor.h>
+#include <sys/kdebug.h>
+#include <console/serial_protos.h>
 #include <vm/vm_page.h>
 #include <vm/pmap.h>
 #include <vm/vm_kern.h>
+#include <machine/pal_routines.h>
 #include <i386/fpu.h>
 #include <i386/pmap.h>
-#include <i386/ipl.h>
-#include <i386/pio.h>
 #include <i386/misc_protos.h>
+#include <i386/cpu_threads.h>
 #include <i386/cpuid.h>
+#include <i386/lapic.h>
 #include <i386/mp.h>
+#include <i386/mp_desc.h>
+#if CONFIG_MTRR
+#include <i386/mtrr.h>
+#endif
 #include <i386/machine_routines.h>
+#if CONFIG_MCA
+#include <i386/machine_check.h>
+#endif
+#include <i386/ucode.h>
 #include <i386/postcode.h>
-#if    MACH_KDB
-#include <ddb/db_aout.h>
-#endif /* MACH_KDB */
-#include <ddb/tr.h>
-#ifdef __MACHO__
-#include <mach/thread_status.h>
+#include <i386/Diagnostics.h>
+#include <i386/pmCPU.h>
+#include <i386/tsc.h>
+#include <i386/locks.h> /* LcksOpts */
+#include <i386/acpi.h>
+#if DEBUG
+#include <machine/pal_routines.h>
+#endif
+extern void xcpm_bootstrap(void);
+#if DEVELOPMENT || DEBUG
+#include <i386/trap.h>
+#endif
+
+#if MONOTONIC
+#include <kern/monotonic.h>
+#endif /* MONOTONIC */
 
-static KernelBootArgs_t *kernelBootArgs;
+#include <san/kasan.h>
+
+#if DEBUG || DEVELOPMENT
+#define DBG(x, ...)          kprintf(x, ##__VA_ARGS__)
+#define dyldLogFunc(x, ...) kprintf(x, ##__VA_ARGS__)
+#else
+#define DBG(x ...)
 #endif
 
-vm_offset_t    boot_args_start = 0;    /* pointer to kernel arguments, set in start.s */
+#include <libkern/kernel_mach_header.h>
+#include <mach/dyld_kernel_fixups.h>
+
+
+int                     debug_task;
 
-#ifdef __MACHO__
-#include       <mach-o/loader.h>
-vm_offset_t     edata, etext, end;
+int                     early_boot = 1;
 
-/* operations only against currently loaded 32 bit mach kernel */
-extern struct segment_command *getsegbyname(const char *);
-extern struct section *firstsect(struct segment_command *);
-extern struct section *nextsect(struct segment_command *, struct section *);
+bool                    serial_console_enabled = false;
+
+static boot_args        *kernelBootArgs;
+
+extern int              disableConsoleOutput;
+extern const char       version[];
+extern const char       version_variant[];
+extern int              nx_enabled;
 
 /*
- * Called first for a mach-o kernel before paging is set up.
- * Returns the first available physical address in memory.
+ * Set initial values so that ml_phys_* routines can use the booter's ID mapping
+ * to touch physical space before the kernel's physical aperture exists.
  */
+uint64_t                physmap_base = 0;
+uint64_t                physmap_max = 4 * GB;
 
-void
-i386_preinit(void)
+pd_entry_t              *KPTphys;
+pd_entry_t              *IdlePTD;
+pdpt_entry_t            *IdlePDPT;
+pml4_entry_t            *IdlePML4;
+
+int                     kernPhysPML4Index;
+int                     kernPhysPML4EntryCount;
+
+/*
+ * These are 4K mapping page table pages from KPTphys[] that we wound
+ * up not using. They get ml_static_mfree()'d once the VM is initialized.
+ */
+ppnum_t                 released_PT_ppn = 0;
+uint32_t                released_PT_cnt = 0;
+
+#if DEVELOPMENT || DEBUG
+int panic_on_cacheline_mismatch = -1;
+char panic_on_trap_procname[64];
+uint32_t panic_on_trap_mask;
+#endif
+bool last_branch_support_enabled;
+int insn_copyin_count;
+#if DEVELOPMENT || DEBUG
+#define DEFAULT_INSN_COPYIN_COUNT x86_INSTRUCTION_STATE_MAX_INSN_BYTES
+#else
+#define DEFAULT_INSN_COPYIN_COUNT 192
+#endif
+
+char *physfree;
+void idt64_remap(void);
+
+/*
+ * Note: ALLOCPAGES() can only be used safely within Idle_PTs_init()
+ * due to the mutation of physfree.
+ */
+static void *
+ALLOCPAGES(int npages)
+{
+       uintptr_t tmp = (uintptr_t)physfree;
+       bzero(physfree, npages * PAGE_SIZE);
+       physfree += npages * PAGE_SIZE;
+       tmp += VM_MIN_KERNEL_ADDRESS & ~LOW_4GB_MASK;
+       return (void *)tmp;
+}
+
+static void
+fillkpt(pt_entry_t *base, int prot, uintptr_t src, int index, int count)
 {
-       struct segment_command  *sgp;
-       struct section          *sp;
-       struct KernelBootArgs *pp;
        int i;
+       for (i = 0; i < count; i++) {
+               base[index] = src | prot | INTEL_PTE_VALID;
+               src += PAGE_SIZE;
+               index++;
+       }
+}
+
+extern pmap_paddr_t first_avail;
+
+int break_kprintf = 0;
+
+uint64_t
+x86_64_pre_sleep(void)
+{
+       IdlePML4[0] = IdlePML4[KERNEL_PML4_INDEX];
+       uint64_t oldcr3 = get_cr3_raw();
+       set_cr3_raw((uint32_t) (uintptr_t)ID_MAP_VTOP(IdlePML4));
+       return oldcr3;
+}
+
+void
+x86_64_post_sleep(uint64_t new_cr3)
+{
+       IdlePML4[0] = 0;
+       set_cr3_raw((uint32_t) new_cr3);
+}
+
+
+
+
+// Set up the physical mapping - NPHYSMAP GB of memory mapped at a high address
+// NPHYSMAP is determined by the maximum supported RAM size plus 4GB to account
+// the PCI hole (which is less 4GB but not more).
 
-       sgp = getsegbyname("__DATA");
-       if (sgp) {
-               sp = firstsect(sgp);
-               if (sp) {
-                       do {
-                               if ((sp->flags & S_ZEROFILL))
-                                       bzero((char *) sp->addr, sp->size);
-                       } while ((sp = nextsect(sgp, sp)));
+static int
+physmap_init_L2(uint64_t *physStart, pt_entry_t **l2ptep)
+{
+       unsigned i;
+       pt_entry_t *physmapL2 = ALLOCPAGES(1);
+
+       if (physmapL2 == NULL) {
+               DBG("physmap_init_L2 page alloc failed when initting L2 for physAddr 0x%llx.\n", *physStart);
+               *l2ptep = NULL;
+               return -1;
+       }
+
+       for (i = 0; i < NPDPG; i++) {
+               physmapL2[i] = *physStart
+                   | INTEL_PTE_PS
+                   | INTEL_PTE_VALID
+                   | INTEL_PTE_NX
+                   | INTEL_PTE_WRITE;
+
+               *physStart += NBPD;
+       }
+       *l2ptep = physmapL2;
+       return 0;
+}
+
+static int
+physmap_init_L3(int startIndex, uint64_t highest_phys, uint64_t *physStart, pt_entry_t **l3ptep)
+{
+       unsigned i;
+       int ret;
+       pt_entry_t *l2pte;
+       pt_entry_t *physmapL3 = ALLOCPAGES(1);  /* ALLOCPAGES bzeroes the memory */
+
+       if (physmapL3 == NULL) {
+               DBG("physmap_init_L3 page alloc failed when initting L3 for  physAddr 0x%llx.\n", *physStart);
+               *l3ptep = NULL;
+               return -1;
+       }
+
+       for (i = startIndex; i < NPDPTPG && *physStart < highest_phys; i++) {
+               if ((ret = physmap_init_L2(physStart, &l2pte)) < 0) {
+                       return ret;
                }
+
+               physmapL3[i] =  ((uintptr_t)ID_MAP_VTOP(l2pte))
+                   | INTEL_PTE_VALID
+                   | INTEL_PTE_NX
+                   | INTEL_PTE_WRITE;
+       }
+
+       *l3ptep = physmapL3;
+
+       return 0;
+}
+
+static void
+physmap_init(uint8_t phys_random_L3, uint64_t *new_physmap_base, uint64_t *new_physmap_max)
+{
+       pt_entry_t *l3pte;
+       int pml4_index, i;
+       int L3_start_index;
+       uint64_t physAddr = 0;
+       uint64_t highest_physaddr;
+       unsigned pdpte_count;
+
+#if DEVELOPMENT || DEBUG
+       if (kernelBootArgs->PhysicalMemorySize > K64_MAXMEM) {
+               panic("Installed physical memory exceeds configured maximum.");
+       }
+#endif
+
+       /*
+        * Add 4GB to the loader-provided physical memory size to account for MMIO space
+        * XXX in a perfect world, we'd scan PCI buses and count the max memory requested in BARs by
+        * XXX all enumerated device, then add more for hot-pluggable devices.
+        */
+       highest_physaddr = kernelBootArgs->PhysicalMemorySize + 4 * GB;
+
+       /*
+        * Calculate the number of PML4 entries we'll need.  The total number of entries is
+        * pdpte_count = (((highest_physaddr) >> PDPT_SHIFT) + entropy_value +
+        *               ((highest_physaddr & PDPT_MASK) == 0 ? 0 : 1))
+        * pml4e_count = pdpte_count >> (PML4_SHIFT - PDPT_SHIFT)
+        */
+       assert(highest_physaddr < (UINT64_MAX - PDPTMASK));
+       pdpte_count = (unsigned) (((highest_physaddr + PDPTMASK) >> PDPTSHIFT) + phys_random_L3);
+       kernPhysPML4EntryCount = (pdpte_count + ((1U << (PML4SHIFT - PDPTSHIFT)) - 1)) >> (PML4SHIFT - PDPTSHIFT);
+       if (kernPhysPML4EntryCount == 0) {
+               kernPhysPML4EntryCount = 1;
+       }
+       if (kernPhysPML4EntryCount > KERNEL_PHYSMAP_PML4_COUNT_MAX) {
+#if DEVELOPMENT || DEBUG
+               panic("physmap too large");
+#else
+               kprintf("[pmap] Limiting physmap to %d PML4s (was %d)\n", KERNEL_PHYSMAP_PML4_COUNT_MAX,
+                   kernPhysPML4EntryCount);
+               kernPhysPML4EntryCount = KERNEL_PHYSMAP_PML4_COUNT_MAX;
+#endif
        }
 
-       kernelBootArgs = (KernelBootArgs_t *)
-               ml_static_ptovirt(boot_args_start);
-       pp = (struct KernelBootArgs *) kernelBootArgs;
-       pp->configEnd = (char *)
-               ml_static_ptovirt((vm_offset_t) pp->configEnd);
-       for (i = 0; i < pp->numBootDrivers; i++) {
-               pp->driverConfig[i].address = (unsigned)
-                       ml_static_ptovirt(pp->driverConfig[i].address);
+       kernPhysPML4Index = KERNEL_KEXTS_INDEX - kernPhysPML4EntryCount;        /* utb: KERNEL_PHYSMAP_PML4_INDEX */
+
+       /*
+        * XXX: Make sure that the addresses returned for physmapL3 and physmapL2 plus their extents
+        * are in the system-available memory range
+        */
+
+
+       /* We assume NX support. Mark all levels of the PHYSMAP NX
+        * to avoid granting executability via a single bit flip.
+        */
+#if DEVELOPMENT || DEBUG
+       uint32_t reg[4];
+       do_cpuid(0x80000000, reg);
+       if (reg[eax] >= 0x80000001) {
+               do_cpuid(0x80000001, reg);
+               assert(reg[edx] & CPUID_EXTFEATURE_XD);
+       }
+#endif /* DEVELOPMENT || DEBUG */
+
+       L3_start_index = phys_random_L3;
+
+       for (pml4_index = kernPhysPML4Index;
+           pml4_index < (kernPhysPML4Index + kernPhysPML4EntryCount) && physAddr < highest_physaddr;
+           pml4_index++) {
+               if (physmap_init_L3(L3_start_index, highest_physaddr, &physAddr, &l3pte) < 0) {
+                       panic("Physmap page table initialization failed");
+                       /* NOTREACHED */
+               }
+
+               L3_start_index = 0;
+
+               IdlePML4[pml4_index] = ((uintptr_t)ID_MAP_VTOP(l3pte))
+                   | INTEL_PTE_VALID
+                   | INTEL_PTE_NX
+                   | INTEL_PTE_WRITE;
+       }
+
+       *new_physmap_base = KVADDR(kernPhysPML4Index, phys_random_L3, 0, 0);
+       /*
+        * physAddr contains the last-mapped physical address, so that's what we
+        * add to physmap_base to derive the ending VA for the physmap.
+        */
+       *new_physmap_max = *new_physmap_base + physAddr;
+
+       DBG("Physical address map base: 0x%qx\n", *new_physmap_base);
+       for (i = kernPhysPML4Index; i < (kernPhysPML4Index + kernPhysPML4EntryCount); i++) {
+               DBG("Physical map idlepml4[%d]: 0x%llx\n", i, IdlePML4[i]);
        }
-       return;
 }
+
+void doublemap_init(uint8_t);
+
+static void
+Idle_PTs_init(void)
+{
+       uint64_t        rand64;
+       uint64_t        new_physmap_base, new_physmap_max;
+
+       /* Allocate the "idle" kernel page tables: */
+       KPTphys  = ALLOCPAGES(NKPT);            /* level 1 */
+       IdlePTD  = ALLOCPAGES(NPGPTD);          /* level 2 */
+       IdlePDPT = ALLOCPAGES(1);               /* level 3 */
+       IdlePML4 = ALLOCPAGES(1);               /* level 4 */
+
+       // Fill the lowest level with everything up to physfree
+       fillkpt(KPTphys,
+           INTEL_PTE_WRITE, 0, 0, (int)(((uintptr_t)physfree) >> PAGE_SHIFT));
+
+       /* IdlePTD */
+       fillkpt(IdlePTD,
+           INTEL_PTE_WRITE, (uintptr_t)ID_MAP_VTOP(KPTphys), 0, NKPT);
+
+       // IdlePDPT entries
+       fillkpt(IdlePDPT,
+           INTEL_PTE_WRITE, (uintptr_t)ID_MAP_VTOP(IdlePTD), 0, NPGPTD);
+
+       // IdlePML4 single entry for kernel space.
+       fillkpt(IdlePML4 + KERNEL_PML4_INDEX,
+           INTEL_PTE_WRITE, (uintptr_t)ID_MAP_VTOP(IdlePDPT), 0, 1);
+
+       postcode(VSTART_PHYSMAP_INIT);
+
+       /*
+        * early_random() cannot be called more than one time before the cpu's
+        * gsbase is initialized, so use the full 64-bit value to extract the
+        * two 8-bit entropy values needed for address randomization.
+        */
+       rand64 = early_random();
+       physmap_init(rand64 & 0xFF, &new_physmap_base, &new_physmap_max);
+       doublemap_init((rand64 >> 8) & 0xFF);
+       idt64_remap();
+
+       postcode(VSTART_SET_CR3);
+
+       /*
+        * Switch to the page tables. We set physmap_base and physmap_max just
+        * before switching to the new page tables to avoid someone calling
+        * kprintf() or otherwise using physical memory in between.
+        * This is needed because kprintf() writes to physical memory using
+        * ml_phys_read_data and PHYSMAP_PTOV, which requires physmap_base to be
+        * set correctly.
+        */
+       physmap_base = new_physmap_base;
+       physmap_max = new_physmap_max;
+       set_cr3_raw((uintptr_t)ID_MAP_VTOP(IdlePML4));
+}
+
+/*
+ * Release any still unused, preallocated boot kernel page tables.
+ * start..end is the VA range currently unused.
+ */
+void
+Idle_PTs_release(vm_offset_t start, vm_offset_t end)
+{
+       uint32_t i;
+       uint32_t index_start;
+       uint32_t index_limit;
+       ppnum_t pn_first;
+       ppnum_t pn;
+       uint32_t cnt;
+
+       /*
+        * Align start to the next large page boundary
+        */
+       start = ((start + I386_LPGMASK) & ~I386_LPGMASK);
+
+       /*
+        * convert start into an index in KPTphys[]
+        */
+       index_start = (uint32_t)((start - KERNEL_BASE) >> PAGE_SHIFT);
+
+       /*
+        * Find the ending index in KPTphys[]
+        */
+       index_limit = (uint32_t)((end - KERNEL_BASE) >> PAGE_SHIFT);
+
+       if (index_limit > NKPT * PTE_PER_PAGE) {
+               index_limit = NKPT * PTE_PER_PAGE;
+       }
+
+       /*
+        * Make sure all the 4K page tables are empty.
+        * If not, panic a development/debug kernel.
+        * On a production kernel, since this would stop us from booting,
+        * just abort the operation.
+        */
+       for (i = index_start; i < index_limit; ++i) {
+               assert(KPTphys[i] == 0);
+               if (KPTphys[i] != 0) {
+                       return;
+               }
+       }
+
+       /*
+        * Now figure out the indices into the 2nd level page tables, IdlePTD[].
+        */
+       index_start >>= PTPGSHIFT;
+       index_limit >>= PTPGSHIFT;
+       if (index_limit > NPGPTD * PTE_PER_PAGE) {
+               index_limit = NPGPTD * PTE_PER_PAGE;
+       }
+
+       if (index_limit <= index_start) {
+               return;
+       }
+
+
+       /*
+        * Now check the pages referenced from Level 2 tables.
+        * They should be contiguous, assert fail if not on development/debug.
+        * In production, just fail the removal to allow the system to boot.
+        */
+       pn_first = 0;
+       cnt = 0;
+       for (i = index_start; i < index_limit; ++i) {
+               assert(IdlePTD[i] != 0);
+               if (IdlePTD[i] == 0) {
+                       return;
+               }
+
+               pn = (ppnum_t)((PG_FRAME & IdlePTD[i]) >> PTSHIFT);
+               if (cnt == 0) {
+                       pn_first = pn;
+               } else {
+                       assert(pn == pn_first + cnt);
+                       if (pn != pn_first + cnt) {
+                               return;
+                       }
+               }
+               ++cnt;
+       }
+
+       /*
+        * Good to go, clear the level 2 entries and invalidate the TLB
+        */
+       for (i = index_start; i < index_limit; ++i) {
+               IdlePTD[i] = 0;
+       }
+       set_cr3_raw(get_cr3_raw());
+
+       /*
+        * Remember these PFNs to be released later in pmap_lowmem_finalize()
+        */
+       released_PT_ppn = pn_first;
+       released_PT_cnt = cnt;
+#if DEVELOPMENT || DEBUG
+       printf("Idle_PTs_release %d pages from PFN 0x%x\n", released_PT_cnt, released_PT_ppn);
 #endif
+}
 
-extern const char version[];
-extern const char version_variant[];
+extern void vstart_trap_handler;
+
+#define BOOT_TRAP_VECTOR(t)                             \
+       [t] = {                                         \
+               (uintptr_t) &vstart_trap_handler,       \
+               KERNEL64_CS,                            \
+               0,                                      \
+               ACC_P|ACC_PL_K|ACC_INTR_GATE,           \
+               0                                       \
+       },
+
+/* Recursive macro to iterate 0..31 */
+#define L0(x, n)  x(n)
+#define L1(x, n)  L0(x,n-1)     L0(x,n)
+#define L2(x, n)  L1(x,n-2)     L1(x,n)
+#define L3(x, n)  L2(x,n-4)     L2(x,n)
+#define L4(x, n)  L3(x,n-8)     L3(x,n)
+#define L5(x, n)  L4(x,n-16)    L4(x,n)
+#define FOR_0_TO_31(x) L5(x,31)
+
+/*
+ * Bootstrap IDT. Active only during early startup.
+ * Only the trap vectors are defined since interrupts are masked.
+ * All traps point to a common handler.
+ */
+struct fake_descriptor64 master_boot_idt64[IDTSZ]
+__attribute__((section("__HIB,__desc")))
+__attribute__((aligned(PAGE_SIZE))) = {
+       FOR_0_TO_31(BOOT_TRAP_VECTOR)
+};
+
+static void
+vstart_idt_init(boolean_t master)
+{
+       x86_64_desc_register_t  vstart_idt = {
+               sizeof(master_boot_idt64),
+               master_boot_idt64
+       };
+
+       if (master) {
+               fix_desc64(master_boot_idt64, 32);
+       }
+       lidt((void *)&vstart_idt);
+}
+
+extern void *collection_base_pointers[KCNumKinds];
+
+kern_return_t
+i386_slide_individual_kext(kernel_mach_header_t *mh, uintptr_t slide)
+{
+       int ret = kernel_collection_slide(mh, (const void **) (void *)collection_base_pointers);
+       if (ret != 0) {
+               printf("Sliding pageable kc was stopped\n");
+               return KERN_FAILURE;
+       }
+
+       kernel_collection_adjust_fileset_entry_addrs(mh, slide);
+       return KERN_SUCCESS;
+}
+
+kern_return_t
+i386_slide_kext_collection_mh_addrs(kernel_mach_header_t *mh, uintptr_t slide, bool adjust_mach_headers)
+{
+       int ret = kernel_collection_slide(mh, (const void **) (void *)collection_base_pointers);
+       if (ret != KERN_SUCCESS) {
+               printf("Kernel Collection slide was stopped with value %d\n", ret);
+               return KERN_FAILURE;
+       }
+
+       kernel_collection_adjust_mh_addrs(mh, slide, adjust_mach_headers,
+           NULL, NULL, NULL, NULL, NULL, NULL, NULL);
+
+       return KERN_SUCCESS;
+}
+
+static void
+i386_slide_and_rebase_image(uintptr_t kstart_addr)
+{
+       extern uintptr_t kc_highest_nonlinkedit_vmaddr;
+       kernel_mach_header_t *k_mh, *kc_mh = NULL;
+       kernel_segment_command_t *seg;
+       uintptr_t slide;
+
+       k_mh = &_mh_execute_header;
+       /*
+        * If we're not booting, an MH_FILESET, we don't need to slide
+        * anything because EFI has done that for us. When booting an
+        * MH_FILESET, EFI will slide the kernel proper, but not the kexts.
+        * Below, we infer the slide by comparing the slid address of the
+        * kernel's mach-o header and the unslid vmaddr of the first segment
+        * of the mach-o (which is assumed to always point to the mach-o
+        * header).
+        */
+       if (!kernel_mach_header_is_in_fileset(k_mh)) {
+               DBG("[MH] kcgen-style KC\n");
+               return;
+       }
+
+       /*
+        * The kernel is part of a MH_FILESET kernel collection: determine slide
+        * based on first segment's mach-o vmaddr.
+        */
+       seg = (kernel_segment_command_t *)((uintptr_t)k_mh + sizeof(*k_mh));
+       assert(seg->cmd == LC_SEGMENT_KERNEL);
+       slide = (uintptr_t)k_mh - seg->vmaddr;
+       DBG("[MH] Sliding new-style KC: %llu\n", (unsigned long long)slide);
+
+       /*
+        * The kernel collection mach-o header should be the start address
+        * passed to us by EFI.
+        */
+       kc_mh  = (kernel_mach_header_t *)(kstart_addr);
+       assert(kc_mh->filetype == MH_FILESET);
+
+       PE_set_kc_header(KCKindPrimary, kc_mh, slide);
+
+       /*
+        * rebase/slide all the kexts in the collection
+        * (EFI should have already rebased the kernel)
+        */
+       kernel_collection_slide(kc_mh, (const void **) (void *)collection_base_pointers);
+
+
+       /*
+        * Now adjust the vmaddr fields of all mach-o headers
+        * and symbols in this MH_FILESET
+        */
+       kernel_collection_adjust_mh_addrs(kc_mh, slide, false,
+           NULL, NULL, NULL, NULL, NULL, NULL, &kc_highest_nonlinkedit_vmaddr);
+}
+
+/*
+ * vstart() is called in the natural mode (64bit for K64, 32 for K32)
+ * on a set of bootstrap pagetables which use large, 2MB pages to map
+ * all of physical memory in both. See idle_pt.c for details.
+ *
+ * In K64 this identity mapping is mirrored the top and bottom 512GB
+ * slots of PML4.
+ *
+ * The bootstrap processor called with argument boot_args_start pointing to
+ * the boot-args block. The kernel's (4K page) page tables are allocated and
+ * initialized before switching to these.
+ *
+ * Non-bootstrap processors are called with argument boot_args_start NULL.
+ * These processors switch immediately to the existing kernel page tables.
+ */
+__attribute__((noreturn))
+void
+vstart(vm_offset_t boot_args_start)
+{
+       boolean_t       is_boot_cpu = !(boot_args_start == 0);
+       int             cpu = 0;
+       uint32_t        lphysfree;
+#if DEBUG
+       uint64_t        gsbase;
+#endif
+
+
+       postcode(VSTART_ENTRY);
+
+       /*
+        * Set-up temporary trap handlers during page-table set-up.
+        */
+
+       if (is_boot_cpu) {
+               vstart_idt_init(TRUE);
+               postcode(VSTART_IDT_INIT);
+
+               /*
+                * Ensure that any %gs-relative access results in an immediate fault
+                * until gsbase is properly initialized below
+                */
+               wrmsr64(MSR_IA32_GS_BASE, EARLY_GSBASE_MAGIC);
+
+               /*
+                * Get startup parameters.
+                */
+               kernelBootArgs = (boot_args *)boot_args_start;
+               lphysfree = kernelBootArgs->kaddr + kernelBootArgs->ksize;
+               physfree = (void *)(uintptr_t)((lphysfree + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1));
+
+               pal_serial_init();
+
+               DBG("revision      0x%x\n", kernelBootArgs->Revision);
+               DBG("version       0x%x\n", kernelBootArgs->Version);
+               DBG("command line  %s\n", kernelBootArgs->CommandLine);
+               DBG("memory map    0x%x\n", kernelBootArgs->MemoryMap);
+               DBG("memory map sz 0x%x\n", kernelBootArgs->MemoryMapSize);
+               DBG("kaddr         0x%x\n", kernelBootArgs->kaddr);
+               DBG("ksize         0x%x\n", kernelBootArgs->ksize);
+               DBG("physfree      %p\n", physfree);
+               DBG("bootargs: %p, &ksize: %p &kaddr: %p\n",
+                   kernelBootArgs,
+                   &kernelBootArgs->ksize,
+                   &kernelBootArgs->kaddr);
+               DBG("SMBIOS mem sz 0x%llx\n", kernelBootArgs->PhysicalMemorySize);
+               DBG("KC_hdrs_vaddr %p\n", (void *)kernelBootArgs->KC_hdrs_vaddr);
+
+               if (kernelBootArgs->Version >= 2 && kernelBootArgs->Revision >= 1 &&
+                   kernelBootArgs->KC_hdrs_vaddr != 0) {
+                       /*
+                        * slide the header addresses in all mach-o segments and sections, and
+                        * perform any new-style chained-fixup sliding for kexts, as necessary.
+                        * Note that efiboot has already loaded the kernel and all LC_SEGMENT_64s
+                        * that correspond to the kexts present in the primary KC, into slid addresses.
+                        */
+                       i386_slide_and_rebase_image((uintptr_t)ml_static_ptovirt(kernelBootArgs->KC_hdrs_vaddr));
+               }
+
+               /*
+                * Setup boot args given the physical start address.
+                * Note: PE_init_platform needs to be called before Idle_PTs_init
+                * because access to the DeviceTree is required to read the
+                * random seed before generating a random physical map slide.
+                */
+               kernelBootArgs = (boot_args *)
+                   ml_static_ptovirt(boot_args_start);
+               DBG("i386_init(0x%lx) kernelBootArgs=%p\n",
+                   (unsigned long)boot_args_start, kernelBootArgs);
+
+#if KASAN
+               kasan_reserve_memory(kernelBootArgs);
+#endif
+
+               PE_init_platform(FALSE, kernelBootArgs);
+               postcode(PE_INIT_PLATFORM_D);
+
+               Idle_PTs_init();
+               postcode(VSTART_IDLE_PTS_INIT);
+
+#if KASAN
+               /* Init kasan and map whatever was stolen from physfree */
+               kasan_init();
+               kasan_notify_stolen((uintptr_t)ml_static_ptovirt((vm_offset_t)physfree));
+#endif
+
+#if MONOTONIC
+               mt_early_init();
+#endif /* MONOTONIC */
+
+               first_avail = (vm_offset_t)ID_MAP_VTOP(physfree);
+
+               cpu_data_alloc(TRUE);
+
+               cpu_desc_init(cpu_datap(0));
+               postcode(VSTART_CPU_DESC_INIT);
+               cpu_desc_load(cpu_datap(0));
+
+               postcode(VSTART_CPU_MODE_INIT);
+               cpu_syscall_init(cpu_datap(0)); /* cpu_syscall_init() will be
+                                                * invoked on the APs
+                                                * via i386_init_slave()
+                                                */
+       } else {
+               /* Slave CPUs should use the basic IDT until i386_init_slave() */
+               vstart_idt_init(FALSE);
+
+               /* Switch to kernel's page tables (from the Boot PTs) */
+               set_cr3_raw((uintptr_t)ID_MAP_VTOP(IdlePML4));
+
+               /* Find our logical cpu number */
+               cpu = lapic_to_cpu[lapic_safe_apicid()];
+#if DEBUG
+               gsbase = rdmsr64(MSR_IA32_GS_BASE);
+#endif
+               cpu_desc_load(cpu_datap(cpu));
+#if DEBUG
+               DBG("CPU: %d, GSBASE initial value: 0x%llx\n", cpu, (unsigned long long)gsbase);
+#endif
+
+               /*
+                * Before we can discover our local APIC ID, we need to potentially
+                * initialize X2APIC, if it's enabled and firmware started us with
+                * the APIC in legacy mode.
+                */
+               lapic_init_slave();
+       }
+
+       early_boot = 0;
+       postcode(VSTART_EXIT);
+       x86_init_wrapper(is_boot_cpu ? (uintptr_t) i386_init
+           : (uintptr_t) i386_init_slave,
+           cpu_datap(cpu)->cpu_int_stack_top);
+}
+
+void
+pstate_trace(void)
+{
+}
 
 /*
  *     Cpu initialization.  Running virtual, but without MACH VM
- *     set up.  First C routine called, unless i386_preinit() was called first.
+ *     set up.
  */
 void
 i386_init(void)
 {
-       unsigned int    maxmem;
-       unsigned int    cpus;
+       unsigned int    maxmem;
+       uint64_t        maxmemtouse;
+       unsigned int    cpus = 0;
+       boolean_t       fidn;
+       boolean_t       IA32e = TRUE;
 
        postcode(I386_INIT_ENTRY);
 
-       master_cpu = 0;
-       cpu_data_alloc(TRUE);
-       cpu_init();
-       postcode(CPU_INIT_D);
+       pal_i386_init();
+       tsc_init();
+       rtclock_early_init();   /* mach_absolute_time() now functional */
 
-       /*
-        * Setup some processor related structures to satisfy funnels.
-        * Must be done before using unparallelized device drivers.
-        */
-       processor_bootstrap();
+       kernel_debug_string_early("i386_init");
+       pstate_trace();
 
-       PE_init_platform(FALSE, kernelBootArgs);
-       postcode(PE_INIT_PLATFORM_D);
+#if CONFIG_MCA
+       /* Initialize machine-check handling */
+       mca_cpu_init();
+#endif
+
+       master_cpu = 0;
+
+       kernel_debug_string_early("kernel_startup_bootstrap");
+       kernel_startup_bootstrap();
 
        /*
-        * Set up initial thread so current_thread() works early on
+        * Initialize the timer callout world
         */
-       thread_bootstrap();
-       postcode(THREAD_BOOTSTRAP_D);
+       timer_call_init();
+
+       cpu_init();
 
-       printf_init();                  /* Init this in case we need debugger */
-       panic_init();                   /* Init this in case we need debugger */
+       postcode(CPU_INIT_D);
 
        /* setup debugging output if one has been chosen */
-       PE_init_kprintf(FALSE);
+       kernel_startup_initialize_upto(STARTUP_SUB_KPRINTF);
+       kprintf("kprintf initialized\n");
+
+       if (!PE_parse_boot_argn("diag", &dgWork.dgFlags, sizeof(dgWork.dgFlags))) {
+               dgWork.dgFlags = 0;
+       }
+
+       if (PE_parse_boot_argn("insn_capcnt", &insn_copyin_count, sizeof(insn_copyin_count))) {
+               /*
+                * Enforce max and min values (allowing 0 to disable copying completely)
+                * for the instruction copyin count
+                */
+               if (insn_copyin_count > x86_INSTRUCTION_STATE_MAX_INSN_BYTES ||
+                   (insn_copyin_count != 0 && insn_copyin_count < 64)) {
+                       insn_copyin_count = DEFAULT_INSN_COPYIN_COUNT;
+               }
+       } else {
+               insn_copyin_count = DEFAULT_INSN_COPYIN_COUNT;
+       }
+
+#if DEVELOPMENT || DEBUG
+       if (!PE_parse_boot_argn("panic_clmismatch", &panic_on_cacheline_mismatch,
+           sizeof(panic_on_cacheline_mismatch))) {
+               panic_on_cacheline_mismatch = 0;
+       }
+
+       if (!PE_parse_boot_argn("panic_on_trap_procname", &panic_on_trap_procname[0],
+           sizeof(panic_on_trap_procname))) {
+               panic_on_trap_procname[0] = 0;
+       }
+
+       if (!PE_parse_boot_argn("panic_on_trap_mask", &panic_on_trap_mask,
+           sizeof(panic_on_trap_mask))) {
+               if (panic_on_trap_procname[0] != 0) {
+                       panic_on_trap_mask = DEFAULT_PANIC_ON_TRAP_MASK;
+               } else {
+                       panic_on_trap_mask = 0;
+               }
+       }
+#endif
+       /* But allow that to be overridden via boot-arg: */
+       if (!PE_parse_boot_argn("lbr_support", &last_branch_support_enabled,
+           sizeof(last_branch_support_enabled))) {
+               /* Disable LBR support by default due to its high context switch overhead */
+               last_branch_support_enabled = false;
+       }
+
+       serialmode = 0;
+       if (PE_parse_boot_argn("serial", &serialmode, sizeof(serialmode))) {
+               /* We want a serial keyboard and/or console */
+               kprintf("Serial mode specified: %08X\n", serialmode);
+               int force_sync = serialmode & SERIALMODE_SYNCDRAIN;
+               if (force_sync || PE_parse_boot_argn("drain_uart_sync", &force_sync, sizeof(force_sync))) {
+                       if (force_sync) {
+                               serialmode |= SERIALMODE_SYNCDRAIN;
+                               kprintf(
+                                       "WARNING: Forcing uart driver to output synchronously."
+                                       "printf()s/IOLogs will impact kernel performance.\n"
+                                       "You are advised to avoid using 'drain_uart_sync' boot-arg.\n");
+                       }
+               }
+       }
+       if (serialmode & SERIALMODE_OUTPUT) {
+               serial_console_enabled = true;
+               (void)switch_to_serial_console();
+               disableConsoleOutput = FALSE; /* Allow printfs to happen */
+       }
 
        /* setup console output */
+       kernel_debug_string_early("PE_init_printf");
        PE_init_printf(FALSE);
 
        kprintf("version_variant = %s\n", version_variant);
        kprintf("version         = %s\n", version);
 
-       /*   
-        * VM initialization, after this we're using page tables...
-        * The maximum number of cpus must be set beforehand.
+       if (!PE_parse_boot_argn("maxmem", &maxmem, sizeof(maxmem))) {
+               maxmemtouse = 0;
+       } else {
+               maxmemtouse = ((uint64_t)maxmem) * MB;
+       }
+
+       max_cpus_from_firmware = acpi_count_enabled_logical_processors();
+
+       if (PE_parse_boot_argn("cpus", &cpus, sizeof(cpus))) {
+               if ((0 < cpus) && (cpus < max_ncpus)) {
+                       max_ncpus = cpus;
+               }
+       }
+
+       /*
+        * debug support for > 4G systems
         */
-       if (!PE_parse_boot_arg("maxmem", &maxmem))
-               maxmem=0;
-       else
-               maxmem = maxmem * (1024 * 1024);
+       PE_parse_boot_argn("himemory_mode", &vm_himemory_mode, sizeof(vm_himemory_mode));
+       if (!vm_himemory_mode) {
+               kprintf("himemory_mode disabled\n");
+       }
 
-       if (PE_parse_boot_arg("cpus", &cpus)) {
-               if ((0 < cpus) && (cpus < max_ncpus))
-                        max_ncpus = cpus;
+       if (!PE_parse_boot_argn("immediate_NMI", &fidn, sizeof(fidn))) {
+               force_immediate_debugger_NMI = FALSE;
+       } else {
+               force_immediate_debugger_NMI = fidn;
        }
 
-       i386_vm_init(maxmem, kernelBootArgs);
+#if DEBUG
+       nanoseconds_to_absolutetime(URGENCY_NOTIFICATION_ASSERT_NS, &urgency_notification_assert_abstime_threshold);
+#endif
+       PE_parse_boot_argn("urgency_notification_abstime",
+           &urgency_notification_assert_abstime_threshold,
+           sizeof(urgency_notification_assert_abstime_threshold));
+
+       if (!(cpuid_extfeatures() & CPUID_EXTFEATURE_XD)) {
+               nx_enabled = 0;
+       }
 
-       PE_init_platform(TRUE, kernelBootArgs);
+       /*
+        * VM initialization, after this we're using page tables...
+        * Thn maximum number of cpus must be set beforehand.
+        */
+       kernel_debug_string_early("i386_vm_init");
+       i386_vm_init(maxmemtouse, IA32e, kernelBootArgs);
 
        /* create the console for verbose or pretty mode */
+       /* Note: doing this prior to tsc_init() allows for graceful panic! */
+       PE_init_platform(TRUE, kernelBootArgs);
        PE_create_console();
 
+       kernel_debug_string_early("power_management_init");
+       power_management_init();
+       xcpm_bootstrap();
+
+#if MONOTONIC
+       mt_cpu_up(cpu_datap(0));
+#endif /* MONOTONIC */
+
+       processor_bootstrap();
+       thread_t thread = thread_bootstrap();
+       machine_set_current_thread(thread);
+
+       pstate_trace();
+       kernel_debug_string_early("machine_startup");
        machine_startup();
+       pstate_trace();
+}
+
+static void __dead2
+do_init_slave(boolean_t fast_restart)
+{
+       void    *init_param     = FULL_SLAVE_INIT;
+
+       postcode(I386_INIT_SLAVE);
+
+       if (!fast_restart) {
+               /* Ensure that caching and write-through are enabled */
+               set_cr0(get_cr0() & ~(CR0_NW | CR0_CD));
+
+               DBG("i386_init_slave() CPU%d: phys (%d) active.\n",
+                   get_cpu_number(), get_cpu_phys_number());
+
+               assert(!ml_get_interrupts_enabled());
+
+               cpu_syscall_init(current_cpu_datap());
+               pmap_cpu_init();
+
+#if CONFIG_MCA
+               mca_cpu_init();
+#endif
+
+               LAPIC_INIT();
+               /*
+                * Note that the true argument here does not necessarily mean we're
+                * here from a resume (this code path is also executed on boot).
+                * The implementation of lapic_configure checks to see if the
+                * state variable has been initialized, as it would be before
+                * sleep.  If it has not been, it's construed as an indicator of
+                * first boot.
+                */
+               lapic_configure(true);
+               LAPIC_DUMP();
+               LAPIC_CPU_MAP_DUMP();
+
+               init_fpu();
+
+#if CONFIG_MTRR
+               mtrr_update_cpu();
+#endif
+               /* update CPU microcode and apply CPU workarounds */
+               ucode_update_wake_and_apply_cpu_was();
+
+               /* Enable LBRs on non-boot CPUs */
+               i386_lbr_init(cpuid_info(), false);
+       } else {
+               init_param = FAST_SLAVE_INIT;
+       }
+
+#if CONFIG_VMX
+       /* resume VT operation */
+       vmx_resume(FALSE);
+#endif
+
+#if CONFIG_MTRR
+       if (!fast_restart) {
+               pat_init();
+       }
+#endif
+
+       cpu_thread_init();      /* not strictly necessary */
+
+       cpu_init();     /* Sets cpu_running which starter cpu waits for */
+
+
+#if MONOTONIC
+       mt_cpu_up(current_cpu_datap());
+#endif /* MONOTONIC */
+
+       slave_main(init_param);
+
+       panic("do_init_slave() returned from slave_main()");
+}
+
+/*
+ * i386_init_slave() is called from pstart.
+ * We're in the cpu's interrupt stack with interrupts disabled.
+ * At this point we are in legacy mode. We need to switch on IA32e
+ * if the mode is set to 64-bits.
+ */
+void
+i386_init_slave(void)
+{
+       do_init_slave(FALSE);
+}
+
+/*
+ * i386_init_slave_fast() is called from pmCPUHalt.
+ * We're running on the idle thread and need to fix up
+ * some accounting and get it so that the scheduler sees this
+ * CPU again.
+ */
+void
+i386_init_slave_fast(void)
+{
+       do_init_slave(TRUE);
+}
+
+
+/* TODO: Evaluate global PTEs for the double-mapped translations */
+
+uint64_t dblmap_base, dblmap_max;
+kernel_segment_command_t *hdescseg;
+
+pt_entry_t *dblmapL3;
+unsigned int dblallocs;
+uint64_t dblmap_dist;
+extern uint64_t idt64_hndl_table0[];
+
+
+void
+doublemap_init(uint8_t randL3)
+{
+       dblmapL3 = ALLOCPAGES(1); // for 512 1GiB entries
+       dblallocs++;
+
+       struct {
+               pt_entry_t entries[PTE_PER_PAGE];
+       } * dblmapL2 = ALLOCPAGES(1); // for 512 2MiB entries
+       dblallocs++;
+
+       dblmapL3[randL3] = ((uintptr_t)ID_MAP_VTOP(&dblmapL2[0]))
+           | INTEL_PTE_VALID
+           | INTEL_PTE_WRITE;
+
+       hdescseg = getsegbynamefromheader(&_mh_execute_header, "__HIB");
+
+       vm_offset_t hdescb = hdescseg->vmaddr;
+       unsigned long hdescsz = hdescseg->vmsize;
+       unsigned long hdescszr = round_page_64(hdescsz);
+       vm_offset_t hdescc = hdescb, hdesce = hdescb + hdescszr;
 
+       kernel_section_t *thdescsect = getsectbynamefromheader(&_mh_execute_header, "__HIB", "__text");
+       vm_offset_t thdescb = thdescsect->addr;
+       unsigned long thdescsz = thdescsect->size;
+       unsigned long thdescszr = round_page_64(thdescsz);
+       vm_offset_t thdesce = thdescb + thdescszr;
+
+       assert((hdescb & 0xFFF) == 0);
+       /* Mirror HIB translations into the double-mapped pagetable subtree*/
+       for (int i = 0; hdescc < hdesce; i++) {
+               struct {
+                       pt_entry_t entries[PTE_PER_PAGE];
+               } * dblmapL1 = ALLOCPAGES(1);
+               dblallocs++;
+               dblmapL2[0].entries[i] = ((uintptr_t)ID_MAP_VTOP(&dblmapL1[0])) | INTEL_PTE_VALID | INTEL_PTE_WRITE | INTEL_PTE_REF;
+               int hdescn = (int) ((hdesce - hdescc) / PAGE_SIZE);
+               for (int j = 0; j < MIN(PTE_PER_PAGE, hdescn); j++) {
+                       uint64_t template = INTEL_PTE_VALID;
+                       if ((hdescc >= thdescb) && (hdescc < thdesce)) {
+                               /* executable */
+                       } else {
+                               template |= INTEL_PTE_WRITE | INTEL_PTE_NX;  /* Writeable, NX */
+                       }
+                       dblmapL1[0].entries[j] = ((uintptr_t)ID_MAP_VTOP(hdescc)) | template;
+                       hdescc += PAGE_SIZE;
+               }
+       }
+
+       IdlePML4[KERNEL_DBLMAP_PML4_INDEX] = ((uintptr_t)ID_MAP_VTOP(dblmapL3)) | INTEL_PTE_VALID | INTEL_PTE_WRITE | INTEL_PTE_REF;
+
+       dblmap_base = KVADDR(KERNEL_DBLMAP_PML4_INDEX, randL3, 0, 0);
+       dblmap_max = dblmap_base + hdescszr;
+       /* Calculate the double-map distance, which accounts for the current
+        * KASLR slide
+        */
+
+       dblmap_dist = dblmap_base - hdescb;
+       idt64_hndl_table0[1] = DBLMAP(idt64_hndl_table0[1]);    /* 64-bit exit trampoline */
+       idt64_hndl_table0[3] = DBLMAP(idt64_hndl_table0[3]);    /* 32-bit exit trampoline */
+       idt64_hndl_table0[6] = (uint64_t)(uintptr_t)&kernel_stack_mask;
+
+       extern cpu_data_t cpshadows[], scdatas[];
+       uintptr_t cd1 = (uintptr_t) &cpshadows[0];
+       uintptr_t cd2 = (uintptr_t) &scdatas[0];
+/* Record the displacement from the kernel's per-CPU data pointer, eventually
+ * programmed into GSBASE, to the "shadows" in the doublemapped
+ * region. These are not aliases, but separate physical allocations
+ * containing data required in the doublemapped trampolines.
+ */
+       idt64_hndl_table0[2] = dblmap_dist + cd1 - cd2;
+
+       DBG("Double map base: 0x%qx\n", dblmap_base);
+       DBG("double map idlepml4[%d]: 0x%llx\n", KERNEL_DBLMAP_PML4_INDEX, IdlePML4[KERNEL_DBLMAP_PML4_INDEX]);
+       assert(LDTSZ > LDTSZ_MIN);
+}
+
+vm_offset_t dyn_dblmap(vm_offset_t, vm_offset_t);
+
+#include <i386/pmap_internal.h>
+
+/* Use of this routine is expected to be synchronized by callers
+ * Creates non-executable aliases.
+ */
+vm_offset_t
+dyn_dblmap(vm_offset_t cva, vm_offset_t sz)
+{
+       vm_offset_t ava = dblmap_max;
+
+       assert((sz & PAGE_MASK) == 0);
+       assert(cva != 0);
+
+       pmap_alias(ava, cva, cva + sz, VM_PROT_READ | VM_PROT_WRITE, PMAP_EXPAND_OPTIONS_ALIASMAP);
+       dblmap_max += sz;
+       return ava - cva;
+}
+/* Adjust offsets interior to the bootstrap interrupt descriptor table to redirect
+ * control to the double-mapped interrupt vectors. The IDTR proper will be
+ * programmed via cpu_desc_load()
+ */
+void
+idt64_remap(void)
+{
+       for (int i = 0; i < IDTSZ; i++) {
+               master_idt64[i].offset64 = DBLMAP(master_idt64[i].offset64);
+       }
 }