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[apple/xnu.git] / pexpert / i386 / pe_init.c
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 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
- * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * @APPLE_OSREFERENCE_LICENSE_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.
+ *
+ * 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 OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
- * 
- * @APPLE_LICENSE_HEADER_END@
+ * 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_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * file: pe_init.c
  *    i386 platform expert initialization.
  */
+
+#include <console/video_console.h>
 #include <sys/types.h>
 #include <mach/vm_param.h>
+#include <machine/machine_routines.h>
 #include <pexpert/protos.h>
 #include <pexpert/pexpert.h>
 #include <pexpert/boot.h>
 #include <pexpert/device_tree.h>
 #include <pexpert/pe_images.h>
+#include <kern/sched_prim.h>
 #include <kern/debug.h>
 
-#include "fakePPCStructs.h"
-#include "fakePPCDeviceTree.h"
+#if CONFIG_CSR
+#include <sys/csr.h>
+#endif
+
+#include "boot_images.h"
 
 /* extern references */
 extern void pe_identify_machine(void * args);
-extern void initialize_screen(void *, unsigned int);
-
-/* Local references */
-static vm_offset_t mapframebuffer(caddr_t,int);
-static vm_offset_t PE_fb_vaddr = 0;
-static int         PE_fb_mode  = TEXT_MODE;
-
+extern int kdb_printf(const char *format, ...) __printflike(1, 2);
 /* private globals */
-PE_state_t PE_state;
+PE_state_t  PE_state;
 
 /* Clock Frequency Info */
 clock_frequency_info_t gPEClockFrequencyInfo;
 
-int PE_initialize_console( PE_Video * info, int op )
-{
-    static int   last_console = -1;
-    Boot_Video   bootInfo;
-    Boot_Video * bInfo;
-
-    /*
-     * Refuse changes from outside pexpert.
-     * The video mode setup by the booter cannot be changed.
-     */
-    if ( info && (info == &PE_state.video) )
-    {
-        bootInfo.v_baseAddr     = PE_fb_vaddr;
-        bootInfo.v_rowBytes     = info->v_rowBytes;
-        bootInfo.v_width     = info->v_width;
-        bootInfo.v_height    = info->v_height;
-        bootInfo.v_depth     = info->v_depth;
-        bootInfo.v_display   = PE_fb_mode;
-        bInfo = &bootInfo;
-    }
-    else
-        bInfo = 0;
-
-    switch ( op ) {
-
-        case kPEDisableScreen:
-            initialize_screen((void *) bInfo, op);
-#ifdef FIXME
-            last_console = switch_to_serial_console();
-#endif
-            kprintf("kPEDisableScreen %d\n", last_console);
-            break;
-
-        case kPEEnableScreen:
-            initialize_screen((void *) bInfo, op);
-            kprintf("kPEEnableScreen %d\n", last_console);
-#ifdef FIXME
-            if( last_console != -1)
-                switch_to_old_console( last_console);
-#endif
-            break;
-       
-        default:
-            initialize_screen((void *) bInfo, op);
-            break;
-    }
-
-    return 0;
-}
+void *gPEEFISystemTable;
+void *gPEEFIRuntimeServices;
 
-void PE_init_iokit(void)
+static boot_icon_element* norootIcon_lzss;
+static const uint8_t*     norootClut_lzss;
+
+int
+PE_initialize_console( PE_Video * info, int op )
 {
-    long *          dt;
-    void *          desc;
-    unsigned char * data;
-    unsigned char * clut;
+       static int   last_console = -1;
 
-    dt = (long *) createdt(
-               fakePPCDeviceTree,
-               &((boot_args*)PE_state.fakePPCBootArgs)->deviceTreeLength);
+       if (info) {
+               info->v_offset  = 0;
+               info->v_length  = 0;
+               info->v_display = GRAPHICS_MODE;
+       }
 
-    /* Setup powermac_info and powermac_machine_info structures */
+       switch (op) {
+       case kPEDisableScreen:
+               initialize_screen(info, op);
+               kprintf("kPEDisableScreen %d\n", last_console);
+               if (!console_is_serial()) {
+                       last_console = switch_to_serial_console();
+               }
+               break;
+
+       case kPEEnableScreen:
+               initialize_screen(info, op);
+               if (info) {
+                       PE_state.video = *info;
+               }
+               kprintf("kPEEnableScreen %d\n", last_console);
+               if (last_console != -1) {
+                       switch_to_old_console( last_console);
+               }
+               break;
+
+       case kPEBaseAddressChange:
+               if (info) {
+                       PE_state.video = *info;
+               }
+               OS_FALLTHROUGH;
+
+       default:
+               initialize_screen(info, op);
+               break;
+       }
 
-    ((boot_args*)PE_state.fakePPCBootArgs)->deviceTreeP        = (unsigned long *) dt;
-    ((boot_args*)PE_state.fakePPCBootArgs)->topOfKernelData    = (unsigned int) kalloc(0x2000);
+       return 0;
+}
 
-    /* 
-     * Setup the OpenFirmware Device Tree routines
-     * so the console can be found and the right I/O space 
-     * can be used..
-     */
-    DTInit(dt);
+void
+PE_init_iokit(void)
+{
+       enum { kMaxBootVar = 128 };
+
+       boolean_t bootClutInitialized = FALSE;
+       boolean_t noroot_rle_Initialized = FALSE;
+
+       DTEntry             entry;
+       unsigned int        size;
+       uint32_t const      *map;
+       boot_progress_element *bootPict;
+
+       norootIcon_lzss = NULL;
+       norootClut_lzss = NULL;
+
+       PE_init_printf(TRUE);
+
+       kprintf("Kernel boot args: '%s'\n", PE_boot_args());
+
+       /*
+        * Fetch the CLUT and the noroot image.
+        */
+
+       if (kSuccess == SecureDTLookupEntry(NULL, "/chosen/memory-map", &entry)) {
+               if (kSuccess == SecureDTGetProperty(entry, "BootCLUT", (void const **) &map, &size)) {
+                       if (sizeof(appleClut8) <= map[1]) {
+                               bcopy((void *)ml_static_ptovirt(map[0]), appleClut8, sizeof(appleClut8));
+                               bootClutInitialized = TRUE;
+                       }
+               }
+
+               if (kSuccess == SecureDTGetProperty(entry, "Pict-FailedBoot", (void const **) &map, &size)) {
+                       bootPict = (boot_progress_element *) ml_static_ptovirt(map[0]);
+                       default_noroot.width  = bootPict->width;
+                       default_noroot.height = bootPict->height;
+                       default_noroot.dx     = 0;
+                       default_noroot.dy     = bootPict->yOffset;
+                       default_noroot_data   = &bootPict->data[0];
+                       noroot_rle_Initialized = TRUE;
+               }
+
+               if (kSuccess == SecureDTGetProperty(entry, "FailedCLUT", (void const **) &map, &size)) {
+                       norootClut_lzss = (uint8_t*) ml_static_ptovirt(map[0]);
+               }
+
+               if (kSuccess == SecureDTGetProperty(entry, "FailedImage", (void const **) &map, &size)) {
+                       norootIcon_lzss = (boot_icon_element *) ml_static_ptovirt(map[0]);
+                       if (norootClut_lzss == NULL) {
+                               printf("ERROR: No FailedCLUT provided for noroot icon!\n");
+                       }
+               }
+       }
 
-    /*
-     * Initialize the spinning wheel (progress indicator).
-     */
-    clut = appleClut8;
-    desc = &default_progress;
-    data = default_progress_data;
+       if (!bootClutInitialized) {
+               bcopy((void *) (uintptr_t) bootClut, (void *) appleClut8, sizeof(appleClut8));
+       }
 
-    vc_progress_initialize( desc, data, clut );
+       if (!noroot_rle_Initialized) {
+               default_noroot.width  = kFailedBootWidth;
+               default_noroot.height = kFailedBootHeight;
+               default_noroot.dx     = 0;
+               default_noroot.dy     = kFailedBootOffset;
+               default_noroot_data   = failedBootPict;
+       }
 
-    PE_initialize_console( (PE_Video *) 0, kPEAcquireScreen );
+       /*
+        * Initialize the spinning wheel (progress indicator).
+        */
+       vc_progress_initialize(&default_progress,
+           default_progress_data1x,
+           default_progress_data2x,
+           default_progress_data3x,
+           (unsigned char *) appleClut8);
+
+       /*
+        * x86 only minimally enforces lockdown in hardware.  Additionally, some pre-lockdown functionality
+        * such as commpage initialization requires IOKit enumeration of CPUs, which is heavily entangled
+        * with the ACPI stack.  Therefore, we start the IOKit matching process immediately on x86.
+        */
+       InitIOKit(PE_state.deviceTreeHead);
+       StartIOKitMatching();
+}
 
-    (void) StartIOKit( (void*)dt, (void*)PE_state.fakePPCBootArgs, 0, 0);
+void
+PE_lockdown_iokit(void)
+{
+       /* Ensure that at least the CPUs have been enumerated before moving forward. */
+       ml_wait_max_cpus();
 }
 
-void PE_init_platform(boolean_t vm_initialized, void * args)
+void
+PE_init_platform(boolean_t vm_initialized, void * _args)
 {
-       if (PE_state.initialized == FALSE)
-       {
-        extern unsigned int halt_in_debugger, disableDebugOuput;
-        unsigned int debug_arg;
-
-           PE_state.initialized        = TRUE;
-           PE_state.bootArgs           = args;
-           PE_state.video.v_baseAddr   = ((KERNBOOTSTRUCT *)args)->video.v_baseAddr;
-           PE_state.video.v_rowBytes   = ((KERNBOOTSTRUCT *)args)->video.v_rowBytes;
-           PE_state.video.v_height     = ((KERNBOOTSTRUCT *)args)->video.v_height;
-           PE_state.video.v_width      = ((KERNBOOTSTRUCT *)args)->video.v_width;
-           PE_state.video.v_depth      = ((KERNBOOTSTRUCT *)args)->video.v_depth;
-        PE_state.video.v_display    = ((KERNBOOTSTRUCT *)args)->video.v_display;
-        PE_fb_mode                  = ((KERNBOOTSTRUCT *)args)->graphicsMode;
-           PE_state.fakePPCBootArgs    = (boot_args *)&fakePPCBootArgs;
-           ((boot_args *)PE_state.fakePPCBootArgs)->machineType        = 386;
-
-        if (PE_fb_mode == TEXT_MODE)
-        {
-            /* Force a text display if the booter did not setup a
-             * VESA frame buffer.
-             */
-            PE_state.video.v_display = 0;
-        }
-
-        /*
-         * If DB_HALT flag is set, then cause a breakpoint to the debugger
-         * immediately after the kernel debugger has been initialized.
-         *
-         * If DB_PRT flag is set, then enable debugger printf.
-         */
-        disableDebugOuput = TRUE; /* FIXME: override osfmk/i386/AT386/model_dep.c */
-
-        if (PE_parse_boot_arg("debug", &debug_arg)) {
-            if (debug_arg & DB_HALT) halt_in_debugger = 1;
-            if (debug_arg & DB_PRT)  disableDebugOuput = FALSE; 
+       boot_args *args = (boot_args *)_args;
+
+       if (PE_state.initialized == FALSE) {
+               PE_state.initialized        = TRUE;
+
+               // New EFI-style
+               PE_state.bootArgs           = _args;
+               PE_state.deviceTreeHead     = (void *) ml_static_ptovirt(args->deviceTreeP);
+               PE_state.deviceTreeSize     = args->deviceTreeLength;
+               if (args->Video.v_baseAddr) {
+                       PE_state.video.v_baseAddr   = args->Video.v_baseAddr;// remains physical address
+                       PE_state.video.v_rowBytes   = args->Video.v_rowBytes;
+                       PE_state.video.v_depth      = args->Video.v_depth;
+                       PE_state.video.v_display    = args->Video.v_display;
+                       PE_state.video.v_rotate     = args->Video.v_rotate;
+
+                       /* EFI doesn't have a good way of describing rotation internally,
+                        * so it flips width and height in portrait mode. We flip it back. */
+                       if (PE_state.video.v_rotate == kDataRotate90 ||
+                           PE_state.video.v_rotate == kDataRotate270) {
+                               PE_state.video.v_width  = args->Video.v_height;
+                               PE_state.video.v_height = args->Video.v_width;
+                       } else {
+                               PE_state.video.v_width  = args->Video.v_width;
+                               PE_state.video.v_height = args->Video.v_height;
+                       }
+
+                       strlcpy(PE_state.video.v_pixelFormat, "PPPPPPPP",
+                           sizeof(PE_state.video.v_pixelFormat));
+               } else {
+                       PE_state.video.v_baseAddr   = args->VideoV1.v_baseAddr;// remains physical address
+                       PE_state.video.v_rowBytes   = args->VideoV1.v_rowBytes;
+                       PE_state.video.v_width      = args->VideoV1.v_width;
+                       PE_state.video.v_height     = args->VideoV1.v_height;
+                       PE_state.video.v_depth      = args->VideoV1.v_depth;
+                       PE_state.video.v_display    = args->VideoV1.v_display;
+                       PE_state.video.v_rotate     = kDataRotate0; /* no room for rotation info */
+                       strlcpy(PE_state.video.v_pixelFormat, "PPPPPPPP",
+                           sizeof(PE_state.video.v_pixelFormat));
+               }
+
+#ifdef  kBootArgsFlagHiDPI
+               if (args->flags & kBootArgsFlagHiDPI) {
+                       PE_state.video.v_scale = kPEScaleFactor2x;
+               } else {
+                       PE_state.video.v_scale = kPEScaleFactor1x;
+               }
+#else
+               PE_state.video.v_scale = kPEScaleFactor1x;
+#endif
        }
+
+       if (!vm_initialized) {
+               if (PE_state.deviceTreeHead) {
+                       SecureDTInit(PE_state.deviceTreeHead, PE_state.deviceTreeSize);
+               }
+
+               pe_identify_machine(args);
+               pe_init_debug();
        }
+}
 
-       if (!vm_initialized)
-       {
-               /* Hack! FIXME.. */ 
-        outb(0x21, 0xff);   /* Maskout all interrupts Pic1 */
-        outb(0xa1, 0xff);   /* Maskout all interrupts Pic2 */
-       pe_identify_machine(args);
+void
+PE_create_console( void )
+{
+       if (PE_state.video.v_display == GRAPHICS_MODE) {
+               PE_initialize_console( &PE_state.video, kPEGraphicsMode );
+       } else {
+               PE_initialize_console( &PE_state.video, kPETextMode );
        }
-       else
-       {
-         pe_init_debug();
-        
-         PE_create_console();
+}
+
+int
+PE_current_console( PE_Video * info )
+{
+       *info = PE_state.video;
+
+       return 0;
+}
+
+void
+PE_display_icon( __unused unsigned int flags, __unused const char * name )
+{
+       if (norootIcon_lzss && norootClut_lzss) {
+               uint32_t width  = norootIcon_lzss->width;
+               uint32_t height = norootIcon_lzss->height;
+               uint32_t x = ((PE_state.video.v_width  - width) / 2);
+               uint32_t y = ((PE_state.video.v_height - height) / 2) + norootIcon_lzss->y_offset_from_center;
+
+               vc_display_lzss_icon(x, y, width, height,
+                   &norootIcon_lzss->data[0],
+                   norootIcon_lzss->data_size,
+                   norootClut_lzss);
+       } else if (default_noroot_data) {
+               vc_display_icon( &default_noroot, default_noroot_data );
+       } else {
+               printf("ERROR: No data found for noroot icon!\n");
        }
 }
 
-void PE_create_console( void )
+boolean_t
+PE_get_hotkey(__unused unsigned char key)
 {
-    if ( (PE_fb_vaddr == 0) && (PE_state.video.v_baseAddr != 0) )
-    {
-        PE_fb_vaddr = mapframebuffer((caddr_t) PE_state.video.v_baseAddr,
-                                     (PE_fb_mode == TEXT_MODE)  ?
-                      /* text mode */  PE_state.video.v_rowBytes :
-                      /* grfx mode */  PE_state.video.v_rowBytes *
-                                        PE_state.video.v_height);
-    }
-
-       if (PE_state.video.v_display)
-        PE_initialize_console( &PE_state.video, kPEGraphicsMode );
-    else
-        PE_initialize_console( &PE_state.video, kPETextMode );
+       return FALSE;
 }
 
-int PE_current_console( PE_Video * info )
+static timebase_callback_func gTimebaseCallback;
+
+void
+PE_register_timebase_callback(timebase_callback_func callback)
 {
-    *info = PE_state.video;
-
-    if ( PE_fb_mode == TEXT_MODE )
-    {
-        /*
-         * FIXME: Prevent the IOBootFrameBuffer from starting up
-         * when we are in Text mode.
-         */
-        info->v_baseAddr = 0;
-    }
-
-    return (0);
+       gTimebaseCallback = callback;
+
+       PE_call_timebase_callback();
+}
+
+void
+PE_call_timebase_callback(void)
+{
+       struct timebase_freq_t timebase_freq;
+       unsigned long          num, den, cnt;
+
+       num = gPEClockFrequencyInfo.bus_clock_rate_num * gPEClockFrequencyInfo.bus_to_dec_rate_num;
+       den = gPEClockFrequencyInfo.bus_clock_rate_den * gPEClockFrequencyInfo.bus_to_dec_rate_den;
+
+       cnt = 2;
+       while (cnt <= den) {
+               if ((num % cnt) || (den % cnt)) {
+                       cnt++;
+                       continue;
+               }
+
+               num /= cnt;
+               den /= cnt;
+       }
+
+       timebase_freq.timebase_num = num;
+       timebase_freq.timebase_den = den;
+
+       if (gTimebaseCallback) {
+               gTimebaseCallback(&timebase_freq);
+       }
 }
 
-void PE_display_icon( unsigned int flags,
-                      const char * name )
+/*
+ * The default (non-functional) PE_poll_input handler.
+ */
+int
+PE_stub_poll_input(__unused unsigned int options, char * c)
 {
+       *c = 0xff;
+       return 1; /* 0 for success, 1 for unsupported */
 }
 
-extern boolean_t PE_get_hotkey( unsigned char key )
+boolean_t
+PE_reboot_on_panic(void)
 {
-    return (FALSE);
+       boot_args *args = (boot_args *)PE_state.bootArgs;
+
+       if (args->flags & kBootArgsFlagRebootOnPanic) {
+               return TRUE;
+       } else {
+               return FALSE;
+       }
 }
 
-static timebase_callback_func gTimebaseCallback;
+void
+PE_sync_panic_buffers(void)
+{
+}
 
-void PE_register_timebase_callback(timebase_callback_func callback)
+/* rdar://problem/21244753 */
+uint32_t
+PE_i_can_has_debugger(uint32_t *debug_flags)
 {
-    gTimebaseCallback = callback;
-  
-    PE_call_timebase_callback();
+#if DEVELOPMENT || DEBUG
+       if (debug_flags) {
+               assert(startup_phase >= STARTUP_SUB_TUNABLES);
+       }
+#endif
+
+#if CONFIG_CSR
+       if (csr_check(CSR_ALLOW_KERNEL_DEBUGGER) != 0) {
+               if (debug_flags) {
+                       *debug_flags = 0;
+               }
+               return FALSE;
+       }
+#endif
+       if (debug_flags) {
+               *debug_flags = debug_boot_arg;
+       }
+       return TRUE;
+}
+
+uint32_t
+PE_get_offset_into_panic_region(char *location)
+{
+       assert(panic_info != NULL);
+       assert(location > (char *) panic_info);
+
+       return (uint32_t) (location - (char *) panic_info);
 }
 
-void PE_call_timebase_callback(void)
+void
+PE_init_panicheader()
 {
-  struct timebase_freq_t timebase_freq;
-  unsigned long          num, den, cnt;
-  
-  num = gPEClockFrequencyInfo.bus_clock_rate_num * gPEClockFrequencyInfo.bus_to_dec_rate_num;
-  den = gPEClockFrequencyInfo.bus_clock_rate_den * gPEClockFrequencyInfo.bus_to_dec_rate_den;
-  
-  cnt = 2;
-  while (cnt <= den) {
-    if ((num % cnt) || (den % cnt)) {
-      cnt++;
-      continue;
-    }
-    
-    num /= cnt;
-    den /= cnt;
-  }
-  
-  timebase_freq.timebase_num = num;
-  timebase_freq.timebase_den = den;
-  
-  if (gTimebaseCallback) gTimebaseCallback(&timebase_freq);
+       bzero(panic_info, offsetof(struct macos_panic_header, mph_data));
+       panic_info->mph_panic_log_offset = PE_get_offset_into_panic_region(debug_buf_base);
+
+       panic_info->mph_magic = MACOS_PANIC_MAGIC;
+       panic_info->mph_version = MACOS_PANIC_HEADER_CURRENT_VERSION;
+
+       return;
 }
 
 /*
- * map the framebuffer into kernel vm and return the (virtual)
- * address.
+ * Tries to update the panic header to keep it consistent on nested panics.
+ *
+ * NOTE: The purpose of this function is NOT to detect/correct corruption in the panic region,
+ *       it is to update the panic header to make it consistent when we nest panics.
+ *
+ * We try to avoid nested panics/asserts on x86 because they are difficult to debug, so log any
+ * inconsistencies we find.
  */
-static vm_offset_t
-mapframebuffer( caddr_t physaddr,  /* start of framebuffer */
-                int     length)    /* num bytes to map */
+void
+PE_update_panicheader_nestedpanic()
 {
-    vm_offset_t vmaddr;
+       /* If the panic log offset is not set, re-init the panic header */
+       if (panic_info->mph_panic_log_offset == 0) {
+               PE_init_panicheader();
+               panic_info->mph_panic_flags |= MACOS_PANIC_HEADER_FLAG_NESTED_PANIC;
+               return;
+       }
+
+       panic_info->mph_panic_flags |= MACOS_PANIC_HEADER_FLAG_NESTED_PANIC;
 
-       if (physaddr != (caddr_t)trunc_page(physaddr))
-        panic("Framebuffer not on page boundary");
+       /* Usually indicative of corruption in the panic region */
+       if (!(((panic_info->mph_stackshot_offset == 0) && (panic_info->mph_stackshot_len == 0)) ||
+           ((panic_info->mph_stackshot_offset != 0) && (panic_info->mph_stackshot_len != 0)))) {
+               kdb_printf("panic_info contains invalid stackshot metadata: mph_stackshot_offset 0x%x mph_stackshot_len 0x%x\n",
+                   panic_info->mph_stackshot_offset, panic_info->mph_stackshot_len);
+       }
 
-       vmaddr = io_map((vm_offset_t)physaddr, length);
-       if (vmaddr == 0)
-        panic("can't alloc VM for framebuffer");
+       /*
+        * macOS panic logs contain nested panic data, if we've already closed the panic log,
+        * begin the other log.
+        */
+       if ((panic_info->mph_panic_log_len != 0) && (panic_info->mph_other_log_offset == 0)) {
+               panic_info->mph_other_log_offset = PE_get_offset_into_panic_region(debug_buf_ptr);
+
+               /* Usually indicative of corruption in the panic region */
+               if (panic_info->mph_other_log_len != 0) {
+                       kdb_printf("panic_info contains invalid other log metadata (zero offset but non-zero length), length was 0x%x, zeroing value\n",
+                           panic_info->mph_other_log_len);
+                       panic_info->mph_other_log_len = 0;
+               }
+       }
 
-    return vmaddr;
+       return;
 }