xref: /xnu-10002.61.3/osfmk/kern/startup.h (revision 0f4c859e951fba394238ab619495c4e1d54d0f34)
1 /*
2  * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*
29  * @OSF_COPYRIGHT@
30  */
31 
32 #ifdef  XNU_KERNEL_PRIVATE
33 
34 #ifndef _KERN_STARTUP_H_
35 #define _KERN_STARTUP_H_
36 
37 #include <stdbool.h>
38 #include <stddef.h>
39 #include <stdint.h>
40 
41 #include <libkern/section_keywords.h>
42 
43 __BEGIN_DECLS
44 
45 #pragma GCC visibility push(hidden)
46 
47 /*!
48  * @enum startup_subsystem_id_t
49  *
50  * @abstract
51  * Represents a stage of kernel intialization, ubnd allows for subsystems
52  * to register initializers for a specific stage.
53  *
54  * @discussion
55  * Documentation of each subsystem initialization sequence exists in
56  * @file doc/startup.md.
57  */
58 __enum_decl(startup_subsystem_id_t, uint32_t, {
59 	STARTUP_SUB_NONE = 0,         /**< reserved for the startup subsystem  */
60 
61 	STARTUP_SUB_TUNABLES,         /**< support for the tunables subsystem  */
62 	STARTUP_SUB_TIMEOUTS,         /**< configurable machine timeouts       */
63 	STARTUP_SUB_LOCKS,            /**< various subsystem locks             */
64 	STARTUP_SUB_KPRINTF,          /**< kprintf initialization              */
65 
66 	STARTUP_SUB_PMAP_STEAL,       /**< to perform various pmap carveouts   */
67 	STARTUP_SUB_KMEM,             /**< once kmem_alloc is ready            */
68 	STARTUP_SUB_ZALLOC,           /**< initialize zalloc and kalloc        */
69 	STARTUP_SUB_KTRACE,           /**< initialize kernel trace             */
70 	STARTUP_SUB_PERCPU,           /**< initialize the percpu subsystem     */
71 	STARTUP_SUB_EVENT,            /**< initiailze the event subsystem      */
72 
73 	STARTUP_SUB_CODESIGNING,      /**< codesigning subsystem               */
74 	STARTUP_SUB_OSLOG,            /**< oslog and kernel logging            */
75 	STARTUP_SUB_MACH_IPC,         /**< Mach IPC                            */
76 	STARTUP_SUB_THREAD_CALL,      /**< Thread calls                        */
77 	STARTUP_SUB_SYSCTL,           /**< registers sysctls                   */
78 	STARTUP_SUB_EARLY_BOOT,       /**< interrupts/preemption are turned on */
79 
80 	STARTUP_SUB_LOCKDOWN = ~0u,   /**< reserved for the startup subsystem  */
81 });
82 
83 /*!
84  * Stores the last subsystem to have been fully initialized;
85  */
86 extern startup_subsystem_id_t startup_phase;
87 
88 /*!
89  * @enum startup_debug_t
90  *
91  * @abstract
92  * Flags set in the @c startup_debug global to configure startup debugging.
93  */
94 __options_decl(startup_debug_t, uint32_t, {
95 	STARTUP_DEBUG_NONE    = 0x00000000,
96 	STARTUP_DEBUG_VERBOSE = 0x00000001,
97 });
98 
99 extern startup_debug_t startup_debug;
100 
101 /*!
102  * @enum startup_rank
103  *
104  * @abstract
105  * Specifies in which rank a given initializer runs within a given section
106  * to register initializers for a specific rank within the subsystem.
107  *
108  * @description
109  * A startup function, declared with @c STARTUP or @c STARTUP_ARG, can specify
110  * a rank within the subsystem they initialize.
111  *
112  * @c STARTUP_RANK_NTH(n) will let callbacks be run at stage @c n (0-based).
113  *
114  * @c STARTUP_RANK_FIRST, @c STARTUP_RANK_SECOND, @c STARTUP_RANK_THIRD and
115  * @c STARTUP_RANK_FOURTH are given as convenient names for these.
116  *
117  * @c STARTUP_RANK_MIDDLE is a reserved value that will let startup functions
118  * run after all the @c STARTUP_RANK_NTH(n) ones have.
119  *
120  * @c STARTUP_RANK_NTH_LATE_NTH(n) will let callbacks be run then in @c n rank
121  * after the @c STARTUP_RANK_MIDDLE ones (0-based).
122  *
123  * @c STARTUP_RANK_LAST callbacks will run absolutely last after everything
124  * else did for this subsystem.
125  */
126 __enum_decl(startup_rank_t, uint32_t, {
127 #define STARTUP_RANK_NTH(n)           ((startup_rank_t)(n - 1))
128 	STARTUP_RANK_FIRST          = 0,
129 	STARTUP_RANK_SECOND         = 1,
130 	STARTUP_RANK_THIRD          = 2,
131 	STARTUP_RANK_FOURTH         = 3,
132 
133 	STARTUP_RANK_MIDDLE         = 0x7fffffff,
134 
135 #define STARTUP_RANK_LATE_NTH(n) \
136 	((startup_rank_t)(STARTUP_RANK_MIDDLE + 1 + (n)))
137 
138 	STARTUP_RANK_LAST           = 0xffffffff,
139 });
140 
141 #if KASAN
142 /*
143  * The use of weird sections that get unmapped confuse the hell out of kasan,
144  * so for KASAN leave things in regular __TEXT/__DATA segments
145  */
146 #define STARTUP_CODE_SEGSECT "__TEXT,__text"
147 #define STARTUP_DATA_SEGSECT "__DATA,__init"
148 #define STARTUP_HOOK_SEGMENT "__DATA"
149 #define STARTUP_HOOK_SECTION "__init_entry_set"
150 #elif defined(__x86_64__)
151 /* Intel doesn't have a __BOOTDATA but doesn't protect __KLD */
152 #define STARTUP_CODE_SEGSECT "__TEXT,__text"
153 #define STARTUP_DATA_SEGSECT "__KLDDATA,__init"
154 #define STARTUP_HOOK_SEGMENT "__KLDDATA"
155 #define STARTUP_HOOK_SECTION "__init_entry_set"
156 #else
157 /* arm protects __KLD early, so use __BOOTDATA for data */
158 #define STARTUP_CODE_SEGSECT "__TEXT,__text"
159 #define STARTUP_DATA_SEGSECT "__BOOTDATA,__init"
160 #define STARTUP_HOOK_SEGMENT "__BOOTDATA"
161 #define STARTUP_HOOK_SECTION "__init_entry_set"
162 #endif
163 
164 /*!
165  * @macro __startup_func
166  *
167  * @abstract
168  * Attribute to place on functions used only during the kernel startup phase.
169  *
170  * @description
171  * Code marked with this attribute will be unmapped after kernel lockdown.
172  */
173 #define __startup_func \
174 	__PLACE_IN_SECTION(STARTUP_CODE_SEGSECT) \
175 	__attribute__((cold, visibility("hidden")))
176 
177 /*!
178  * @macro __startup_data
179  *
180  * @abstract
181  * Attribute to place on globals used during the kernel startup phase.
182  *
183  * @description
184  * Data marked with this attribute will be unmapped after kernel lockdown.
185  */
186 #define __startup_data \
187 	__PLACE_IN_SECTION(STARTUP_DATA_SEGSECT)
188 
189 /*!
190  * @macro STARTUP
191  *
192  * @abstract
193  * Declares a kernel startup callback.
194  */
195 #define STARTUP(subsystem, rank, func) \
196 	__STARTUP(func, __LINE__, subsystem, rank, func)
197 
198 /*!
199  * @macro STARTUP_ARG
200  *
201  * @abstract
202  * Declares a kernel startup callback that takes an argument.
203  */
204 #define STARTUP_ARG(subsystem, rank, func, arg) \
205 	__STARTUP_ARG(func, __LINE__, subsystem, rank, func, arg)
206 
207 /*!
208  * @macro TUNABLE
209  *
210  * @abstract
211  * Declares a read-only kernel tunable that is read from a boot-arg with
212  * a default value, without further processing.
213  *
214  * @param type_t
215  * Should be an integer type or bool.
216  *
217  * @param var
218  * The name of the C variable to use for storage.
219  *
220  * @param boot_arg
221  * The name of the boot-arg to parse for initialization
222  *
223  * @param default_value
224  * The default value for the tunable if the boot-arg is absent.
225  */
226 #define TUNABLE(type_t, var, boot_arg, default_value) \
227 	SECURITY_READ_ONLY_LATE(type_t) var = default_value; \
228 	__TUNABLE(type_t, var, boot_arg)
229 
230 /*!
231  * @macro TUNABLE_WRITEABLE
232  *
233  * @abstract
234  * Declares a writeable kernel tunable that is read from a boot-arg with
235  * a default value, without further processing.
236  *
237  * @param type_t
238  * Should be an integer type or bool.
239  *
240  * @param var
241  * The name of the C variable to use for storage.
242  *
243  * @param boot_arg
244  * The name of the boot-arg to parse for initialization
245  *
246  * @param default_value
247  * The default value for the tunable if the boot-arg is absent.
248  */
249 #define TUNABLE_WRITEABLE(type_t, var, boot_arg, default_value) \
250 	type_t var = default_value; \
251 	__TUNABLE(type_t, var, boot_arg)
252 
253 #if DEBUG || DEVELOPMENT
254 #define TUNABLE_DEV_WRITEABLE(type_t, var, boot_arg, default_value) \
255 	TUNABLE_WRITEABLE(type_t, var, boot_arg, default_value)
256 #else
257 #define TUNABLE_DEV_WRITEABLE(type_t, var, boot_arg, default_value) \
258 	TUNABLE(type_t, var, boot_arg, default_value)
259 #endif
260 
261 /*!
262  * @macro TUNABLE_STR
263  *
264  * @abstract
265  * Declares a read-only kernel tunable that is read from a boot-arg with
266  * a default value, without further processing.
267  *
268  * @param var
269  * The name of the C variable to use for storage.
270  *
271  * @param count
272  * The number of bytes in the buffer.
273  *
274  * @param boot_arg
275  * The name of the boot-arg to parse for initialization
276  *
277  * @param default_value
278  * The default value for the tunable if the boot-arg is absent.
279  */
280 #define TUNABLE_STR(var, count, boot_arg, default_value) \
281 	char __security_const_late var[count] = default_value; \
282 	__TUNABLE_STR(var, boot_arg)
283 
284 /*!
285  * @enum tunable_dt_flags_t
286  *
287  * @abstract
288  * Flags used with the @c TUNABLE_DT* macros.
289  *
290  * @description
291  * If TUNABLE_DT_CHECK_CHOSEN is set, a value in
292  * /chosen/<dt_base>/<dt_name> takes precedence over any value in
293  * /<dt_base>/<dt_name>. /chosen is by convention the area where
294  * synthesized values not coming from the serialized device tree are
295  * being added, so this provides a way for e.g. the boot-loader to
296  * set/override tunables.
297  */
298 __options_decl(tunable_dt_flags_t, uint32_t, {
299 	TUNABLE_DT_NONE         = 0x00000000,
300 	TUNABLE_DT_CHECK_CHOSEN = 0x00000001,
301 });
302 
303 /*!
304  * @macro TUNABLE_DT
305  *
306  * @abstract
307  * Like TUNABLE, but gets the initial value from both Device Tree and
308  * boot-args. The order in which the initial value is resolved is as
309  * follows, with later steps overriding previous ones (if they are
310  * specified):
311  *
312  * 1. Device Tree Entry "/<dt_base>/<dt_name>",
313  * 2. If TUNABLE_DT_CHECK_CHOSEN is set, Device Tree Entry
314  *    "/chosen/<dt_base>/<dt_name>" (see the description for
315  *    @c tunable_dt_flags_t),
316  * 3. boot-args.
317  *
318  * @param type_t
319  * Should be an integer type or bool.
320  *
321  * @param var
322  * The name of the C variable to use for storage.
323  *
324  * @param dt_base
325  * The name of the DT node containing the property.
326  *
327  * @param dt_name
328  * The name of the DT property containing the default value.
329  *
330  * @param boot_arg
331  * The name of the boot-arg overriding the initial value from the DT.
332  *
333  * @param default_value
334  * The default value for the tunable if both DT entry and boot-arg are
335  * absent.
336  *
337  * @param flags
338  * See the description for @c tunable_dt_flags_t.
339  */
340 #define TUNABLE_DT(type_t, var, dt_base, dt_name, boot_arg, default_value, flags) \
341 	SECURITY_READ_ONLY_LATE(type_t) var = default_value; \
342 	__TUNABLE_DT(type_t, var, dt_base, dt_name, boot_arg, flags)
343 
344 /*!
345  * @macro TUNABLE_DT_WRITEABLE
346  *
347  * @abstract
348  * Like TUNABLE_WRITEABLE, but gets the initial value from both Device
349  * Tree and boot-args. The order in which the initial value is
350  * resolved is as follows, with later steps overriding previous ones
351  * (if they are specified):
352  *
353  * 1. Device Tree Entry "/<dt_base>/<dt_name>",
354  * 2. If TUNABLE_DT_CHECK_CHOSEN is set, Device Tree Entry
355  *    "/chosen/<dt_base>/<dt_name>" (see the description for
356  *    @c tunable_dt_flags_t),
357  * 3. boot-args.
358  *
359  * @param type_t
360  * Should be an integer type or bool.
361  *
362  * @param var
363  * The name of the C variable to use for storage.
364  *
365  * @param dt_base
366  * The name of the DT node containing the property.
367  *
368  * @param dt_name
369  * The name of the DT property containing the default value.
370  *
371  * @param boot_arg
372  * The name of the boot-arg overriding the initial value from the DT.
373  *
374  * @param default_value
375  * The default value for the tunable if both DT entry and boot-arg are
376  * absent.
377  *
378  * @param flags
379  * See the description for @c tunable_dt_flags_t.
380  */
381 #define TUNABLE_DT_WRITEABLE(type_t, var, dt_base, dt_name, boot_arg, default_value, flags) \
382 	type_t var = default_value; \
383 	__TUNABLE_DT(type_t, var, dt_base, dt_name, boot_arg, flags)
384 
385 #if DEBUG || DEVELOPMENT
386 #define TUNABLE_DT_DEV_WRITEABLE(type_t, var, dt_base, dt_name, boot_arg, default_value, flags) \
387 	TUNABLE_DT_WRITEABLE(type_t, var, dt_base, dt_name, boot_arg, default_value, flags)
388 #else
389 #define TUNABLE_DT_DEV_WRITEABLE(type_t, var, dt_base, dt_name, boot_arg, default_value, flags) \
390 	TUNABLE_DT(type_t, var, dt_base, dt_name, boot_arg, default_value, flags)
391 #endif
392 
393 /*
394  * Machine Timeouts
395  *
396  * Machine Timeouts are timeouts for low level kernel code manifesting
397  * as _Atomic uint64_t variables, whose default value can be
398  * overridden and scaled via the device tree and boot-args.
399  *
400  * Each timeout has a name, looked up directly as the property name in
401  * the device tree in both the "/machine-timeouts" and
402  * "/chosen/machine-timeouts" nodes. The "chosen" property always
403  * overrides the other one. This allows fixed per-device timeouts in
404  * the device tree to be overridden by iBoot in "chosen".
405  *
406  * Additionally, the same name with "-scale" appended is looked up as
407  * properties for optional scale factors. Scale factors are not
408  * overridden by chosen, instead all scale factors (including global
409  * and/or boot-arg scale factors) combine by multiplication.
410  *
411  * The special name "global-scale" provides a scale that applies to
412  * every timeout.
413  *
414  * All property names can be used as boot-args by prefixing
415  * "ml-timeout-", e.g. th global scale is available as the
416  * "ml-timeout-global-scale" boot-arg.
417  *
418  * By convention, if the timeout value resolves to 0, the timeout
419  * should be disabled.
420  */
421 
422 /*
423  * Machine Timeouts types. See the next section for what unit
424  * they are in.
425  *
426  * We use _Atomic, but only with relaxed ordering: This is just to
427  * make sure all devices see consistent values all the time.  Since
428  * the actual timeout value will be seen as 0 before initializaton,
429  * relaxed ordering means that code that runs concurrently with
430  * initialization only risks to see a disabled timeout during early
431  * boot.
432  */
433 typedef _Atomic uint64_t machine_timeout_t;
434 
435 /*
436  * Units
437  *
438  * Machine Timeouts are ALWAYS in picoseconds in the device tree or
439  * boot-args, to avoid confusion when changing or comparing timeouts
440  * as a user, but the actual storage value might contain the same
441  * duration in another unit, calculated by the initialization code.
442  *
443  * This is done because otherwise we would likely introduce another
444  * multiplication in potentially hot code paths, given that code that
445  * actually uses the timeout storage variable is unlikely to work with
446  * picosecond values when comparing against the timeout deadline.
447  *
448  * This unit scale is *only* applied during initialization at early
449  * boot, and only if the timeout's default value was overridden
450  * through the device tree or a boot-arg.
451  */
452 #define MACHINE_TIMEOUT_UNIT_PSEC 1
453 #define MACHINE_TIMEOUT_UNIT_NSEC 1000
454 #define MACHINE_TIMEOUT_UNIT_USEC (1000*1000)
455 #define MACHINE_TIMEOUT_UNIT_MSEC (1000*1000*1000)
456 // Special unit for timebase ticks (usually 1/24MHz)
457 #define MACHINE_TIMEOUT_UNIT_TIMEBASE 0
458 
459 // DT property names are limited to 31 chars, minus "-global" suffix
460 #define MACHINE_TIMEOUT_MAX_NAME_LEN 25
461 struct machine_timeout_spec {
462 	void *ptr;
463 	uint64_t default_value;
464 	uint64_t unit_scale;
465 	char name[MACHINE_TIMEOUT_MAX_NAME_LEN + 1];
466 	bool (*skip_predicate)(struct machine_timeout_spec const *);
467 };
468 
469 extern void
470 machine_timeout_init_with_suffix(const struct machine_timeout_spec *spec, char const *phase_suffix);
471 
472 extern void
473 machine_timeout_init(const struct machine_timeout_spec *spec);
474 
475 #if DEVELOPMENT || DEBUG
476 // Late timeout (re-)initialization, at the end of bsd_init()
477 extern void
478 machine_timeout_bsd_init(void);
479 #endif /* DEVELOPMENT || DEBUG */
480 
481 /*!
482  * @macro MACHINE_TIMEOUT and MACHINE_TIMEOUT_DEV_WRITEABLE
483  *
484  * @abstract
485  * Defines a Machine Timeout that can be overridden and
486  * scaled through the device tree and boot-args.
487  *
488  * The variant with the _DEV_WRITEABLE suffix does not mark the timeout as
489  * SECURITY_READ_ONLY_LATE on DEVELOPMENT kernels, so that e.g.
490  * machine_timeout_init_with_suffix or sysctls can change it after lockdown.
491  *
492  * @param var
493  * The name of the C variable to use for storage. If the storage value
494  * contains 0, the timeout is considered disabled by convention.
495  *
496  * @param timeout_name
497  * The name of the timeout, used for property and boot-arg names. See
498  * the general description of Machine Timeouts above for how this name
499  * ends up being used.
500  *
501  * @param timeout_default
502  * The default value for the timeout if not specified through device
503  * tree or boot-arg. Will still be scaled if a scale factor exists.
504  *
505  * @param var_unit
506  * The unit that the storage variable is in. Note that timeout values
507  * must always be specified as picoseconds in the device tree and
508  * boot-args, but timeout initialization will convert the value to the
509  * unit specified here before writing it to the storage variable.
510  *
511  * @param skip_predicate
512  * Optionally, a function to call to decide whether the timeout should
513  * be set or not.  If NULL, the timeout will always be set (if
514  * specified anywhere). A predicate has the following signature:
515  *     bool skip_predicate (struct machine_timeout_spec const *)
516  */
517 
518 #define _MACHINE_TIMEOUT(var, timeout_name, timeout_default, var_unit, skip_pred) \
519 	struct machine_timeout_spec \
520 	__machine_timeout_spec_ ## var = { \
521 	        .ptr = &var, \
522 	        .default_value = timeout_default, \
523 	        .unit_scale = var_unit, \
524 	        .name = timeout_name, \
525 	        .skip_predicate = skip_pred, \
526 	}; \
527 	__STARTUP_ARG(var, __LINE__, TIMEOUTS, STARTUP_RANK_FIRST, \
528 	    machine_timeout_init, &__machine_timeout_spec_ ## var)
529 
530 #define MACHINE_TIMEOUT(var, name, default, unit, skip_predicate)       \
531 	SECURITY_READ_ONLY_LATE(machine_timeout_t) var = 0;                                     \
532 	_MACHINE_TIMEOUT(var, name, default, unit, skip_predicate)
533 
534 #if DEVELOPMENT || DEBUG
535 #define MACHINE_TIMEOUT_DEV_WRITEABLE(var, name, default, unit, skip_predicate)       \
536 	machine_timeout_t var = 0; \
537 	_MACHINE_TIMEOUT(var, name, default, unit, skip_predicate)
538 #else
539 #define MACHINE_TIMEOUT_DEV_WRITEABLE(var, name, default, unit, skip_predicate) \
540 	MACHINE_TIMEOUT(var, name, default, unit, skip_predicate)
541 #endif /* DEVELOPMENT || DEBUG */
542 
543 /*!
544  * @macro MACHINE_TIMEOUT_SPEC_REF
545  *
546  * @abstract
547  * References a previously defined MACHINE_TIMEOUT.
548  *
549  * This is primarily useful for overriding individual timeouts
550  * at arbitrary times (even after boot), by manually calling
551  * machine_timeout_init_with_suffix() with this macro
552  * as first argument, and a suffix to apply to both device tree and
553  * boot-arg as second argument.
554  *
555  * @param var
556  * The name of the C variable used for storage, as it was specified
557  * in MACHINE_TIMEOUT.
558  */
559 #define MACHINE_TIMEOUT_SPEC_REF(var) (&__machine_timeout_spec_ ## var)
560 
561 /*!
562  * @macro MACHINE_TIMEOUT_SPEC_DECL
563  *
564  * @abstract
565  * Declaration of machine timeout spec, mostly useful to make it known
566  * for MACHINE_TIMEOUT_SPEC_REF.
567  *
568  * @param var
569  * The name of the C variable used for storage, as it was specified
570  * in MACHINE_TIMEOUT.
571  */
572 #define MACHINE_TIMEOUT_SPEC_DECL(var) extern struct machine_timeout_spec __machine_timeout_spec_ ## var
573 
574 /*
575  * Event subsystem
576  *
577  * This allows to define a few system-wide events that allow for loose coupling
578  * between subsystems interested in those events and the emitter.
579  */
580 
581 /*!
582  * @macro EVENT_DECLARE()
583  *
584  * @brief
585  * Declares an event namespace with a given callback type.
586  *
587  * @param name          The name for the event (typically in all caps).
588  * @param cb_type_t     A function type for the callbacks.
589  */
590 #define EVENT_DECLARE(name, cb_type_t) \
591 	struct name##_event {                                                   \
592 	        struct event_hdr        evt_link;                               \
593 	        cb_type_t              *evt_cb;                                 \
594 	};                                                                      \
595 	extern struct event_hdr name##_HEAD
596 
597 /*!
598  * @macro EVENT_DEFINE()
599  *
600  * @brief
601  * Defines the head for the event corresponding to an EVENT_DECLARE()
602  */
603 #define EVENT_DEFINE(name) \
604 	__security_const_late struct event_hdr name##_HEAD
605 
606 /*!
607  * @macro EVENT_REGISTER_HANDLER()
608  *
609  * @brief
610  * Registers a handler for a given event.
611  *
612  * @param name          The name for the event as declared in EVENT_DECLARE()
613  * @param handler       The handler to register for this event.
614  */
615 #define EVENT_REGISTER_HANDLER(name, handler) \
616 	__EVENT_REGISTER(name, __LINE__, handler)
617 
618 
619 /*!
620  * @macro EVENT_INVOKE()
621  *
622  * @brief
623  * Call all the events handlers with the specified arguments.
624  *
625  * @param name          The name for the event as declared in EVENT_DECLARE()
626  * @param handler       The handler to register for this event.
627  */
628 #define EVENT_INVOKE(name, ...) \
629 	for (struct event_hdr *__e = &name##_HEAD; (__e = __e->next);) {        \
630 	        __container_of(__e, struct name##_event,                        \
631 	            evt_link)->evt_cb(__VA_ARGS__);                             \
632 	}
633 
634 
635 #if DEBUG || DEVELOPMENT
636 
637 /*!
638  * @macro SYSCTL_TEST_REGISTER
639  *
640  * @abstract
641  * Declares a test that will appear under @c debug.test.${name}.
642  *
643  * @param name
644  * An identifier that will be stringified to form the sysctl test name.
645  *
646  * @param cb
647  * The callback to run, of type:
648  * <code>
649  *     int (callback *)(int64_t value, int64_t *);
650  * </code>
651  */
652 #define SYSCTL_TEST_REGISTER(name, cb) \
653 	static __startup_data struct sysctl_test_setup_spec \
654 	__startup_SYSCTL_TEST_ ## name = { \
655 	        .st_name = #name, \
656 	        .st_func = &cb, \
657 	}; \
658 	STARTUP_ARG(SYSCTL, STARTUP_RANK_MIDDLE, \
659 	    sysctl_register_test_startup, &__startup_SYSCTL_TEST_ ## name)
660 
661 #endif /* DEBUG || DEVELOPMENT */
662 #pragma mark - internals
663 
664 __END_DECLS
665 
666 #ifdef __cplusplus
667 template <typename T>
668 struct __startup_tunable {
669 	static const bool value  = false;
670 };
671 
672 template <>
673 struct __startup_tunable <bool>{
674 	static const bool value = true;
675 };
676 #define __startup_type_is_bool(type_t) __startup_tunable<type_t>::value
677 #else
678 #define __startup_type_is_bool(type_t) __builtin_types_compatible_p(bool, type_t)
679 #endif
680 
681 __BEGIN_DECLS
682 
683 #define __TUNABLE(type_t, var, key) \
684 	static __startup_data char __startup_TUNABLES_name_ ## var[] = key; \
685 	static __startup_data struct startup_tunable_spec \
686 	__startup_TUNABLES_spec_ ## var = { \
687 	        .name = __startup_TUNABLES_name_ ## var, \
688 	        .var_addr = (void *)&var, \
689 	        .var_len = sizeof(type_t), \
690 	        .var_is_bool = __startup_type_is_bool(type_t), \
691 	}; \
692 	__STARTUP_ARG(var, __LINE__, TUNABLES, STARTUP_RANK_FIRST, \
693 	    kernel_startup_tunable_init, &__startup_TUNABLES_spec_ ## var)
694 
695 #define __TUNABLE_STR(var, key) \
696 	static __startup_data char __startup_TUNABLES_name_ ## var[] = key; \
697 	static __startup_data struct startup_tunable_spec \
698 	__startup_TUNABLES_spec_ ## var = { \
699 	        .name = __startup_TUNABLES_name_ ## var, \
700 	        .var_addr = (void *)&var, \
701 	        .var_len = sizeof(var), \
702 	        .var_is_str = true, \
703 	}; \
704 	__STARTUP_ARG(var, __LINE__, TUNABLES, STARTUP_RANK_FIRST, \
705 	    kernel_startup_tunable_init, &__startup_TUNABLES_spec_ ## var)
706 
707 #define __TUNABLE_DT(type_t, var, dt_base_key, dt_name_key, boot_arg_key, flags) \
708 	static __startup_data char __startup_TUNABLES_dt_base_ ## var[] = dt_base_key; \
709 	static __startup_data char __startup_TUNABLES_dt_name_ ## var[] = dt_name_key; \
710 	static __startup_data char __startup_TUNABLES_name_ ## var[] = boot_arg_key; \
711 	static __startup_data struct startup_tunable_dt_spec \
712 	__startup_TUNABLES_DT_spec_ ## var = { \
713 	        .dt_base = __startup_TUNABLES_dt_base_ ## var, \
714 	        .dt_name = __startup_TUNABLES_dt_name_ ## var, \
715 	        .dt_chosen_override = (bool)((flags) & TUNABLE_DT_CHECK_CHOSEN), \
716 	        .boot_arg_name = __startup_TUNABLES_name_ ## var, \
717 	        .var_addr = (void *)&var, \
718 	        .var_len = sizeof(type_t), \
719 	        .var_is_bool = __startup_type_is_bool(type_t), \
720 	}; \
721 	__STARTUP_ARG(var, __LINE__, TUNABLES, STARTUP_RANK_FIRST, \
722 	    kernel_startup_tunable_dt_init, &__startup_TUNABLES_DT_spec_ ## var)
723 
724 #ifdef __cplusplus
725 #define __STARTUP_FUNC_CAST(func, a) \
726 	    (void(*)(const void *))func
727 #else
728 #define __STARTUP_FUNC_CAST(func, a) \
729 	    (typeof(func(a))(*)(const void *))func
730 #endif
731 
732 
733 #define __STARTUP1(name, line, subsystem, rank, func, a, b) \
734 	__PLACE_IN_SECTION(STARTUP_HOOK_SEGMENT "," STARTUP_HOOK_SECTION) \
735 	static const struct startup_entry \
736 	__startup_ ## subsystem ## _entry_ ## name ## _ ## line = { \
737 	    STARTUP_SUB_ ## subsystem, \
738 	    rank, __STARTUP_FUNC_CAST(func, a), b, \
739 	}
740 
741 #define __STARTUP(name, line, subsystem, rank, func) \
742 	__STARTUP1(name, line, subsystem, rank, func, , NULL)
743 
744 #define __STARTUP_ARG(name, line, subsystem, rank, func, arg) \
745 	__STARTUP1(name, line, subsystem, rank, func, arg, arg)
746 
747 struct startup_entry {
748 	startup_subsystem_id_t subsystem;
749 	startup_rank_t         rank;
750 	void                 (*func)(const void *);
751 	const void            *arg;
752 };
753 
754 struct startup_tunable_spec {
755 	const char *name;
756 	void       *var_addr;
757 	int         var_len;
758 	bool        var_is_bool;
759 	bool        var_is_str;
760 };
761 
762 struct startup_tunable_dt_spec {
763 	const char *dt_base;
764 	const char *dt_name;
765 	bool        dt_chosen_override;
766 	const char *boot_arg_name;
767 	void       *var_addr;
768 	int         var_len;
769 	bool        var_is_bool;
770 };
771 
772 #if DEBUG || DEVELOPMENT
773 struct sysctl_test_setup_spec {
774 	const char *st_name;
775 	int (*st_func)(int64_t, int64_t *);
776 };
777 
778 extern void sysctl_register_test_startup(
779 	struct sysctl_test_setup_spec *spec);
780 #endif /* DEBUG || DEVELOPMENT */
781 
782 /*
783  * Kernel and machine startup declarations
784  */
785 
786 /* Initialize kernel */
787 extern void kernel_startup_bootstrap(void);
788 extern void kernel_startup_initialize_upto(startup_subsystem_id_t upto);
789 extern void kernel_startup_tunable_init(const struct startup_tunable_spec *);
790 extern void kernel_startup_tunable_dt_init(const struct startup_tunable_dt_spec *);
791 extern void kernel_bootstrap(void);
792 
793 /* Initialize machine dependent stuff */
794 extern void machine_init(void);
795 
796 extern void slave_main(void *machine_param);
797 
798 /*
799  * The following must be implemented in machine dependent code.
800  */
801 
802 /* Slave cpu initialization */
803 extern void slave_machine_init(void *machine_param);
804 
805 /* Device subsystem initialization */
806 extern void device_service_create(void);
807 
808 struct event_hdr {
809 	struct event_hdr *next;
810 };
811 
812 extern void event_register_handler(struct event_hdr *event_hdr);
813 
814 #define __EVENT_REGISTER(name, lno, handler) \
815 	static __security_const_late struct name##_event name##_event_##lno = { \
816 	        .evt_link.next = &name##_HEAD,                                  \
817 	        .evt_cb = (handler),                                            \
818 	};                                                                      \
819 	__STARTUP_ARG(name, lno, EVENT, STARTUP_RANK_FIRST,                     \
820 	    event_register_handler, &name##_event_##lno.evt_link)
821 
822 #ifdef  MACH_BSD
823 
824 /* BSD subsystem initialization */
825 extern void bsd_init(void);
826 
827 #endif  /* MACH_BSD */
828 
829 #pragma GCC visibility pop
830 
831 __END_DECLS
832 
833 #endif  /* _KERN_STARTUP_H_ */
834 
835 #endif  /* XNU_KERNEL_PRIVATE */
836