xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision 61eb2860)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  EFI application runtime services
4  *
5  *  Copyright (c) 2016 Alexander Graf
6  */
7 
8 #include <common.h>
9 #include <command.h>
10 #include <dm.h>
11 #include <elf.h>
12 #include <efi_loader.h>
13 #include <rtc.h>
14 
15 /* For manual relocation support */
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 struct efi_runtime_mmio_list {
19 	struct list_head link;
20 	void **ptr;
21 	u64 paddr;
22 	u64 len;
23 };
24 
25 /* This list contains all runtime available mmio regions */
26 LIST_HEAD(efi_runtime_mmio);
27 
28 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void);
29 static efi_status_t __efi_runtime EFIAPI efi_device_error(void);
30 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void);
31 
32 /*
33  * TODO(sjg@chromium.org): These defines and structures should come from the ELF
34  * header for each architecture (or a generic header) rather than being repeated
35  * here.
36  */
37 #if defined(__aarch64__)
38 #define R_RELATIVE	R_AARCH64_RELATIVE
39 #define R_MASK		0xffffffffULL
40 #define IS_RELA		1
41 #elif defined(__arm__)
42 #define R_RELATIVE	R_ARM_RELATIVE
43 #define R_MASK		0xffULL
44 #elif defined(__i386__)
45 #define R_RELATIVE	R_386_RELATIVE
46 #define R_MASK		0xffULL
47 #elif defined(__x86_64__)
48 #define R_RELATIVE	R_X86_64_RELATIVE
49 #define R_MASK		0xffffffffULL
50 #define IS_RELA		1
51 #elif defined(__riscv)
52 #define R_RELATIVE	R_RISCV_RELATIVE
53 #define R_MASK		0xffULL
54 #define IS_RELA		1
55 
56 struct dyn_sym {
57 	ulong foo1;
58 	ulong addr;
59 	u32 foo2;
60 	u32 foo3;
61 };
62 #if (__riscv_xlen == 32)
63 #define R_ABSOLUTE	R_RISCV_32
64 #define SYM_INDEX	8
65 #elif (__riscv_xlen == 64)
66 #define R_ABSOLUTE	R_RISCV_64
67 #define SYM_INDEX	32
68 #else
69 #error unknown riscv target
70 #endif
71 #else
72 #error Need to add relocation awareness
73 #endif
74 
75 struct elf_rel {
76 	ulong *offset;
77 	ulong info;
78 };
79 
80 struct elf_rela {
81 	ulong *offset;
82 	ulong info;
83 	long addend;
84 };
85 
86 /*
87  * EFI runtime code lives in two stages. In the first stage, U-Boot and an EFI
88  * payload are running concurrently at the same time. In this mode, we can
89  * handle a good number of runtime callbacks
90  */
91 
92 /**
93  * efi_update_table_header_crc32() - Update crc32 in table header
94  *
95  * @table:	EFI table
96  */
97 void __efi_runtime efi_update_table_header_crc32(struct efi_table_hdr *table)
98 {
99 	table->crc32 = 0;
100 	table->crc32 = crc32(0, (const unsigned char *)table,
101 			     table->headersize);
102 }
103 
104 /**
105  * efi_reset_system_boottime() - reset system at boot time
106  *
107  * This function implements the ResetSystem() runtime service before
108  * SetVirtualAddressMap() is called.
109  *
110  * See the Unified Extensible Firmware Interface (UEFI) specification for
111  * details.
112  *
113  * @reset_type:		type of reset to perform
114  * @reset_status:	status code for the reset
115  * @data_size:		size of reset_data
116  * @reset_data:		information about the reset
117  */
118 static void EFIAPI efi_reset_system_boottime(
119 			enum efi_reset_type reset_type,
120 			efi_status_t reset_status,
121 			unsigned long data_size, void *reset_data)
122 {
123 	struct efi_event *evt;
124 
125 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
126 		  reset_data);
127 
128 	/* Notify reset */
129 	list_for_each_entry(evt, &efi_events, link) {
130 		if (evt->group &&
131 		    !guidcmp(evt->group,
132 			     &efi_guid_event_group_reset_system)) {
133 			efi_signal_event(evt, false);
134 			break;
135 		}
136 	}
137 	switch (reset_type) {
138 	case EFI_RESET_COLD:
139 	case EFI_RESET_WARM:
140 	case EFI_RESET_PLATFORM_SPECIFIC:
141 		do_reset(NULL, 0, 0, NULL);
142 		break;
143 	case EFI_RESET_SHUTDOWN:
144 		/* We don't have anything to map this to */
145 		break;
146 	}
147 
148 	while (1) { }
149 }
150 
151 /**
152  * efi_get_time_boottime() - get current time at boot time
153  *
154  * This function implements the GetTime runtime service before
155  * SetVirtualAddressMap() is called.
156  *
157  * See the Unified Extensible Firmware Interface (UEFI) specification
158  * for details.
159  *
160  * @time:		pointer to structure to receive current time
161  * @capabilities:	pointer to structure to receive RTC properties
162  * Returns:		status code
163  */
164 static efi_status_t EFIAPI efi_get_time_boottime(
165 			struct efi_time *time,
166 			struct efi_time_cap *capabilities)
167 {
168 #ifdef CONFIG_DM_RTC
169 	efi_status_t ret = EFI_SUCCESS;
170 	int r;
171 	struct rtc_time tm;
172 	struct udevice *dev;
173 
174 	EFI_ENTRY("%p %p", time, capabilities);
175 
176 	if (!time) {
177 		ret = EFI_INVALID_PARAMETER;
178 		goto out;
179 	}
180 
181 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
182 	if (!r)
183 		r = dm_rtc_get(dev, &tm);
184 	if (r) {
185 		ret = EFI_DEVICE_ERROR;
186 		goto out;
187 	}
188 
189 	memset(time, 0, sizeof(*time));
190 	time->year = tm.tm_year;
191 	time->month = tm.tm_mon;
192 	time->day = tm.tm_mday;
193 	time->hour = tm.tm_hour;
194 	time->minute = tm.tm_min;
195 	time->second = tm.tm_sec;
196 	time->daylight = EFI_TIME_ADJUST_DAYLIGHT;
197 	if (tm.tm_isdst > 0)
198 		time->daylight |= EFI_TIME_IN_DAYLIGHT;
199 	time->timezone = EFI_UNSPECIFIED_TIMEZONE;
200 
201 	if (capabilities) {
202 		/* Set reasonable dummy values */
203 		capabilities->resolution = 1;		/* 1 Hz */
204 		capabilities->accuracy = 100000000;	/* 100 ppm */
205 		capabilities->sets_to_zero = false;
206 	}
207 out:
208 	return EFI_EXIT(ret);
209 #else
210 	EFI_ENTRY("%p %p", time, capabilities);
211 	return EFI_EXIT(EFI_DEVICE_ERROR);
212 #endif
213 }
214 
215 
216 /**
217  * efi_reset_system() - reset system
218  *
219  * This function implements the ResetSystem() runtime service after
220  * SetVirtualAddressMap() is called. It only executes an endless loop.
221  * Boards may override the helpers below to implement reset functionality.
222  *
223  * See the Unified Extensible Firmware Interface (UEFI) specification for
224  * details.
225  *
226  * @reset_type:		type of reset to perform
227  * @reset_status:	status code for the reset
228  * @data_size:		size of reset_data
229  * @reset_data:		information about the reset
230  */
231 void __weak __efi_runtime EFIAPI efi_reset_system(
232 			enum efi_reset_type reset_type,
233 			efi_status_t reset_status,
234 			unsigned long data_size, void *reset_data)
235 {
236 	/* Nothing we can do */
237 	while (1) { }
238 }
239 
240 /**
241  * efi_reset_system_init() - initialize the reset driver
242  *
243  * Boards may override this function to initialize the reset driver.
244  */
245 efi_status_t __weak efi_reset_system_init(void)
246 {
247 	return EFI_SUCCESS;
248 }
249 
250 /**
251  * efi_get_time() - get current time
252  *
253  * This function implements the GetTime runtime service after
254  * SetVirtualAddressMap() is called. As the U-Boot driver are not available
255  * anymore only an error code is returned.
256  *
257  * See the Unified Extensible Firmware Interface (UEFI) specification
258  * for details.
259  *
260  * @time:		pointer to structure to receive current time
261  * @capabilities:	pointer to structure to receive RTC properties
262  * Returns:		status code
263  */
264 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
265 			struct efi_time *time,
266 			struct efi_time_cap *capabilities)
267 {
268 	/* Nothing we can do */
269 	return EFI_DEVICE_ERROR;
270 }
271 
272 struct efi_runtime_detach_list_struct {
273 	void *ptr;
274 	void *patchto;
275 };
276 
277 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
278 	{
279 		/* do_reset is gone */
280 		.ptr = &efi_runtime_services.reset_system,
281 		.patchto = efi_reset_system,
282 	}, {
283 		/* invalidate_*cache_all are gone */
284 		.ptr = &efi_runtime_services.set_virtual_address_map,
285 		.patchto = &efi_invalid_parameter,
286 	}, {
287 		/* RTC accessors are gone */
288 		.ptr = &efi_runtime_services.get_time,
289 		.patchto = &efi_get_time,
290 	}, {
291 		/* Clean up system table */
292 		.ptr = &systab.con_in,
293 		.patchto = NULL,
294 	}, {
295 		/* Clean up system table */
296 		.ptr = &systab.con_out,
297 		.patchto = NULL,
298 	}, {
299 		/* Clean up system table */
300 		.ptr = &systab.std_err,
301 		.patchto = NULL,
302 	}, {
303 		/* Clean up system table */
304 		.ptr = &systab.boottime,
305 		.patchto = NULL,
306 	}, {
307 		.ptr = &efi_runtime_services.get_variable,
308 		.patchto = &efi_device_error,
309 	}, {
310 		.ptr = &efi_runtime_services.get_next_variable_name,
311 		.patchto = &efi_device_error,
312 	}, {
313 		.ptr = &efi_runtime_services.set_variable,
314 		.patchto = &efi_device_error,
315 	}
316 };
317 
318 static bool efi_runtime_tobedetached(void *p)
319 {
320 	int i;
321 
322 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
323 		if (efi_runtime_detach_list[i].ptr == p)
324 			return true;
325 
326 	return false;
327 }
328 
329 static void efi_runtime_detach(ulong offset)
330 {
331 	int i;
332 	ulong patchoff = offset - (ulong)gd->relocaddr;
333 
334 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
335 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
336 		ulong *p = efi_runtime_detach_list[i].ptr;
337 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
338 
339 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
340 		*p = newaddr;
341 	}
342 
343 	/* Update CRC32 */
344 	efi_update_table_header_crc32(&efi_runtime_services.hdr);
345 }
346 
347 /* Relocate EFI runtime to uboot_reloc_base = offset */
348 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
349 {
350 #ifdef IS_RELA
351 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
352 #else
353 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
354 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
355 #endif
356 
357 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
358 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
359 		ulong base = CONFIG_SYS_TEXT_BASE;
360 		ulong *p;
361 		ulong newaddr;
362 
363 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
364 
365 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__,
366 		      rel->info, *p, rel->offset);
367 
368 		switch (rel->info & R_MASK) {
369 		case R_RELATIVE:
370 #ifdef IS_RELA
371 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
372 #else
373 		newaddr = *p - lastoff + offset;
374 #endif
375 			break;
376 #ifdef R_ABSOLUTE
377 		case R_ABSOLUTE: {
378 			ulong symidx = rel->info >> SYM_INDEX;
379 			extern struct dyn_sym __dyn_sym_start[];
380 			newaddr = __dyn_sym_start[symidx].addr + offset;
381 			break;
382 		}
383 #endif
384 		default:
385 			if (!efi_runtime_tobedetached(p))
386 				printf("%s: Unknown relocation type %llx\n",
387 				       __func__, rel->info & R_MASK);
388 			continue;
389 		}
390 
391 		/* Check if the relocation is inside bounds */
392 		if (map && ((newaddr < map->virtual_start) ||
393 		    newaddr > (map->virtual_start +
394 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
395 			if (!efi_runtime_tobedetached(p))
396 				printf("%s: Relocation at %p is out of "
397 				       "range (%lx)\n", __func__, p, newaddr);
398 			continue;
399 		}
400 
401 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
402 		*p = newaddr;
403 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
404 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
405 	}
406 
407 #ifndef IS_RELA
408 	lastoff = offset;
409 #endif
410 
411         invalidate_icache_all();
412 }
413 
414 /**
415  * efi_set_virtual_address_map() - change from physical to virtual mapping
416  *
417  * This function implements the SetVirtualAddressMap() runtime service.
418  *
419  * See the Unified Extensible Firmware Interface (UEFI) specification for
420  * details.
421  *
422  * @memory_map_size:	size of the virtual map
423  * @descriptor_size:	size of an entry in the map
424  * @descriptor_version:	version of the map entries
425  * @virtmap:		virtual address mapping information
426  * Return:		status code
427  */
428 static efi_status_t EFIAPI efi_set_virtual_address_map(
429 			unsigned long memory_map_size,
430 			unsigned long descriptor_size,
431 			uint32_t descriptor_version,
432 			struct efi_mem_desc *virtmap)
433 {
434 	ulong runtime_start = (ulong)&__efi_runtime_start &
435 			      ~(ulong)EFI_PAGE_MASK;
436 	int n = memory_map_size / descriptor_size;
437 	int i;
438 
439 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
440 		  descriptor_version, virtmap);
441 
442 	/* Rebind mmio pointers */
443 	for (i = 0; i < n; i++) {
444 		struct efi_mem_desc *map = (void*)virtmap +
445 					   (descriptor_size * i);
446 		struct list_head *lhandle;
447 		efi_physical_addr_t map_start = map->physical_start;
448 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
449 		efi_physical_addr_t map_end = map_start + map_len;
450 		u64 off = map->virtual_start - map_start;
451 
452 		/* Adjust all mmio pointers in this region */
453 		list_for_each(lhandle, &efi_runtime_mmio) {
454 			struct efi_runtime_mmio_list *lmmio;
455 
456 			lmmio = list_entry(lhandle,
457 					   struct efi_runtime_mmio_list,
458 					   link);
459 			if ((map_start <= lmmio->paddr) &&
460 			    (map_end >= lmmio->paddr)) {
461 				uintptr_t new_addr = lmmio->paddr + off;
462 				*lmmio->ptr = (void *)new_addr;
463 			}
464 		}
465 		if ((map_start <= (uintptr_t)systab.tables) &&
466 		    (map_end >= (uintptr_t)systab.tables)) {
467 			char *ptr = (char *)systab.tables;
468 
469 			ptr += off;
470 			systab.tables = (struct efi_configuration_table *)ptr;
471 		}
472 	}
473 
474 	/* Move the actual runtime code over */
475 	for (i = 0; i < n; i++) {
476 		struct efi_mem_desc *map;
477 
478 		map = (void*)virtmap + (descriptor_size * i);
479 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
480 			ulong new_offset = map->virtual_start -
481 					   (runtime_start - gd->relocaddr);
482 
483 			efi_runtime_relocate(new_offset, map);
484 			/* Once we're virtual, we can no longer handle
485 			   complex callbacks */
486 			efi_runtime_detach(new_offset);
487 			return EFI_EXIT(EFI_SUCCESS);
488 		}
489 	}
490 
491 	return EFI_EXIT(EFI_INVALID_PARAMETER);
492 }
493 
494 /**
495  * efi_add_runtime_mmio() - add memory-mapped IO region
496  *
497  * This function adds a memory-mapped IO region to the memory map to make it
498  * available at runtime.
499  *
500  * @mmio_ptr:		address of the memory-mapped IO region
501  * @len:		size of the memory-mapped IO region
502  * Returns:		status code
503  */
504 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
505 {
506 	struct efi_runtime_mmio_list *newmmio;
507 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
508 	uint64_t addr = *(uintptr_t *)mmio_ptr;
509 	uint64_t retaddr;
510 
511 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
512 	if (retaddr != addr)
513 		return EFI_OUT_OF_RESOURCES;
514 
515 	newmmio = calloc(1, sizeof(*newmmio));
516 	if (!newmmio)
517 		return EFI_OUT_OF_RESOURCES;
518 	newmmio->ptr = mmio_ptr;
519 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
520 	newmmio->len = len;
521 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
522 
523 	return EFI_SUCCESS;
524 }
525 
526 /*
527  * In the second stage, U-Boot has disappeared. To isolate our runtime code
528  * that at this point still exists from the rest, we put it into a special
529  * section.
530  *
531  *        !!WARNING!!
532  *
533  * This means that we can not rely on any code outside of this file in any
534  * function or variable below this line.
535  *
536  * Please keep everything fully self-contained and annotated with
537  * __efi_runtime and __efi_runtime_data markers.
538  */
539 
540 /*
541  * Relocate the EFI runtime stub to a different place. We need to call this
542  * the first time we expose the runtime interface to a user and on set virtual
543  * address map calls.
544  */
545 
546 /**
547  * efi_unimplemented() - replacement function, returns EFI_UNSUPPORTED
548  *
549  * This function is used after SetVirtualAddressMap() is called as replacement
550  * for services that are not available anymore due to constraints of the U-Boot
551  * implementation.
552  *
553  * Return:	EFI_UNSUPPORTED
554  */
555 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
556 {
557 	return EFI_UNSUPPORTED;
558 }
559 
560 /**
561  * efi_device_error() - replacement function, returns EFI_DEVICE_ERROR
562  *
563  * This function is used after SetVirtualAddressMap() is called as replacement
564  * for services that are not available anymore due to constraints of the U-Boot
565  * implementation.
566  *
567  * Return:	EFI_DEVICE_ERROR
568  */
569 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
570 {
571 	return EFI_DEVICE_ERROR;
572 }
573 
574 /**
575  * efi_invalid_parameter() - replacement function, returns EFI_INVALID_PARAMETER
576  *
577  * This function is used after SetVirtualAddressMap() is called as replacement
578  * for services that are not available anymore due to constraints of the U-Boot
579  * implementation.
580  *
581  * Return:	EFI_INVALID_PARAMETER
582  */
583 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
584 {
585 	return EFI_INVALID_PARAMETER;
586 }
587 
588 /**
589  * efi_update_capsule() - process information from operating system
590  *
591  * This function implements the UpdateCapsule() runtime service.
592  *
593  * See the Unified Extensible Firmware Interface (UEFI) specification for
594  * details.
595  *
596  * @capsule_header_array:	pointer to array of virtual pointers
597  * @capsule_count:		number of pointers in capsule_header_array
598  * @scatter_gather_list:	pointer to arry of physical pointers
599  * Returns:			status code
600  */
601 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
602 			struct efi_capsule_header **capsule_header_array,
603 			efi_uintn_t capsule_count,
604 			u64 scatter_gather_list)
605 {
606 	return EFI_UNSUPPORTED;
607 }
608 
609 /**
610  * efi_query_capsule_caps() - check if capsule is supported
611  *
612  * This function implements the QueryCapsuleCapabilities() runtime service.
613  *
614  * See the Unified Extensible Firmware Interface (UEFI) specification for
615  * details.
616  *
617  * @capsule_header_array:	pointer to array of virtual pointers
618  * @capsule_count:		number of pointers in capsule_header_array
619  * @maximum_capsule_size:	maximum capsule size
620  * @reset_type:			type of reset needed for capsule update
621  * Returns:			status code
622  */
623 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
624 			struct efi_capsule_header **capsule_header_array,
625 			efi_uintn_t capsule_count,
626 			u64 maximum_capsule_size,
627 			u32 reset_type)
628 {
629 	return EFI_UNSUPPORTED;
630 }
631 
632 /**
633  * efi_query_variable_info() - get information about EFI variables
634  *
635  * This function implements the QueryVariableInfo() runtime service.
636  *
637  * See the Unified Extensible Firmware Interface (UEFI) specification for
638  * details.
639  *
640  * @attributes:				bitmask to select variables to be
641  *					queried
642  * @maximum_variable_storage_size:	maximum size of storage area for the
643  *					selected variable types
644  * @remaining_variable_storage_size:	remaining size of storage are for the
645  *					selected variable types
646  * @maximum_variable_size:		maximum size of a variable of the
647  *					selected type
648  * Returns:				status code
649  */
650 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
651 			u32 attributes,
652 			u64 *maximum_variable_storage_size,
653 			u64 *remaining_variable_storage_size,
654 			u64 *maximum_variable_size)
655 {
656 	return EFI_UNSUPPORTED;
657 }
658 
659 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
660 	.hdr = {
661 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
662 		.revision = EFI_SPECIFICATION_VERSION,
663 		.headersize = sizeof(struct efi_runtime_services),
664 	},
665 	.get_time = &efi_get_time_boottime,
666 	.set_time = (void *)&efi_device_error,
667 	.get_wakeup_time = (void *)&efi_unimplemented,
668 	.set_wakeup_time = (void *)&efi_unimplemented,
669 	.set_virtual_address_map = &efi_set_virtual_address_map,
670 	.convert_pointer = (void *)&efi_invalid_parameter,
671 	.get_variable = efi_get_variable,
672 	.get_next_variable_name = efi_get_next_variable_name,
673 	.set_variable = efi_set_variable,
674 	.get_next_high_mono_count = (void *)&efi_device_error,
675 	.reset_system = &efi_reset_system_boottime,
676 	.update_capsule = efi_update_capsule,
677 	.query_capsule_caps = efi_query_capsule_caps,
678 	.query_variable_info = efi_query_variable_info,
679 };
680