xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision a370e429)
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(__x86_64__) || defined(__i386__)
45 #define R_RELATIVE	R_386_RELATIVE
46 #define R_MASK		0xffULL
47 #elif defined(__riscv)
48 #define R_RELATIVE	R_RISCV_RELATIVE
49 #define R_MASK		0xffULL
50 #define IS_RELA		1
51 
52 struct dyn_sym {
53 	ulong foo1;
54 	ulong addr;
55 	u32 foo2;
56 	u32 foo3;
57 };
58 #if (__riscv_xlen == 32)
59 #define R_ABSOLUTE	R_RISCV_32
60 #define SYM_INDEX	8
61 #elif (__riscv_xlen == 64)
62 #define R_ABSOLUTE	R_RISCV_64
63 #define SYM_INDEX	32
64 #else
65 #error unknown riscv target
66 #endif
67 #else
68 #error Need to add relocation awareness
69 #endif
70 
71 struct elf_rel {
72 	ulong *offset;
73 	ulong info;
74 };
75 
76 struct elf_rela {
77 	ulong *offset;
78 	ulong info;
79 	long addend;
80 };
81 
82 /*
83  * EFI runtime code lives in two stages. In the first stage, U-Boot and an EFI
84  * payload are running concurrently at the same time. In this mode, we can
85  * handle a good number of runtime callbacks
86  */
87 
88 /**
89  * efi_update_table_header_crc32() - Update crc32 in table header
90  *
91  * @table:	EFI table
92  */
93 void __efi_runtime efi_update_table_header_crc32(struct efi_table_hdr *table)
94 {
95 	table->crc32 = 0;
96 	table->crc32 = crc32(0, (const unsigned char *)table,
97 			     table->headersize);
98 }
99 
100 /**
101  * efi_reset_system_boottime() - reset system at boot time
102  *
103  * This function implements the ResetSystem() runtime service before
104  * SetVirtualAddressMap() is called.
105  *
106  * See the Unified Extensible Firmware Interface (UEFI) specification for
107  * details.
108  *
109  * @reset_type:		type of reset to perform
110  * @reset_status:	status code for the reset
111  * @data_size:		size of reset_data
112  * @reset_data:		information about the reset
113  */
114 static void EFIAPI efi_reset_system_boottime(
115 			enum efi_reset_type reset_type,
116 			efi_status_t reset_status,
117 			unsigned long data_size, void *reset_data)
118 {
119 	struct efi_event *evt;
120 
121 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
122 		  reset_data);
123 
124 	/* Notify reset */
125 	list_for_each_entry(evt, &efi_events, link) {
126 		if (evt->group &&
127 		    !guidcmp(evt->group,
128 			     &efi_guid_event_group_reset_system)) {
129 			efi_signal_event(evt, false);
130 			break;
131 		}
132 	}
133 	switch (reset_type) {
134 	case EFI_RESET_COLD:
135 	case EFI_RESET_WARM:
136 	case EFI_RESET_PLATFORM_SPECIFIC:
137 		do_reset(NULL, 0, 0, NULL);
138 		break;
139 	case EFI_RESET_SHUTDOWN:
140 		/* We don't have anything to map this to */
141 		break;
142 	}
143 
144 	while (1) { }
145 }
146 
147 /**
148  * efi_get_time_boottime() - get current time at boot time
149  *
150  * This function implements the GetTime runtime service before
151  * SetVirtualAddressMap() is called.
152  *
153  * See the Unified Extensible Firmware Interface (UEFI) specification
154  * for details.
155  *
156  * @time:		pointer to structure to receive current time
157  * @capabilities:	pointer to structure to receive RTC properties
158  * Returns:		status code
159  */
160 static efi_status_t EFIAPI efi_get_time_boottime(
161 			struct efi_time *time,
162 			struct efi_time_cap *capabilities)
163 {
164 #ifdef CONFIG_DM_RTC
165 	efi_status_t ret = EFI_SUCCESS;
166 	int r;
167 	struct rtc_time tm;
168 	struct udevice *dev;
169 
170 	EFI_ENTRY("%p %p", time, capabilities);
171 
172 	if (!time) {
173 		ret = EFI_INVALID_PARAMETER;
174 		goto out;
175 	}
176 
177 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
178 	if (!r)
179 		r = dm_rtc_get(dev, &tm);
180 	if (r) {
181 		ret = EFI_DEVICE_ERROR;
182 		goto out;
183 	}
184 
185 	memset(time, 0, sizeof(*time));
186 	time->year = tm.tm_year;
187 	time->month = tm.tm_mon;
188 	time->day = tm.tm_mday;
189 	time->hour = tm.tm_hour;
190 	time->minute = tm.tm_min;
191 	time->second = tm.tm_sec;
192 	time->daylight = EFI_TIME_ADJUST_DAYLIGHT;
193 	if (tm.tm_isdst > 0)
194 		time->daylight |= EFI_TIME_IN_DAYLIGHT;
195 	time->timezone = EFI_UNSPECIFIED_TIMEZONE;
196 
197 	if (capabilities) {
198 		/* Set reasonable dummy values */
199 		capabilities->resolution = 1;		/* 1 Hz */
200 		capabilities->accuracy = 100000000;	/* 100 ppm */
201 		capabilities->sets_to_zero = false;
202 	}
203 out:
204 	return EFI_EXIT(ret);
205 #else
206 	EFI_ENTRY("%p %p", time, capabilities);
207 	return EFI_EXIT(EFI_DEVICE_ERROR);
208 #endif
209 }
210 
211 
212 /**
213  * efi_reset_system() - reset system
214  *
215  * This function implements the ResetSystem() runtime service after
216  * SetVirtualAddressMap() is called. It only executes an endless loop.
217  * Boards may override the helpers below to implement reset functionality.
218  *
219  * See the Unified Extensible Firmware Interface (UEFI) specification for
220  * details.
221  *
222  * @reset_type:		type of reset to perform
223  * @reset_status:	status code for the reset
224  * @data_size:		size of reset_data
225  * @reset_data:		information about the reset
226  */
227 void __weak __efi_runtime EFIAPI efi_reset_system(
228 			enum efi_reset_type reset_type,
229 			efi_status_t reset_status,
230 			unsigned long data_size, void *reset_data)
231 {
232 	/* Nothing we can do */
233 	while (1) { }
234 }
235 
236 /**
237  * efi_reset_system_init() - initialize the reset driver
238  *
239  * Boards may override this function to initialize the reset driver.
240  */
241 efi_status_t __weak efi_reset_system_init(void)
242 {
243 	return EFI_SUCCESS;
244 }
245 
246 /**
247  * efi_get_time() - get current time
248  *
249  * This function implements the GetTime runtime service after
250  * SetVirtualAddressMap() is called. As the U-Boot driver are not available
251  * anymore only an error code is returned.
252  *
253  * See the Unified Extensible Firmware Interface (UEFI) specification
254  * for details.
255  *
256  * @time:		pointer to structure to receive current time
257  * @capabilities:	pointer to structure to receive RTC properties
258  * Returns:		status code
259  */
260 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
261 			struct efi_time *time,
262 			struct efi_time_cap *capabilities)
263 {
264 	/* Nothing we can do */
265 	return EFI_DEVICE_ERROR;
266 }
267 
268 struct efi_runtime_detach_list_struct {
269 	void *ptr;
270 	void *patchto;
271 };
272 
273 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
274 	{
275 		/* do_reset is gone */
276 		.ptr = &efi_runtime_services.reset_system,
277 		.patchto = efi_reset_system,
278 	}, {
279 		/* invalidate_*cache_all are gone */
280 		.ptr = &efi_runtime_services.set_virtual_address_map,
281 		.patchto = &efi_invalid_parameter,
282 	}, {
283 		/* RTC accessors are gone */
284 		.ptr = &efi_runtime_services.get_time,
285 		.patchto = &efi_get_time,
286 	}, {
287 		/* Clean up system table */
288 		.ptr = &systab.con_in,
289 		.patchto = NULL,
290 	}, {
291 		/* Clean up system table */
292 		.ptr = &systab.con_out,
293 		.patchto = NULL,
294 	}, {
295 		/* Clean up system table */
296 		.ptr = &systab.std_err,
297 		.patchto = NULL,
298 	}, {
299 		/* Clean up system table */
300 		.ptr = &systab.boottime,
301 		.patchto = NULL,
302 	}, {
303 		.ptr = &efi_runtime_services.get_variable,
304 		.patchto = &efi_device_error,
305 	}, {
306 		.ptr = &efi_runtime_services.get_next_variable_name,
307 		.patchto = &efi_device_error,
308 	}, {
309 		.ptr = &efi_runtime_services.set_variable,
310 		.patchto = &efi_device_error,
311 	}
312 };
313 
314 static bool efi_runtime_tobedetached(void *p)
315 {
316 	int i;
317 
318 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
319 		if (efi_runtime_detach_list[i].ptr == p)
320 			return true;
321 
322 	return false;
323 }
324 
325 static void efi_runtime_detach(ulong offset)
326 {
327 	int i;
328 	ulong patchoff = offset - (ulong)gd->relocaddr;
329 
330 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
331 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
332 		ulong *p = efi_runtime_detach_list[i].ptr;
333 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
334 
335 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
336 		*p = newaddr;
337 	}
338 
339 	/* Update CRC32 */
340 	efi_update_table_header_crc32(&efi_runtime_services.hdr);
341 }
342 
343 /* Relocate EFI runtime to uboot_reloc_base = offset */
344 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
345 {
346 #ifdef IS_RELA
347 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
348 #else
349 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
350 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
351 #endif
352 
353 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
354 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
355 		ulong base = CONFIG_SYS_TEXT_BASE;
356 		ulong *p;
357 		ulong newaddr;
358 
359 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
360 
361 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__, rel->info, *p, rel->offset);
362 
363 		switch (rel->info & R_MASK) {
364 		case R_RELATIVE:
365 #ifdef IS_RELA
366 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
367 #else
368 		newaddr = *p - lastoff + offset;
369 #endif
370 			break;
371 #ifdef R_ABSOLUTE
372 		case R_ABSOLUTE: {
373 			ulong symidx = rel->info >> SYM_INDEX;
374 			extern struct dyn_sym __dyn_sym_start[];
375 			newaddr = __dyn_sym_start[symidx].addr + offset;
376 			break;
377 		}
378 #endif
379 		default:
380 			continue;
381 		}
382 
383 		/* Check if the relocation is inside bounds */
384 		if (map && ((newaddr < map->virtual_start) ||
385 		    newaddr > (map->virtual_start +
386 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
387 			if (!efi_runtime_tobedetached(p))
388 				printf("U-Boot EFI: Relocation at %p is out of "
389 				       "range (%lx)\n", p, newaddr);
390 			continue;
391 		}
392 
393 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
394 		*p = newaddr;
395 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
396 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
397 	}
398 
399 #ifndef IS_RELA
400 	lastoff = offset;
401 #endif
402 
403         invalidate_icache_all();
404 }
405 
406 /**
407  * efi_set_virtual_address_map() - change from physical to virtual mapping
408  *
409  * This function implements the SetVirtualAddressMap() runtime service.
410  *
411  * See the Unified Extensible Firmware Interface (UEFI) specification for
412  * details.
413  *
414  * @memory_map_size:	size of the virtual map
415  * @descriptor_size:	size of an entry in the map
416  * @descriptor_version:	version of the map entries
417  * @virtmap:		virtual address mapping information
418  * Return:		status code
419  */
420 static efi_status_t EFIAPI efi_set_virtual_address_map(
421 			unsigned long memory_map_size,
422 			unsigned long descriptor_size,
423 			uint32_t descriptor_version,
424 			struct efi_mem_desc *virtmap)
425 {
426 	ulong runtime_start = (ulong)&__efi_runtime_start &
427 			      ~(ulong)EFI_PAGE_MASK;
428 	int n = memory_map_size / descriptor_size;
429 	int i;
430 
431 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
432 		  descriptor_version, virtmap);
433 
434 	/* Rebind mmio pointers */
435 	for (i = 0; i < n; i++) {
436 		struct efi_mem_desc *map = (void*)virtmap +
437 					   (descriptor_size * i);
438 		struct list_head *lhandle;
439 		efi_physical_addr_t map_start = map->physical_start;
440 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
441 		efi_physical_addr_t map_end = map_start + map_len;
442 		u64 off = map->virtual_start - map_start;
443 
444 		/* Adjust all mmio pointers in this region */
445 		list_for_each(lhandle, &efi_runtime_mmio) {
446 			struct efi_runtime_mmio_list *lmmio;
447 
448 			lmmio = list_entry(lhandle,
449 					   struct efi_runtime_mmio_list,
450 					   link);
451 			if ((map_start <= lmmio->paddr) &&
452 			    (map_end >= lmmio->paddr)) {
453 				uintptr_t new_addr = lmmio->paddr + off;
454 				*lmmio->ptr = (void *)new_addr;
455 			}
456 		}
457 		if ((map_start <= (uintptr_t)systab.tables) &&
458 		    (map_end >= (uintptr_t)systab.tables)) {
459 			char *ptr = (char *)systab.tables;
460 
461 			ptr += off;
462 			systab.tables = (struct efi_configuration_table *)ptr;
463 		}
464 	}
465 
466 	/* Move the actual runtime code over */
467 	for (i = 0; i < n; i++) {
468 		struct efi_mem_desc *map;
469 
470 		map = (void*)virtmap + (descriptor_size * i);
471 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
472 			ulong new_offset = map->virtual_start -
473 					   (runtime_start - gd->relocaddr);
474 
475 			efi_runtime_relocate(new_offset, map);
476 			/* Once we're virtual, we can no longer handle
477 			   complex callbacks */
478 			efi_runtime_detach(new_offset);
479 			return EFI_EXIT(EFI_SUCCESS);
480 		}
481 	}
482 
483 	return EFI_EXIT(EFI_INVALID_PARAMETER);
484 }
485 
486 /**
487  * efi_add_runtime_mmio() - add memory-mapped IO region
488  *
489  * This function adds a memory-mapped IO region to the memory map to make it
490  * available at runtime.
491  *
492  * @mmio_ptr:		address of the memory-mapped IO region
493  * @len:		size of the memory-mapped IO region
494  * Returns:		status code
495  */
496 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
497 {
498 	struct efi_runtime_mmio_list *newmmio;
499 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
500 	uint64_t addr = *(uintptr_t *)mmio_ptr;
501 	uint64_t retaddr;
502 
503 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
504 	if (retaddr != addr)
505 		return EFI_OUT_OF_RESOURCES;
506 
507 	newmmio = calloc(1, sizeof(*newmmio));
508 	if (!newmmio)
509 		return EFI_OUT_OF_RESOURCES;
510 	newmmio->ptr = mmio_ptr;
511 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
512 	newmmio->len = len;
513 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
514 
515 	return EFI_SUCCESS;
516 }
517 
518 /*
519  * In the second stage, U-Boot has disappeared. To isolate our runtime code
520  * that at this point still exists from the rest, we put it into a special
521  * section.
522  *
523  *        !!WARNING!!
524  *
525  * This means that we can not rely on any code outside of this file in any
526  * function or variable below this line.
527  *
528  * Please keep everything fully self-contained and annotated with
529  * __efi_runtime and __efi_runtime_data markers.
530  */
531 
532 /*
533  * Relocate the EFI runtime stub to a different place. We need to call this
534  * the first time we expose the runtime interface to a user and on set virtual
535  * address map calls.
536  */
537 
538 /**
539  * efi_unimplemented() - replacement function, returns EFI_UNSUPPORTED
540  *
541  * This function is used after SetVirtualAddressMap() is called as replacement
542  * for services that are not available anymore due to constraints of the U-Boot
543  * implementation.
544  *
545  * Return:	EFI_UNSUPPORTED
546  */
547 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
548 {
549 	return EFI_UNSUPPORTED;
550 }
551 
552 /**
553  * efi_device_error() - replacement function, returns EFI_DEVICE_ERROR
554  *
555  * This function is used after SetVirtualAddressMap() is called as replacement
556  * for services that are not available anymore due to constraints of the U-Boot
557  * implementation.
558  *
559  * Return:	EFI_DEVICE_ERROR
560  */
561 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
562 {
563 	return EFI_DEVICE_ERROR;
564 }
565 
566 /**
567  * efi_invalid_parameter() - replacement function, returns EFI_INVALID_PARAMETER
568  *
569  * This function is used after SetVirtualAddressMap() is called as replacement
570  * for services that are not available anymore due to constraints of the U-Boot
571  * implementation.
572  *
573  * Return:	EFI_INVALID_PARAMETER
574  */
575 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
576 {
577 	return EFI_INVALID_PARAMETER;
578 }
579 
580 /**
581  * efi_update_capsule() - process information from operating system
582  *
583  * This function implements the UpdateCapsule() runtime service.
584  *
585  * See the Unified Extensible Firmware Interface (UEFI) specification for
586  * details.
587  *
588  * @capsule_header_array:	pointer to array of virtual pointers
589  * @capsule_count:		number of pointers in capsule_header_array
590  * @scatter_gather_list:	pointer to arry of physical pointers
591  * Returns:			status code
592  */
593 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
594 			struct efi_capsule_header **capsule_header_array,
595 			efi_uintn_t capsule_count,
596 			u64 scatter_gather_list)
597 {
598 	return EFI_UNSUPPORTED;
599 }
600 
601 /**
602  * efi_query_capsule_caps() - check if capsule is supported
603  *
604  * This function implements the QueryCapsuleCapabilities() runtime service.
605  *
606  * See the Unified Extensible Firmware Interface (UEFI) specification for
607  * details.
608  *
609  * @capsule_header_array:	pointer to array of virtual pointers
610  * @capsule_count:		number of pointers in capsule_header_array
611  * @maximum_capsule_size:	maximum capsule size
612  * @reset_type:			type of reset needed for capsule update
613  * Returns:			status code
614  */
615 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
616 			struct efi_capsule_header **capsule_header_array,
617 			efi_uintn_t capsule_count,
618 			u64 maximum_capsule_size,
619 			u32 reset_type)
620 {
621 	return EFI_UNSUPPORTED;
622 }
623 
624 /**
625  * efi_query_variable_info() - get information about EFI variables
626  *
627  * This function implements the QueryVariableInfo() runtime service.
628  *
629  * See the Unified Extensible Firmware Interface (UEFI) specification for
630  * details.
631  *
632  * @attributes:				bitmask to select variables to be
633  *					queried
634  * @maximum_variable_storage_size:	maximum size of storage area for the
635  *					selected variable types
636  * @remaining_variable_storage_size:	remaining size of storage are for the
637  *					selected variable types
638  * @maximum_variable_size:		maximum size of a variable of the
639  *					selected type
640  * Returns:				status code
641  */
642 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
643 			u32 attributes,
644 			u64 *maximum_variable_storage_size,
645 			u64 *remaining_variable_storage_size,
646 			u64 *maximum_variable_size)
647 {
648 	return EFI_UNSUPPORTED;
649 }
650 
651 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
652 	.hdr = {
653 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
654 		.revision = EFI_SPECIFICATION_VERSION,
655 		.headersize = sizeof(struct efi_runtime_services),
656 	},
657 	.get_time = &efi_get_time_boottime,
658 	.set_time = (void *)&efi_device_error,
659 	.get_wakeup_time = (void *)&efi_unimplemented,
660 	.set_wakeup_time = (void *)&efi_unimplemented,
661 	.set_virtual_address_map = &efi_set_virtual_address_map,
662 	.convert_pointer = (void *)&efi_invalid_parameter,
663 	.get_variable = efi_get_variable,
664 	.get_next_variable_name = efi_get_next_variable_name,
665 	.set_variable = efi_set_variable,
666 	.get_next_high_mono_count = (void *)&efi_device_error,
667 	.reset_system = &efi_reset_system_boottime,
668 	.update_capsule = efi_update_capsule,
669 	.query_capsule_caps = efi_query_capsule_caps,
670 	.query_variable_info = efi_query_variable_info,
671 };
672