xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision 0797f7f0)
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 structs should come from the elf
34  * header for each arch (or a generic header) rather than being repeated here.
35  */
36 #if defined(__aarch64__)
37 #define R_RELATIVE	R_AARCH64_RELATIVE
38 #define R_MASK		0xffffffffULL
39 #define IS_RELA		1
40 #elif defined(__arm__)
41 #define R_RELATIVE	R_ARM_RELATIVE
42 #define R_MASK		0xffULL
43 #elif defined(__x86_64__) || defined(__i386__)
44 #define R_RELATIVE	R_386_RELATIVE
45 #define R_MASK		0xffULL
46 #elif defined(__riscv)
47 #define R_RELATIVE	R_RISCV_RELATIVE
48 #define R_MASK		0xffULL
49 #define IS_RELA		1
50 
51 struct dyn_sym {
52 	ulong foo1;
53 	ulong addr;
54 	u32 foo2;
55 	u32 foo3;
56 };
57 #if (__riscv_xlen == 32)
58 #define R_ABSOLUTE	R_RISCV_32
59 #define SYM_INDEX	8
60 #elif (__riscv_xlen == 64)
61 #define R_ABSOLUTE	R_RISCV_64
62 #define SYM_INDEX	32
63 #else
64 #error unknown riscv target
65 #endif
66 #else
67 #error Need to add relocation awareness
68 #endif
69 
70 struct elf_rel {
71 	ulong *offset;
72 	ulong info;
73 };
74 
75 struct elf_rela {
76 	ulong *offset;
77 	ulong info;
78 	long addend;
79 };
80 
81 /*
82  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
83  * payload are running concurrently at the same time. In this mode, we can
84  * handle a good number of runtime callbacks
85  */
86 
87 /**
88  * efi_update_table_header_crc32() - Update crc32 in table header
89  *
90  * @table:	EFI table
91  */
92 void __efi_runtime efi_update_table_header_crc32(struct efi_table_hdr *table)
93 {
94 	table->crc32 = 0;
95 	table->crc32 = crc32(0, (const unsigned char *)table,
96 			     table->headersize);
97 }
98 
99 /**
100  * efi_reset_system_boottime() - reset system at boottime
101  *
102  * This function implements the ResetSystem() runtime service before
103  * SetVirtualAddressMap() is called.
104  *
105  * See the Unified Extensible Firmware Interface (UEFI) specification for
106  * details.
107  *
108  * @reset_type:		type of reset to perform
109  * @reset_status:	status code for the reset
110  * @data_size:		size of reset_data
111  * @reset_data:		information about the reset
112  */
113 static void EFIAPI efi_reset_system_boottime(
114 			enum efi_reset_type reset_type,
115 			efi_status_t reset_status,
116 			unsigned long data_size, void *reset_data)
117 {
118 	struct efi_event *evt;
119 
120 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
121 		  reset_data);
122 
123 	/* Notify reset */
124 	list_for_each_entry(evt, &efi_events, link) {
125 		if (evt->group &&
126 		    !guidcmp(evt->group,
127 			     &efi_guid_event_group_reset_system)) {
128 			efi_signal_event(evt, false);
129 			break;
130 		}
131 	}
132 	switch (reset_type) {
133 	case EFI_RESET_COLD:
134 	case EFI_RESET_WARM:
135 	case EFI_RESET_PLATFORM_SPECIFIC:
136 		do_reset(NULL, 0, 0, NULL);
137 		break;
138 	case EFI_RESET_SHUTDOWN:
139 		/* We don't have anything to map this to */
140 		break;
141 	}
142 
143 	while (1) { }
144 }
145 
146 /**
147  * efi_get_time_boottime() - get current time at boottime
148  *
149  * This function implements the GetTime runtime service before
150  * SetVirtualAddressMap() is called.
151  *
152  * See the Unified Extensible Firmware Interface (UEFI) specification
153  * for details.
154  *
155  * @time:		pointer to structure to receive current time
156  * @capabilities:	pointer to structure to receive RTC properties
157  * Returns:		status code
158  */
159 static efi_status_t EFIAPI efi_get_time_boottime(
160 			struct efi_time *time,
161 			struct efi_time_cap *capabilities)
162 {
163 #ifdef CONFIG_DM_RTC
164 	efi_status_t ret = EFI_SUCCESS;
165 	int r;
166 	struct rtc_time tm;
167 	struct udevice *dev;
168 
169 	EFI_ENTRY("%p %p", time, capabilities);
170 
171 	if (!time) {
172 		ret = EFI_INVALID_PARAMETER;
173 		goto out;
174 	}
175 
176 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
177 	if (!r)
178 		r = dm_rtc_get(dev, &tm);
179 	if (r) {
180 		ret = EFI_DEVICE_ERROR;
181 		goto out;
182 	}
183 
184 	memset(time, 0, sizeof(*time));
185 	time->year = tm.tm_year;
186 	time->month = tm.tm_mon;
187 	time->day = tm.tm_mday;
188 	time->hour = tm.tm_hour;
189 	time->minute = tm.tm_min;
190 	time->second = tm.tm_sec;
191 	time->daylight = EFI_TIME_ADJUST_DAYLIGHT;
192 	if (tm.tm_isdst > 0)
193 		time->daylight |= EFI_TIME_IN_DAYLIGHT;
194 	time->timezone = EFI_UNSPECIFIED_TIMEZONE;
195 
196 	if (capabilities) {
197 		/* Set reasonable dummy values */
198 		capabilities->resolution = 1;		/* 1 Hz */
199 		capabilities->accuracy = 100000000;	/* 100 ppm */
200 		capabilities->sets_to_zero = false;
201 	}
202 out:
203 	return EFI_EXIT(ret);
204 #else
205 	EFI_ENTRY("%p %p", time, capabilities);
206 	return EFI_EXIT(EFI_DEVICE_ERROR);
207 #endif
208 }
209 
210 
211 /**
212  * efi_reset_system() - reset system
213  *
214  * This function implements the ResetSystem() runtime service after
215  * SetVirtualAddressMap() is called. It only executes an endless loop.
216  * Boards may override the helpers below to implement reset functionality.
217  *
218  * See the Unified Extensible Firmware Interface (UEFI) specification for
219  * details.
220  *
221  * @reset_type:		type of reset to perform
222  * @reset_status:	status code for the reset
223  * @data_size:		size of reset_data
224  * @reset_data:		information about the reset
225  */
226 void __weak __efi_runtime EFIAPI efi_reset_system(
227 			enum efi_reset_type reset_type,
228 			efi_status_t reset_status,
229 			unsigned long data_size, void *reset_data)
230 {
231 	/* Nothing we can do */
232 	while (1) { }
233 }
234 
235 /**
236  * efi_reset_system_init() - initialize the reset driver
237  *
238  * Boards may override this function to initialize the reset driver.
239  */
240 efi_status_t __weak efi_reset_system_init(void)
241 {
242 	return EFI_SUCCESS;
243 }
244 
245 /**
246  * efi_get_time() - get current time
247  *
248  * This function implements the GetTime runtime service after
249  * SetVirtualAddressMap() is called. As the U-Boot driver are not available
250  * anymore only an error code is returned.
251  *
252  * See the Unified Extensible Firmware Interface (UEFI) specification
253  * for details.
254  *
255  * @time:		pointer to structure to receive current time
256  * @capabilities:	pointer to structure to receive RTC properties
257  * Returns:		status code
258  */
259 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
260 			struct efi_time *time,
261 			struct efi_time_cap *capabilities)
262 {
263 	/* Nothing we can do */
264 	return EFI_DEVICE_ERROR;
265 }
266 
267 struct efi_runtime_detach_list_struct {
268 	void *ptr;
269 	void *patchto;
270 };
271 
272 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
273 	{
274 		/* do_reset is gone */
275 		.ptr = &efi_runtime_services.reset_system,
276 		.patchto = efi_reset_system,
277 	}, {
278 		/* invalidate_*cache_all are gone */
279 		.ptr = &efi_runtime_services.set_virtual_address_map,
280 		.patchto = &efi_invalid_parameter,
281 	}, {
282 		/* RTC accessors are gone */
283 		.ptr = &efi_runtime_services.get_time,
284 		.patchto = &efi_get_time,
285 	}, {
286 		/* Clean up system table */
287 		.ptr = &systab.con_in,
288 		.patchto = NULL,
289 	}, {
290 		/* Clean up system table */
291 		.ptr = &systab.con_out,
292 		.patchto = NULL,
293 	}, {
294 		/* Clean up system table */
295 		.ptr = &systab.std_err,
296 		.patchto = NULL,
297 	}, {
298 		/* Clean up system table */
299 		.ptr = &systab.boottime,
300 		.patchto = NULL,
301 	}, {
302 		.ptr = &efi_runtime_services.get_variable,
303 		.patchto = &efi_device_error,
304 	}, {
305 		.ptr = &efi_runtime_services.get_next_variable_name,
306 		.patchto = &efi_device_error,
307 	}, {
308 		.ptr = &efi_runtime_services.set_variable,
309 		.patchto = &efi_device_error,
310 	}
311 };
312 
313 static bool efi_runtime_tobedetached(void *p)
314 {
315 	int i;
316 
317 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
318 		if (efi_runtime_detach_list[i].ptr == p)
319 			return true;
320 
321 	return false;
322 }
323 
324 static void efi_runtime_detach(ulong offset)
325 {
326 	int i;
327 	ulong patchoff = offset - (ulong)gd->relocaddr;
328 
329 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
330 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
331 		ulong *p = efi_runtime_detach_list[i].ptr;
332 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
333 
334 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
335 		*p = newaddr;
336 	}
337 
338 	/* Update crc32 */
339 	efi_update_table_header_crc32(&efi_runtime_services.hdr);
340 }
341 
342 /* Relocate EFI runtime to uboot_reloc_base = offset */
343 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
344 {
345 #ifdef IS_RELA
346 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
347 #else
348 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
349 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
350 #endif
351 
352 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
353 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
354 		ulong base = CONFIG_SYS_TEXT_BASE;
355 		ulong *p;
356 		ulong newaddr;
357 
358 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
359 
360 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__, rel->info, *p, rel->offset);
361 
362 		switch (rel->info & R_MASK) {
363 		case R_RELATIVE:
364 #ifdef IS_RELA
365 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
366 #else
367 		newaddr = *p - lastoff + offset;
368 #endif
369 			break;
370 #ifdef R_ABSOLUTE
371 		case R_ABSOLUTE: {
372 			ulong symidx = rel->info >> SYM_INDEX;
373 			extern struct dyn_sym __dyn_sym_start[];
374 			newaddr = __dyn_sym_start[symidx].addr + offset;
375 			break;
376 		}
377 #endif
378 		default:
379 			continue;
380 		}
381 
382 		/* Check if the relocation is inside bounds */
383 		if (map && ((newaddr < map->virtual_start) ||
384 		    newaddr > (map->virtual_start +
385 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
386 			if (!efi_runtime_tobedetached(p))
387 				printf("U-Boot EFI: Relocation at %p is out of "
388 				       "range (%lx)\n", p, newaddr);
389 			continue;
390 		}
391 
392 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
393 		*p = newaddr;
394 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
395 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
396 	}
397 
398 #ifndef IS_RELA
399 	lastoff = offset;
400 #endif
401 
402         invalidate_icache_all();
403 }
404 
405 /**
406  * efi_set_virtual_address_map() - change from physical to virtual mapping
407  *
408  * This function implements the SetVirtualAddressMap() runtime service.
409  *
410  * See the Unified Extensible Firmware Interface (UEFI) specification for
411  * details.
412  *
413  * @memory_map_size:	size of the virtual map
414  * @descriptor_size:	size of an entry in the map
415  * @descriptor_version:	version of the map entries
416  * @virtmap:		virtual address mapping information
417  * Return:		status code
418  */
419 static efi_status_t EFIAPI efi_set_virtual_address_map(
420 			unsigned long memory_map_size,
421 			unsigned long descriptor_size,
422 			uint32_t descriptor_version,
423 			struct efi_mem_desc *virtmap)
424 {
425 	ulong runtime_start = (ulong)&__efi_runtime_start &
426 			      ~(ulong)EFI_PAGE_MASK;
427 	int n = memory_map_size / descriptor_size;
428 	int i;
429 
430 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
431 		  descriptor_version, virtmap);
432 
433 	/* Rebind mmio pointers */
434 	for (i = 0; i < n; i++) {
435 		struct efi_mem_desc *map = (void*)virtmap +
436 					   (descriptor_size * i);
437 		struct list_head *lhandle;
438 		efi_physical_addr_t map_start = map->physical_start;
439 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
440 		efi_physical_addr_t map_end = map_start + map_len;
441 		u64 off = map->virtual_start - map_start;
442 
443 		/* Adjust all mmio pointers in this region */
444 		list_for_each(lhandle, &efi_runtime_mmio) {
445 			struct efi_runtime_mmio_list *lmmio;
446 
447 			lmmio = list_entry(lhandle,
448 					   struct efi_runtime_mmio_list,
449 					   link);
450 			if ((map_start <= lmmio->paddr) &&
451 			    (map_end >= lmmio->paddr)) {
452 				uintptr_t new_addr = lmmio->paddr + off;
453 				*lmmio->ptr = (void *)new_addr;
454 			}
455 		}
456 		if ((map_start <= (uintptr_t)systab.tables) &&
457 		    (map_end >= (uintptr_t)systab.tables)) {
458 			char *ptr = (char *)systab.tables;
459 
460 			ptr += off;
461 			systab.tables = (struct efi_configuration_table *)ptr;
462 		}
463 	}
464 
465 	/* Move the actual runtime code over */
466 	for (i = 0; i < n; i++) {
467 		struct efi_mem_desc *map;
468 
469 		map = (void*)virtmap + (descriptor_size * i);
470 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
471 			ulong new_offset = map->virtual_start -
472 					   (runtime_start - gd->relocaddr);
473 
474 			efi_runtime_relocate(new_offset, map);
475 			/* Once we're virtual, we can no longer handle
476 			   complex callbacks */
477 			efi_runtime_detach(new_offset);
478 			return EFI_EXIT(EFI_SUCCESS);
479 		}
480 	}
481 
482 	return EFI_EXIT(EFI_INVALID_PARAMETER);
483 }
484 
485 /**
486  * efi_add_runtime_mmio() - add memory-mapped IO region
487  *
488  * This function adds a memory-mapped IO region to the memory map to make it
489  * available at runtime.
490  *
491  * @mmio_ptr:		address of the memory-mapped IO region
492  * @len:		size of thememory-mapped IO region
493  * Returns:		status code
494  */
495 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
496 {
497 	struct efi_runtime_mmio_list *newmmio;
498 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
499 	uint64_t addr = *(uintptr_t *)mmio_ptr;
500 	uint64_t retaddr;
501 
502 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
503 	if (retaddr != addr)
504 		return EFI_OUT_OF_RESOURCES;
505 
506 	newmmio = calloc(1, sizeof(*newmmio));
507 	if (!newmmio)
508 		return EFI_OUT_OF_RESOURCES;
509 	newmmio->ptr = mmio_ptr;
510 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
511 	newmmio->len = len;
512 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
513 
514 	return EFI_SUCCESS;
515 }
516 
517 /*
518  * In the second stage, U-Boot has disappeared. To isolate our runtime code
519  * that at this point still exists from the rest, we put it into a special
520  * section.
521  *
522  *        !!WARNING!!
523  *
524  * This means that we can not rely on any code outside of this file in any
525  * function or variable below this line.
526  *
527  * Please keep everything fully self-contained and annotated with
528  * __efi_runtime and __efi_runtime_data markers.
529  */
530 
531 /*
532  * Relocate the EFI runtime stub to a different place. We need to call this
533  * the first time we expose the runtime interface to a user and on set virtual
534  * address map calls.
535  */
536 
537 /**
538  * efi_unimplemented() - replacement function, returns EFI_UNSUPPORTED
539  *
540  * This function is used after SetVirtualAddressMap() is called as replacement
541  * for services that are not available anymore due to constraints of the U-Boot
542  * implementation.
543  *
544  * Return:	EFI_UNSUPPORTED
545  */
546 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
547 {
548 	return EFI_UNSUPPORTED;
549 }
550 
551 /**
552  * efi_device_error() - replacement function, returns EFI_DEVICE_ERROR
553  *
554  * This function is used after SetVirtualAddressMap() is called as replacement
555  * for services that are not available anymore due to constraints of the U-Boot
556  * implementation.
557  *
558  * Return:	EFI_DEVICE_ERROR
559  */
560 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
561 {
562 	return EFI_DEVICE_ERROR;
563 }
564 
565 /**
566  * efi_invalid_parameter() - replacement function, returns EFI_INVALID_PARAMETER
567  *
568  * This function is used after SetVirtualAddressMap() is called as replacement
569  * for services that are not available anymore due to constraints of the U-Boot
570  * implementation.
571  *
572  * Return:	EFI_INVALID_PARAMETER
573  */
574 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
575 {
576 	return EFI_INVALID_PARAMETER;
577 }
578 
579 /**
580  * efi_update_capsule() - process information from operating system
581  *
582  * This function implements the UpdateCapsule() runtime service.
583  *
584  * See the Unified Extensible Firmware Interface (UEFI) specification for
585  * details.
586  *
587  * @capsule_header_array:	pointer to array of virtual pointers
588  * @capsule_count:		number of pointers in capsule_header_array
589  * @scatter_gather_list:	pointer to arry of physical pointers
590  * Returns:			status code
591  */
592 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
593 			struct efi_capsule_header **capsule_header_array,
594 			efi_uintn_t capsule_count,
595 			u64 scatter_gather_list)
596 {
597 	return EFI_UNSUPPORTED;
598 }
599 
600 /**
601  * efi_query_capsule_caps() - check if capsule is supported
602  *
603  * This function implements the QueryCapsuleCapabilities() runtime service.
604  *
605  * See the Unified Extensible Firmware Interface (UEFI) specification for
606  * details.
607  *
608  * @capsule_header_array:	pointer to array of virtual pointers
609  * @capsule_count:		number of pointers in capsule_header_array
610  * @capsule_size:		maximum capsule size
611  * @reset_type:			type of reset needed for capsule update
612  * Returns:			status code
613  */
614 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
615 			struct efi_capsule_header **capsule_header_array,
616 			efi_uintn_t capsule_count,
617 			u64 maximum_capsule_size,
618 			u32 reset_type)
619 {
620 	return EFI_UNSUPPORTED;
621 }
622 
623 /**
624  * efi_query_variable_info() - get information about EFI variables
625  *
626  * This function implements the QueryVariableInfo() runtime service.
627  *
628  * See the Unified Extensible Firmware Interface (UEFI) specification for
629  * details.
630  *
631  * @attributes:				bitmask to select variables to be
632  *					queried
633  * @maximum_variable_storage_size:	maximum size of storage area for the
634  *					selected variable types
635  * @remaining_variable_storage_size:	remaining size of storage are for the
636  *					selected variable types
637  * @maximum_variable_size:		maximum size of a variable of the
638  *					selected type
639  * Returns:				status code
640  */
641 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
642 			u32 attributes,
643 			u64 *maximum_variable_storage_size,
644 			u64 *remaining_variable_storage_size,
645 			u64 *maximum_variable_size)
646 {
647 	return EFI_UNSUPPORTED;
648 }
649 
650 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
651 	.hdr = {
652 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
653 		.revision = EFI_SPECIFICATION_VERSION,
654 		.headersize = sizeof(struct efi_runtime_services),
655 	},
656 	.get_time = &efi_get_time_boottime,
657 	.set_time = (void *)&efi_device_error,
658 	.get_wakeup_time = (void *)&efi_unimplemented,
659 	.set_wakeup_time = (void *)&efi_unimplemented,
660 	.set_virtual_address_map = &efi_set_virtual_address_map,
661 	.convert_pointer = (void *)&efi_invalid_parameter,
662 	.get_variable = efi_get_variable,
663 	.get_next_variable_name = efi_get_next_variable_name,
664 	.set_variable = efi_set_variable,
665 	.get_next_high_mono_count = (void *)&efi_device_error,
666 	.reset_system = &efi_reset_system_boottime,
667 	.update_capsule = efi_update_capsule,
668 	.query_capsule_caps = efi_query_capsule_caps,
669 	.query_variable_info = efi_query_variable_info,
670 };
671