xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision dd1033e4)
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 #ifdef CONFIG_CMD_POWEROFF
145 		do_poweroff(NULL, 0, 0, NULL);
146 #endif
147 		break;
148 	}
149 
150 	while (1) { }
151 }
152 
153 /**
154  * efi_get_time_boottime() - get current time at boot time
155  *
156  * This function implements the GetTime runtime service before
157  * SetVirtualAddressMap() is called.
158  *
159  * See the Unified Extensible Firmware Interface (UEFI) specification
160  * for details.
161  *
162  * @time:		pointer to structure to receive current time
163  * @capabilities:	pointer to structure to receive RTC properties
164  * Returns:		status code
165  */
166 static efi_status_t EFIAPI efi_get_time_boottime(
167 			struct efi_time *time,
168 			struct efi_time_cap *capabilities)
169 {
170 #ifdef CONFIG_DM_RTC
171 	efi_status_t ret = EFI_SUCCESS;
172 	int r;
173 	struct rtc_time tm;
174 	struct udevice *dev;
175 
176 	EFI_ENTRY("%p %p", time, capabilities);
177 
178 	if (!time) {
179 		ret = EFI_INVALID_PARAMETER;
180 		goto out;
181 	}
182 
183 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
184 	if (!r)
185 		r = dm_rtc_get(dev, &tm);
186 	if (r) {
187 		ret = EFI_DEVICE_ERROR;
188 		goto out;
189 	}
190 
191 	memset(time, 0, sizeof(*time));
192 	time->year = tm.tm_year;
193 	time->month = tm.tm_mon;
194 	time->day = tm.tm_mday;
195 	time->hour = tm.tm_hour;
196 	time->minute = tm.tm_min;
197 	time->second = tm.tm_sec;
198 	time->daylight = EFI_TIME_ADJUST_DAYLIGHT;
199 	if (tm.tm_isdst > 0)
200 		time->daylight |= EFI_TIME_IN_DAYLIGHT;
201 	time->timezone = EFI_UNSPECIFIED_TIMEZONE;
202 
203 	if (capabilities) {
204 		/* Set reasonable dummy values */
205 		capabilities->resolution = 1;		/* 1 Hz */
206 		capabilities->accuracy = 100000000;	/* 100 ppm */
207 		capabilities->sets_to_zero = false;
208 	}
209 out:
210 	return EFI_EXIT(ret);
211 #else
212 	EFI_ENTRY("%p %p", time, capabilities);
213 	return EFI_EXIT(EFI_DEVICE_ERROR);
214 #endif
215 }
216 
217 
218 /**
219  * efi_reset_system() - reset system
220  *
221  * This function implements the ResetSystem() runtime service after
222  * SetVirtualAddressMap() is called. It only executes an endless loop.
223  * Boards may override the helpers below to implement reset functionality.
224  *
225  * See the Unified Extensible Firmware Interface (UEFI) specification for
226  * details.
227  *
228  * @reset_type:		type of reset to perform
229  * @reset_status:	status code for the reset
230  * @data_size:		size of reset_data
231  * @reset_data:		information about the reset
232  */
233 void __weak __efi_runtime EFIAPI efi_reset_system(
234 			enum efi_reset_type reset_type,
235 			efi_status_t reset_status,
236 			unsigned long data_size, void *reset_data)
237 {
238 	/* Nothing we can do */
239 	while (1) { }
240 }
241 
242 /**
243  * efi_reset_system_init() - initialize the reset driver
244  *
245  * Boards may override this function to initialize the reset driver.
246  */
247 efi_status_t __weak efi_reset_system_init(void)
248 {
249 	return EFI_SUCCESS;
250 }
251 
252 /**
253  * efi_get_time() - get current time
254  *
255  * This function implements the GetTime runtime service after
256  * SetVirtualAddressMap() is called. As the U-Boot driver are not available
257  * anymore only an error code is returned.
258  *
259  * See the Unified Extensible Firmware Interface (UEFI) specification
260  * for details.
261  *
262  * @time:		pointer to structure to receive current time
263  * @capabilities:	pointer to structure to receive RTC properties
264  * Returns:		status code
265  */
266 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
267 			struct efi_time *time,
268 			struct efi_time_cap *capabilities)
269 {
270 	/* Nothing we can do */
271 	return EFI_DEVICE_ERROR;
272 }
273 
274 struct efi_runtime_detach_list_struct {
275 	void *ptr;
276 	void *patchto;
277 };
278 
279 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
280 	{
281 		/* do_reset is gone */
282 		.ptr = &efi_runtime_services.reset_system,
283 		.patchto = efi_reset_system,
284 	}, {
285 		/* invalidate_*cache_all are gone */
286 		.ptr = &efi_runtime_services.set_virtual_address_map,
287 		.patchto = &efi_unimplemented,
288 	}, {
289 		/* RTC accessors are gone */
290 		.ptr = &efi_runtime_services.get_time,
291 		.patchto = &efi_get_time,
292 	}, {
293 		/* Clean up system table */
294 		.ptr = &systab.con_in,
295 		.patchto = NULL,
296 	}, {
297 		/* Clean up system table */
298 		.ptr = &systab.con_out,
299 		.patchto = NULL,
300 	}, {
301 		/* Clean up system table */
302 		.ptr = &systab.std_err,
303 		.patchto = NULL,
304 	}, {
305 		/* Clean up system table */
306 		.ptr = &systab.boottime,
307 		.patchto = NULL,
308 	}, {
309 		.ptr = &efi_runtime_services.get_variable,
310 		.patchto = &efi_device_error,
311 	}, {
312 		.ptr = &efi_runtime_services.get_next_variable_name,
313 		.patchto = &efi_device_error,
314 	}, {
315 		.ptr = &efi_runtime_services.set_variable,
316 		.patchto = &efi_device_error,
317 	}
318 };
319 
320 static bool efi_runtime_tobedetached(void *p)
321 {
322 	int i;
323 
324 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
325 		if (efi_runtime_detach_list[i].ptr == p)
326 			return true;
327 
328 	return false;
329 }
330 
331 static void efi_runtime_detach(ulong offset)
332 {
333 	int i;
334 	ulong patchoff = offset - (ulong)gd->relocaddr;
335 
336 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
337 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
338 		ulong *p = efi_runtime_detach_list[i].ptr;
339 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
340 
341 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
342 		*p = newaddr;
343 	}
344 
345 	/* Update CRC32 */
346 	efi_update_table_header_crc32(&efi_runtime_services.hdr);
347 }
348 
349 /* Relocate EFI runtime to uboot_reloc_base = offset */
350 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
351 {
352 #ifdef IS_RELA
353 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
354 #else
355 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
356 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
357 #endif
358 
359 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
360 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
361 		ulong base = CONFIG_SYS_TEXT_BASE;
362 		ulong *p;
363 		ulong newaddr;
364 
365 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
366 
367 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__,
368 		      rel->info, *p, rel->offset);
369 
370 		switch (rel->info & R_MASK) {
371 		case R_RELATIVE:
372 #ifdef IS_RELA
373 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
374 #else
375 		newaddr = *p - lastoff + offset;
376 #endif
377 			break;
378 #ifdef R_ABSOLUTE
379 		case R_ABSOLUTE: {
380 			ulong symidx = rel->info >> SYM_INDEX;
381 			extern struct dyn_sym __dyn_sym_start[];
382 			newaddr = __dyn_sym_start[symidx].addr + offset;
383 #ifdef IS_RELA
384 			newaddr -= CONFIG_SYS_TEXT_BASE;
385 #endif
386 			break;
387 		}
388 #endif
389 		default:
390 			if (!efi_runtime_tobedetached(p))
391 				printf("%s: Unknown relocation type %llx\n",
392 				       __func__, rel->info & R_MASK);
393 			continue;
394 		}
395 
396 		/* Check if the relocation is inside bounds */
397 		if (map && ((newaddr < map->virtual_start) ||
398 		    newaddr > (map->virtual_start +
399 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
400 			if (!efi_runtime_tobedetached(p))
401 				printf("%s: Relocation at %p is out of "
402 				       "range (%lx)\n", __func__, p, newaddr);
403 			continue;
404 		}
405 
406 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
407 		*p = newaddr;
408 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
409 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
410 	}
411 
412 #ifndef IS_RELA
413 	lastoff = offset;
414 #endif
415 
416         invalidate_icache_all();
417 }
418 
419 /**
420  * efi_set_virtual_address_map() - change from physical to virtual mapping
421  *
422  * This function implements the SetVirtualAddressMap() runtime service.
423  *
424  * See the Unified Extensible Firmware Interface (UEFI) specification for
425  * details.
426  *
427  * @memory_map_size:	size of the virtual map
428  * @descriptor_size:	size of an entry in the map
429  * @descriptor_version:	version of the map entries
430  * @virtmap:		virtual address mapping information
431  * Return:		status code
432  */
433 static efi_status_t EFIAPI efi_set_virtual_address_map(
434 			unsigned long memory_map_size,
435 			unsigned long descriptor_size,
436 			uint32_t descriptor_version,
437 			struct efi_mem_desc *virtmap)
438 {
439 	ulong runtime_start = (ulong)&__efi_runtime_start &
440 			      ~(ulong)EFI_PAGE_MASK;
441 	int n = memory_map_size / descriptor_size;
442 	int i;
443 
444 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
445 		  descriptor_version, virtmap);
446 
447 	/* Rebind mmio pointers */
448 	for (i = 0; i < n; i++) {
449 		struct efi_mem_desc *map = (void*)virtmap +
450 					   (descriptor_size * i);
451 		struct list_head *lhandle;
452 		efi_physical_addr_t map_start = map->physical_start;
453 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
454 		efi_physical_addr_t map_end = map_start + map_len;
455 		u64 off = map->virtual_start - map_start;
456 
457 		/* Adjust all mmio pointers in this region */
458 		list_for_each(lhandle, &efi_runtime_mmio) {
459 			struct efi_runtime_mmio_list *lmmio;
460 
461 			lmmio = list_entry(lhandle,
462 					   struct efi_runtime_mmio_list,
463 					   link);
464 			if ((map_start <= lmmio->paddr) &&
465 			    (map_end >= lmmio->paddr)) {
466 				uintptr_t new_addr = lmmio->paddr + off;
467 				*lmmio->ptr = (void *)new_addr;
468 			}
469 		}
470 		if ((map_start <= (uintptr_t)systab.tables) &&
471 		    (map_end >= (uintptr_t)systab.tables)) {
472 			char *ptr = (char *)systab.tables;
473 
474 			ptr += off;
475 			systab.tables = (struct efi_configuration_table *)ptr;
476 		}
477 	}
478 
479 	/* Move the actual runtime code over */
480 	for (i = 0; i < n; i++) {
481 		struct efi_mem_desc *map;
482 
483 		map = (void*)virtmap + (descriptor_size * i);
484 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
485 			ulong new_offset = map->virtual_start -
486 					   (runtime_start - gd->relocaddr);
487 
488 			efi_runtime_relocate(new_offset, map);
489 			/* Once we're virtual, we can no longer handle
490 			   complex callbacks */
491 			efi_runtime_detach(new_offset);
492 			return EFI_EXIT(EFI_SUCCESS);
493 		}
494 	}
495 
496 	return EFI_EXIT(EFI_INVALID_PARAMETER);
497 }
498 
499 /**
500  * efi_add_runtime_mmio() - add memory-mapped IO region
501  *
502  * This function adds a memory-mapped IO region to the memory map to make it
503  * available at runtime.
504  *
505  * @mmio_ptr:		address of the memory-mapped IO region
506  * @len:		size of the memory-mapped IO region
507  * Returns:		status code
508  */
509 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
510 {
511 	struct efi_runtime_mmio_list *newmmio;
512 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
513 	uint64_t addr = *(uintptr_t *)mmio_ptr;
514 	uint64_t retaddr;
515 
516 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
517 	if (retaddr != addr)
518 		return EFI_OUT_OF_RESOURCES;
519 
520 	newmmio = calloc(1, sizeof(*newmmio));
521 	if (!newmmio)
522 		return EFI_OUT_OF_RESOURCES;
523 	newmmio->ptr = mmio_ptr;
524 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
525 	newmmio->len = len;
526 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
527 
528 	return EFI_SUCCESS;
529 }
530 
531 /*
532  * In the second stage, U-Boot has disappeared. To isolate our runtime code
533  * that at this point still exists from the rest, we put it into a special
534  * section.
535  *
536  *        !!WARNING!!
537  *
538  * This means that we can not rely on any code outside of this file in any
539  * function or variable below this line.
540  *
541  * Please keep everything fully self-contained and annotated with
542  * __efi_runtime and __efi_runtime_data markers.
543  */
544 
545 /*
546  * Relocate the EFI runtime stub to a different place. We need to call this
547  * the first time we expose the runtime interface to a user and on set virtual
548  * address map calls.
549  */
550 
551 /**
552  * efi_unimplemented() - replacement function, returns EFI_UNSUPPORTED
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_UNSUPPORTED
559  */
560 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
561 {
562 	return EFI_UNSUPPORTED;
563 }
564 
565 /**
566  * efi_device_error() - replacement function, returns EFI_DEVICE_ERROR
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_DEVICE_ERROR
573  */
574 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
575 {
576 	return EFI_DEVICE_ERROR;
577 }
578 
579 /**
580  * efi_invalid_parameter() - replacement function, returns EFI_INVALID_PARAMETER
581  *
582  * This function is used after SetVirtualAddressMap() is called as replacement
583  * for services that are not available anymore due to constraints of the U-Boot
584  * implementation.
585  *
586  * Return:	EFI_INVALID_PARAMETER
587  */
588 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
589 {
590 	return EFI_INVALID_PARAMETER;
591 }
592 
593 /**
594  * efi_update_capsule() - process information from operating system
595  *
596  * This function implements the UpdateCapsule() runtime service.
597  *
598  * See the Unified Extensible Firmware Interface (UEFI) specification for
599  * details.
600  *
601  * @capsule_header_array:	pointer to array of virtual pointers
602  * @capsule_count:		number of pointers in capsule_header_array
603  * @scatter_gather_list:	pointer to arry of physical pointers
604  * Returns:			status code
605  */
606 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
607 			struct efi_capsule_header **capsule_header_array,
608 			efi_uintn_t capsule_count,
609 			u64 scatter_gather_list)
610 {
611 	return EFI_UNSUPPORTED;
612 }
613 
614 /**
615  * efi_query_capsule_caps() - check if capsule is supported
616  *
617  * This function implements the QueryCapsuleCapabilities() runtime service.
618  *
619  * See the Unified Extensible Firmware Interface (UEFI) specification for
620  * details.
621  *
622  * @capsule_header_array:	pointer to array of virtual pointers
623  * @capsule_count:		number of pointers in capsule_header_array
624  * @maximum_capsule_size:	maximum capsule size
625  * @reset_type:			type of reset needed for capsule update
626  * Returns:			status code
627  */
628 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
629 			struct efi_capsule_header **capsule_header_array,
630 			efi_uintn_t capsule_count,
631 			u64 *maximum_capsule_size,
632 			u32 *reset_type)
633 {
634 	return EFI_UNSUPPORTED;
635 }
636 
637 /**
638  * efi_query_variable_info() - get information about EFI variables
639  *
640  * This function implements the QueryVariableInfo() runtime service.
641  *
642  * See the Unified Extensible Firmware Interface (UEFI) specification for
643  * details.
644  *
645  * @attributes:				bitmask to select variables to be
646  *					queried
647  * @maximum_variable_storage_size:	maximum size of storage area for the
648  *					selected variable types
649  * @remaining_variable_storage_size:	remaining size of storage are for the
650  *					selected variable types
651  * @maximum_variable_size:		maximum size of a variable of the
652  *					selected type
653  * Returns:				status code
654  */
655 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
656 			u32 attributes,
657 			u64 *maximum_variable_storage_size,
658 			u64 *remaining_variable_storage_size,
659 			u64 *maximum_variable_size)
660 {
661 	return EFI_UNSUPPORTED;
662 }
663 
664 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
665 	.hdr = {
666 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
667 		.revision = EFI_SPECIFICATION_VERSION,
668 		.headersize = sizeof(struct efi_runtime_services),
669 	},
670 	.get_time = &efi_get_time_boottime,
671 	.set_time = (void *)&efi_device_error,
672 	.get_wakeup_time = (void *)&efi_unimplemented,
673 	.set_wakeup_time = (void *)&efi_unimplemented,
674 	.set_virtual_address_map = &efi_set_virtual_address_map,
675 	.convert_pointer = (void *)&efi_invalid_parameter,
676 	.get_variable = efi_get_variable,
677 	.get_next_variable_name = efi_get_next_variable_name,
678 	.set_variable = efi_set_variable,
679 	.get_next_high_mono_count = (void *)&efi_device_error,
680 	.reset_system = &efi_reset_system_boottime,
681 	.update_capsule = efi_update_capsule,
682 	.query_capsule_caps = efi_query_capsule_caps,
683 	.query_variable_info = efi_query_variable_info,
684 };
685