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1// SPDX-License-Identifier: GPL-2.0-only
2
3/* -----------------------------------------------------------------------
4 *
5 * Copyright 2011 Intel Corporation; author Matt Fleming
6 *
7 * ----------------------------------------------------------------------- */
8
9#include <linux/efi.h>
10#include <linux/pci.h>
11#include <linux/stddef.h>
12
13#include <asm/efi.h>
14#include <asm/e820/types.h>
15#include <asm/setup.h>
16#include <asm/desc.h>
17#include <asm/boot.h>
18#include <asm/kaslr.h>
19#include <asm/sev.h>
20
21#include "efistub.h"
22#include "x86-stub.h"
23
24extern char _bss[], _ebss[];
25
26const efi_system_table_t *efi_system_table;
27const efi_dxe_services_table_t *efi_dxe_table;
28static efi_loaded_image_t *image = NULL;
29static efi_memory_attribute_protocol_t *memattr;
30
31typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t;
32union sev_memory_acceptance_protocol {
33 struct {
34 efi_status_t (__efiapi * allow_unaccepted_memory)(
35 sev_memory_acceptance_protocol_t *);
36 };
37 struct {
38 u32 allow_unaccepted_memory;
39 } mixed_mode;
40};
41
42static efi_status_t
43preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
44{
45 struct pci_setup_rom *rom = NULL;
46 efi_status_t status;
47 unsigned long size;
48 uint64_t romsize;
49 void *romimage;
50
51 /*
52 * Some firmware images contain EFI function pointers at the place where
53 * the romimage and romsize fields are supposed to be. Typically the EFI
54 * code is mapped at high addresses, translating to an unrealistically
55 * large romsize. The UEFI spec limits the size of option ROMs to 16
56 * MiB so we reject any ROMs over 16 MiB in size to catch this.
57 */
58 romimage = efi_table_attr(pci, romimage);
59 romsize = efi_table_attr(pci, romsize);
60 if (!romimage || !romsize || romsize > SZ_16M)
61 return EFI_INVALID_PARAMETER;
62
63 size = romsize + sizeof(*rom);
64
65 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
66 (void **)&rom);
67 if (status != EFI_SUCCESS) {
68 efi_err("Failed to allocate memory for 'rom'\n");
69 return status;
70 }
71
72 memset(rom, 0, sizeof(*rom));
73
74 rom->data.type = SETUP_PCI;
75 rom->data.len = size - sizeof(struct setup_data);
76 rom->data.next = 0;
77 rom->pcilen = romsize;
78 *__rom = rom;
79
80 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
81 PCI_VENDOR_ID, 1, &rom->vendor);
82
83 if (status != EFI_SUCCESS) {
84 efi_err("Failed to read rom->vendor\n");
85 goto free_struct;
86 }
87
88 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
89 PCI_DEVICE_ID, 1, &rom->devid);
90
91 if (status != EFI_SUCCESS) {
92 efi_err("Failed to read rom->devid\n");
93 goto free_struct;
94 }
95
96 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
97 &rom->device, &rom->function);
98
99 if (status != EFI_SUCCESS)
100 goto free_struct;
101
102 memcpy(rom->romdata, romimage, romsize);
103 return status;
104
105free_struct:
106 efi_bs_call(free_pool, rom);
107 return status;
108}
109
110/*
111 * There's no way to return an informative status from this function,
112 * because any analysis (and printing of error messages) needs to be
113 * done directly at the EFI function call-site.
114 *
115 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
116 * just didn't find any PCI devices, but there's no way to tell outside
117 * the context of the call.
118 */
119static void setup_efi_pci(struct boot_params *params)
120{
121 efi_status_t status;
122 void **pci_handle = NULL;
123 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
124 unsigned long size = 0;
125 struct setup_data *data;
126 efi_handle_t h;
127 int i;
128
129 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
130 &pci_proto, NULL, &size, pci_handle);
131
132 if (status == EFI_BUFFER_TOO_SMALL) {
133 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
134 (void **)&pci_handle);
135
136 if (status != EFI_SUCCESS) {
137 efi_err("Failed to allocate memory for 'pci_handle'\n");
138 return;
139 }
140
141 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
142 &pci_proto, NULL, &size, pci_handle);
143 }
144
145 if (status != EFI_SUCCESS)
146 goto free_handle;
147
148 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
149
150 while (data && data->next)
151 data = (struct setup_data *)(unsigned long)data->next;
152
153 for_each_efi_handle(h, pci_handle, size, i) {
154 efi_pci_io_protocol_t *pci = NULL;
155 struct pci_setup_rom *rom;
156
157 status = efi_bs_call(handle_protocol, h, &pci_proto,
158 (void **)&pci);
159 if (status != EFI_SUCCESS || !pci)
160 continue;
161
162 status = preserve_pci_rom_image(pci, &rom);
163 if (status != EFI_SUCCESS)
164 continue;
165
166 if (data)
167 data->next = (unsigned long)rom;
168 else
169 params->hdr.setup_data = (unsigned long)rom;
170
171 data = (struct setup_data *)rom;
172 }
173
174free_handle:
175 efi_bs_call(free_pool, pci_handle);
176}
177
178static void retrieve_apple_device_properties(struct boot_params *boot_params)
179{
180 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
181 struct setup_data *data, *new;
182 efi_status_t status;
183 u32 size = 0;
184 apple_properties_protocol_t *p;
185
186 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
187 if (status != EFI_SUCCESS)
188 return;
189
190 if (efi_table_attr(p, version) != 0x10000) {
191 efi_err("Unsupported properties proto version\n");
192 return;
193 }
194
195 efi_call_proto(p, get_all, NULL, &size);
196 if (!size)
197 return;
198
199 do {
200 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
201 size + sizeof(struct setup_data),
202 (void **)&new);
203 if (status != EFI_SUCCESS) {
204 efi_err("Failed to allocate memory for 'properties'\n");
205 return;
206 }
207
208 status = efi_call_proto(p, get_all, new->data, &size);
209
210 if (status == EFI_BUFFER_TOO_SMALL)
211 efi_bs_call(free_pool, new);
212 } while (status == EFI_BUFFER_TOO_SMALL);
213
214 new->type = SETUP_APPLE_PROPERTIES;
215 new->len = size;
216 new->next = 0;
217
218 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
219 if (!data) {
220 boot_params->hdr.setup_data = (unsigned long)new;
221 } else {
222 while (data->next)
223 data = (struct setup_data *)(unsigned long)data->next;
224 data->next = (unsigned long)new;
225 }
226}
227
228efi_status_t efi_adjust_memory_range_protection(unsigned long start,
229 unsigned long size)
230{
231 efi_status_t status;
232 efi_gcd_memory_space_desc_t desc;
233 unsigned long end, next;
234 unsigned long rounded_start, rounded_end;
235 unsigned long unprotect_start, unprotect_size;
236
237 rounded_start = rounddown(start, EFI_PAGE_SIZE);
238 rounded_end = roundup(start + size, EFI_PAGE_SIZE);
239
240 if (memattr != NULL) {
241 status = efi_call_proto(memattr, set_memory_attributes,
242 rounded_start,
243 rounded_end - rounded_start,
244 EFI_MEMORY_RO);
245 if (status != EFI_SUCCESS) {
246 efi_warn("Failed to set EFI_MEMORY_RO attribute\n");
247 return status;
248 }
249
250 status = efi_call_proto(memattr, clear_memory_attributes,
251 rounded_start,
252 rounded_end - rounded_start,
253 EFI_MEMORY_XP);
254 if (status != EFI_SUCCESS)
255 efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
256 return status;
257 }
258
259 if (efi_dxe_table == NULL)
260 return EFI_SUCCESS;
261
262 /*
263 * Don't modify memory region attributes, they are
264 * already suitable, to lower the possibility to
265 * encounter firmware bugs.
266 */
267
268 for (end = start + size; start < end; start = next) {
269
270 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
271
272 if (status != EFI_SUCCESS)
273 break;
274
275 next = desc.base_address + desc.length;
276
277 /*
278 * Only system memory is suitable for trampoline/kernel image placement,
279 * so only this type of memory needs its attributes to be modified.
280 */
281
282 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
283 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
284 continue;
285
286 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
287 unprotect_size = min(rounded_end, next) - unprotect_start;
288
289 status = efi_dxe_call(set_memory_space_attributes,
290 unprotect_start, unprotect_size,
291 EFI_MEMORY_WB);
292
293 if (status != EFI_SUCCESS) {
294 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
295 unprotect_start,
296 unprotect_start + unprotect_size,
297 status);
298 break;
299 }
300 }
301 return EFI_SUCCESS;
302}
303
304static void setup_unaccepted_memory(void)
305{
306 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
307 sev_memory_acceptance_protocol_t *proto;
308 efi_status_t status;
309
310 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
311 return;
312
313 /*
314 * Enable unaccepted memory before calling exit boot services in order
315 * for the UEFI to not accept all memory on EBS.
316 */
317 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
318 (void **)&proto);
319 if (status != EFI_SUCCESS)
320 return;
321
322 status = efi_call_proto(proto, allow_unaccepted_memory);
323 if (status != EFI_SUCCESS)
324 efi_err("Memory acceptance protocol failed\n");
325}
326
327static efi_char16_t *efistub_fw_vendor(void)
328{
329 unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
330
331 return (efi_char16_t *)vendor;
332}
333
334static const efi_char16_t apple[] = L"Apple";
335
336static void setup_quirks(struct boot_params *boot_params)
337{
338 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) &&
339 !memcmp(efistub_fw_vendor(), apple, sizeof(apple)))
340 retrieve_apple_device_properties(boot_params);
341}
342
343/*
344 * See if we have Universal Graphics Adapter (UGA) protocol
345 */
346static efi_status_t
347setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
348{
349 efi_status_t status;
350 u32 width, height;
351 void **uga_handle = NULL;
352 efi_uga_draw_protocol_t *uga = NULL, *first_uga;
353 efi_handle_t handle;
354 int i;
355
356 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
357 (void **)&uga_handle);
358 if (status != EFI_SUCCESS)
359 return status;
360
361 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
362 uga_proto, NULL, &size, uga_handle);
363 if (status != EFI_SUCCESS)
364 goto free_handle;
365
366 height = 0;
367 width = 0;
368
369 first_uga = NULL;
370 for_each_efi_handle(handle, uga_handle, size, i) {
371 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
372 u32 w, h, depth, refresh;
373 void *pciio;
374
375 status = efi_bs_call(handle_protocol, handle, uga_proto,
376 (void **)&uga);
377 if (status != EFI_SUCCESS)
378 continue;
379
380 pciio = NULL;
381 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
382
383 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
384 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
385 width = w;
386 height = h;
387
388 /*
389 * Once we've found a UGA supporting PCIIO,
390 * don't bother looking any further.
391 */
392 if (pciio)
393 break;
394
395 first_uga = uga;
396 }
397 }
398
399 if (!width && !height)
400 goto free_handle;
401
402 /* EFI framebuffer */
403 si->orig_video_isVGA = VIDEO_TYPE_EFI;
404
405 si->lfb_depth = 32;
406 si->lfb_width = width;
407 si->lfb_height = height;
408
409 si->red_size = 8;
410 si->red_pos = 16;
411 si->green_size = 8;
412 si->green_pos = 8;
413 si->blue_size = 8;
414 si->blue_pos = 0;
415 si->rsvd_size = 8;
416 si->rsvd_pos = 24;
417
418free_handle:
419 efi_bs_call(free_pool, uga_handle);
420
421 return status;
422}
423
424static void setup_graphics(struct boot_params *boot_params)
425{
426 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
427 struct screen_info *si;
428 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
429 efi_status_t status;
430 unsigned long size;
431 void **gop_handle = NULL;
432 void **uga_handle = NULL;
433
434 si = &boot_params->screen_info;
435 memset(si, 0, sizeof(*si));
436
437 size = 0;
438 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
439 &graphics_proto, NULL, &size, gop_handle);
440 if (status == EFI_BUFFER_TOO_SMALL)
441 status = efi_setup_gop(si, &graphics_proto, size);
442
443 if (status != EFI_SUCCESS) {
444 size = 0;
445 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
446 &uga_proto, NULL, &size, uga_handle);
447 if (status == EFI_BUFFER_TOO_SMALL)
448 setup_uga(si, &uga_proto, size);
449 }
450}
451
452
453static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
454{
455 efi_bs_call(exit, handle, status, 0, NULL);
456 for(;;)
457 asm("hlt");
458}
459
460void __noreturn efi_stub_entry(efi_handle_t handle,
461 efi_system_table_t *sys_table_arg,
462 struct boot_params *boot_params);
463
464/*
465 * Because the x86 boot code expects to be passed a boot_params we
466 * need to create one ourselves (usually the bootloader would create
467 * one for us).
468 */
469efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
470 efi_system_table_t *sys_table_arg)
471{
472 static struct boot_params boot_params __page_aligned_bss;
473 struct setup_header *hdr = &boot_params.hdr;
474 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
475 int options_size = 0;
476 efi_status_t status;
477 char *cmdline_ptr;
478
479 if (efi_is_native())
480 memset(_bss, 0, _ebss - _bss);
481
482 efi_system_table = sys_table_arg;
483
484 /* Check if we were booted by the EFI firmware */
485 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
486 efi_exit(handle, EFI_INVALID_PARAMETER);
487
488 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
489 if (status != EFI_SUCCESS) {
490 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
491 efi_exit(handle, status);
492 }
493
494 /* Assign the setup_header fields that the kernel actually cares about */
495 hdr->root_flags = 1;
496 hdr->vid_mode = 0xffff;
497
498 hdr->type_of_loader = 0x21;
499 hdr->initrd_addr_max = INT_MAX;
500
501 /* Convert unicode cmdline to ascii */
502 cmdline_ptr = efi_convert_cmdline(image, &options_size);
503 if (!cmdline_ptr)
504 goto fail;
505
506 efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
507 &boot_params.ext_cmd_line_ptr);
508
509 efi_stub_entry(handle, sys_table_arg, &boot_params);
510 /* not reached */
511
512fail:
513 efi_exit(handle, status);
514}
515
516static void add_e820ext(struct boot_params *params,
517 struct setup_data *e820ext, u32 nr_entries)
518{
519 struct setup_data *data;
520
521 e820ext->type = SETUP_E820_EXT;
522 e820ext->len = nr_entries * sizeof(struct boot_e820_entry);
523 e820ext->next = 0;
524
525 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
526
527 while (data && data->next)
528 data = (struct setup_data *)(unsigned long)data->next;
529
530 if (data)
531 data->next = (unsigned long)e820ext;
532 else
533 params->hdr.setup_data = (unsigned long)e820ext;
534}
535
536static efi_status_t
537setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
538{
539 struct boot_e820_entry *entry = params->e820_table;
540 struct efi_info *efi = ¶ms->efi_info;
541 struct boot_e820_entry *prev = NULL;
542 u32 nr_entries;
543 u32 nr_desc;
544 int i;
545
546 nr_entries = 0;
547 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
548
549 for (i = 0; i < nr_desc; i++) {
550 efi_memory_desc_t *d;
551 unsigned int e820_type = 0;
552 unsigned long m = efi->efi_memmap;
553
554#ifdef CONFIG_X86_64
555 m |= (u64)efi->efi_memmap_hi << 32;
556#endif
557
558 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
559 switch (d->type) {
560 case EFI_RESERVED_TYPE:
561 case EFI_RUNTIME_SERVICES_CODE:
562 case EFI_RUNTIME_SERVICES_DATA:
563 case EFI_MEMORY_MAPPED_IO:
564 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
565 case EFI_PAL_CODE:
566 e820_type = E820_TYPE_RESERVED;
567 break;
568
569 case EFI_UNUSABLE_MEMORY:
570 e820_type = E820_TYPE_UNUSABLE;
571 break;
572
573 case EFI_ACPI_RECLAIM_MEMORY:
574 e820_type = E820_TYPE_ACPI;
575 break;
576
577 case EFI_LOADER_CODE:
578 case EFI_LOADER_DATA:
579 case EFI_BOOT_SERVICES_CODE:
580 case EFI_BOOT_SERVICES_DATA:
581 case EFI_CONVENTIONAL_MEMORY:
582 if (efi_soft_reserve_enabled() &&
583 (d->attribute & EFI_MEMORY_SP))
584 e820_type = E820_TYPE_SOFT_RESERVED;
585 else
586 e820_type = E820_TYPE_RAM;
587 break;
588
589 case EFI_ACPI_MEMORY_NVS:
590 e820_type = E820_TYPE_NVS;
591 break;
592
593 case EFI_PERSISTENT_MEMORY:
594 e820_type = E820_TYPE_PMEM;
595 break;
596
597 case EFI_UNACCEPTED_MEMORY:
598 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
599 continue;
600 e820_type = E820_TYPE_RAM;
601 process_unaccepted_memory(d->phys_addr,
602 d->phys_addr + PAGE_SIZE * d->num_pages);
603 break;
604 default:
605 continue;
606 }
607
608 /* Merge adjacent mappings */
609 if (prev && prev->type == e820_type &&
610 (prev->addr + prev->size) == d->phys_addr) {
611 prev->size += d->num_pages << 12;
612 continue;
613 }
614
615 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
616 u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
617 sizeof(struct setup_data);
618
619 if (!e820ext || e820ext_size < need)
620 return EFI_BUFFER_TOO_SMALL;
621
622 /* boot_params map full, switch to e820 extended */
623 entry = (struct boot_e820_entry *)e820ext->data;
624 }
625
626 entry->addr = d->phys_addr;
627 entry->size = d->num_pages << PAGE_SHIFT;
628 entry->type = e820_type;
629 prev = entry++;
630 nr_entries++;
631 }
632
633 if (nr_entries > ARRAY_SIZE(params->e820_table)) {
634 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
635
636 add_e820ext(params, e820ext, nr_e820ext);
637 nr_entries -= nr_e820ext;
638 }
639
640 params->e820_entries = (u8)nr_entries;
641
642 return EFI_SUCCESS;
643}
644
645static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
646 u32 *e820ext_size)
647{
648 efi_status_t status;
649 unsigned long size;
650
651 size = sizeof(struct setup_data) +
652 sizeof(struct e820_entry) * nr_desc;
653
654 if (*e820ext) {
655 efi_bs_call(free_pool, *e820ext);
656 *e820ext = NULL;
657 *e820ext_size = 0;
658 }
659
660 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
661 (void **)e820ext);
662 if (status == EFI_SUCCESS)
663 *e820ext_size = size;
664
665 return status;
666}
667
668static efi_status_t allocate_e820(struct boot_params *params,
669 struct setup_data **e820ext,
670 u32 *e820ext_size)
671{
672 struct efi_boot_memmap *map;
673 efi_status_t status;
674 __u32 nr_desc;
675
676 status = efi_get_memory_map(&map, false);
677 if (status != EFI_SUCCESS)
678 return status;
679
680 nr_desc = map->map_size / map->desc_size;
681 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
682 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
683 EFI_MMAP_NR_SLACK_SLOTS;
684
685 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
686 }
687
688 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS)
689 status = allocate_unaccepted_bitmap(nr_desc, map);
690
691 efi_bs_call(free_pool, map);
692 return status;
693}
694
695struct exit_boot_struct {
696 struct boot_params *boot_params;
697 struct efi_info *efi;
698};
699
700static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
701 void *priv)
702{
703 const char *signature;
704 struct exit_boot_struct *p = priv;
705
706 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
707 : EFI32_LOADER_SIGNATURE;
708 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
709
710 efi_set_u64_split((unsigned long)efi_system_table,
711 &p->efi->efi_systab, &p->efi->efi_systab_hi);
712 p->efi->efi_memdesc_size = map->desc_size;
713 p->efi->efi_memdesc_version = map->desc_ver;
714 efi_set_u64_split((unsigned long)map->map,
715 &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
716 p->efi->efi_memmap_size = map->map_size;
717
718 return EFI_SUCCESS;
719}
720
721static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
722{
723 struct setup_data *e820ext = NULL;
724 __u32 e820ext_size = 0;
725 efi_status_t status;
726 struct exit_boot_struct priv;
727
728 priv.boot_params = boot_params;
729 priv.efi = &boot_params->efi_info;
730
731 status = allocate_e820(boot_params, &e820ext, &e820ext_size);
732 if (status != EFI_SUCCESS)
733 return status;
734
735 /* Might as well exit boot services now */
736 status = efi_exit_boot_services(handle, &priv, exit_boot_func);
737 if (status != EFI_SUCCESS)
738 return status;
739
740 /* Historic? */
741 boot_params->alt_mem_k = 32 * 1024;
742
743 status = setup_e820(boot_params, e820ext, e820ext_size);
744 if (status != EFI_SUCCESS)
745 return status;
746
747 return EFI_SUCCESS;
748}
749
750static bool have_unsupported_snp_features(void)
751{
752 u64 unsupported;
753
754 unsupported = snp_get_unsupported_features(sev_get_status());
755 if (unsupported) {
756 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
757 unsupported);
758 return true;
759 }
760 return false;
761}
762
763static void efi_get_seed(void *seed, int size)
764{
765 efi_get_random_bytes(size, seed);
766
767 /*
768 * This only updates seed[0] when running on 32-bit, but in that case,
769 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
770 */
771 *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
772}
773
774static void error(char *str)
775{
776 efi_warn("Decompression failed: %s\n", str);
777}
778
779static const char *cmdline_memmap_override;
780
781static efi_status_t parse_options(const char *cmdline)
782{
783 static const char opts[][14] = {
784 "mem=", "memmap=", "efi_fake_mem=", "hugepages="
785 };
786
787 for (int i = 0; i < ARRAY_SIZE(opts); i++) {
788 const char *p = strstr(cmdline, opts[i]);
789
790 if (p == cmdline || (p > cmdline && isspace(p[-1]))) {
791 cmdline_memmap_override = opts[i];
792 break;
793 }
794 }
795
796 return efi_parse_options(cmdline);
797}
798
799static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
800{
801 unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
802 unsigned long addr, alloc_size, entry;
803 efi_status_t status;
804 u32 seed[2] = {};
805
806 /* determine the required size of the allocation */
807 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
808 MIN_KERNEL_ALIGN);
809
810 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
811 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
812 static const efi_char16_t ami[] = L"American Megatrends";
813
814 efi_get_seed(seed, sizeof(seed));
815
816 virt_addr += (range * seed[1]) >> 32;
817 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
818
819 /*
820 * Older Dell systems with AMI UEFI firmware v2.0 may hang
821 * while decompressing the kernel if physical address
822 * randomization is enabled.
823 *
824 * https://bugzilla.kernel.org/show_bug.cgi?id=218173
825 */
826 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
827 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
828 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
829 seed[0] = 0;
830 } else if (cmdline_memmap_override) {
831 efi_info("%s detected on the kernel command line - disabling physical KASLR\n",
832 cmdline_memmap_override);
833 seed[0] = 0;
834 }
835
836 boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
837 }
838
839 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
840 seed[0], EFI_LOADER_CODE,
841 LOAD_PHYSICAL_ADDR,
842 EFI_X86_KERNEL_ALLOC_LIMIT);
843 if (status != EFI_SUCCESS)
844 return status;
845
846 entry = decompress_kernel((void *)addr, virt_addr, error);
847 if (entry == ULONG_MAX) {
848 efi_free(alloc_size, addr);
849 return EFI_LOAD_ERROR;
850 }
851
852 *kernel_entry = addr + entry;
853
854 return efi_adjust_memory_range_protection(addr, kernel_text_size);
855}
856
857static void __noreturn enter_kernel(unsigned long kernel_addr,
858 struct boot_params *boot_params)
859{
860 /* enter decompressed kernel with boot_params pointer in RSI/ESI */
861 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
862
863 unreachable();
864}
865
866/*
867 * On success, this routine will jump to the relocated image directly and never
868 * return. On failure, it will exit to the firmware via efi_exit() instead of
869 * returning.
870 */
871void __noreturn efi_stub_entry(efi_handle_t handle,
872 efi_system_table_t *sys_table_arg,
873 struct boot_params *boot_params)
874{
875 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
876 struct setup_header *hdr = &boot_params->hdr;
877 const struct linux_efi_initrd *initrd = NULL;
878 unsigned long kernel_entry;
879 efi_status_t status;
880
881 boot_params_ptr = boot_params;
882
883 efi_system_table = sys_table_arg;
884 /* Check if we were booted by the EFI firmware */
885 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
886 efi_exit(handle, EFI_INVALID_PARAMETER);
887
888 if (have_unsupported_snp_features())
889 efi_exit(handle, EFI_UNSUPPORTED);
890
891 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
892 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
893 if (efi_dxe_table &&
894 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
895 efi_warn("Ignoring DXE services table: invalid signature\n");
896 efi_dxe_table = NULL;
897 }
898 }
899
900 /* grab the memory attributes protocol if it exists */
901 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
902
903 status = efi_setup_5level_paging();
904 if (status != EFI_SUCCESS) {
905 efi_err("efi_setup_5level_paging() failed!\n");
906 goto fail;
907 }
908
909#ifdef CONFIG_CMDLINE_BOOL
910 status = parse_options(CONFIG_CMDLINE);
911 if (status != EFI_SUCCESS) {
912 efi_err("Failed to parse options\n");
913 goto fail;
914 }
915#endif
916 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
917 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
918 ((u64)boot_params->ext_cmd_line_ptr << 32));
919 status = parse_options((char *)cmdline_paddr);
920 if (status != EFI_SUCCESS) {
921 efi_err("Failed to parse options\n");
922 goto fail;
923 }
924 }
925
926 if (efi_mem_encrypt > 0)
927 hdr->xloadflags |= XLF_MEM_ENCRYPTION;
928
929 status = efi_decompress_kernel(&kernel_entry);
930 if (status != EFI_SUCCESS) {
931 efi_err("Failed to decompress kernel\n");
932 goto fail;
933 }
934
935 /*
936 * At this point, an initrd may already have been loaded by the
937 * bootloader and passed via bootparams. We permit an initrd loaded
938 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
939 *
940 * If the device path is not present, any command-line initrd=
941 * arguments will be processed only if image is not NULL, which will be
942 * the case only if we were loaded via the PE entry point.
943 */
944 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
945 &initrd);
946 if (status != EFI_SUCCESS)
947 goto fail;
948 if (initrd && initrd->size > 0) {
949 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
950 &boot_params->ext_ramdisk_image);
951 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
952 &boot_params->ext_ramdisk_size);
953 }
954
955
956 /*
957 * If the boot loader gave us a value for secure_boot then we use that,
958 * otherwise we ask the BIOS.
959 */
960 if (boot_params->secure_boot == efi_secureboot_mode_unset)
961 boot_params->secure_boot = efi_get_secureboot();
962
963 /* Ask the firmware to clear memory on unclean shutdown */
964 efi_enable_reset_attack_mitigation();
965
966 efi_random_get_seed();
967
968 efi_retrieve_eventlog();
969
970 setup_graphics(boot_params);
971
972 setup_efi_pci(boot_params);
973
974 setup_quirks(boot_params);
975
976 setup_unaccepted_memory();
977
978 status = exit_boot(boot_params, handle);
979 if (status != EFI_SUCCESS) {
980 efi_err("exit_boot() failed!\n");
981 goto fail;
982 }
983
984 /*
985 * Call the SEV init code while still running with the firmware's
986 * GDT/IDT, so #VC exceptions will be handled by EFI.
987 */
988 sev_enable(boot_params);
989
990 efi_5level_switch();
991
992 enter_kernel(kernel_entry, boot_params);
993fail:
994 efi_err("efi_stub_entry() failed!\n");
995
996 efi_exit(handle, status);
997}
998
999#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
1000void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1001 struct boot_params *boot_params)
1002{
1003 memset(_bss, 0, _ebss - _bss);
1004 efi_stub_entry(handle, sys_table_arg, boot_params);
1005}
1006
1007#ifndef CONFIG_EFI_MIXED
1008extern __alias(efi_handover_entry)
1009void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1010 struct boot_params *boot_params);
1011
1012extern __alias(efi_handover_entry)
1013void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1014 struct boot_params *boot_params);
1015#endif
1016#endif
1// SPDX-License-Identifier: GPL-2.0-only
2
3/* -----------------------------------------------------------------------
4 *
5 * Copyright 2011 Intel Corporation; author Matt Fleming
6 *
7 * ----------------------------------------------------------------------- */
8
9#include <linux/efi.h>
10#include <linux/pci.h>
11#include <linux/stddef.h>
12
13#include <asm/efi.h>
14#include <asm/e820/types.h>
15#include <asm/setup.h>
16#include <asm/desc.h>
17#include <asm/boot.h>
18#include <asm/kaslr.h>
19#include <asm/sev.h>
20
21#include "efistub.h"
22#include "x86-stub.h"
23
24const efi_system_table_t *efi_system_table;
25const efi_dxe_services_table_t *efi_dxe_table;
26static efi_loaded_image_t *image = NULL;
27static efi_memory_attribute_protocol_t *memattr;
28
29typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t;
30union sev_memory_acceptance_protocol {
31 struct {
32 efi_status_t (__efiapi * allow_unaccepted_memory)(
33 sev_memory_acceptance_protocol_t *);
34 };
35 struct {
36 u32 allow_unaccepted_memory;
37 } mixed_mode;
38};
39
40static efi_status_t
41preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
42{
43 struct pci_setup_rom *rom = NULL;
44 efi_status_t status;
45 unsigned long size;
46 uint64_t romsize;
47 void *romimage;
48
49 /*
50 * Some firmware images contain EFI function pointers at the place where
51 * the romimage and romsize fields are supposed to be. Typically the EFI
52 * code is mapped at high addresses, translating to an unrealistically
53 * large romsize. The UEFI spec limits the size of option ROMs to 16
54 * MiB so we reject any ROMs over 16 MiB in size to catch this.
55 */
56 romimage = efi_table_attr(pci, romimage);
57 romsize = efi_table_attr(pci, romsize);
58 if (!romimage || !romsize || romsize > SZ_16M)
59 return EFI_INVALID_PARAMETER;
60
61 size = romsize + sizeof(*rom);
62
63 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
64 (void **)&rom);
65 if (status != EFI_SUCCESS) {
66 efi_err("Failed to allocate memory for 'rom'\n");
67 return status;
68 }
69
70 memset(rom, 0, sizeof(*rom));
71
72 rom->data.type = SETUP_PCI;
73 rom->data.len = size - sizeof(struct setup_data);
74 rom->data.next = 0;
75 rom->pcilen = romsize;
76 *__rom = rom;
77
78 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
79 PCI_VENDOR_ID, 1, &rom->vendor);
80
81 if (status != EFI_SUCCESS) {
82 efi_err("Failed to read rom->vendor\n");
83 goto free_struct;
84 }
85
86 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
87 PCI_DEVICE_ID, 1, &rom->devid);
88
89 if (status != EFI_SUCCESS) {
90 efi_err("Failed to read rom->devid\n");
91 goto free_struct;
92 }
93
94 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
95 &rom->device, &rom->function);
96
97 if (status != EFI_SUCCESS)
98 goto free_struct;
99
100 memcpy(rom->romdata, romimage, romsize);
101 return status;
102
103free_struct:
104 efi_bs_call(free_pool, rom);
105 return status;
106}
107
108/*
109 * There's no way to return an informative status from this function,
110 * because any analysis (and printing of error messages) needs to be
111 * done directly at the EFI function call-site.
112 *
113 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
114 * just didn't find any PCI devices, but there's no way to tell outside
115 * the context of the call.
116 */
117static void setup_efi_pci(struct boot_params *params)
118{
119 efi_status_t status;
120 void **pci_handle = NULL;
121 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
122 unsigned long size = 0;
123 struct setup_data *data;
124 efi_handle_t h;
125 int i;
126
127 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
128 &pci_proto, NULL, &size, pci_handle);
129
130 if (status == EFI_BUFFER_TOO_SMALL) {
131 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
132 (void **)&pci_handle);
133
134 if (status != EFI_SUCCESS) {
135 efi_err("Failed to allocate memory for 'pci_handle'\n");
136 return;
137 }
138
139 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
140 &pci_proto, NULL, &size, pci_handle);
141 }
142
143 if (status != EFI_SUCCESS)
144 goto free_handle;
145
146 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
147
148 while (data && data->next)
149 data = (struct setup_data *)(unsigned long)data->next;
150
151 for_each_efi_handle(h, pci_handle, size, i) {
152 efi_pci_io_protocol_t *pci = NULL;
153 struct pci_setup_rom *rom;
154
155 status = efi_bs_call(handle_protocol, h, &pci_proto,
156 (void **)&pci);
157 if (status != EFI_SUCCESS || !pci)
158 continue;
159
160 status = preserve_pci_rom_image(pci, &rom);
161 if (status != EFI_SUCCESS)
162 continue;
163
164 if (data)
165 data->next = (unsigned long)rom;
166 else
167 params->hdr.setup_data = (unsigned long)rom;
168
169 data = (struct setup_data *)rom;
170 }
171
172free_handle:
173 efi_bs_call(free_pool, pci_handle);
174}
175
176static void retrieve_apple_device_properties(struct boot_params *boot_params)
177{
178 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
179 struct setup_data *data, *new;
180 efi_status_t status;
181 u32 size = 0;
182 apple_properties_protocol_t *p;
183
184 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
185 if (status != EFI_SUCCESS)
186 return;
187
188 if (efi_table_attr(p, version) != 0x10000) {
189 efi_err("Unsupported properties proto version\n");
190 return;
191 }
192
193 efi_call_proto(p, get_all, NULL, &size);
194 if (!size)
195 return;
196
197 do {
198 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
199 size + sizeof(struct setup_data),
200 (void **)&new);
201 if (status != EFI_SUCCESS) {
202 efi_err("Failed to allocate memory for 'properties'\n");
203 return;
204 }
205
206 status = efi_call_proto(p, get_all, new->data, &size);
207
208 if (status == EFI_BUFFER_TOO_SMALL)
209 efi_bs_call(free_pool, new);
210 } while (status == EFI_BUFFER_TOO_SMALL);
211
212 new->type = SETUP_APPLE_PROPERTIES;
213 new->len = size;
214 new->next = 0;
215
216 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
217 if (!data) {
218 boot_params->hdr.setup_data = (unsigned long)new;
219 } else {
220 while (data->next)
221 data = (struct setup_data *)(unsigned long)data->next;
222 data->next = (unsigned long)new;
223 }
224}
225
226efi_status_t efi_adjust_memory_range_protection(unsigned long start,
227 unsigned long size)
228{
229 efi_status_t status;
230 efi_gcd_memory_space_desc_t desc;
231 unsigned long end, next;
232 unsigned long rounded_start, rounded_end;
233 unsigned long unprotect_start, unprotect_size;
234
235 rounded_start = rounddown(start, EFI_PAGE_SIZE);
236 rounded_end = roundup(start + size, EFI_PAGE_SIZE);
237
238 if (memattr != NULL) {
239 status = efi_call_proto(memattr, clear_memory_attributes,
240 rounded_start,
241 rounded_end - rounded_start,
242 EFI_MEMORY_XP);
243 if (status != EFI_SUCCESS)
244 efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
245 return status;
246 }
247
248 if (efi_dxe_table == NULL)
249 return EFI_SUCCESS;
250
251 /*
252 * Don't modify memory region attributes, they are
253 * already suitable, to lower the possibility to
254 * encounter firmware bugs.
255 */
256
257 for (end = start + size; start < end; start = next) {
258
259 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
260
261 if (status != EFI_SUCCESS)
262 break;
263
264 next = desc.base_address + desc.length;
265
266 /*
267 * Only system memory is suitable for trampoline/kernel image placement,
268 * so only this type of memory needs its attributes to be modified.
269 */
270
271 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
272 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
273 continue;
274
275 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
276 unprotect_size = min(rounded_end, next) - unprotect_start;
277
278 status = efi_dxe_call(set_memory_space_attributes,
279 unprotect_start, unprotect_size,
280 EFI_MEMORY_WB);
281
282 if (status != EFI_SUCCESS) {
283 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
284 unprotect_start,
285 unprotect_start + unprotect_size,
286 status);
287 break;
288 }
289 }
290 return EFI_SUCCESS;
291}
292
293static void setup_unaccepted_memory(void)
294{
295 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
296 sev_memory_acceptance_protocol_t *proto;
297 efi_status_t status;
298
299 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
300 return;
301
302 /*
303 * Enable unaccepted memory before calling exit boot services in order
304 * for the UEFI to not accept all memory on EBS.
305 */
306 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
307 (void **)&proto);
308 if (status != EFI_SUCCESS)
309 return;
310
311 status = efi_call_proto(proto, allow_unaccepted_memory);
312 if (status != EFI_SUCCESS)
313 efi_err("Memory acceptance protocol failed\n");
314}
315
316static efi_char16_t *efistub_fw_vendor(void)
317{
318 unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
319
320 return (efi_char16_t *)vendor;
321}
322
323static const efi_char16_t apple[] = L"Apple";
324
325static void setup_quirks(struct boot_params *boot_params)
326{
327 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) &&
328 !memcmp(efistub_fw_vendor(), apple, sizeof(apple)))
329 retrieve_apple_device_properties(boot_params);
330}
331
332/*
333 * See if we have Universal Graphics Adapter (UGA) protocol
334 */
335static efi_status_t
336setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
337{
338 efi_status_t status;
339 u32 width, height;
340 void **uga_handle = NULL;
341 efi_uga_draw_protocol_t *uga = NULL, *first_uga;
342 efi_handle_t handle;
343 int i;
344
345 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
346 (void **)&uga_handle);
347 if (status != EFI_SUCCESS)
348 return status;
349
350 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
351 uga_proto, NULL, &size, uga_handle);
352 if (status != EFI_SUCCESS)
353 goto free_handle;
354
355 height = 0;
356 width = 0;
357
358 first_uga = NULL;
359 for_each_efi_handle(handle, uga_handle, size, i) {
360 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
361 u32 w, h, depth, refresh;
362 void *pciio;
363
364 status = efi_bs_call(handle_protocol, handle, uga_proto,
365 (void **)&uga);
366 if (status != EFI_SUCCESS)
367 continue;
368
369 pciio = NULL;
370 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
371
372 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
373 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
374 width = w;
375 height = h;
376
377 /*
378 * Once we've found a UGA supporting PCIIO,
379 * don't bother looking any further.
380 */
381 if (pciio)
382 break;
383
384 first_uga = uga;
385 }
386 }
387
388 if (!width && !height)
389 goto free_handle;
390
391 /* EFI framebuffer */
392 si->orig_video_isVGA = VIDEO_TYPE_EFI;
393
394 si->lfb_depth = 32;
395 si->lfb_width = width;
396 si->lfb_height = height;
397
398 si->red_size = 8;
399 si->red_pos = 16;
400 si->green_size = 8;
401 si->green_pos = 8;
402 si->blue_size = 8;
403 si->blue_pos = 0;
404 si->rsvd_size = 8;
405 si->rsvd_pos = 24;
406
407free_handle:
408 efi_bs_call(free_pool, uga_handle);
409
410 return status;
411}
412
413static void setup_graphics(struct boot_params *boot_params)
414{
415 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
416 struct screen_info *si;
417 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
418 efi_status_t status;
419 unsigned long size;
420 void **gop_handle = NULL;
421 void **uga_handle = NULL;
422
423 si = &boot_params->screen_info;
424 memset(si, 0, sizeof(*si));
425
426 size = 0;
427 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
428 &graphics_proto, NULL, &size, gop_handle);
429 if (status == EFI_BUFFER_TOO_SMALL)
430 status = efi_setup_gop(si, &graphics_proto, size);
431
432 if (status != EFI_SUCCESS) {
433 size = 0;
434 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
435 &uga_proto, NULL, &size, uga_handle);
436 if (status == EFI_BUFFER_TOO_SMALL)
437 setup_uga(si, &uga_proto, size);
438 }
439}
440
441
442static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
443{
444 efi_bs_call(exit, handle, status, 0, NULL);
445 for(;;)
446 asm("hlt");
447}
448
449void __noreturn efi_stub_entry(efi_handle_t handle,
450 efi_system_table_t *sys_table_arg,
451 struct boot_params *boot_params);
452
453/*
454 * Because the x86 boot code expects to be passed a boot_params we
455 * need to create one ourselves (usually the bootloader would create
456 * one for us).
457 */
458efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
459 efi_system_table_t *sys_table_arg)
460{
461 static struct boot_params boot_params __page_aligned_bss;
462 struct setup_header *hdr = &boot_params.hdr;
463 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
464 int options_size = 0;
465 efi_status_t status;
466 char *cmdline_ptr;
467
468 efi_system_table = sys_table_arg;
469
470 /* Check if we were booted by the EFI firmware */
471 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
472 efi_exit(handle, EFI_INVALID_PARAMETER);
473
474 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
475 if (status != EFI_SUCCESS) {
476 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
477 efi_exit(handle, status);
478 }
479
480 /* Assign the setup_header fields that the kernel actually cares about */
481 hdr->root_flags = 1;
482 hdr->vid_mode = 0xffff;
483
484 hdr->type_of_loader = 0x21;
485
486 /* Convert unicode cmdline to ascii */
487 cmdline_ptr = efi_convert_cmdline(image, &options_size);
488 if (!cmdline_ptr)
489 goto fail;
490
491 efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
492 &boot_params.ext_cmd_line_ptr);
493
494 efi_stub_entry(handle, sys_table_arg, &boot_params);
495 /* not reached */
496
497fail:
498 efi_exit(handle, status);
499}
500
501static void add_e820ext(struct boot_params *params,
502 struct setup_data *e820ext, u32 nr_entries)
503{
504 struct setup_data *data;
505
506 e820ext->type = SETUP_E820_EXT;
507 e820ext->len = nr_entries * sizeof(struct boot_e820_entry);
508 e820ext->next = 0;
509
510 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
511
512 while (data && data->next)
513 data = (struct setup_data *)(unsigned long)data->next;
514
515 if (data)
516 data->next = (unsigned long)e820ext;
517 else
518 params->hdr.setup_data = (unsigned long)e820ext;
519}
520
521static efi_status_t
522setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
523{
524 struct boot_e820_entry *entry = params->e820_table;
525 struct efi_info *efi = ¶ms->efi_info;
526 struct boot_e820_entry *prev = NULL;
527 u32 nr_entries;
528 u32 nr_desc;
529 int i;
530
531 nr_entries = 0;
532 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
533
534 for (i = 0; i < nr_desc; i++) {
535 efi_memory_desc_t *d;
536 unsigned int e820_type = 0;
537 unsigned long m = efi->efi_memmap;
538
539#ifdef CONFIG_X86_64
540 m |= (u64)efi->efi_memmap_hi << 32;
541#endif
542
543 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
544 switch (d->type) {
545 case EFI_RESERVED_TYPE:
546 case EFI_RUNTIME_SERVICES_CODE:
547 case EFI_RUNTIME_SERVICES_DATA:
548 case EFI_MEMORY_MAPPED_IO:
549 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
550 case EFI_PAL_CODE:
551 e820_type = E820_TYPE_RESERVED;
552 break;
553
554 case EFI_UNUSABLE_MEMORY:
555 e820_type = E820_TYPE_UNUSABLE;
556 break;
557
558 case EFI_ACPI_RECLAIM_MEMORY:
559 e820_type = E820_TYPE_ACPI;
560 break;
561
562 case EFI_LOADER_CODE:
563 case EFI_LOADER_DATA:
564 case EFI_BOOT_SERVICES_CODE:
565 case EFI_BOOT_SERVICES_DATA:
566 case EFI_CONVENTIONAL_MEMORY:
567 if (efi_soft_reserve_enabled() &&
568 (d->attribute & EFI_MEMORY_SP))
569 e820_type = E820_TYPE_SOFT_RESERVED;
570 else
571 e820_type = E820_TYPE_RAM;
572 break;
573
574 case EFI_ACPI_MEMORY_NVS:
575 e820_type = E820_TYPE_NVS;
576 break;
577
578 case EFI_PERSISTENT_MEMORY:
579 e820_type = E820_TYPE_PMEM;
580 break;
581
582 case EFI_UNACCEPTED_MEMORY:
583 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
584 continue;
585 e820_type = E820_TYPE_RAM;
586 process_unaccepted_memory(d->phys_addr,
587 d->phys_addr + PAGE_SIZE * d->num_pages);
588 break;
589 default:
590 continue;
591 }
592
593 /* Merge adjacent mappings */
594 if (prev && prev->type == e820_type &&
595 (prev->addr + prev->size) == d->phys_addr) {
596 prev->size += d->num_pages << 12;
597 continue;
598 }
599
600 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
601 u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
602 sizeof(struct setup_data);
603
604 if (!e820ext || e820ext_size < need)
605 return EFI_BUFFER_TOO_SMALL;
606
607 /* boot_params map full, switch to e820 extended */
608 entry = (struct boot_e820_entry *)e820ext->data;
609 }
610
611 entry->addr = d->phys_addr;
612 entry->size = d->num_pages << PAGE_SHIFT;
613 entry->type = e820_type;
614 prev = entry++;
615 nr_entries++;
616 }
617
618 if (nr_entries > ARRAY_SIZE(params->e820_table)) {
619 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
620
621 add_e820ext(params, e820ext, nr_e820ext);
622 nr_entries -= nr_e820ext;
623 }
624
625 params->e820_entries = (u8)nr_entries;
626
627 return EFI_SUCCESS;
628}
629
630static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
631 u32 *e820ext_size)
632{
633 efi_status_t status;
634 unsigned long size;
635
636 size = sizeof(struct setup_data) +
637 sizeof(struct e820_entry) * nr_desc;
638
639 if (*e820ext) {
640 efi_bs_call(free_pool, *e820ext);
641 *e820ext = NULL;
642 *e820ext_size = 0;
643 }
644
645 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
646 (void **)e820ext);
647 if (status == EFI_SUCCESS)
648 *e820ext_size = size;
649
650 return status;
651}
652
653static efi_status_t allocate_e820(struct boot_params *params,
654 struct setup_data **e820ext,
655 u32 *e820ext_size)
656{
657 struct efi_boot_memmap *map;
658 efi_status_t status;
659 __u32 nr_desc;
660
661 status = efi_get_memory_map(&map, false);
662 if (status != EFI_SUCCESS)
663 return status;
664
665 nr_desc = map->map_size / map->desc_size;
666 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
667 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
668 EFI_MMAP_NR_SLACK_SLOTS;
669
670 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
671 }
672
673 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS)
674 status = allocate_unaccepted_bitmap(nr_desc, map);
675
676 efi_bs_call(free_pool, map);
677 return status;
678}
679
680struct exit_boot_struct {
681 struct boot_params *boot_params;
682 struct efi_info *efi;
683};
684
685static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
686 void *priv)
687{
688 const char *signature;
689 struct exit_boot_struct *p = priv;
690
691 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
692 : EFI32_LOADER_SIGNATURE;
693 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
694
695 efi_set_u64_split((unsigned long)efi_system_table,
696 &p->efi->efi_systab, &p->efi->efi_systab_hi);
697 p->efi->efi_memdesc_size = map->desc_size;
698 p->efi->efi_memdesc_version = map->desc_ver;
699 efi_set_u64_split((unsigned long)map->map,
700 &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
701 p->efi->efi_memmap_size = map->map_size;
702
703 return EFI_SUCCESS;
704}
705
706static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
707{
708 struct setup_data *e820ext = NULL;
709 __u32 e820ext_size = 0;
710 efi_status_t status;
711 struct exit_boot_struct priv;
712
713 priv.boot_params = boot_params;
714 priv.efi = &boot_params->efi_info;
715
716 status = allocate_e820(boot_params, &e820ext, &e820ext_size);
717 if (status != EFI_SUCCESS)
718 return status;
719
720 /* Might as well exit boot services now */
721 status = efi_exit_boot_services(handle, &priv, exit_boot_func);
722 if (status != EFI_SUCCESS)
723 return status;
724
725 /* Historic? */
726 boot_params->alt_mem_k = 32 * 1024;
727
728 status = setup_e820(boot_params, e820ext, e820ext_size);
729 if (status != EFI_SUCCESS)
730 return status;
731
732 return EFI_SUCCESS;
733}
734
735static bool have_unsupported_snp_features(void)
736{
737 u64 unsupported;
738
739 unsupported = snp_get_unsupported_features(sev_get_status());
740 if (unsupported) {
741 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
742 unsupported);
743 return true;
744 }
745 return false;
746}
747
748static void efi_get_seed(void *seed, int size)
749{
750 efi_get_random_bytes(size, seed);
751
752 /*
753 * This only updates seed[0] when running on 32-bit, but in that case,
754 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
755 */
756 *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
757}
758
759static void error(char *str)
760{
761 efi_warn("Decompression failed: %s\n", str);
762}
763
764static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
765{
766 unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
767 unsigned long addr, alloc_size, entry;
768 efi_status_t status;
769 u32 seed[2] = {};
770
771 /* determine the required size of the allocation */
772 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
773 MIN_KERNEL_ALIGN);
774
775 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
776 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
777 static const efi_char16_t ami[] = L"American Megatrends";
778
779 efi_get_seed(seed, sizeof(seed));
780
781 virt_addr += (range * seed[1]) >> 32;
782 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
783
784 /*
785 * Older Dell systems with AMI UEFI firmware v2.0 may hang
786 * while decompressing the kernel if physical address
787 * randomization is enabled.
788 *
789 * https://bugzilla.kernel.org/show_bug.cgi?id=218173
790 */
791 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
792 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
793 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
794 seed[0] = 0;
795 }
796
797 boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
798 }
799
800 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
801 seed[0], EFI_LOADER_CODE,
802 LOAD_PHYSICAL_ADDR,
803 EFI_X86_KERNEL_ALLOC_LIMIT);
804 if (status != EFI_SUCCESS)
805 return status;
806
807 entry = decompress_kernel((void *)addr, virt_addr, error);
808 if (entry == ULONG_MAX) {
809 efi_free(alloc_size, addr);
810 return EFI_LOAD_ERROR;
811 }
812
813 *kernel_entry = addr + entry;
814
815 return efi_adjust_memory_range_protection(addr, kernel_total_size);
816}
817
818static void __noreturn enter_kernel(unsigned long kernel_addr,
819 struct boot_params *boot_params)
820{
821 /* enter decompressed kernel with boot_params pointer in RSI/ESI */
822 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
823
824 unreachable();
825}
826
827/*
828 * On success, this routine will jump to the relocated image directly and never
829 * return. On failure, it will exit to the firmware via efi_exit() instead of
830 * returning.
831 */
832void __noreturn efi_stub_entry(efi_handle_t handle,
833 efi_system_table_t *sys_table_arg,
834 struct boot_params *boot_params)
835{
836 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
837 struct setup_header *hdr = &boot_params->hdr;
838 const struct linux_efi_initrd *initrd = NULL;
839 unsigned long kernel_entry;
840 efi_status_t status;
841
842 boot_params_ptr = boot_params;
843
844 efi_system_table = sys_table_arg;
845 /* Check if we were booted by the EFI firmware */
846 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
847 efi_exit(handle, EFI_INVALID_PARAMETER);
848
849 if (have_unsupported_snp_features())
850 efi_exit(handle, EFI_UNSUPPORTED);
851
852 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
853 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
854 if (efi_dxe_table &&
855 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
856 efi_warn("Ignoring DXE services table: invalid signature\n");
857 efi_dxe_table = NULL;
858 }
859 }
860
861 /* grab the memory attributes protocol if it exists */
862 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
863
864 status = efi_setup_5level_paging();
865 if (status != EFI_SUCCESS) {
866 efi_err("efi_setup_5level_paging() failed!\n");
867 goto fail;
868 }
869
870#ifdef CONFIG_CMDLINE_BOOL
871 status = efi_parse_options(CONFIG_CMDLINE);
872 if (status != EFI_SUCCESS) {
873 efi_err("Failed to parse options\n");
874 goto fail;
875 }
876#endif
877 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
878 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
879 ((u64)boot_params->ext_cmd_line_ptr << 32));
880 status = efi_parse_options((char *)cmdline_paddr);
881 if (status != EFI_SUCCESS) {
882 efi_err("Failed to parse options\n");
883 goto fail;
884 }
885 }
886
887 status = efi_decompress_kernel(&kernel_entry);
888 if (status != EFI_SUCCESS) {
889 efi_err("Failed to decompress kernel\n");
890 goto fail;
891 }
892
893 /*
894 * At this point, an initrd may already have been loaded by the
895 * bootloader and passed via bootparams. We permit an initrd loaded
896 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
897 *
898 * If the device path is not present, any command-line initrd=
899 * arguments will be processed only if image is not NULL, which will be
900 * the case only if we were loaded via the PE entry point.
901 */
902 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
903 &initrd);
904 if (status != EFI_SUCCESS)
905 goto fail;
906 if (initrd && initrd->size > 0) {
907 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
908 &boot_params->ext_ramdisk_image);
909 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
910 &boot_params->ext_ramdisk_size);
911 }
912
913
914 /*
915 * If the boot loader gave us a value for secure_boot then we use that,
916 * otherwise we ask the BIOS.
917 */
918 if (boot_params->secure_boot == efi_secureboot_mode_unset)
919 boot_params->secure_boot = efi_get_secureboot();
920
921 /* Ask the firmware to clear memory on unclean shutdown */
922 efi_enable_reset_attack_mitigation();
923
924 efi_random_get_seed();
925
926 efi_retrieve_tpm2_eventlog();
927
928 setup_graphics(boot_params);
929
930 setup_efi_pci(boot_params);
931
932 setup_quirks(boot_params);
933
934 setup_unaccepted_memory();
935
936 status = exit_boot(boot_params, handle);
937 if (status != EFI_SUCCESS) {
938 efi_err("exit_boot() failed!\n");
939 goto fail;
940 }
941
942 /*
943 * Call the SEV init code while still running with the firmware's
944 * GDT/IDT, so #VC exceptions will be handled by EFI.
945 */
946 sev_enable(boot_params);
947
948 efi_5level_switch();
949
950 enter_kernel(kernel_entry, boot_params);
951fail:
952 efi_err("efi_stub_entry() failed!\n");
953
954 efi_exit(handle, status);
955}
956
957#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
958void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
959 struct boot_params *boot_params)
960{
961 extern char _bss[], _ebss[];
962
963 memset(_bss, 0, _ebss - _bss);
964 efi_stub_entry(handle, sys_table_arg, boot_params);
965}
966
967#ifndef CONFIG_EFI_MIXED
968extern __alias(efi_handover_entry)
969void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
970 struct boot_params *boot_params);
971
972extern __alias(efi_handover_entry)
973void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
974 struct boot_params *boot_params);
975#endif
976#endif