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
19 #include "efistub.h"
20
21 /* Maximum physical address for 64-bit kernel with 4-level paging */
22 #define MAXMEM_X86_64_4LEVEL (1ull << 46)
23
24 const efi_system_table_t *efi_system_table;
25 const efi_dxe_services_table_t *efi_dxe_table;
26 extern u32 image_offset;
27 static efi_loaded_image_t *image = NULL;
28
29 static efi_status_t
preserve_pci_rom_image(efi_pci_io_protocol_t * pci,struct pci_setup_rom ** __rom)30 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
31 {
32 struct pci_setup_rom *rom = NULL;
33 efi_status_t status;
34 unsigned long size;
35 uint64_t romsize;
36 void *romimage;
37
38 /*
39 * Some firmware images contain EFI function pointers at the place where
40 * the romimage and romsize fields are supposed to be. Typically the EFI
41 * code is mapped at high addresses, translating to an unrealistically
42 * large romsize. The UEFI spec limits the size of option ROMs to 16
43 * MiB so we reject any ROMs over 16 MiB in size to catch this.
44 */
45 romimage = efi_table_attr(pci, romimage);
46 romsize = efi_table_attr(pci, romsize);
47 if (!romimage || !romsize || romsize > SZ_16M)
48 return EFI_INVALID_PARAMETER;
49
50 size = romsize + sizeof(*rom);
51
52 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
53 (void **)&rom);
54 if (status != EFI_SUCCESS) {
55 efi_err("Failed to allocate memory for 'rom'\n");
56 return status;
57 }
58
59 memset(rom, 0, sizeof(*rom));
60
61 rom->data.type = SETUP_PCI;
62 rom->data.len = size - sizeof(struct setup_data);
63 rom->data.next = 0;
64 rom->pcilen = pci->romsize;
65 *__rom = rom;
66
67 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
68 PCI_VENDOR_ID, 1, &rom->vendor);
69
70 if (status != EFI_SUCCESS) {
71 efi_err("Failed to read rom->vendor\n");
72 goto free_struct;
73 }
74
75 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
76 PCI_DEVICE_ID, 1, &rom->devid);
77
78 if (status != EFI_SUCCESS) {
79 efi_err("Failed to read rom->devid\n");
80 goto free_struct;
81 }
82
83 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
84 &rom->device, &rom->function);
85
86 if (status != EFI_SUCCESS)
87 goto free_struct;
88
89 memcpy(rom->romdata, romimage, romsize);
90 return status;
91
92 free_struct:
93 efi_bs_call(free_pool, rom);
94 return status;
95 }
96
97 /*
98 * There's no way to return an informative status from this function,
99 * because any analysis (and printing of error messages) needs to be
100 * done directly at the EFI function call-site.
101 *
102 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
103 * just didn't find any PCI devices, but there's no way to tell outside
104 * the context of the call.
105 */
setup_efi_pci(struct boot_params * params)106 static void setup_efi_pci(struct boot_params *params)
107 {
108 efi_status_t status;
109 void **pci_handle = NULL;
110 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
111 unsigned long size = 0;
112 struct setup_data *data;
113 efi_handle_t h;
114 int i;
115
116 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
117 &pci_proto, NULL, &size, pci_handle);
118
119 if (status == EFI_BUFFER_TOO_SMALL) {
120 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
121 (void **)&pci_handle);
122
123 if (status != EFI_SUCCESS) {
124 efi_err("Failed to allocate memory for 'pci_handle'\n");
125 return;
126 }
127
128 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
129 &pci_proto, NULL, &size, pci_handle);
130 }
131
132 if (status != EFI_SUCCESS)
133 goto free_handle;
134
135 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
136
137 while (data && data->next)
138 data = (struct setup_data *)(unsigned long)data->next;
139
140 for_each_efi_handle(h, pci_handle, size, i) {
141 efi_pci_io_protocol_t *pci = NULL;
142 struct pci_setup_rom *rom;
143
144 status = efi_bs_call(handle_protocol, h, &pci_proto,
145 (void **)&pci);
146 if (status != EFI_SUCCESS || !pci)
147 continue;
148
149 status = preserve_pci_rom_image(pci, &rom);
150 if (status != EFI_SUCCESS)
151 continue;
152
153 if (data)
154 data->next = (unsigned long)rom;
155 else
156 params->hdr.setup_data = (unsigned long)rom;
157
158 data = (struct setup_data *)rom;
159 }
160
161 free_handle:
162 efi_bs_call(free_pool, pci_handle);
163 }
164
retrieve_apple_device_properties(struct boot_params * boot_params)165 static void retrieve_apple_device_properties(struct boot_params *boot_params)
166 {
167 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
168 struct setup_data *data, *new;
169 efi_status_t status;
170 u32 size = 0;
171 apple_properties_protocol_t *p;
172
173 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
174 if (status != EFI_SUCCESS)
175 return;
176
177 if (efi_table_attr(p, version) != 0x10000) {
178 efi_err("Unsupported properties proto version\n");
179 return;
180 }
181
182 efi_call_proto(p, get_all, NULL, &size);
183 if (!size)
184 return;
185
186 do {
187 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
188 size + sizeof(struct setup_data),
189 (void **)&new);
190 if (status != EFI_SUCCESS) {
191 efi_err("Failed to allocate memory for 'properties'\n");
192 return;
193 }
194
195 status = efi_call_proto(p, get_all, new->data, &size);
196
197 if (status == EFI_BUFFER_TOO_SMALL)
198 efi_bs_call(free_pool, new);
199 } while (status == EFI_BUFFER_TOO_SMALL);
200
201 new->type = SETUP_APPLE_PROPERTIES;
202 new->len = size;
203 new->next = 0;
204
205 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
206 if (!data) {
207 boot_params->hdr.setup_data = (unsigned long)new;
208 } else {
209 while (data->next)
210 data = (struct setup_data *)(unsigned long)data->next;
211 data->next = (unsigned long)new;
212 }
213 }
214
215 static void
adjust_memory_range_protection(unsigned long start,unsigned long size)216 adjust_memory_range_protection(unsigned long start, unsigned long size)
217 {
218 efi_status_t status;
219 efi_gcd_memory_space_desc_t desc;
220 unsigned long end, next;
221 unsigned long rounded_start, rounded_end;
222 unsigned long unprotect_start, unprotect_size;
223
224 if (efi_dxe_table == NULL)
225 return;
226
227 rounded_start = rounddown(start, EFI_PAGE_SIZE);
228 rounded_end = roundup(start + size, EFI_PAGE_SIZE);
229
230 /*
231 * Don't modify memory region attributes, they are
232 * already suitable, to lower the possibility to
233 * encounter firmware bugs.
234 */
235
236 for (end = start + size; start < end; start = next) {
237
238 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
239
240 if (status != EFI_SUCCESS)
241 return;
242
243 next = desc.base_address + desc.length;
244
245 /*
246 * Only system memory is suitable for trampoline/kernel image placement,
247 * so only this type of memory needs its attributes to be modified.
248 */
249
250 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
251 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
252 continue;
253
254 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
255 unprotect_size = min(rounded_end, next) - unprotect_start;
256
257 status = efi_dxe_call(set_memory_space_attributes,
258 unprotect_start, unprotect_size,
259 EFI_MEMORY_WB);
260
261 if (status != EFI_SUCCESS) {
262 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
263 unprotect_start,
264 unprotect_start + unprotect_size,
265 status);
266 }
267 }
268 }
269
270 /*
271 * Trampoline takes 2 pages and can be loaded in first megabyte of memory
272 * with its end placed between 128k and 640k where BIOS might start.
273 * (see arch/x86/boot/compressed/pgtable_64.c)
274 *
275 * We cannot find exact trampoline placement since memory map
276 * can be modified by UEFI, and it can alter the computed address.
277 */
278
279 #define TRAMPOLINE_PLACEMENT_BASE ((128 - 8)*1024)
280 #define TRAMPOLINE_PLACEMENT_SIZE (640*1024 - (128 - 8)*1024)
281
282 void startup_32(struct boot_params *boot_params);
283
284 static void
setup_memory_protection(unsigned long image_base,unsigned long image_size)285 setup_memory_protection(unsigned long image_base, unsigned long image_size)
286 {
287 /*
288 * Allow execution of possible trampoline used
289 * for switching between 4- and 5-level page tables
290 * and relocated kernel image.
291 */
292
293 adjust_memory_range_protection(TRAMPOLINE_PLACEMENT_BASE,
294 TRAMPOLINE_PLACEMENT_SIZE);
295
296 #ifdef CONFIG_64BIT
297 if (image_base != (unsigned long)startup_32)
298 adjust_memory_range_protection(image_base, image_size);
299 #else
300 /*
301 * Clear protection flags on a whole range of possible
302 * addresses used for KASLR. We don't need to do that
303 * on x86_64, since KASLR/extraction is performed after
304 * dedicated identity page tables are built and we only
305 * need to remove possible protection on relocated image
306 * itself disregarding further relocations.
307 */
308 adjust_memory_range_protection(LOAD_PHYSICAL_ADDR,
309 KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR);
310 #endif
311 }
312
313 static const efi_char16_t apple[] = L"Apple";
314
setup_quirks(struct boot_params * boot_params,unsigned long image_base,unsigned long image_size)315 static void setup_quirks(struct boot_params *boot_params,
316 unsigned long image_base,
317 unsigned long image_size)
318 {
319 efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
320 efi_table_attr(efi_system_table, fw_vendor);
321
322 if (!memcmp(fw_vendor, apple, sizeof(apple))) {
323 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
324 retrieve_apple_device_properties(boot_params);
325 }
326
327 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES))
328 setup_memory_protection(image_base, image_size);
329 }
330
331 /*
332 * See if we have Universal Graphics Adapter (UGA) protocol
333 */
334 static efi_status_t
setup_uga(struct screen_info * si,efi_guid_t * uga_proto,unsigned long size)335 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
336 {
337 efi_status_t status;
338 u32 width, height;
339 void **uga_handle = NULL;
340 efi_uga_draw_protocol_t *uga = NULL, *first_uga;
341 efi_handle_t handle;
342 int i;
343
344 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
345 (void **)&uga_handle);
346 if (status != EFI_SUCCESS)
347 return status;
348
349 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
350 uga_proto, NULL, &size, uga_handle);
351 if (status != EFI_SUCCESS)
352 goto free_handle;
353
354 height = 0;
355 width = 0;
356
357 first_uga = NULL;
358 for_each_efi_handle(handle, uga_handle, size, i) {
359 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
360 u32 w, h, depth, refresh;
361 void *pciio;
362
363 status = efi_bs_call(handle_protocol, handle, uga_proto,
364 (void **)&uga);
365 if (status != EFI_SUCCESS)
366 continue;
367
368 pciio = NULL;
369 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
370
371 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
372 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
373 width = w;
374 height = h;
375
376 /*
377 * Once we've found a UGA supporting PCIIO,
378 * don't bother looking any further.
379 */
380 if (pciio)
381 break;
382
383 first_uga = uga;
384 }
385 }
386
387 if (!width && !height)
388 goto free_handle;
389
390 /* EFI framebuffer */
391 si->orig_video_isVGA = VIDEO_TYPE_EFI;
392
393 si->lfb_depth = 32;
394 si->lfb_width = width;
395 si->lfb_height = height;
396
397 si->red_size = 8;
398 si->red_pos = 16;
399 si->green_size = 8;
400 si->green_pos = 8;
401 si->blue_size = 8;
402 si->blue_pos = 0;
403 si->rsvd_size = 8;
404 si->rsvd_pos = 24;
405
406 free_handle:
407 efi_bs_call(free_pool, uga_handle);
408
409 return status;
410 }
411
setup_graphics(struct boot_params * boot_params)412 static void setup_graphics(struct boot_params *boot_params)
413 {
414 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
415 struct screen_info *si;
416 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
417 efi_status_t status;
418 unsigned long size;
419 void **gop_handle = NULL;
420 void **uga_handle = NULL;
421
422 si = &boot_params->screen_info;
423 memset(si, 0, sizeof(*si));
424
425 size = 0;
426 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
427 &graphics_proto, NULL, &size, gop_handle);
428 if (status == EFI_BUFFER_TOO_SMALL)
429 status = efi_setup_gop(si, &graphics_proto, size);
430
431 if (status != EFI_SUCCESS) {
432 size = 0;
433 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
434 &uga_proto, NULL, &size, uga_handle);
435 if (status == EFI_BUFFER_TOO_SMALL)
436 setup_uga(si, &uga_proto, size);
437 }
438 }
439
440
efi_exit(efi_handle_t handle,efi_status_t status)441 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
442 {
443 efi_bs_call(exit, handle, status, 0, NULL);
444 for(;;)
445 asm("hlt");
446 }
447
448 void __noreturn efi_stub_entry(efi_handle_t handle,
449 efi_system_table_t *sys_table_arg,
450 struct boot_params *boot_params);
451
452 /*
453 * Because the x86 boot code expects to be passed a boot_params we
454 * need to create one ourselves (usually the bootloader would create
455 * one for us).
456 */
efi_pe_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg)457 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
458 efi_system_table_t *sys_table_arg)
459 {
460 struct boot_params *boot_params;
461 struct setup_header *hdr;
462 void *image_base;
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 image_base = efi_table_attr(image, image_base);
481 image_offset = (void *)startup_32 - image_base;
482
483 status = efi_allocate_pages(sizeof(struct boot_params),
484 (unsigned long *)&boot_params, ULONG_MAX);
485 if (status != EFI_SUCCESS) {
486 efi_err("Failed to allocate lowmem for boot params\n");
487 efi_exit(handle, status);
488 }
489
490 memset(boot_params, 0x0, sizeof(struct boot_params));
491
492 hdr = &boot_params->hdr;
493
494 /* Copy the setup header from the second sector to boot_params */
495 memcpy(&hdr->jump, image_base + 512,
496 sizeof(struct setup_header) - offsetof(struct setup_header, jump));
497
498 /*
499 * Fill out some of the header fields ourselves because the
500 * EFI firmware loader doesn't load the first sector.
501 */
502 hdr->root_flags = 1;
503 hdr->vid_mode = 0xffff;
504 hdr->boot_flag = 0xAA55;
505
506 hdr->type_of_loader = 0x21;
507
508 /* Convert unicode cmdline to ascii */
509 cmdline_ptr = efi_convert_cmdline(image, &options_size);
510 if (!cmdline_ptr)
511 goto fail;
512
513 efi_set_u64_split((unsigned long)cmdline_ptr,
514 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr);
515
516 hdr->ramdisk_image = 0;
517 hdr->ramdisk_size = 0;
518
519 /*
520 * Disregard any setup data that was provided by the bootloader:
521 * setup_data could be pointing anywhere, and we have no way of
522 * authenticating or validating the payload.
523 */
524 hdr->setup_data = 0;
525
526 efi_stub_entry(handle, sys_table_arg, boot_params);
527 /* not reached */
528
529 fail:
530 efi_free(sizeof(struct boot_params), (unsigned long)boot_params);
531
532 efi_exit(handle, status);
533 }
534
add_e820ext(struct boot_params * params,struct setup_data * e820ext,u32 nr_entries)535 static void add_e820ext(struct boot_params *params,
536 struct setup_data *e820ext, u32 nr_entries)
537 {
538 struct setup_data *data;
539
540 e820ext->type = SETUP_E820_EXT;
541 e820ext->len = nr_entries * sizeof(struct boot_e820_entry);
542 e820ext->next = 0;
543
544 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
545
546 while (data && data->next)
547 data = (struct setup_data *)(unsigned long)data->next;
548
549 if (data)
550 data->next = (unsigned long)e820ext;
551 else
552 params->hdr.setup_data = (unsigned long)e820ext;
553 }
554
555 static efi_status_t
setup_e820(struct boot_params * params,struct setup_data * e820ext,u32 e820ext_size)556 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
557 {
558 struct boot_e820_entry *entry = params->e820_table;
559 struct efi_info *efi = ¶ms->efi_info;
560 struct boot_e820_entry *prev = NULL;
561 u32 nr_entries;
562 u32 nr_desc;
563 int i;
564
565 nr_entries = 0;
566 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
567
568 for (i = 0; i < nr_desc; i++) {
569 efi_memory_desc_t *d;
570 unsigned int e820_type = 0;
571 unsigned long m = efi->efi_memmap;
572
573 #ifdef CONFIG_X86_64
574 m |= (u64)efi->efi_memmap_hi << 32;
575 #endif
576
577 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
578 switch (d->type) {
579 case EFI_RESERVED_TYPE:
580 case EFI_RUNTIME_SERVICES_CODE:
581 case EFI_RUNTIME_SERVICES_DATA:
582 case EFI_MEMORY_MAPPED_IO:
583 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
584 case EFI_PAL_CODE:
585 e820_type = E820_TYPE_RESERVED;
586 break;
587
588 case EFI_UNUSABLE_MEMORY:
589 e820_type = E820_TYPE_UNUSABLE;
590 break;
591
592 case EFI_ACPI_RECLAIM_MEMORY:
593 e820_type = E820_TYPE_ACPI;
594 break;
595
596 case EFI_LOADER_CODE:
597 case EFI_LOADER_DATA:
598 case EFI_BOOT_SERVICES_CODE:
599 case EFI_BOOT_SERVICES_DATA:
600 case EFI_CONVENTIONAL_MEMORY:
601 if (efi_soft_reserve_enabled() &&
602 (d->attribute & EFI_MEMORY_SP))
603 e820_type = E820_TYPE_SOFT_RESERVED;
604 else
605 e820_type = E820_TYPE_RAM;
606 break;
607
608 case EFI_ACPI_MEMORY_NVS:
609 e820_type = E820_TYPE_NVS;
610 break;
611
612 case EFI_PERSISTENT_MEMORY:
613 e820_type = E820_TYPE_PMEM;
614 break;
615
616 default:
617 continue;
618 }
619
620 /* Merge adjacent mappings */
621 if (prev && prev->type == e820_type &&
622 (prev->addr + prev->size) == d->phys_addr) {
623 prev->size += d->num_pages << 12;
624 continue;
625 }
626
627 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
628 u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
629 sizeof(struct setup_data);
630
631 if (!e820ext || e820ext_size < need)
632 return EFI_BUFFER_TOO_SMALL;
633
634 /* boot_params map full, switch to e820 extended */
635 entry = (struct boot_e820_entry *)e820ext->data;
636 }
637
638 entry->addr = d->phys_addr;
639 entry->size = d->num_pages << PAGE_SHIFT;
640 entry->type = e820_type;
641 prev = entry++;
642 nr_entries++;
643 }
644
645 if (nr_entries > ARRAY_SIZE(params->e820_table)) {
646 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
647
648 add_e820ext(params, e820ext, nr_e820ext);
649 nr_entries -= nr_e820ext;
650 }
651
652 params->e820_entries = (u8)nr_entries;
653
654 return EFI_SUCCESS;
655 }
656
alloc_e820ext(u32 nr_desc,struct setup_data ** e820ext,u32 * e820ext_size)657 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
658 u32 *e820ext_size)
659 {
660 efi_status_t status;
661 unsigned long size;
662
663 size = sizeof(struct setup_data) +
664 sizeof(struct e820_entry) * nr_desc;
665
666 if (*e820ext) {
667 efi_bs_call(free_pool, *e820ext);
668 *e820ext = NULL;
669 *e820ext_size = 0;
670 }
671
672 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
673 (void **)e820ext);
674 if (status == EFI_SUCCESS)
675 *e820ext_size = size;
676
677 return status;
678 }
679
allocate_e820(struct boot_params * params,struct setup_data ** e820ext,u32 * e820ext_size)680 static efi_status_t allocate_e820(struct boot_params *params,
681 struct setup_data **e820ext,
682 u32 *e820ext_size)
683 {
684 unsigned long map_size, desc_size, map_key;
685 efi_status_t status;
686 __u32 nr_desc, desc_version;
687
688 /* Only need the size of the mem map and size of each mem descriptor */
689 map_size = 0;
690 status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,
691 &desc_size, &desc_version);
692 if (status != EFI_BUFFER_TOO_SMALL)
693 return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;
694
695 nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;
696
697 if (nr_desc > ARRAY_SIZE(params->e820_table)) {
698 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
699
700 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
701 if (status != EFI_SUCCESS)
702 return status;
703 }
704
705 return EFI_SUCCESS;
706 }
707
708 struct exit_boot_struct {
709 struct boot_params *boot_params;
710 struct efi_info *efi;
711 };
712
exit_boot_func(struct efi_boot_memmap * map,void * priv)713 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
714 void *priv)
715 {
716 const char *signature;
717 struct exit_boot_struct *p = priv;
718
719 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
720 : EFI32_LOADER_SIGNATURE;
721 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
722
723 efi_set_u64_split((unsigned long)efi_system_table,
724 &p->efi->efi_systab, &p->efi->efi_systab_hi);
725 p->efi->efi_memdesc_size = map->desc_size;
726 p->efi->efi_memdesc_version = map->desc_ver;
727 efi_set_u64_split((unsigned long)map->map,
728 &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
729 p->efi->efi_memmap_size = map->map_size;
730
731 return EFI_SUCCESS;
732 }
733
exit_boot(struct boot_params * boot_params,void * handle)734 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
735 {
736 struct setup_data *e820ext = NULL;
737 __u32 e820ext_size = 0;
738 efi_status_t status;
739 struct exit_boot_struct priv;
740
741 priv.boot_params = boot_params;
742 priv.efi = &boot_params->efi_info;
743
744 status = allocate_e820(boot_params, &e820ext, &e820ext_size);
745 if (status != EFI_SUCCESS)
746 return status;
747
748 /* Might as well exit boot services now */
749 status = efi_exit_boot_services(handle, &priv, exit_boot_func);
750 if (status != EFI_SUCCESS)
751 return status;
752
753 /* Historic? */
754 boot_params->alt_mem_k = 32 * 1024;
755
756 status = setup_e820(boot_params, e820ext, e820ext_size);
757 if (status != EFI_SUCCESS)
758 return status;
759
760 return EFI_SUCCESS;
761 }
762
763 /*
764 * On success, we return the address of startup_32, which has potentially been
765 * relocated by efi_relocate_kernel.
766 * On failure, we exit to the firmware via efi_exit instead of returning.
767 */
efi_main(efi_handle_t handle,efi_system_table_t * sys_table_arg,struct boot_params * boot_params)768 asmlinkage unsigned long efi_main(efi_handle_t handle,
769 efi_system_table_t *sys_table_arg,
770 struct boot_params *boot_params)
771 {
772 unsigned long bzimage_addr = (unsigned long)startup_32;
773 unsigned long buffer_start, buffer_end;
774 struct setup_header *hdr = &boot_params->hdr;
775 const struct linux_efi_initrd *initrd = NULL;
776 efi_status_t status;
777
778 efi_system_table = sys_table_arg;
779 /* Check if we were booted by the EFI firmware */
780 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
781 efi_exit(handle, EFI_INVALID_PARAMETER);
782
783 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
784 if (efi_dxe_table &&
785 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
786 efi_warn("Ignoring DXE services table: invalid signature\n");
787 efi_dxe_table = NULL;
788 }
789
790 /*
791 * If the kernel isn't already loaded at a suitable address,
792 * relocate it.
793 *
794 * It must be loaded above LOAD_PHYSICAL_ADDR.
795 *
796 * The maximum address for 64-bit is 1 << 46 for 4-level paging. This
797 * is defined as the macro MAXMEM, but unfortunately that is not a
798 * compile-time constant if 5-level paging is configured, so we instead
799 * define our own macro for use here.
800 *
801 * For 32-bit, the maximum address is complicated to figure out, for
802 * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what
803 * KASLR uses.
804 *
805 * Also relocate it if image_offset is zero, i.e. the kernel wasn't
806 * loaded by LoadImage, but rather by a bootloader that called the
807 * handover entry. The reason we must always relocate in this case is
808 * to handle the case of systemd-boot booting a unified kernel image,
809 * which is a PE executable that contains the bzImage and an initrd as
810 * COFF sections. The initrd section is placed after the bzImage
811 * without ensuring that there are at least init_size bytes available
812 * for the bzImage, and thus the compressed kernel's startup code may
813 * overwrite the initrd unless it is moved out of the way.
814 */
815
816 buffer_start = ALIGN(bzimage_addr - image_offset,
817 hdr->kernel_alignment);
818 buffer_end = buffer_start + hdr->init_size;
819
820 if ((buffer_start < LOAD_PHYSICAL_ADDR) ||
821 (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE) ||
822 (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) ||
823 (image_offset == 0)) {
824 extern char _bss[];
825
826 status = efi_relocate_kernel(&bzimage_addr,
827 (unsigned long)_bss - bzimage_addr,
828 hdr->init_size,
829 hdr->pref_address,
830 hdr->kernel_alignment,
831 LOAD_PHYSICAL_ADDR);
832 if (status != EFI_SUCCESS) {
833 efi_err("efi_relocate_kernel() failed!\n");
834 goto fail;
835 }
836 /*
837 * Now that we've copied the kernel elsewhere, we no longer
838 * have a set up block before startup_32(), so reset image_offset
839 * to zero in case it was set earlier.
840 */
841 image_offset = 0;
842 }
843
844 #ifdef CONFIG_CMDLINE_BOOL
845 status = efi_parse_options(CONFIG_CMDLINE);
846 if (status != EFI_SUCCESS) {
847 efi_err("Failed to parse options\n");
848 goto fail;
849 }
850 #endif
851 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
852 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
853 ((u64)boot_params->ext_cmd_line_ptr << 32));
854 status = efi_parse_options((char *)cmdline_paddr);
855 if (status != EFI_SUCCESS) {
856 efi_err("Failed to parse options\n");
857 goto fail;
858 }
859 }
860
861 /*
862 * At this point, an initrd may already have been loaded by the
863 * bootloader and passed via bootparams. We permit an initrd loaded
864 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
865 *
866 * If the device path is not present, any command-line initrd=
867 * arguments will be processed only if image is not NULL, which will be
868 * the case only if we were loaded via the PE entry point.
869 */
870 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
871 &initrd);
872 if (status != EFI_SUCCESS)
873 goto fail;
874 if (initrd && initrd->size > 0) {
875 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
876 &boot_params->ext_ramdisk_image);
877 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
878 &boot_params->ext_ramdisk_size);
879 }
880
881
882 /*
883 * If the boot loader gave us a value for secure_boot then we use that,
884 * otherwise we ask the BIOS.
885 */
886 if (boot_params->secure_boot == efi_secureboot_mode_unset)
887 boot_params->secure_boot = efi_get_secureboot();
888
889 /* Ask the firmware to clear memory on unclean shutdown */
890 efi_enable_reset_attack_mitigation();
891
892 efi_random_get_seed();
893
894 efi_retrieve_tpm2_eventlog();
895
896 setup_graphics(boot_params);
897
898 setup_efi_pci(boot_params);
899
900 setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start);
901
902 status = exit_boot(boot_params, handle);
903 if (status != EFI_SUCCESS) {
904 efi_err("exit_boot() failed!\n");
905 goto fail;
906 }
907
908 return bzimage_addr;
909 fail:
910 efi_err("efi_main() failed!\n");
911
912 efi_exit(handle, status);
913 }
914