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 extern u32 image_offset;
26 static efi_loaded_image_t *image = NULL;
27
28 static efi_status_t
preserve_pci_rom_image(efi_pci_io_protocol_t * pci,struct pci_setup_rom ** __rom)29 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
30 {
31 struct pci_setup_rom *rom = NULL;
32 efi_status_t status;
33 unsigned long size;
34 uint64_t romsize;
35 void *romimage;
36
37 /*
38 * Some firmware images contain EFI function pointers at the place where
39 * the romimage and romsize fields are supposed to be. Typically the EFI
40 * code is mapped at high addresses, translating to an unrealistically
41 * large romsize. The UEFI spec limits the size of option ROMs to 16
42 * MiB so we reject any ROMs over 16 MiB in size to catch this.
43 */
44 romimage = efi_table_attr(pci, romimage);
45 romsize = efi_table_attr(pci, romsize);
46 if (!romimage || !romsize || romsize > SZ_16M)
47 return EFI_INVALID_PARAMETER;
48
49 size = romsize + sizeof(*rom);
50
51 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
52 (void **)&rom);
53 if (status != EFI_SUCCESS) {
54 efi_err("Failed to allocate memory for 'rom'\n");
55 return status;
56 }
57
58 memset(rom, 0, sizeof(*rom));
59
60 rom->data.type = SETUP_PCI;
61 rom->data.len = size - sizeof(struct setup_data);
62 rom->data.next = 0;
63 rom->pcilen = romsize;
64 *__rom = rom;
65
66 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
67 PCI_VENDOR_ID, 1, &rom->vendor);
68
69 if (status != EFI_SUCCESS) {
70 efi_err("Failed to read rom->vendor\n");
71 goto free_struct;
72 }
73
74 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
75 PCI_DEVICE_ID, 1, &rom->devid);
76
77 if (status != EFI_SUCCESS) {
78 efi_err("Failed to read rom->devid\n");
79 goto free_struct;
80 }
81
82 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
83 &rom->device, &rom->function);
84
85 if (status != EFI_SUCCESS)
86 goto free_struct;
87
88 memcpy(rom->romdata, romimage, romsize);
89 return status;
90
91 free_struct:
92 efi_bs_call(free_pool, rom);
93 return status;
94 }
95
96 /*
97 * There's no way to return an informative status from this function,
98 * because any analysis (and printing of error messages) needs to be
99 * done directly at the EFI function call-site.
100 *
101 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
102 * just didn't find any PCI devices, but there's no way to tell outside
103 * the context of the call.
104 */
setup_efi_pci(struct boot_params * params)105 static void setup_efi_pci(struct boot_params *params)
106 {
107 efi_status_t status;
108 void **pci_handle = NULL;
109 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
110 unsigned long size = 0;
111 struct setup_data *data;
112 efi_handle_t h;
113 int i;
114
115 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
116 &pci_proto, NULL, &size, pci_handle);
117
118 if (status == EFI_BUFFER_TOO_SMALL) {
119 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
120 (void **)&pci_handle);
121
122 if (status != EFI_SUCCESS) {
123 efi_err("Failed to allocate memory for 'pci_handle'\n");
124 return;
125 }
126
127 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
128 &pci_proto, NULL, &size, pci_handle);
129 }
130
131 if (status != EFI_SUCCESS)
132 goto free_handle;
133
134 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
135
136 while (data && data->next)
137 data = (struct setup_data *)(unsigned long)data->next;
138
139 for_each_efi_handle(h, pci_handle, size, i) {
140 efi_pci_io_protocol_t *pci = NULL;
141 struct pci_setup_rom *rom;
142
143 status = efi_bs_call(handle_protocol, h, &pci_proto,
144 (void **)&pci);
145 if (status != EFI_SUCCESS || !pci)
146 continue;
147
148 status = preserve_pci_rom_image(pci, &rom);
149 if (status != EFI_SUCCESS)
150 continue;
151
152 if (data)
153 data->next = (unsigned long)rom;
154 else
155 params->hdr.setup_data = (unsigned long)rom;
156
157 data = (struct setup_data *)rom;
158 }
159
160 free_handle:
161 efi_bs_call(free_pool, pci_handle);
162 }
163
retrieve_apple_device_properties(struct boot_params * boot_params)164 static void retrieve_apple_device_properties(struct boot_params *boot_params)
165 {
166 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
167 struct setup_data *data, *new;
168 efi_status_t status;
169 u32 size = 0;
170 apple_properties_protocol_t *p;
171
172 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
173 if (status != EFI_SUCCESS)
174 return;
175
176 if (efi_table_attr(p, version) != 0x10000) {
177 efi_err("Unsupported properties proto version\n");
178 return;
179 }
180
181 efi_call_proto(p, get_all, NULL, &size);
182 if (!size)
183 return;
184
185 do {
186 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
187 size + sizeof(struct setup_data),
188 (void **)&new);
189 if (status != EFI_SUCCESS) {
190 efi_err("Failed to allocate memory for 'properties'\n");
191 return;
192 }
193
194 status = efi_call_proto(p, get_all, new->data, &size);
195
196 if (status == EFI_BUFFER_TOO_SMALL)
197 efi_bs_call(free_pool, new);
198 } while (status == EFI_BUFFER_TOO_SMALL);
199
200 new->type = SETUP_APPLE_PROPERTIES;
201 new->len = size;
202 new->next = 0;
203
204 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
205 if (!data) {
206 boot_params->hdr.setup_data = (unsigned long)new;
207 } else {
208 while (data->next)
209 data = (struct setup_data *)(unsigned long)data->next;
210 data->next = (unsigned long)new;
211 }
212 }
213
214 static const efi_char16_t apple[] = L"Apple";
215
setup_quirks(struct boot_params * boot_params)216 static void setup_quirks(struct boot_params *boot_params)
217 {
218 efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
219 efi_table_attr(efi_system_table, fw_vendor);
220
221 if (!memcmp(fw_vendor, apple, sizeof(apple))) {
222 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
223 retrieve_apple_device_properties(boot_params);
224 }
225 }
226
227 /*
228 * See if we have Universal Graphics Adapter (UGA) protocol
229 */
230 static efi_status_t
setup_uga(struct screen_info * si,efi_guid_t * uga_proto,unsigned long size)231 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
232 {
233 efi_status_t status;
234 u32 width, height;
235 void **uga_handle = NULL;
236 efi_uga_draw_protocol_t *uga = NULL, *first_uga;
237 efi_handle_t handle;
238 int i;
239
240 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
241 (void **)&uga_handle);
242 if (status != EFI_SUCCESS)
243 return status;
244
245 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
246 uga_proto, NULL, &size, uga_handle);
247 if (status != EFI_SUCCESS)
248 goto free_handle;
249
250 height = 0;
251 width = 0;
252
253 first_uga = NULL;
254 for_each_efi_handle(handle, uga_handle, size, i) {
255 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
256 u32 w, h, depth, refresh;
257 void *pciio;
258
259 status = efi_bs_call(handle_protocol, handle, uga_proto,
260 (void **)&uga);
261 if (status != EFI_SUCCESS)
262 continue;
263
264 pciio = NULL;
265 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
266
267 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
268 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
269 width = w;
270 height = h;
271
272 /*
273 * Once we've found a UGA supporting PCIIO,
274 * don't bother looking any further.
275 */
276 if (pciio)
277 break;
278
279 first_uga = uga;
280 }
281 }
282
283 if (!width && !height)
284 goto free_handle;
285
286 /* EFI framebuffer */
287 si->orig_video_isVGA = VIDEO_TYPE_EFI;
288
289 si->lfb_depth = 32;
290 si->lfb_width = width;
291 si->lfb_height = height;
292
293 si->red_size = 8;
294 si->red_pos = 16;
295 si->green_size = 8;
296 si->green_pos = 8;
297 si->blue_size = 8;
298 si->blue_pos = 0;
299 si->rsvd_size = 8;
300 si->rsvd_pos = 24;
301
302 free_handle:
303 efi_bs_call(free_pool, uga_handle);
304
305 return status;
306 }
307
setup_graphics(struct boot_params * boot_params)308 static void setup_graphics(struct boot_params *boot_params)
309 {
310 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
311 struct screen_info *si;
312 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
313 efi_status_t status;
314 unsigned long size;
315 void **gop_handle = NULL;
316 void **uga_handle = NULL;
317
318 si = &boot_params->screen_info;
319 memset(si, 0, sizeof(*si));
320
321 size = 0;
322 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
323 &graphics_proto, NULL, &size, gop_handle);
324 if (status == EFI_BUFFER_TOO_SMALL)
325 status = efi_setup_gop(si, &graphics_proto, size);
326
327 if (status != EFI_SUCCESS) {
328 size = 0;
329 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
330 &uga_proto, NULL, &size, uga_handle);
331 if (status == EFI_BUFFER_TOO_SMALL)
332 setup_uga(si, &uga_proto, size);
333 }
334 }
335
336
efi_exit(efi_handle_t handle,efi_status_t status)337 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
338 {
339 efi_bs_call(exit, handle, status, 0, NULL);
340 for(;;)
341 asm("hlt");
342 }
343
344 void startup_32(struct boot_params *boot_params);
345
346 void __noreturn efi_stub_entry(efi_handle_t handle,
347 efi_system_table_t *sys_table_arg,
348 struct boot_params *boot_params);
349
350 /*
351 * Because the x86 boot code expects to be passed a boot_params we
352 * need to create one ourselves (usually the bootloader would create
353 * one for us).
354 */
efi_pe_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg)355 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
356 efi_system_table_t *sys_table_arg)
357 {
358 struct boot_params *boot_params;
359 struct setup_header *hdr;
360 void *image_base;
361 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
362 int options_size = 0;
363 efi_status_t status;
364 char *cmdline_ptr;
365
366 efi_system_table = sys_table_arg;
367
368 /* Check if we were booted by the EFI firmware */
369 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
370 efi_exit(handle, EFI_INVALID_PARAMETER);
371
372 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
373 if (status != EFI_SUCCESS) {
374 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
375 efi_exit(handle, status);
376 }
377
378 image_base = efi_table_attr(image, image_base);
379 image_offset = (void *)startup_32 - image_base;
380
381 status = efi_allocate_pages(sizeof(struct boot_params),
382 (unsigned long *)&boot_params, ULONG_MAX);
383 if (status != EFI_SUCCESS) {
384 efi_err("Failed to allocate lowmem for boot params\n");
385 efi_exit(handle, status);
386 }
387
388 memset(boot_params, 0x0, sizeof(struct boot_params));
389
390 hdr = &boot_params->hdr;
391
392 /* Copy the setup header from the second sector to boot_params */
393 memcpy(&hdr->jump, image_base + 512,
394 sizeof(struct setup_header) - offsetof(struct setup_header, jump));
395
396 /*
397 * Fill out some of the header fields ourselves because the
398 * EFI firmware loader doesn't load the first sector.
399 */
400 hdr->root_flags = 1;
401 hdr->vid_mode = 0xffff;
402 hdr->boot_flag = 0xAA55;
403
404 hdr->type_of_loader = 0x21;
405
406 /* Convert unicode cmdline to ascii */
407 cmdline_ptr = efi_convert_cmdline(image, &options_size);
408 if (!cmdline_ptr)
409 goto fail;
410
411 efi_set_u64_split((unsigned long)cmdline_ptr,
412 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr);
413
414 hdr->ramdisk_image = 0;
415 hdr->ramdisk_size = 0;
416
417 /*
418 * Disregard any setup data that was provided by the bootloader:
419 * setup_data could be pointing anywhere, and we have no way of
420 * authenticating or validating the payload.
421 */
422 hdr->setup_data = 0;
423
424 efi_stub_entry(handle, sys_table_arg, boot_params);
425 /* not reached */
426
427 fail:
428 efi_free(sizeof(struct boot_params), (unsigned long)boot_params);
429
430 efi_exit(handle, status);
431 }
432
add_e820ext(struct boot_params * params,struct setup_data * e820ext,u32 nr_entries)433 static void add_e820ext(struct boot_params *params,
434 struct setup_data *e820ext, u32 nr_entries)
435 {
436 struct setup_data *data;
437
438 e820ext->type = SETUP_E820_EXT;
439 e820ext->len = nr_entries * sizeof(struct boot_e820_entry);
440 e820ext->next = 0;
441
442 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
443
444 while (data && data->next)
445 data = (struct setup_data *)(unsigned long)data->next;
446
447 if (data)
448 data->next = (unsigned long)e820ext;
449 else
450 params->hdr.setup_data = (unsigned long)e820ext;
451 }
452
453 static efi_status_t
setup_e820(struct boot_params * params,struct setup_data * e820ext,u32 e820ext_size)454 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
455 {
456 struct boot_e820_entry *entry = params->e820_table;
457 struct efi_info *efi = ¶ms->efi_info;
458 struct boot_e820_entry *prev = NULL;
459 u32 nr_entries;
460 u32 nr_desc;
461 int i;
462
463 nr_entries = 0;
464 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
465
466 for (i = 0; i < nr_desc; i++) {
467 efi_memory_desc_t *d;
468 unsigned int e820_type = 0;
469 unsigned long m = efi->efi_memmap;
470
471 #ifdef CONFIG_X86_64
472 m |= (u64)efi->efi_memmap_hi << 32;
473 #endif
474
475 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
476 switch (d->type) {
477 case EFI_RESERVED_TYPE:
478 case EFI_RUNTIME_SERVICES_CODE:
479 case EFI_RUNTIME_SERVICES_DATA:
480 case EFI_MEMORY_MAPPED_IO:
481 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
482 case EFI_PAL_CODE:
483 e820_type = E820_TYPE_RESERVED;
484 break;
485
486 case EFI_UNUSABLE_MEMORY:
487 e820_type = E820_TYPE_UNUSABLE;
488 break;
489
490 case EFI_ACPI_RECLAIM_MEMORY:
491 e820_type = E820_TYPE_ACPI;
492 break;
493
494 case EFI_LOADER_CODE:
495 case EFI_LOADER_DATA:
496 case EFI_BOOT_SERVICES_CODE:
497 case EFI_BOOT_SERVICES_DATA:
498 case EFI_CONVENTIONAL_MEMORY:
499 if (efi_soft_reserve_enabled() &&
500 (d->attribute & EFI_MEMORY_SP))
501 e820_type = E820_TYPE_SOFT_RESERVED;
502 else
503 e820_type = E820_TYPE_RAM;
504 break;
505
506 case EFI_ACPI_MEMORY_NVS:
507 e820_type = E820_TYPE_NVS;
508 break;
509
510 case EFI_PERSISTENT_MEMORY:
511 e820_type = E820_TYPE_PMEM;
512 break;
513
514 default:
515 continue;
516 }
517
518 /* Merge adjacent mappings */
519 if (prev && prev->type == e820_type &&
520 (prev->addr + prev->size) == d->phys_addr) {
521 prev->size += d->num_pages << 12;
522 continue;
523 }
524
525 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
526 u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
527 sizeof(struct setup_data);
528
529 if (!e820ext || e820ext_size < need)
530 return EFI_BUFFER_TOO_SMALL;
531
532 /* boot_params map full, switch to e820 extended */
533 entry = (struct boot_e820_entry *)e820ext->data;
534 }
535
536 entry->addr = d->phys_addr;
537 entry->size = d->num_pages << PAGE_SHIFT;
538 entry->type = e820_type;
539 prev = entry++;
540 nr_entries++;
541 }
542
543 if (nr_entries > ARRAY_SIZE(params->e820_table)) {
544 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
545
546 add_e820ext(params, e820ext, nr_e820ext);
547 nr_entries -= nr_e820ext;
548 }
549
550 params->e820_entries = (u8)nr_entries;
551
552 return EFI_SUCCESS;
553 }
554
alloc_e820ext(u32 nr_desc,struct setup_data ** e820ext,u32 * e820ext_size)555 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
556 u32 *e820ext_size)
557 {
558 efi_status_t status;
559 unsigned long size;
560
561 size = sizeof(struct setup_data) +
562 sizeof(struct e820_entry) * nr_desc;
563
564 if (*e820ext) {
565 efi_bs_call(free_pool, *e820ext);
566 *e820ext = NULL;
567 *e820ext_size = 0;
568 }
569
570 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
571 (void **)e820ext);
572 if (status == EFI_SUCCESS)
573 *e820ext_size = size;
574
575 return status;
576 }
577
allocate_e820(struct boot_params * params,struct setup_data ** e820ext,u32 * e820ext_size)578 static efi_status_t allocate_e820(struct boot_params *params,
579 struct setup_data **e820ext,
580 u32 *e820ext_size)
581 {
582 unsigned long map_size, desc_size, map_key;
583 efi_status_t status;
584 __u32 nr_desc, desc_version;
585
586 /* Only need the size of the mem map and size of each mem descriptor */
587 map_size = 0;
588 status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,
589 &desc_size, &desc_version);
590 if (status != EFI_BUFFER_TOO_SMALL)
591 return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;
592
593 nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;
594
595 if (nr_desc > ARRAY_SIZE(params->e820_table)) {
596 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
597
598 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
599 if (status != EFI_SUCCESS)
600 return status;
601 }
602
603 return EFI_SUCCESS;
604 }
605
606 struct exit_boot_struct {
607 struct boot_params *boot_params;
608 struct efi_info *efi;
609 };
610
exit_boot_func(struct efi_boot_memmap * map,void * priv)611 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
612 void *priv)
613 {
614 const char *signature;
615 struct exit_boot_struct *p = priv;
616
617 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
618 : EFI32_LOADER_SIGNATURE;
619 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
620
621 efi_set_u64_split((unsigned long)efi_system_table,
622 &p->efi->efi_systab, &p->efi->efi_systab_hi);
623 p->efi->efi_memdesc_size = *map->desc_size;
624 p->efi->efi_memdesc_version = *map->desc_ver;
625 efi_set_u64_split((unsigned long)*map->map,
626 &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
627 p->efi->efi_memmap_size = *map->map_size;
628
629 return EFI_SUCCESS;
630 }
631
exit_boot(struct boot_params * boot_params,void * handle)632 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
633 {
634 unsigned long map_sz, key, desc_size, buff_size;
635 efi_memory_desc_t *mem_map;
636 struct setup_data *e820ext = NULL;
637 __u32 e820ext_size = 0;
638 efi_status_t status;
639 __u32 desc_version;
640 struct efi_boot_memmap map;
641 struct exit_boot_struct priv;
642
643 map.map = &mem_map;
644 map.map_size = &map_sz;
645 map.desc_size = &desc_size;
646 map.desc_ver = &desc_version;
647 map.key_ptr = &key;
648 map.buff_size = &buff_size;
649 priv.boot_params = boot_params;
650 priv.efi = &boot_params->efi_info;
651
652 status = allocate_e820(boot_params, &e820ext, &e820ext_size);
653 if (status != EFI_SUCCESS)
654 return status;
655
656 /* Might as well exit boot services now */
657 status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func);
658 if (status != EFI_SUCCESS)
659 return status;
660
661 /* Historic? */
662 boot_params->alt_mem_k = 32 * 1024;
663
664 status = setup_e820(boot_params, e820ext, e820ext_size);
665 if (status != EFI_SUCCESS)
666 return status;
667
668 return EFI_SUCCESS;
669 }
670
671 /*
672 * On success, we return the address of startup_32, which has potentially been
673 * relocated by efi_relocate_kernel.
674 * On failure, we exit to the firmware via efi_exit instead of returning.
675 */
efi_main(efi_handle_t handle,efi_system_table_t * sys_table_arg,struct boot_params * boot_params)676 unsigned long efi_main(efi_handle_t handle,
677 efi_system_table_t *sys_table_arg,
678 struct boot_params *boot_params)
679 {
680 unsigned long bzimage_addr = (unsigned long)startup_32;
681 unsigned long buffer_start, buffer_end;
682 struct setup_header *hdr = &boot_params->hdr;
683 efi_status_t status;
684
685 efi_system_table = sys_table_arg;
686
687 /* Check if we were booted by the EFI firmware */
688 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
689 efi_exit(handle, EFI_INVALID_PARAMETER);
690
691 /*
692 * If the kernel isn't already loaded at a suitable address,
693 * relocate it.
694 *
695 * It must be loaded above LOAD_PHYSICAL_ADDR.
696 *
697 * The maximum address for 64-bit is 1 << 46 for 4-level paging. This
698 * is defined as the macro MAXMEM, but unfortunately that is not a
699 * compile-time constant if 5-level paging is configured, so we instead
700 * define our own macro for use here.
701 *
702 * For 32-bit, the maximum address is complicated to figure out, for
703 * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what
704 * KASLR uses.
705 *
706 * Also relocate it if image_offset is zero, i.e. the kernel wasn't
707 * loaded by LoadImage, but rather by a bootloader that called the
708 * handover entry. The reason we must always relocate in this case is
709 * to handle the case of systemd-boot booting a unified kernel image,
710 * which is a PE executable that contains the bzImage and an initrd as
711 * COFF sections. The initrd section is placed after the bzImage
712 * without ensuring that there are at least init_size bytes available
713 * for the bzImage, and thus the compressed kernel's startup code may
714 * overwrite the initrd unless it is moved out of the way.
715 */
716
717 buffer_start = ALIGN(bzimage_addr - image_offset,
718 hdr->kernel_alignment);
719 buffer_end = buffer_start + hdr->init_size;
720
721 if ((buffer_start < LOAD_PHYSICAL_ADDR) ||
722 (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE) ||
723 (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) ||
724 (image_offset == 0)) {
725 extern char _bss[];
726
727 status = efi_relocate_kernel(&bzimage_addr,
728 (unsigned long)_bss - bzimage_addr,
729 hdr->init_size,
730 hdr->pref_address,
731 hdr->kernel_alignment,
732 LOAD_PHYSICAL_ADDR);
733 if (status != EFI_SUCCESS) {
734 efi_err("efi_relocate_kernel() failed!\n");
735 goto fail;
736 }
737 /*
738 * Now that we've copied the kernel elsewhere, we no longer
739 * have a set up block before startup_32(), so reset image_offset
740 * to zero in case it was set earlier.
741 */
742 image_offset = 0;
743 }
744
745 #ifdef CONFIG_CMDLINE_BOOL
746 status = efi_parse_options(CONFIG_CMDLINE);
747 if (status != EFI_SUCCESS) {
748 efi_err("Failed to parse options\n");
749 goto fail;
750 }
751 #endif
752 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
753 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
754 ((u64)boot_params->ext_cmd_line_ptr << 32));
755 status = efi_parse_options((char *)cmdline_paddr);
756 if (status != EFI_SUCCESS) {
757 efi_err("Failed to parse options\n");
758 goto fail;
759 }
760 }
761
762 /*
763 * At this point, an initrd may already have been loaded by the
764 * bootloader and passed via bootparams. We permit an initrd loaded
765 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
766 *
767 * If the device path is not present, any command-line initrd=
768 * arguments will be processed only if image is not NULL, which will be
769 * the case only if we were loaded via the PE entry point.
770 */
771 if (!efi_noinitrd) {
772 unsigned long addr, size;
773
774 status = efi_load_initrd(image, &addr, &size,
775 hdr->initrd_addr_max, ULONG_MAX);
776
777 if (status != EFI_SUCCESS) {
778 efi_err("Failed to load initrd!\n");
779 goto fail;
780 }
781 if (size > 0) {
782 efi_set_u64_split(addr, &hdr->ramdisk_image,
783 &boot_params->ext_ramdisk_image);
784 efi_set_u64_split(size, &hdr->ramdisk_size,
785 &boot_params->ext_ramdisk_size);
786 }
787 }
788
789 /*
790 * If the boot loader gave us a value for secure_boot then we use that,
791 * otherwise we ask the BIOS.
792 */
793 if (boot_params->secure_boot == efi_secureboot_mode_unset)
794 boot_params->secure_boot = efi_get_secureboot();
795
796 /* Ask the firmware to clear memory on unclean shutdown */
797 efi_enable_reset_attack_mitigation();
798
799 efi_random_get_seed();
800
801 efi_retrieve_tpm2_eventlog();
802
803 setup_graphics(boot_params);
804
805 setup_efi_pci(boot_params);
806
807 setup_quirks(boot_params);
808
809 status = exit_boot(boot_params, handle);
810 if (status != EFI_SUCCESS) {
811 efi_err("exit_boot() failed!\n");
812 goto fail;
813 }
814
815 return bzimage_addr;
816 fail:
817 efi_err("efi_main() failed!\n");
818
819 efi_exit(handle, status);
820 }
821