summaryrefslogtreecommitdiffstats
path: root/arch/x86/boot/compressed/eboot.c
blob: beb07a4529ac0f41ecfc6f832f4c31fc0976a986 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
/* -----------------------------------------------------------------------
 *
 *   Copyright 2011 Intel Corporation; author Matt Fleming
 *
 *   This file is part of the Linux kernel, and is made available under
 *   the terms of the GNU General Public License version 2.
 *
 * ----------------------------------------------------------------------- */

#include <linux/efi.h>
#include <linux/pci.h>
#include <asm/efi.h>
#include <asm/setup.h>
#include <asm/desc.h>

#undef memcpy			/* Use memcpy from misc.c */

#include "eboot.h"

static efi_system_table_t *sys_table;


#include "../../../../drivers/firmware/efi/efi-stub-helper.c"



static void find_bits(unsigned long mask, u8 *pos, u8 *size)
{
	u8 first, len;

	first = 0;
	len = 0;

	if (mask) {
		while (!(mask & 0x1)) {
			mask = mask >> 1;
			first++;
		}

		while (mask & 0x1) {
			mask = mask >> 1;
			len++;
		}
	}

	*pos = first;
	*size = len;
}

static efi_status_t setup_efi_pci(struct boot_params *params)
{
	efi_pci_io_protocol *pci;
	efi_status_t status;
	void **pci_handle;
	efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
	unsigned long nr_pci, size = 0;
	int i;
	struct setup_data *data;

	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;

	while (data && data->next)
		data = (struct setup_data *)(unsigned long)data->next;

	status = efi_call_phys5(sys_table->boottime->locate_handle,
				EFI_LOCATE_BY_PROTOCOL, &pci_proto,
				NULL, &size, pci_handle);

	if (status == EFI_BUFFER_TOO_SMALL) {
		status = efi_call_phys3(sys_table->boottime->allocate_pool,
					EFI_LOADER_DATA, size, &pci_handle);

		if (status != EFI_SUCCESS)
			return status;

		status = efi_call_phys5(sys_table->boottime->locate_handle,
					EFI_LOCATE_BY_PROTOCOL, &pci_proto,
					NULL, &size, pci_handle);
	}

	if (status != EFI_SUCCESS)
		goto free_handle;

	nr_pci = size / sizeof(void *);
	for (i = 0; i < nr_pci; i++) {
		void *h = pci_handle[i];
		uint64_t attributes;
		struct pci_setup_rom *rom;

		status = efi_call_phys3(sys_table->boottime->handle_protocol,
					h, &pci_proto, &pci);

		if (status != EFI_SUCCESS)
			continue;

		if (!pci)
			continue;

#ifdef CONFIG_X86_64
		status = efi_call_phys4(pci->attributes, pci,
					EfiPciIoAttributeOperationGet, 0,
					&attributes);
#else
		status = efi_call_phys5(pci->attributes, pci,
					EfiPciIoAttributeOperationGet, 0, 0,
					&attributes);
#endif
		if (status != EFI_SUCCESS)
			continue;

		if (!pci->romimage || !pci->romsize)
			continue;

		size = pci->romsize + sizeof(*rom);

		status = efi_call_phys3(sys_table->boottime->allocate_pool,
				EFI_LOADER_DATA, size, &rom);

		if (status != EFI_SUCCESS)
			continue;

		rom->data.type = SETUP_PCI;
		rom->data.len = size - sizeof(struct setup_data);
		rom->data.next = 0;
		rom->pcilen = pci->romsize;

		status = efi_call_phys5(pci->pci.read, pci,
					EfiPciIoWidthUint16, PCI_VENDOR_ID,
					1, &(rom->vendor));

		if (status != EFI_SUCCESS)
			goto free_struct;

		status = efi_call_phys5(pci->pci.read, pci,
					EfiPciIoWidthUint16, PCI_DEVICE_ID,
					1, &(rom->devid));

		if (status != EFI_SUCCESS)
			goto free_struct;

		status = efi_call_phys5(pci->get_location, pci,
					&(rom->segment), &(rom->bus),
					&(rom->device), &(rom->function));

		if (status != EFI_SUCCESS)
			goto free_struct;

		memcpy(rom->romdata, pci->romimage, pci->romsize);

		if (data)
			data->next = (unsigned long)rom;
		else
			params->hdr.setup_data = (unsigned long)rom;

		data = (struct setup_data *)rom;

		continue;
	free_struct:
		efi_call_phys1(sys_table->boottime->free_pool, rom);
	}

free_handle:
	efi_call_phys1(sys_table->boottime->free_pool, pci_handle);
	return status;
}

/*
 * See if we have Graphics Output Protocol
 */
static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
			      unsigned long size)
{
	struct efi_graphics_output_protocol *gop, *first_gop;
	struct efi_pixel_bitmask pixel_info;
	unsigned long nr_gops;
	efi_status_t status;
	void **gop_handle;
	u16 width, height;
	u32 fb_base, fb_size;
	u32 pixels_per_scan_line;
	int pixel_format;
	int i;

	status = efi_call_phys3(sys_table->boottime->allocate_pool,
				EFI_LOADER_DATA, size, &gop_handle);
	if (status != EFI_SUCCESS)
		return status;

	status = efi_call_phys5(sys_table->boottime->locate_handle,
				EFI_LOCATE_BY_PROTOCOL, proto,
				NULL, &size, gop_handle);
	if (status != EFI_SUCCESS)
		goto free_handle;

	first_gop = NULL;

	nr_gops = size / sizeof(void *);
	for (i = 0; i < nr_gops; i++) {
		struct efi_graphics_output_mode_info *info;
		efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
		bool conout_found = false;
		void *dummy;
		void *h = gop_handle[i];

		status = efi_call_phys3(sys_table->boottime->handle_protocol,
					h, proto, &gop);
		if (status != EFI_SUCCESS)
			continue;

		status = efi_call_phys3(sys_table->boottime->handle_protocol,
					h, &conout_proto, &dummy);

		if (status == EFI_SUCCESS)
			conout_found = true;

		status = efi_call_phys4(gop->query_mode, gop,
					gop->mode->mode, &size, &info);
		if (status == EFI_SUCCESS && (!first_gop || conout_found)) {
			/*
			 * Systems that use the UEFI Console Splitter may
			 * provide multiple GOP devices, not all of which are
			 * backed by real hardware. The workaround is to search
			 * for a GOP implementing the ConOut protocol, and if
			 * one isn't found, to just fall back to the first GOP.
			 */
			width = info->horizontal_resolution;
			height = info->vertical_resolution;
			fb_base = gop->mode->frame_buffer_base;
			fb_size = gop->mode->frame_buffer_size;
			pixel_format = info->pixel_format;
			pixel_info = info->pixel_information;
			pixels_per_scan_line = info->pixels_per_scan_line;

			/*
			 * Once we've found a GOP supporting ConOut,
			 * don't bother looking any further.
			 */
			first_gop = gop;
			if (conout_found)
				break;
		}
	}

	/* Did we find any GOPs? */
	if (!first_gop)
		goto free_handle;

	/* EFI framebuffer */
	si->orig_video_isVGA = VIDEO_TYPE_EFI;

	si->lfb_width = width;
	si->lfb_height = height;
	si->lfb_base = fb_base;
	si->pages = 1;

	if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
		si->lfb_depth = 32;
		si->lfb_linelength = pixels_per_scan_line * 4;
		si->red_size = 8;
		si->red_pos = 0;
		si->green_size = 8;
		si->green_pos = 8;
		si->blue_size = 8;
		si->blue_pos = 16;
		si->rsvd_size = 8;
		si->rsvd_pos = 24;
	} else if (pixel_format == PIXEL_BGR_RESERVED_8BIT_PER_COLOR) {
		si->lfb_depth = 32;
		si->lfb_linelength = pixels_per_scan_line * 4;
		si->red_size = 8;
		si->red_pos = 16;
		si->green_size = 8;
		si->green_pos = 8;
		si->blue_size = 8;
		si->blue_pos = 0;
		si->rsvd_size = 8;
		si->rsvd_pos = 24;
	} else if (pixel_format == PIXEL_BIT_MASK) {
		find_bits(pixel_info.red_mask, &si->red_pos, &si->red_size);
		find_bits(pixel_info.green_mask, &si->green_pos,
			  &si->green_size);
		find_bits(pixel_info.blue_mask, &si->blue_pos, &si->blue_size);
		find_bits(pixel_info.reserved_mask, &si->rsvd_pos,
			  &si->rsvd_size);
		si->lfb_depth = si->red_size + si->green_size +
			si->blue_size + si->rsvd_size;
		si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8;
	} else {
		si->lfb_depth = 4;
		si->lfb_linelength = si->lfb_width / 2;
		si->red_size = 0;
		si->red_pos = 0;
		si->green_size = 0;
		si->green_pos = 0;
		si->blue_size = 0;
		si->blue_pos = 0;
		si->rsvd_size = 0;
		si->rsvd_pos = 0;
	}

	si->lfb_size = si->lfb_linelength * si->lfb_height;

	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;

free_handle:
	efi_call_phys1(sys_table->boottime->free_pool, gop_handle);
	return status;
}

/*
 * See if we have Universal Graphics Adapter (UGA) protocol
 */
static efi_status_t setup_uga(struct screen_info *si, efi_guid_t *uga_proto,
			      unsigned long size)
{
	struct efi_uga_draw_protocol *uga, *first_uga;
	unsigned long nr_ugas;
	efi_status_t status;
	u32 width, height;
	void **uga_handle = NULL;
	int i;

	status = efi_call_phys3(sys_table->boottime->allocate_pool,
				EFI_LOADER_DATA, size, &uga_handle);
	if (status != EFI_SUCCESS)
		return status;

	status = efi_call_phys5(sys_table->boottime->locate_handle,
				EFI_LOCATE_BY_PROTOCOL, uga_proto,
				NULL, &size, uga_handle);
	if (status != EFI_SUCCESS)
		goto free_handle;

	first_uga = NULL;

	nr_ugas = size / sizeof(void *);
	for (i = 0; i < nr_ugas; i++) {
		efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
		void *handle = uga_handle[i];
		u32 w, h, depth, refresh;
		void *pciio;

		status = efi_call_phys3(sys_table->boottime->handle_protocol,
					handle, uga_proto, &uga);
		if (status != EFI_SUCCESS)
			continue;

		efi_call_phys3(sys_table->boottime->handle_protocol,
			       handle, &pciio_proto, &pciio);

		status = efi_call_phys5(uga->get_mode, uga, &w, &h,
					&depth, &refresh);
		if (status == EFI_SUCCESS && (!first_uga || pciio)) {
			width = w;
			height = h;

			/*
			 * Once we've found a UGA supporting PCIIO,
			 * don't bother looking any further.
			 */
			if (pciio)
				break;

			first_uga = uga;
		}
	}

	if (!first_uga)
		goto free_handle;

	/* EFI framebuffer */
	si->orig_video_isVGA = VIDEO_TYPE_EFI;

	si->lfb_depth = 32;
	si->lfb_width = width;
	si->lfb_height = height;

	si->red_size = 8;
	si->red_pos = 16;
	si->green_size = 8;
	si->green_pos = 8;
	si->blue_size = 8;
	si->blue_pos = 0;
	si->rsvd_size = 8;
	si->rsvd_pos = 24;


free_handle:
	efi_call_phys1(sys_table->boottime->free_pool, uga_handle);
	return status;
}

void setup_graphics(struct boot_params *boot_params)
{
	efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
	struct screen_info *si;
	efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
	efi_status_t status;
	unsigned long size;
	void **gop_handle = NULL;
	void **uga_handle = NULL;

	si = &boot_params->screen_info;
	memset(si, 0, sizeof(*si));

	size = 0;
	status = efi_call_phys5(sys_table->boottime->locate_handle,
				EFI_LOCATE_BY_PROTOCOL, &graphics_proto,
				NULL, &size, gop_handle);
	if (status == EFI_BUFFER_TOO_SMALL)
		status = setup_gop(si, &graphics_proto, size);

	if (status != EFI_SUCCESS) {
		size = 0;
		status = efi_call_phys5(sys_table->boottime->locate_handle,
					EFI_LOCATE_BY_PROTOCOL, &uga_proto,
					NULL, &size, uga_handle);
		if (status == EFI_BUFFER_TOO_SMALL)
			setup_uga(si, &uga_proto, size);
	}
}


/*
 * Because the x86 boot code expects to be passed a boot_params we
 * need to create one ourselves (usually the bootloader would create
 * one for us).
 */
struct boot_params *make_boot_params(void *handle, efi_system_table_t *_table)
{
	struct boot_params *boot_params;
	struct sys_desc_table *sdt;
	struct apm_bios_info *bi;
	struct setup_header *hdr;
	struct efi_info *efi;
	efi_loaded_image_t *image;
	void *options;
	efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
	int options_size = 0;
	efi_status_t status;
	char *cmdline_ptr;
	u16 *s2;
	u8 *s1;
	int i;
	unsigned long ramdisk_addr;
	unsigned long ramdisk_size;

	sys_table = _table;

	/* Check if we were booted by the EFI firmware */
	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
		return NULL;

	status = efi_call_phys3(sys_table->boottime->handle_protocol,
				handle, &proto, (void *)&image);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table, "Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
		return NULL;
	}

	status = efi_low_alloc(sys_table, 0x4000, 1,
			       (unsigned long *)&boot_params);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table, "Failed to alloc lowmem for boot params\n");
		return NULL;
	}

	memset(boot_params, 0x0, 0x4000);

	hdr = &boot_params->hdr;
	efi = &boot_params->efi_info;
	bi = &boot_params->apm_bios_info;
	sdt = &boot_params->sys_desc_table;

	/* Copy the second sector to boot_params */
	memcpy(&hdr->jump, image->image_base + 512, 512);

	/*
	 * Fill out some of the header fields ourselves because the
	 * EFI firmware loader doesn't load the first sector.
	 */
	hdr->root_flags = 1;
	hdr->vid_mode = 0xffff;
	hdr->boot_flag = 0xAA55;

	hdr->code32_start = (__u64)(unsigned long)image->image_base;

	hdr->type_of_loader = 0x21;

	/* Convert unicode cmdline to ascii */
	cmdline_ptr = efi_convert_cmdline_to_ascii(sys_table, image,
						   &options_size);
	if (!cmdline_ptr)
		goto fail;
	hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;

	hdr->ramdisk_image = 0;
	hdr->ramdisk_size = 0;

	/* Clear APM BIOS info */
	memset(bi, 0, sizeof(*bi));

	memset(sdt, 0, sizeof(*sdt));

	status = handle_cmdline_files(sys_table, image,
				      (char *)(unsigned long)hdr->cmd_line_ptr,
				      "initrd=", hdr->initrd_addr_max,
				      &ramdisk_addr, &ramdisk_size);
	if (status != EFI_SUCCESS)
		goto fail2;
	hdr->ramdisk_image = ramdisk_addr;
	hdr->ramdisk_size = ramdisk_size;

	return boot_params;
fail2:
	efi_free(sys_table, options_size, hdr->cmd_line_ptr);
fail:
	efi_free(sys_table, 0x4000, (unsigned long)boot_params);
	return NULL;
}

static efi_status_t exit_boot(struct boot_params *boot_params,
			      void *handle)
{
	struct efi_info *efi = &boot_params->efi_info;
	struct e820entry *e820_map = &boot_params->e820_map[0];
	struct e820entry *prev = NULL;
	unsigned long size, key, desc_size, _size;
	efi_memory_desc_t *mem_map;
	efi_status_t status;
	__u32 desc_version;
	bool called_exit = false;
	u8 nr_entries;
	int i;

get_map:
	status = efi_get_memory_map(sys_table, &mem_map, &size, &desc_size,
				    &desc_version, &key);

	if (status != EFI_SUCCESS)
		return status;

	memcpy(&efi->efi_loader_signature, EFI_LOADER_SIGNATURE, sizeof(__u32));
	efi->efi_systab = (unsigned long)sys_table;
	efi->efi_memdesc_size = desc_size;
	efi->efi_memdesc_version = desc_version;
	efi->efi_memmap = (unsigned long)mem_map;
	efi->efi_memmap_size = size;

#ifdef CONFIG_X86_64
	efi->efi_systab_hi = (unsigned long)sys_table >> 32;
	efi->efi_memmap_hi = (unsigned long)mem_map >> 32;
#endif

	/* Might as well exit boot services now */
	status = efi_call_phys2(sys_table->boottime->exit_boot_services,
				handle, key);
	if (status != EFI_SUCCESS) {
		/*
		 * ExitBootServices() will fail if any of the event
		 * handlers change the memory map. In which case, we
		 * must be prepared to retry, but only once so that
		 * we're guaranteed to exit on repeated failures instead
		 * of spinning forever.
		 */
		if (called_exit)
			goto free_mem_map;

		called_exit = true;
		efi_call_phys1(sys_table->boottime->free_pool, mem_map);
		goto get_map;
	}

	/* Historic? */
	boot_params->alt_mem_k = 32 * 1024;

	/*
	 * Convert the EFI memory map to E820.
	 */
	nr_entries = 0;
	for (i = 0; i < size / desc_size; i++) {
		efi_memory_desc_t *d;
		unsigned int e820_type = 0;
		unsigned long m = (unsigned long)mem_map;

		d = (efi_memory_desc_t *)(m + (i * desc_size));
		switch (d->type) {
		case EFI_RESERVED_TYPE:
		case EFI_RUNTIME_SERVICES_CODE:
		case EFI_RUNTIME_SERVICES_DATA:
		case EFI_MEMORY_MAPPED_IO:
		case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
		case EFI_PAL_CODE:
			e820_type = E820_RESERVED;
			break;

		case EFI_UNUSABLE_MEMORY:
			e820_type = E820_UNUSABLE;
			break;

		case EFI_ACPI_RECLAIM_MEMORY:
			e820_type = E820_ACPI;
			break;

		case EFI_LOADER_CODE:
		case EFI_LOADER_DATA:
		case EFI_BOOT_SERVICES_CODE:
		case EFI_BOOT_SERVICES_DATA:
		case EFI_CONVENTIONAL_MEMORY:
			e820_type = E820_RAM;
			break;

		case EFI_ACPI_MEMORY_NVS:
			e820_type = E820_NVS;
			break;

		default:
			continue;
		}

		/* Merge adjacent mappings */
		if (prev && prev->type == e820_type &&
		    (prev->addr + prev->size) == d->phys_addr)
			prev->size += d->num_pages << 12;
		else {
			e820_map->addr = d->phys_addr;
			e820_map->size = d->num_pages << 12;
			e820_map->type = e820_type;
			prev = e820_map++;
			nr_entries++;
		}
	}

	boot_params->e820_entries = nr_entries;

	return EFI_SUCCESS;

free_mem_map:
	efi_call_phys1(sys_table->boottime->free_pool, mem_map);
	return status;
}


/*
 * On success we return a pointer to a boot_params structure, and NULL
 * on failure.
 */
struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
			     struct boot_params *boot_params)
{
	struct desc_ptr *gdt, *idt;
	efi_loaded_image_t *image;
	struct setup_header *hdr = &boot_params->hdr;
	efi_status_t status;
	struct desc_struct *desc;

	sys_table = _table;

	/* Check if we were booted by the EFI firmware */
	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
		goto fail;

	setup_graphics(boot_params);

	setup_efi_pci(boot_params);

	status = efi_call_phys3(sys_table->boottime->allocate_pool,
				EFI_LOADER_DATA, sizeof(*gdt),
				(void **)&gdt);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table, "Failed to alloc mem for gdt structure\n");
		goto fail;
	}

	gdt->size = 0x800;
	status = efi_low_alloc(sys_table, gdt->size, 8,
			   (unsigned long *)&gdt->address);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table, "Failed to alloc mem for gdt\n");
		goto fail;
	}

	status = efi_call_phys3(sys_table->boottime->allocate_pool,
				EFI_LOADER_DATA, sizeof(*idt),
				(void **)&idt);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table, "Failed to alloc mem for idt structure\n");
		goto fail;
	}

	idt->size = 0;
	idt->address = 0;

	/*
	 * If the kernel isn't already loaded at the preferred load
	 * address, relocate it.
	 */
	if (hdr->pref_address != hdr->code32_start) {
		unsigned long bzimage_addr = hdr->code32_start;
		status = efi_relocate_kernel(sys_table, &bzimage_addr,
					     hdr->init_size, hdr->init_size,
					     hdr->pref_address,
					     hdr->kernel_alignment);
		if (status != EFI_SUCCESS)
			goto fail;

		hdr->pref_address = hdr->code32_start;
		hdr->code32_start = bzimage_addr;
	}

	status = exit_boot(boot_params, handle);
	if (status != EFI_SUCCESS)
		goto fail;

	memset((char *)gdt->address, 0x0, gdt->size);
	desc = (struct desc_struct *)gdt->address;

	/* The first GDT is a dummy and the second is unused. */
	desc += 2;

	desc->limit0 = 0xffff;
	desc->base0 = 0x0000;
	desc->base1 = 0x0000;
	desc->type = SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
	desc->s = DESC_TYPE_CODE_DATA;
	desc->dpl = 0;
	desc->p = 1;
	desc->limit = 0xf;
	desc->avl = 0;
	desc->l = 0;
	desc->d = SEG_OP_SIZE_32BIT;
	desc->g = SEG_GRANULARITY_4KB;
	desc->base2 = 0x00;

	desc++;
	desc->limit0 = 0xffff;
	desc->base0 = 0x0000;
	desc->base1 = 0x0000;
	desc->type = SEG_TYPE_DATA | SEG_TYPE_READ_WRITE;
	desc->s = DESC_TYPE_CODE_DATA;
	desc->dpl = 0;
	desc->p = 1;
	desc->limit = 0xf;
	desc->avl = 0;
	desc->l = 0;
	desc->d = SEG_OP_SIZE_32BIT;
	desc->g = SEG_GRANULARITY_4KB;
	desc->base2 = 0x00;

#ifdef CONFIG_X86_64
	/* Task segment value */
	desc++;
	desc->limit0 = 0x0000;
	desc->base0 = 0x0000;
	desc->base1 = 0x0000;
	desc->type = SEG_TYPE_TSS;
	desc->s = 0;
	desc->dpl = 0;
	desc->p = 1;
	desc->limit = 0x0;
	desc->avl = 0;
	desc->l = 0;
	desc->d = 0;
	desc->g = SEG_GRANULARITY_4KB;
	desc->base2 = 0x00;
#endif /* CONFIG_X86_64 */

	asm volatile ("lidt %0" : : "m" (*idt));
	asm volatile ("lgdt %0" : : "m" (*gdt));

	asm volatile("cli");

	return boot_params;
fail:
	return NULL;
}