summaryrefslogtreecommitdiffstats
path: root/recipes-kernel/linux/linux-hierofalcon/01-arm64-boot-BE-kernels-from-UEFI.patch
blob: 6790315e9255b0243b4edc1543ddb2e5500d19ae (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
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
From c55fa726d3e67da11a7ccd16ca367e9094265e4e Mon Sep 17 00:00:00 2001
From: Adrian Calianu <adrian.calianu@enea.com>
Date: Mon, 16 Feb 2015 13:56:36 +0100
Subject: [PATCH 1/1] arm64: boot BE kernels from UEFI

Adds support for booting BE kernels from UEFI. As UEFI is defined to
be strictly little endian, some workarounds are required to combine a little
endian EFI stub with a big endian kernel. Also, runtime services need to be
wrapped so they can be executed in little endian mode.

This patch is the resulting of porting on 3.19 kernel of a patch set
([RFC PATCH 00/10] arm64: boot BE kernels from UEFI) provided by
Ard Biesheuvel ard.biesheuvel at linaro.org for 3.17 kernel. 

http://lists.infradead.org/pipermail/linux-arm-kernel/2014-July/274208.html

Signed-off-by: Adrian Calianu <adrian.calianu@enea.com>
---
 arch/arm64/Kconfig                          |  10 ++-
 arch/arm64/include/asm/assembler.h          |  18 +++++
 arch/arm64/include/asm/efi.h                |   2 +
 arch/arm64/kernel/Makefile                  |   7 +-
 arch/arm64/kernel/efi-be-call.S             |  55 +++++++++++++++
 arch/arm64/kernel/efi-be-runtime.c          | 104 ++++++++++++++++++++++++++++
 arch/arm64/kernel/efi-entry.S               |  43 +++++++++---
 arch/arm64/kernel/efi-stub.c                |  10 +--
 arch/arm64/kernel/efi.c                     |  64 ++++++++++-------
 arch/arm64/kernel/efistub-le/Makefile       |  52 ++++++++++++++
 arch/arm64/kernel/efistub-le/efi-le-entry.S |  12 ++++
 arch/arm64/kernel/efistub-le/efistub-le.lds |  35 ++++++++++
 arch/arm64/kernel/efistub-le/le.h           |  12 ++++
 arch/arm64/kernel/efistub-le/strstr.c       |  20 ++++++
 arch/arm64/kernel/head.S                    |  48 +++++++------
 arch/arm64/kernel/image.h                   |  16 ++++-
 drivers/firmware/efi/efi.c                  |  26 ++++---
 drivers/firmware/efi/efivars.c              |   2 +-
 drivers/firmware/efi/libstub/fdt.c          |   4 ++
 19 files changed, 459 insertions(+), 81 deletions(-)
 create mode 100644 arch/arm64/kernel/efi-be-call.S
 create mode 100644 arch/arm64/kernel/efi-be-runtime.c
 create mode 100644 arch/arm64/kernel/efistub-le/Makefile
 create mode 100644 arch/arm64/kernel/efistub-le/efi-le-entry.S
 create mode 100644 arch/arm64/kernel/efistub-le/efistub-le.lds
 create mode 100644 arch/arm64/kernel/efistub-le/le.h
 create mode 100644 arch/arm64/kernel/efistub-le/strstr.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3f08727..d35a06c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -573,16 +573,20 @@ config CMDLINE_FORCE
 config EFI_STUB
 	bool
 
+config EFI_LE_STUB
+    bool
+
 config EFI
 	bool "UEFI runtime support"
-	depends on OF && !CPU_BIG_ENDIAN
+	depends on OF
 	select LIBFDT
 	select UCS2_STRING
 	select EFI_PARAMS_FROM_FDT
 	select EFI_RUNTIME_WRAPPERS
-	select EFI_STUB
+    select EFI_STUB if !CPU_BIG_ENDIAN
+    select EFI_LE_STUB if CPU_BIG_ENDIAN
 	select EFI_ARMSTUB
-	default y
+	default y if !CPU_BIG_ENDIAN
 	help
 	  This option provides support for runtime services provided
 	  by UEFI firmware (such as non-volatile variables, realtime
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 5901480..ad3aa92 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -155,3 +155,21 @@ lr	.req	x30		// link register
 #endif
 	orr	\rd, \lbits, \hbits, lsl #32
 	.endm
+
+    /*
+     * Define LE constants
+     */
+    .macro      le16, x
+    .byte       \x & 0xff
+    .byte       (\x >> 8) & 0xff
+    .endm
+
+    .macro      le32, x
+    le16        \x
+    le16        \x >> 16
+    .endm
+
+    .macro      le64, x
+    le32        \x
+    le32        \x >> 32
+    .endm
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index a34fd3b..44e642b 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -44,4 +44,6 @@ extern void efi_idmap_init(void);
 
 #define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
 
+extern void efi_be_runtime_setup(void);
+
 #endif /* _ASM_EFI_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 79bdd3b..1ab3ff4 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -32,7 +32,12 @@ arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND)	+= sleep.o suspend.o
 arm64-obj-$(CONFIG_CPU_IDLE)		+= cpuidle.o
 arm64-obj-$(CONFIG_JUMP_LABEL)		+= jump_label.o
 arm64-obj-$(CONFIG_KGDB)		+= kgdb.o
-arm64-obj-$(CONFIG_EFI)			+= efi.o efi-stub.o efi-entry.o
+arm64-efi-obj-y                := efi.o
+arm64-efi-obj-$(CONFIG_EFI_STUB)   += efi-stub.o efi-entry.o
+arm64-efi-obj-$(CONFIG_EFI_LE_STUB)    += efistub-le/
+arm64-efi-obj-$(CONFIG_CPU_BIG_ENDIAN) += efi-be-runtime.o efi-be-call.o
+arm64-obj-$(CONFIG_EFI)            += $(arm64-efi-obj-y)
+
 arm64-obj-$(CONFIG_PCI)			+= pci.o
 arm64-obj-$(CONFIG_ARMV8_DEPRECATED)	+= armv8_deprecated.o
 arm64-obj-$(CONFIG_ACPI)		+= acpi.o
diff --git a/arch/arm64/kernel/efi-be-call.S b/arch/arm64/kernel/efi-be-call.S
new file mode 100644
index 0000000..b395c8c
--- /dev/null
+++ b/arch/arm64/kernel/efi-be-call.S
@@ -0,0 +1,55 @@
+
+#include <linux/linkage.h>
+
+   .text
+   .align      3
+ENTRY(efi_be_phys_call)
+   /*
+    * Entered at physical address with 1:1 mapping enabled.
+    */
+   stp x29, x30, [sp, #-96]!
+   mov x29, sp
+   str x27, [sp, #16]
+
+   ldr x8, =efi_be_phys_call   // virt address of this function
+   adr x9, efi_be_phys_call    // phys address of this function
+   sub x9, x8, x9      // calculate virt to phys offset in x9
+
+   /* preserve all inputs */
+   stp x0, x1, [sp, #32]
+   stp x2, x3, [sp, #48]
+   stp x4, x5, [sp, #64]
+   stp x6, x7, [sp, #80]
+
+   /* get phys address of stack */
+   sub sp, sp, x9
+
+   /* switch to LE, disable MMU and D-cache but leave I-cache enabled */
+   mrs x27, sctlr_el1
+   bic x8, x27, #1 << 2    // clear SCTLR.C
+   msr sctlr_el1, x8
+
+   bl  flush_cache_all
+
+   /* restore inputs but rotated by 1 register */
+   ldp x7, x0, [sp, #32]
+   ldp x1, x2, [sp, #48]
+   ldp x3, x4, [sp, #64]
+   ldp x5, x6, [sp, #80]
+
+   bic x8, x27, #1 << 2    // clear SCTLR.C
+   bic x8, x8, #1 << 0     // clear SCTLR.M
+   bic x8, x8, #1 << 25    // clear SCTLR.EE
+   msr sctlr_el1, x8
+   isb
+
+   blr x7
+
+   /* switch back to BE and reenable MMU and D-cache */
+   msr sctlr_el1, x27
+
+   mov sp, x29
+   ldr x27, [sp, #16]
+   ldp x29, x30, [sp], #96
+   ret
+ENDPROC(efi_be_phys_call)
diff --git a/arch/arm64/kernel/efi-be-runtime.c b/arch/arm64/kernel/efi-be-runtime.c
new file mode 100644
index 0000000..28d7406
--- /dev/null
+++ b/arch/arm64/kernel/efi-be-runtime.c
@@ -0,0 +1,104 @@
+
+#include <linux/efi.h>
+#include <linux/spinlock.h>
+#include <asm/efi.h>
+#include <asm/neon.h>
+#include <asm/tlbflush.h>
+
+static efi_runtime_services_t *runtime;
+static efi_status_t (*efi_be_call)(phys_addr_t func, ...);
+
+static DEFINE_SPINLOCK(efi_be_rt_lock);
+
+static unsigned long efi_be_call_pre(void)
+{
+   unsigned long flags;
+
+   kernel_neon_begin();
+   spin_lock_irqsave(&efi_be_rt_lock, flags);
+   cpu_switch_mm(idmap_pg_dir, &init_mm);
+   flush_tlb_all();
+   return flags;
+}
+
+static void efi_be_call_post(unsigned long flags)
+{
+   cpu_switch_mm(current, current->active_mm);
+   flush_tlb_all();
+   spin_unlock_irqrestore(&efi_be_rt_lock, flags);
+   kernel_neon_end();
+}
+
+static efi_status_t efi_be_get_variable(efi_char16_t *name,
+                   efi_guid_t *vendor,
+                   u32 *attr,
+                   unsigned long *data_size,
+                   void *data)
+{
+   unsigned long flags;
+   efi_status_t status;
+
+   *data_size = cpu_to_le64(*data_size);
+   flags = efi_be_call_pre();
+   status = efi_be_call(le64_to_cpu(runtime->get_variable),
+                virt_to_phys(name), virt_to_phys(vendor),
+                virt_to_phys(attr), virt_to_phys(data_size),
+                virt_to_phys(data));
+   efi_be_call_post(flags);
+   *attr = le32_to_cpu(*attr);
+   *data_size = le64_to_cpu(*data_size);
+   return status;
+}
+
+static efi_status_t efi_be_get_next_variable(unsigned long *name_size,
+                        efi_char16_t *name,
+                        efi_guid_t *vendor)
+{
+   unsigned long flags;
+   efi_status_t status;
+
+   *name_size = cpu_to_le64(*name_size);
+   flags = efi_be_call_pre();
+   status = efi_be_call(le64_to_cpu(runtime->get_next_variable),
+                virt_to_phys(name_size), virt_to_phys(name),
+                virt_to_phys(vendor));
+   efi_be_call_post(flags);
+   *name_size = le64_to_cpu(*name_size);
+   return status;
+}
+
+static efi_status_t efi_be_set_variable(efi_char16_t *name,
+                   efi_guid_t *vendor,
+                   u32 attr,
+                   unsigned long data_size,
+                   void *data)
+{
+   unsigned long flags;
+   efi_status_t status;
+
+   flags = efi_be_call_pre();
+   status = efi_be_call(le64_to_cpu(runtime->set_variable),
+                virt_to_phys(name), virt_to_phys(vendor),
+                cpu_to_le32(attr), cpu_to_le64(data_size),
+                virt_to_phys(data));
+   efi_be_call_post(flags);
+   return status;
+}
+
+void efi_be_runtime_setup(void)
+{
+   extern u8 efi_be_phys_call[];
+
+   runtime = ioremap_cache(le64_to_cpu(efi.systab->runtime),
+               sizeof(efi_runtime_services_t));
+   if (!runtime) {
+       pr_err("Failed to set up BE wrappers for UEFI Runtime Services!\n");
+       return;
+   }
+
+   efi_be_call = (void *)virt_to_phys(efi_be_phys_call);
+
+   efi.get_variable = efi_be_get_variable;
+   efi.get_next_variable = efi_be_get_next_variable;
+   efi.set_variable = efi_be_set_variable;
+}
diff --git a/arch/arm64/kernel/efi-entry.S b/arch/arm64/kernel/efi-entry.S
index 8ce9b05..760fbb5 100644
--- a/arch/arm64/kernel/efi-entry.S
+++ b/arch/arm64/kernel/efi-entry.S
@@ -34,7 +34,34 @@ ENTRY(efi_stub_entry)
 	 * Create a stack frame to save FP/LR with extra space
 	 * for image_addr variable passed to efi_entry().
 	 */
-	stp	x29, x30, [sp, #-32]!
+   stp x29, x30, [sp, #-48]!
+   stp x22, x23, [sp, #32]
+
+#ifdef CONFIG_EFI_LE_STUB
+   adr x4, efi_stub_entry
+   ldp w8, w9, [x4, #-32]
+STUB_BE(rev    w8, w8      )
+STUB_BE(rev    w9, w9      )
+   add x8, x4, w8, sxtw        // x8: base of Image
+   add x9, x4, w9, sxtw        // x9: offset of linux_banner
+
+   ldp x22, x23, [x4, #-24]        // x22: size of Image
+STUB_BE(rev    x23, x23    )       // x23: stext offset
+
+   /*
+    * Get a pointer to linux_banner in the outer image and store it
+    * in this image.
+    */
+   adrp    x4, le_linux_banner
+   str x9, [x4, #:lo12:le_linux_banner]
+#else
+   adrp    x8, _text
+   add x8, x8, #:lo12:_text        // x8: base of Image
+   adrp    x9, _edata
+   add x9, x9, #:lo12:_edata
+   sub x22, x9, x8         // x22: size of Image
+   ldr x23, =stext_offset      // x23: stext offset
+#endif
 
 	/*
 	 * Call efi_entry to do the real work.
@@ -45,8 +72,6 @@ ENTRY(efi_stub_entry)
 	 *                         efi_system_table_t *sys_table,
 	 *                         unsigned long *image_addr) ;
 	 */
-	adrp	x8, _text
-	add	x8, x8, #:lo12:_text
 	add	x2, sp, 16
 	str	x8, [x2]
 	bl	efi_entry
@@ -61,17 +86,12 @@ ENTRY(efi_stub_entry)
 	 */
 	mov	x20, x0		// DTB address
 	ldr	x0, [sp, #16]	// relocated _text address
-	ldr	x21, =stext_offset
-	add	x21, x0, x21
+	add	x21, x0, x23
 
 	/*
 	 * Calculate size of the kernel Image (same for original and copy).
 	 */
-	adrp	x1, _text
-	add	x1, x1, #:lo12:_text
-	adrp	x2, _edata
-	add	x2, x2, #:lo12:_edata
-	sub	x1, x2, x1
+    mov x1, x22
 
 	/*
 	 * Flush the copied Image to the PoC, and ensure it is not shadowed by
@@ -117,7 +137,8 @@ ENTRY(efi_stub_entry)
 
 efi_load_fail:
 	mov	x0, #EFI_LOAD_ERROR
-	ldp	x29, x30, [sp], #32
+    ldp x22, x23, [sp, #32]
+    ldp x29, x30, [sp], #48
 	ret
 
 efi_stub_entry_end:
diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
index d27dd98..dd6d6bc 100644
--- a/arch/arm64/kernel/efi-stub.c
+++ b/arch/arm64/kernel/efi-stub.c
@@ -11,7 +11,6 @@
  */
 #include <linux/efi.h>
 #include <asm/efi.h>
-#include <asm/sections.h>
 
 efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
 				 unsigned long *image_addr,
@@ -22,22 +21,19 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
 				 efi_loaded_image_t *image)
 {
 	efi_status_t status;
-	unsigned long kernel_size, kernel_memsize = 0;
 
 	/* Relocate the image, if required. */
-	kernel_size = _edata - _text;
 	if (*image_addr != (dram_base + TEXT_OFFSET)) {
-		kernel_memsize = kernel_size + (_end - _edata);
-		status = efi_low_alloc(sys_table, kernel_memsize + TEXT_OFFSET,
+		status = efi_low_alloc(sys_table, image->image_size + TEXT_OFFSET,
 				       SZ_2M, reserve_addr);
 		if (status != EFI_SUCCESS) {
 			pr_efi_err(sys_table, "Failed to relocate kernel\n");
 			return status;
 		}
 		memcpy((void *)*reserve_addr + TEXT_OFFSET, (void *)*image_addr,
-		       kernel_size);
+		       image->image_size);
 		*image_addr = *reserve_addr + TEXT_OFFSET;
-		*reserve_size = kernel_memsize + TEXT_OFFSET;
+		*reserve_size = image->image_size + TEXT_OFFSET;
 	}
 
 
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 4178e9e..133c599 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -43,7 +43,7 @@ early_param("uefi_debug", uefi_debug_setup);
 
 static int __init is_normal_ram(efi_memory_desc_t *md)
 {
-	if (md->attribute & EFI_MEMORY_WB)
+	if (le64_to_cpu(md->attribute) & EFI_MEMORY_WB)
 		return 1;
 	return 0;
 }
@@ -59,10 +59,10 @@ static void __init efi_setup_idmap(void)
 
 	/* map runtime io spaces */
 	for_each_efi_memory_desc(&memmap, md) {
-		if (!(md->attribute & EFI_MEMORY_RUNTIME) || is_normal_ram(md))
+		if (!(le64_to_cpu(md->attribute) & EFI_MEMORY_RUNTIME) || is_normal_ram(md))
 			continue;
-		paddr = md->phys_addr;
-		npages = md->num_pages;
+        paddr = le64_to_cpu(md->phys_addr);
+        npages = le64_to_cpu(md->num_pages);
 		memrange_efi_to_native(&paddr, &npages);
 		size = npages << PAGE_SHIFT;
 		create_id_mapping(paddr, size, 1);
@@ -88,29 +88,29 @@ static int __init uefi_init(void)
 	/*
 	 * Verify the EFI Table
 	 */
-	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
+	if (le64_to_cpu(efi.systab->hdr.signature) != EFI_SYSTEM_TABLE_SIGNATURE) {
 		pr_err("System table signature incorrect\n");
 		retval = -EINVAL;
 		goto out;
 	}
-	if ((efi.systab->hdr.revision >> 16) < 2)
+	if ((le32_to_cpu(efi.systab->hdr.revision) >> 16) < 2)
 		pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
 			efi.systab->hdr.revision >> 16,
 			efi.systab->hdr.revision & 0xffff);
 
 	/* Show what we know for posterity */
-	c16 = early_memremap(efi.systab->fw_vendor,
+	c16 = early_memremap(le64_to_cpu(efi.systab->fw_vendor),
 			     sizeof(vendor));
 	if (c16) {
 		for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
-			vendor[i] = c16[i];
+			vendor[i] = le16_to_cpu(c16[i]);
 		vendor[i] = '\0';
 		early_memunmap(c16, sizeof(vendor));
 	}
 
 	pr_info("EFI v%u.%.02u by %s\n",
-		efi.systab->hdr.revision >> 16,
-		efi.systab->hdr.revision & 0xffff, vendor);
+       le32_to_cpu(efi.systab->hdr.revision) >> 16,
+       le32_to_cpu(efi.systab->hdr.revision) & 0xffff, vendor);
 
 	retval = efi_config_init(NULL);
 
@@ -124,7 +124,7 @@ out:
  */
 static __init int is_reserve_region(efi_memory_desc_t *md)
 {
-	switch (md->type) {
+	switch (le32_to_cpu(md->type)) {
 	case EFI_LOADER_CODE:
 	case EFI_LOADER_DATA:
 	case EFI_BOOT_SERVICES_CODE:
@@ -146,8 +146,9 @@ static __init void reserve_regions(void)
 		pr_info("Processing EFI memory map:\n");
 
 	for_each_efi_memory_desc(&memmap, md) {
-		paddr = md->phys_addr;
-		npages = md->num_pages;
+        u32 md_type = le32_to_cpu(md->type);
+		paddr = le64_to_cpu(md->phys_addr);
+		npages = le64_to_cpu(md->num_pages);
 
 		if (uefi_debug) {
 			char buf[64];
@@ -164,8 +165,8 @@ static __init void reserve_regions(void)
 			early_init_dt_add_memory_arch(paddr, size);
 
 		if (is_reserve_region(md) ||
-		    md->type == EFI_BOOT_SERVICES_CODE ||
-		    md->type == EFI_BOOT_SERVICES_DATA) {
+		    md_type == EFI_BOOT_SERVICES_CODE ||
+		    md_type == EFI_BOOT_SERVICES_DATA) {
 			memblock_reserve(paddr, size);
 			if (uefi_debug)
 				pr_cont("*");
@@ -246,17 +247,17 @@ static void __init free_boot_services(void)
 			 */
 			if (free_start) {
 				/* adjust free_end then free region */
-				if (free_end > md->phys_addr)
+				if (free_end > le64_to_cpu(md->phys_addr))
 					free_end -= PAGE_SIZE;
 				total_freed += free_region(free_start, free_end);
 				free_start = 0;
 			}
-			keep_end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
+			keep_end = le64_to_cpu(md->phys_addr) + (le64_to_cpu(md->num_pages) << EFI_PAGE_SHIFT);
 			continue;
 		}
 
-		if (md->type != EFI_BOOT_SERVICES_CODE &&
-		    md->type != EFI_BOOT_SERVICES_DATA) {
+		if (le32_to_cpu(md->type) != EFI_BOOT_SERVICES_CODE &&
+		    le32_to_cpu(md->type) != EFI_BOOT_SERVICES_DATA) {
 			/* no need to free this region */
 			continue;
 		}
@@ -264,8 +265,8 @@ static void __init free_boot_services(void)
 		/*
 		 * We want to free memory from this region.
 		 */
-		paddr = md->phys_addr;
-		npages = md->num_pages;
+		paddr = le64_to_cpu(md->phys_addr);
+		npages = le64_to_cpu(md->num_pages);
 		memrange_efi_to_native(&paddr, &npages);
 		size = npages << PAGE_SHIFT;
 
@@ -333,8 +334,8 @@ static int __init remap_region(efi_memory_desc_t *md, void **new)
 {
 	u64 paddr, vaddr, npages, size;
 
-	paddr = md->phys_addr;
-	npages = md->num_pages;
+	paddr = le64_to_cpu(md->phys_addr);
+	npages = le64_to_cpu(md->num_pages);
 	memrange_efi_to_native(&paddr, &npages);
 	size = npages << PAGE_SHIFT;
 
@@ -350,7 +351,7 @@ static int __init remap_region(efi_memory_desc_t *md, void **new)
 	}
 
 	/* adjust for any rounding when EFI and system pagesize differs */
-	md->virt_addr = vaddr + (md->phys_addr - paddr);
+	md->virt_addr = vaddr + (le64_to_cpu(md->phys_addr) - paddr);
 
 	if (uefi_debug)
 		pr_info("  EFI remap 0x%012llx => %p\n",
@@ -395,6 +396,21 @@ static int __init arm64_enter_virtual_mode(void)
 
 	efi.memmap = &memmap;
 
+    if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
+       efi.systab = ioremap_cache(efi_system_table,
+                      sizeof(efi_system_table_t));
+       if (!efi.systab) {
+           pr_err("Failed to remap EFI system table!\n");
+           return -1;
+       }
+       free_boot_services();
+       efi_be_runtime_setup();
+
+       set_bit(EFI_SYSTEM_TABLES, &efi.flags);
+       set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+       return 0;
+    }
+
 	/* Map the runtime regions */
 	virtmap = kmalloc(mapsize, GFP_KERNEL);
 	if (!virtmap) {
diff --git a/arch/arm64/kernel/efistub-le/Makefile b/arch/arm64/kernel/efistub-le/Makefile
new file mode 100644
index 0000000..8a1c2a8
--- /dev/null
+++ b/arch/arm64/kernel/efistub-le/Makefile
@@ -0,0 +1,52 @@
+
+#
+# Build a little endian EFI stub and wrap it into a single .o
+#
+
+# the LE objects making up the LE efi stub
+le-objs := efi-entry.o efi-stub.o strstr.o cache.o         \
+      lib-memchr.o lib-memcmp.o lib-memcpy.o lib-memmove.o     \
+       lib-memset.o lib-strchr.o lib-strlen.o lib-strncmp.o    \
+      fdt-fdt.o fdt-fdt_ro.o fdt-fdt_rw.o fdt-fdt_sw.o         \
+       fdt-fdt_wip.o fdt-fdt_empty_tree.o          \
+      libstub-fdt.o libstub-arm-stub.o libstub-efi-stub-helper.o
+
+extra-y := efi-le-stub.bin efi-le-stub.elf $(le-objs)
+
+KBUILD_CFLAGS := $(subst -pg,,$(KBUILD_CFLAGS)) -fno-stack-protector   \
+        -mlittle-endian -I$(srctree)/scripts/dtc/libfdt
+
+le-targets := $(addprefix $(obj)/, $(le-objs))
+$(le-targets): KBUILD_AFLAGS += -mlittle-endian -include $(srctree)/$(src)/le.h
+
+$(obj)/efi-entry.o: $(obj)/../efi-entry.S FORCE
+	$(call if_changed_dep,as_o_S)
+
+CFLAGS_efi-stub.o += -DTEXT_OFFSET=$(TEXT_OFFSET)
+$(obj)/efi-stub.o: $(obj)/../efi-stub.c FORCE
+	   $(call if_changed_dep,cc_o_c)
+
+$(obj)/cache.o: $(src)/../../mm/cache.S FORCE
+	   $(call if_changed_dep,as_o_S)
+
+$(obj)/lib-%.o: $(src)/../../lib/%.S FORCE
+	   $(call if_changed_dep,as_o_S)
+
+$(obj)/fdt-%.o: $(srctree)/lib/%.c FORCE
+	   $(call if_changed_dep,cc_o_c)
+
+$(obj)/libstub-%.o: $(srctree)/drivers/firmware/efi/libstub/%.c FORCE
+	   $(call if_changed_dep,cc_o_c)
+
+$(obj)/efi-le-stub.elf: LDFLAGS=-EL -Map $@.map -T
+$(obj)/efi-le-stub.elf: $(src)/efistub-le.lds $(le-targets) FORCE
+	   $(call if_changed,ld)
+
+$(obj)/efi-le-stub.bin: OBJCOPYFLAGS=-O binary
+$(obj)/efi-le-stub.bin: $(obj)/efi-le-stub.elf FORCE
+	   $(call if_changed,objcopy)
+
+# the BE object containing the entire LE stub
+obj-y := efi-le-entry.o
+
+$(obj)/efi-le-entry.o: $(obj)/efi-le-stub.bin
diff --git a/arch/arm64/kernel/efistub-le/efi-le-entry.S b/arch/arm64/kernel/efistub-le/efi-le-entry.S
new file mode 100644
index 0000000..755364c
--- /dev/null
+++ b/arch/arm64/kernel/efistub-le/efi-le-entry.S
@@ -0,0 +1,12 @@
+#include <linux/linkage.h>
+
+   .text
+   .align      12
+   .long       _text - efi_stub_entry
+   .long       linux_banner - efi_stub_entry
+   .quad       _kernel_size_le
+   .quad       stext_offset
+   .quad       0
+ENTRY(efi_stub_entry)
+   .incbin     "arch/arm64/kernel/efistub-le/efi-le-stub.bin"
+ENDPROC(efi_stub_entry)
diff --git a/arch/arm64/kernel/efistub-le/efistub-le.lds b/arch/arm64/kernel/efistub-le/efistub-le.lds
new file mode 100644
index 0000000..f64d542
--- /dev/null
+++ b/arch/arm64/kernel/efistub-le/efistub-le.lds
@@ -0,0 +1,35 @@
+
+ENTRY(efi_stub_entry)
+
+SECTIONS {
+   /*
+    * The inner and outer alignment of this chunk of code need to be the
+    * same so that PC relative references using adrp/add or adrp/ldr pairs
+    * will work correctly.
+    * Skip 32 bytes here, so we can put the binary blob at an offset of
+    * 4k + 0x20 in the outer image, and use the gap to share constants
+    * emitted by the outer linker but required in the stub.
+    */
+   .text 0x20 : {
+       arch/arm64/kernel/efistub-le/efi-entry.o(.init.text)
+       *(.init.text)
+       *(.text)
+       *(.text*)
+   }
+   .rodata : {
+       . = ALIGN(16);
+       *(.rodata)
+       *(.rodata*)
+       *(.init.rodata)
+   }
+   .data : {
+       . = ALIGN(16);
+       *(.data)
+       *(.data*)
+       le_linux_banner = .;
+       . += 8;
+   }
+   /DISCARD/ : {
+       *(__ex_table)
+   }
+}
diff --git a/arch/arm64/kernel/efistub-le/le.h b/arch/arm64/kernel/efistub-le/le.h
new file mode 100644
index 0000000..a9f6dfc
--- /dev/null
+++ b/arch/arm64/kernel/efistub-le/le.h
@@ -0,0 +1,12 @@
+
+/*
+ * This is a bit of a hack, but it is necessary to correctly compile .S files
+ * that contain CPU_LE()/CPU_BE() statements, as these are defined to depend on
+ * CONFIG_ symbols and not on the endianness of the compiler.
+ */
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define STUB_BE(code...)   code
+#else
+#define STUB_BE(code...)
+#endif
+#undef CONFIG_CPU_BIG_ENDIAN
diff --git a/arch/arm64/kernel/efistub-le/strstr.c b/arch/arm64/kernel/efistub-le/strstr.c
new file mode 100644
index 0000000..bd16094
--- /dev/null
+++ b/arch/arm64/kernel/efistub-le/strstr.c
@@ -0,0 +1,20 @@
+
+#include <linux/types.h>
+#include <linux/string.h>
+
+char *strstr(const char *s1, const char *s2)
+{
+   size_t l1, l2;
+
+   l2 = strlen(s2);
+   if (!l2)
+       return (char *)s1;
+   l1 = strlen(s1);
+   while (l1 >= l2) {
+       l1--;
+       if (!memcmp(s1, s2, l2))
+           return (char *)s1;
+       s1++;
+   }
+   return NULL;
+}
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 8ce88e0..8b1eba5 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -126,7 +126,10 @@ efi_head:
 	.byte	0x4d
 	.byte	0x64
 #ifdef CONFIG_EFI
-	.long	pe_header - efi_head		// Offset to the PE header.
+    .byte   pe_header - efi_head        // Offset to the PE header.
+    .byte   0
+    .byte   0
+    .byte   0
 #else
 	.word	0				// reserved
 #endif
@@ -139,30 +142,31 @@ pe_header:
 	.ascii	"PE"
 	.short 	0
 coff_header:
-	.short	0xaa64				// AArch64
-	.short	2				// nr_sections
+    le16    0xaa64          // AArch64
+    le16    2               // nr_sections
 	.long	0 				// TimeDateStamp
 	.long	0				// PointerToSymbolTable
-	.long	1				// NumberOfSymbols
-	.short	section_table - optional_header	// SizeOfOptionalHeader
-	.short	0x206				// Characteristics.
+    le32    1               // NumberOfSymbols
+    .byte   section_table - optional_header // SizeOfOptionalHeader
+    .byte   0
+    le16    0x206           // Characteristics.
 						// IMAGE_FILE_DEBUG_STRIPPED |
 						// IMAGE_FILE_EXECUTABLE_IMAGE |
 						// IMAGE_FILE_LINE_NUMS_STRIPPED
 optional_header:
-	.short	0x20b				// PE32+ format
+    le16    0x20b               // PE32+ format
 	.byte	0x02				// MajorLinkerVersion
 	.byte	0x14				// MinorLinkerVersion
-	.long	_end - stext			// SizeOfCode
+    .long   _efi_code_virtsize_le       // SizeOfCode
 	.long	0				// SizeOfInitializedData
 	.long	0				// SizeOfUninitializedData
-	.long	efi_stub_entry - efi_head	// AddressOfEntryPoint
-	.long	stext_offset			// BaseOfCode
+    .long   _efi_entry_point_le     // AddressOfEntryPoint
+    .long   _efi_stext_offset_le        // BaseOfCode
 
 extra_header_fields:
 	.quad	0				// ImageBase
-	.long	0x1000				// SectionAlignment
-	.long	PECOFF_FILE_ALIGNMENT		// FileAlignment
+	le32	0x1000			// SectionAlignment
+	le32	0x200		    // FileAlignment
 	.short	0				// MajorOperatingSystemVersion
 	.short	0				// MinorOperatingSystemVersion
 	.short	0				// MajorImageVersion
@@ -171,19 +175,19 @@ extra_header_fields:
 	.short	0				// MinorSubsystemVersion
 	.long	0				// Win32VersionValue
 
-	.long	_end - efi_head			// SizeOfImage
+	.long	_efi_image_size_le		// SizeOfImage
 
 	// Everything before the kernel image is considered part of the header
-	.long	stext_offset			// SizeOfHeaders
+	.long	_efi_stext_offset_le // SizeOfHeaders
 	.long	0				// CheckSum
-	.short	0xa				// Subsystem (EFI application)
+	le16	0xa				// Subsystem (EFI application)
 	.short	0				// DllCharacteristics
 	.quad	0				// SizeOfStackReserve
 	.quad	0				// SizeOfStackCommit
 	.quad	0				// SizeOfHeapReserve
 	.quad	0				// SizeOfHeapCommit
 	.long	0				// LoaderFlags
-	.long	0x6				// NumberOfRvaAndSizes
+	le32	0x6				// NumberOfRvaAndSizes
 
 	.quad	0				// ExportTable
 	.quad	0				// ImportTable
@@ -211,23 +215,23 @@ section_table:
 	.long	0			// PointerToLineNumbers
 	.short	0			// NumberOfRelocations
 	.short	0			// NumberOfLineNumbers
-	.long	0x42100040		// Characteristics (section flags)
+	le32	0x42100040		// Characteristics (section flags)
 
 
 	.ascii	".text"
 	.byte	0
 	.byte	0
 	.byte	0        		// end of 0 padding of section name
-	.long	_end - stext		// VirtualSize
-	.long	stext_offset		// VirtualAddress
-	.long	_edata - stext		// SizeOfRawData
-	.long	stext_offset		// PointerToRawData
+    .long   _efi_code_virtsize_le   // VirtualSize
+    .long   _efi_stext_offset_le    // VirtualAddress
+    .long   _efi_code_rawsize_le    // SizeOfRawData
+    .long   _efi_stext_offset_le    // PointerToRawData
 
 	.long	0		// PointerToRelocations (0 for executables)
 	.long	0		// PointerToLineNumbers (0 for executables)
 	.short	0		// NumberOfRelocations  (0 for executables)
 	.short	0		// NumberOfLineNumbers  (0 for executables)
-	.long	0xe0500020	// Characteristics (section flags)
+	le32	0xe0500020	// Characteristics (section flags)
 
 	/*
 	 * EFI will load stext onwards at the 4k section alignment
diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h
index 8fae075..d08ce56 100644
--- a/arch/arm64/kernel/image.h
+++ b/arch/arm64/kernel/image.h
@@ -37,8 +37,10 @@
 	 (((data) & 0x0000ff0000000000) >> 24) |	\
 	 (((data) & 0x00ff000000000000) >> 40) |	\
 	 (((data) & 0xff00000000000000) >> 56))
+#define DATA_LE32(data) (DATA_LE64(data) >> 32)
 #else
 #define DATA_LE64(data) ((data) & 0xffffffffffffffff)
+#define DATA_LE32(data) ((data) & 0xffffffff)
 #endif
 
 #ifdef CONFIG_CPU_BIG_ENDIAN
@@ -57,6 +59,18 @@
 #define HEAD_SYMBOLS						\
 	_kernel_size_le		= DATA_LE64(_end - _text);	\
 	_kernel_offset_le	= DATA_LE64(TEXT_OFFSET);	\
-	_kernel_flags_le	= DATA_LE64(__HEAD_FLAGS);
+    _kernel_flags_le    = DATA_LE64(__HEAD_FLAGS);  \
+    EFI_HEAD_SYMBOLS
+
+#ifdef CONFIG_EFI
+#define EFI_HEAD_SYMBOLS                           \
+    _efi_stext_offset_le    = DATA_LE32(stext_offset);          \
+    _efi_code_virtsize_le   = DATA_LE32(_end - _text - stext_offset);   \
+    _efi_code_rawsize_le    = DATA_LE32(_edata - _text - stext_offset); \
+    _efi_image_size_le  = DATA_LE32(_end - _text);          \
+    _efi_entry_point_le = DATA_LE32(efi_stub_entry - _text);
+#else
+#define  EFI_HEAD_SYMBOLS
+#endif
 
 #endif /* __ASM_IMAGE_H */
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 9035c1b..4e98daa 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -296,18 +296,23 @@ static __init int match_config_table(efi_guid_t *guid,
 int __init efi_config_init(efi_config_table_type_t *arch_tables)
 {
 	void *config_tables, *tablep;
-	int i, sz;
+    unsigned long __tables;
+	int i, sz, nr_tables;
 
-	if (efi_enabled(EFI_64BIT))
+	if (efi_enabled(EFI_64BIT)) {
 		sz = sizeof(efi_config_table_64_t);
-	else
+        nr_tables = le64_to_cpu((__force __le64)efi.systab->nr_tables);
+        __tables = le64_to_cpu((__force __le64)efi.systab->tables);
+	} else {
 		sz = sizeof(efi_config_table_32_t);
+        nr_tables = le32_to_cpu((__force __le32)efi.systab->nr_tables);
+        __tables = le32_to_cpu((__force __le32)efi.systab->tables);
+    }
 
 	/*
 	 * Let's see what config tables the firmware passed to us.
 	 */
-	config_tables = early_memremap(efi.systab->tables,
-				       efi.systab->nr_tables * sz);
+    config_tables = early_memremap(__tables, nr_tables * sz);
 	if (config_tables == NULL) {
 		pr_err("Could not map Configuration table!\n");
 		return -ENOMEM;
@@ -315,21 +320,20 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables)
 
 	tablep = config_tables;
 	pr_info("");
-	for (i = 0; i < efi.systab->nr_tables; i++) {
+    for (i = 0; i < nr_tables; i++) {
 		efi_guid_t guid;
 		unsigned long table;
 
 		if (efi_enabled(EFI_64BIT)) {
 			u64 table64;
 			guid = ((efi_config_table_64_t *)tablep)->guid;
-			table64 = ((efi_config_table_64_t *)tablep)->table;
-			table = table64;
+            table = table64 = le64_to_cpu((__force __le64)
+                           ((efi_config_table_64_t *)tablep)->table);
 #ifndef CONFIG_64BIT
 			if (table64 >> 32) {
 				pr_cont("\n");
 				pr_err("Table located above 4GB, disabling EFI.\n");
-				early_memunmap(config_tables,
-					       efi.systab->nr_tables * sz);
+                early_memunmap(config_tables, nr_tables * sz);
 				return -EINVAL;
 			}
 #endif
@@ -344,7 +348,7 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables)
 		tablep += sz;
 	}
 	pr_cont("\n");
-	early_memunmap(config_tables, efi.systab->nr_tables * sz);
+    early_memunmap(config_tables, nr_tables * sz);
 
 	set_bit(EFI_CONFIG_TABLES, &efi.flags);
 
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index f256ecd..2b1c8be 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -563,7 +563,7 @@ efivar_create_sysfs_entry(struct efivar_entry *new_var)
 	/* Convert Unicode to normal chars (assume top bits are 0),
 	   ala UTF-8 */
 	for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
-		short_name[i] = variable_name[i] & 0xFF;
+        short_name[i] = le16_to_cpu((__force __le16)variable_name[i]);
 	}
 	/* This is ugly, but necessary to separate one vendor's
 	   private variables from another's.         */
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index c846a96..f0f9d54 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -22,6 +22,10 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
 			unsigned long map_size, unsigned long desc_size,
 			u32 desc_ver)
 {
+#ifdef CONFIG_EFI_LE_STUB
+   extern char const *le_linux_banner;
+   char const *linux_banner = le_linux_banner;
+#endif
 	int node, prev, num_rsv;
 	int status;
 	u32 fdt_val32;
-- 
1.9.1