2 * Helper functions used by the EFI stub on multiple
3 * architectures. This should be #included by the EFI stub
4 * implementation files.
6 * Copyright 2011 Intel Corporation; author Matt Fleming
8 * This file is part of the Linux kernel, and is made available
9 * under the terms of the GNU General Public License version 2.
13 #include <linux/efi.h>
19 * Some firmware implementations have problems reading files in one go.
20 * A read chunk size of 1MB seems to work for most platforms.
22 * Unfortunately, reading files in chunks triggers *other* bugs on some
23 * platforms, so we provide a way to disable this workaround, which can
24 * be done by passing "efi=nochunk" on the EFI boot stub command line.
26 * If you experience issues with initrd images being corrupt it's worth
27 * trying efi=nochunk, but chunking is enabled by default because there
28 * are far more machines that require the workaround than those that
29 * break with it enabled.
31 #define EFI_READ_CHUNK_SIZE (1024 * 1024)
33 static unsigned long __chunk_size
= EFI_READ_CHUNK_SIZE
;
35 #define EFI_MMAP_NR_SLACK_SLOTS 8
38 efi_file_handle_t
*handle
;
42 void efi_printk(efi_system_table_t
*sys_table_arg
, char *str
)
46 for (s8
= str
; *s8
; s8
++) {
47 efi_char16_t ch
[2] = { 0 };
51 efi_char16_t nl
[2] = { '\r', 0 };
52 efi_char16_printk(sys_table_arg
, nl
);
55 efi_char16_printk(sys_table_arg
, ch
);
59 static inline bool mmap_has_headroom(unsigned long buff_size
,
60 unsigned long map_size
,
61 unsigned long desc_size
)
63 unsigned long slack
= buff_size
- map_size
;
65 return slack
/ desc_size
>= EFI_MMAP_NR_SLACK_SLOTS
;
68 efi_status_t
efi_get_memory_map(efi_system_table_t
*sys_table_arg
,
69 struct efi_boot_memmap
*map
)
71 efi_memory_desc_t
*m
= NULL
;
76 *map
->desc_size
= sizeof(*m
);
77 *map
->map_size
= *map
->desc_size
* 32;
78 *map
->buff_size
= *map
->map_size
;
80 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
81 *map
->map_size
, (void **)&m
);
82 if (status
!= EFI_SUCCESS
)
87 status
= efi_call_early(get_memory_map
, map
->map_size
, m
,
88 &key
, map
->desc_size
, &desc_version
);
89 if (status
== EFI_BUFFER_TOO_SMALL
||
90 !mmap_has_headroom(*map
->buff_size
, *map
->map_size
,
92 efi_call_early(free_pool
, m
);
94 * Make sure there is some entries of headroom so that the
95 * buffer can be reused for a new map after allocations are
96 * no longer permitted. Its unlikely that the map will grow to
97 * exceed this headroom once we are ready to trigger
100 *map
->map_size
+= *map
->desc_size
* EFI_MMAP_NR_SLACK_SLOTS
;
101 *map
->buff_size
= *map
->map_size
;
105 if (status
!= EFI_SUCCESS
)
106 efi_call_early(free_pool
, m
);
108 if (map
->key_ptr
&& status
== EFI_SUCCESS
)
110 if (map
->desc_ver
&& status
== EFI_SUCCESS
)
111 *map
->desc_ver
= desc_version
;
119 unsigned long get_dram_base(efi_system_table_t
*sys_table_arg
)
122 unsigned long map_size
, buff_size
;
123 unsigned long membase
= EFI_ERROR
;
124 struct efi_memory_map map
;
125 efi_memory_desc_t
*md
;
126 struct efi_boot_memmap boot_map
;
128 boot_map
.map
= (efi_memory_desc_t
**)&map
.map
;
129 boot_map
.map_size
= &map_size
;
130 boot_map
.desc_size
= &map
.desc_size
;
131 boot_map
.desc_ver
= NULL
;
132 boot_map
.key_ptr
= NULL
;
133 boot_map
.buff_size
= &buff_size
;
135 status
= efi_get_memory_map(sys_table_arg
, &boot_map
);
136 if (status
!= EFI_SUCCESS
)
139 map
.map_end
= map
.map
+ map_size
;
141 for_each_efi_memory_desc_in_map(&map
, md
) {
142 if (md
->attribute
& EFI_MEMORY_WB
) {
143 if (membase
> md
->phys_addr
)
144 membase
= md
->phys_addr
;
148 efi_call_early(free_pool
, map
.map
);
154 * Allocate at the highest possible address that is not above 'max'.
156 efi_status_t
efi_high_alloc(efi_system_table_t
*sys_table_arg
,
157 unsigned long size
, unsigned long align
,
158 unsigned long *addr
, unsigned long max
)
160 unsigned long map_size
, desc_size
, buff_size
;
161 efi_memory_desc_t
*map
;
163 unsigned long nr_pages
;
166 struct efi_boot_memmap boot_map
;
169 boot_map
.map_size
= &map_size
;
170 boot_map
.desc_size
= &desc_size
;
171 boot_map
.desc_ver
= NULL
;
172 boot_map
.key_ptr
= NULL
;
173 boot_map
.buff_size
= &buff_size
;
175 status
= efi_get_memory_map(sys_table_arg
, &boot_map
);
176 if (status
!= EFI_SUCCESS
)
180 * Enforce minimum alignment that EFI or Linux requires when
181 * requesting a specific address. We are doing page-based (or
182 * larger) allocations, and both the address and size must meet
183 * alignment constraints.
185 if (align
< EFI_ALLOC_ALIGN
)
186 align
= EFI_ALLOC_ALIGN
;
188 size
= round_up(size
, EFI_ALLOC_ALIGN
);
189 nr_pages
= size
/ EFI_PAGE_SIZE
;
191 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
192 efi_memory_desc_t
*desc
;
193 unsigned long m
= (unsigned long)map
;
196 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
197 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
200 if (desc
->num_pages
< nr_pages
)
203 start
= desc
->phys_addr
;
204 end
= start
+ desc
->num_pages
* EFI_PAGE_SIZE
;
209 if ((start
+ size
) > end
)
212 if (round_down(end
- size
, align
) < start
)
215 start
= round_down(end
- size
, align
);
218 * Don't allocate at 0x0. It will confuse code that
219 * checks pointers against NULL.
224 if (start
> max_addr
)
229 status
= EFI_NOT_FOUND
;
231 status
= efi_call_early(allocate_pages
,
232 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
233 nr_pages
, &max_addr
);
234 if (status
!= EFI_SUCCESS
) {
243 efi_call_early(free_pool
, map
);
249 * Allocate at the lowest possible address.
251 efi_status_t
efi_low_alloc(efi_system_table_t
*sys_table_arg
,
252 unsigned long size
, unsigned long align
,
255 unsigned long map_size
, desc_size
, buff_size
;
256 efi_memory_desc_t
*map
;
258 unsigned long nr_pages
;
260 struct efi_boot_memmap boot_map
;
263 boot_map
.map_size
= &map_size
;
264 boot_map
.desc_size
= &desc_size
;
265 boot_map
.desc_ver
= NULL
;
266 boot_map
.key_ptr
= NULL
;
267 boot_map
.buff_size
= &buff_size
;
269 status
= efi_get_memory_map(sys_table_arg
, &boot_map
);
270 if (status
!= EFI_SUCCESS
)
274 * Enforce minimum alignment that EFI or Linux requires when
275 * requesting a specific address. We are doing page-based (or
276 * larger) allocations, and both the address and size must meet
277 * alignment constraints.
279 if (align
< EFI_ALLOC_ALIGN
)
280 align
= EFI_ALLOC_ALIGN
;
282 size
= round_up(size
, EFI_ALLOC_ALIGN
);
283 nr_pages
= size
/ EFI_PAGE_SIZE
;
284 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
285 efi_memory_desc_t
*desc
;
286 unsigned long m
= (unsigned long)map
;
289 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
291 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
294 if (desc
->num_pages
< nr_pages
)
297 start
= desc
->phys_addr
;
298 end
= start
+ desc
->num_pages
* EFI_PAGE_SIZE
;
301 * Don't allocate at 0x0. It will confuse code that
302 * checks pointers against NULL. Skip the first 8
303 * bytes so we start at a nice even number.
308 start
= round_up(start
, align
);
309 if ((start
+ size
) > end
)
312 status
= efi_call_early(allocate_pages
,
313 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
315 if (status
== EFI_SUCCESS
) {
321 if (i
== map_size
/ desc_size
)
322 status
= EFI_NOT_FOUND
;
324 efi_call_early(free_pool
, map
);
329 void efi_free(efi_system_table_t
*sys_table_arg
, unsigned long size
,
332 unsigned long nr_pages
;
337 nr_pages
= round_up(size
, EFI_ALLOC_ALIGN
) / EFI_PAGE_SIZE
;
338 efi_call_early(free_pages
, addr
, nr_pages
);
342 * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
343 * option, e.g. efi=nochunk.
345 * It should be noted that efi= is parsed in two very different
346 * environments, first in the early boot environment of the EFI boot
347 * stub, and subsequently during the kernel boot.
349 efi_status_t
efi_parse_options(char *cmdline
)
354 * If no EFI parameters were specified on the cmdline we've got
357 str
= strstr(cmdline
, "efi=");
361 /* Skip ahead to first argument */
362 str
+= strlen("efi=");
365 * Remember, because efi= is also used by the kernel we need to
366 * skip over arguments we don't understand.
369 if (!strncmp(str
, "nochunk", 7)) {
370 str
+= strlen("nochunk");
374 /* Group words together, delimited by "," */
375 while (*str
&& *str
!= ',')
386 * Check the cmdline for a LILO-style file= arguments.
388 * We only support loading a file from the same filesystem as
391 efi_status_t
handle_cmdline_files(efi_system_table_t
*sys_table_arg
,
392 efi_loaded_image_t
*image
,
393 char *cmd_line
, char *option_string
,
394 unsigned long max_addr
,
395 unsigned long *load_addr
,
396 unsigned long *load_size
)
398 struct file_info
*files
;
399 unsigned long file_addr
;
401 efi_file_handle_t
*fh
= NULL
;
412 j
= 0; /* See close_handles */
414 if (!load_addr
|| !load_size
)
415 return EFI_INVALID_PARAMETER
;
423 for (nr_files
= 0; *str
; nr_files
++) {
424 str
= strstr(str
, option_string
);
428 str
+= strlen(option_string
);
430 /* Skip any leading slashes */
431 while (*str
== '/' || *str
== '\\')
434 while (*str
&& *str
!= ' ' && *str
!= '\n')
441 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
442 nr_files
* sizeof(*files
), (void **)&files
);
443 if (status
!= EFI_SUCCESS
) {
444 pr_efi_err(sys_table_arg
, "Failed to alloc mem for file handle list\n");
449 for (i
= 0; i
< nr_files
; i
++) {
450 struct file_info
*file
;
451 efi_char16_t filename_16
[256];
454 str
= strstr(str
, option_string
);
458 str
+= strlen(option_string
);
463 /* Skip any leading slashes */
464 while (*str
== '/' || *str
== '\\')
467 while (*str
&& *str
!= ' ' && *str
!= '\n') {
468 if ((u8
*)p
>= (u8
*)filename_16
+ sizeof(filename_16
))
481 /* Only open the volume once. */
483 status
= efi_open_volume(sys_table_arg
, image
,
485 if (status
!= EFI_SUCCESS
)
489 status
= efi_file_size(sys_table_arg
, fh
, filename_16
,
490 (void **)&file
->handle
, &file
->size
);
491 if (status
!= EFI_SUCCESS
)
494 file_size_total
+= file
->size
;
497 if (file_size_total
) {
501 * Multiple files need to be at consecutive addresses in memory,
502 * so allocate enough memory for all the files. This is used
503 * for loading multiple files.
505 status
= efi_high_alloc(sys_table_arg
, file_size_total
, 0x1000,
506 &file_addr
, max_addr
);
507 if (status
!= EFI_SUCCESS
) {
508 pr_efi_err(sys_table_arg
, "Failed to alloc highmem for files\n");
512 /* We've run out of free low memory. */
513 if (file_addr
> max_addr
) {
514 pr_efi_err(sys_table_arg
, "We've run out of free low memory\n");
515 status
= EFI_INVALID_PARAMETER
;
516 goto free_file_total
;
520 for (j
= 0; j
< nr_files
; j
++) {
523 size
= files
[j
].size
;
525 unsigned long chunksize
;
526 if (size
> __chunk_size
)
527 chunksize
= __chunk_size
;
531 status
= efi_file_read(files
[j
].handle
,
534 if (status
!= EFI_SUCCESS
) {
535 pr_efi_err(sys_table_arg
, "Failed to read file\n");
536 goto free_file_total
;
542 efi_file_close(files
[j
].handle
);
547 efi_call_early(free_pool
, files
);
549 *load_addr
= file_addr
;
550 *load_size
= file_size_total
;
555 efi_free(sys_table_arg
, file_size_total
, file_addr
);
558 for (k
= j
; k
< i
; k
++)
559 efi_file_close(files
[k
].handle
);
561 efi_call_early(free_pool
, files
);
569 * Relocate a kernel image, either compressed or uncompressed.
570 * In the ARM64 case, all kernel images are currently
571 * uncompressed, and as such when we relocate it we need to
572 * allocate additional space for the BSS segment. Any low
573 * memory that this function should avoid needs to be
574 * unavailable in the EFI memory map, as if the preferred
575 * address is not available the lowest available address will
578 efi_status_t
efi_relocate_kernel(efi_system_table_t
*sys_table_arg
,
579 unsigned long *image_addr
,
580 unsigned long image_size
,
581 unsigned long alloc_size
,
582 unsigned long preferred_addr
,
583 unsigned long alignment
)
585 unsigned long cur_image_addr
;
586 unsigned long new_addr
= 0;
588 unsigned long nr_pages
;
589 efi_physical_addr_t efi_addr
= preferred_addr
;
591 if (!image_addr
|| !image_size
|| !alloc_size
)
592 return EFI_INVALID_PARAMETER
;
593 if (alloc_size
< image_size
)
594 return EFI_INVALID_PARAMETER
;
596 cur_image_addr
= *image_addr
;
599 * The EFI firmware loader could have placed the kernel image
600 * anywhere in memory, but the kernel has restrictions on the
601 * max physical address it can run at. Some architectures
602 * also have a prefered address, so first try to relocate
603 * to the preferred address. If that fails, allocate as low
604 * as possible while respecting the required alignment.
606 nr_pages
= round_up(alloc_size
, EFI_ALLOC_ALIGN
) / EFI_PAGE_SIZE
;
607 status
= efi_call_early(allocate_pages
,
608 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
609 nr_pages
, &efi_addr
);
612 * If preferred address allocation failed allocate as low as
615 if (status
!= EFI_SUCCESS
) {
616 status
= efi_low_alloc(sys_table_arg
, alloc_size
, alignment
,
619 if (status
!= EFI_SUCCESS
) {
620 pr_efi_err(sys_table_arg
, "Failed to allocate usable memory for kernel.\n");
625 * We know source/dest won't overlap since both memory ranges
626 * have been allocated by UEFI, so we can safely use memcpy.
628 memcpy((void *)new_addr
, (void *)cur_image_addr
, image_size
);
630 /* Return the new address of the relocated image. */
631 *image_addr
= new_addr
;
637 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
638 * This overestimates for surrogates, but that is okay.
640 static int efi_utf8_bytes(u16 c
)
642 return 1 + (c
>= 0x80) + (c
>= 0x800);
646 * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
648 static u8
*efi_utf16_to_utf8(u8
*dst
, const u16
*src
, int n
)
654 if (n
&& c
>= 0xd800 && c
<= 0xdbff &&
655 *src
>= 0xdc00 && *src
<= 0xdfff) {
656 c
= 0x10000 + ((c
& 0x3ff) << 10) + (*src
& 0x3ff);
660 if (c
>= 0xd800 && c
<= 0xdfff)
661 c
= 0xfffd; /* Unmatched surrogate */
667 *dst
++ = 0xc0 + (c
>> 6);
671 *dst
++ = 0xe0 + (c
>> 12);
674 *dst
++ = 0xf0 + (c
>> 18);
675 *dst
++ = 0x80 + ((c
>> 12) & 0x3f);
677 *dst
++ = 0x80 + ((c
>> 6) & 0x3f);
679 *dst
++ = 0x80 + (c
& 0x3f);
685 #ifndef MAX_CMDLINE_ADDRESS
686 #define MAX_CMDLINE_ADDRESS ULONG_MAX
690 * Convert the unicode UEFI command line to ASCII to pass to kernel.
691 * Size of memory allocated return in *cmd_line_len.
692 * Returns NULL on error.
694 char *efi_convert_cmdline(efi_system_table_t
*sys_table_arg
,
695 efi_loaded_image_t
*image
,
700 unsigned long cmdline_addr
= 0;
701 int load_options_chars
= image
->load_options_size
/ 2; /* UTF-16 */
702 const u16
*options
= image
->load_options
;
703 int options_bytes
= 0; /* UTF-8 bytes */
704 int options_chars
= 0; /* UTF-16 chars */
710 while (*s2
&& *s2
!= '\n'
711 && options_chars
< load_options_chars
) {
712 options_bytes
+= efi_utf8_bytes(*s2
++);
717 if (!options_chars
) {
718 /* No command line options, so return empty string*/
722 options_bytes
++; /* NUL termination */
724 status
= efi_high_alloc(sys_table_arg
, options_bytes
, 0,
725 &cmdline_addr
, MAX_CMDLINE_ADDRESS
);
726 if (status
!= EFI_SUCCESS
)
729 s1
= (u8
*)cmdline_addr
;
730 s2
= (const u16
*)options
;
732 s1
= efi_utf16_to_utf8(s1
, s2
, options_chars
);
735 *cmd_line_len
= options_bytes
;
736 return (char *)cmdline_addr
;
740 * Handle calling ExitBootServices according to the requirements set out by the
741 * spec. Obtains the current memory map, and returns that info after calling
742 * ExitBootServices. The client must specify a function to perform any
743 * processing of the memory map data prior to ExitBootServices. A client
744 * specific structure may be passed to the function via priv. The client
745 * function may be called multiple times.
747 efi_status_t
efi_exit_boot_services(efi_system_table_t
*sys_table_arg
,
749 struct efi_boot_memmap
*map
,
751 efi_exit_boot_map_processing priv_func
)
755 status
= efi_get_memory_map(sys_table_arg
, map
);
757 if (status
!= EFI_SUCCESS
)
760 status
= priv_func(sys_table_arg
, map
, priv
);
761 if (status
!= EFI_SUCCESS
)
764 status
= efi_call_early(exit_boot_services
, handle
, *map
->key_ptr
);
766 if (status
== EFI_INVALID_PARAMETER
) {
768 * The memory map changed between efi_get_memory_map() and
769 * exit_boot_services(). Per the UEFI Spec v2.6, Section 6.4:
770 * EFI_BOOT_SERVICES.ExitBootServices we need to get the
771 * updated map, and try again. The spec implies one retry
772 * should be sufficent, which is confirmed against the EDK2
773 * implementation. Per the spec, we can only invoke
774 * get_memory_map() and exit_boot_services() - we cannot alloc
775 * so efi_get_memory_map() cannot be used, and we must reuse
776 * the buffer. For all practical purposes, the headroom in the
777 * buffer should account for any changes in the map so the call
778 * to get_memory_map() is expected to succeed here.
780 *map
->map_size
= *map
->buff_size
;
781 status
= efi_call_early(get_memory_map
,
788 /* exit_boot_services() was called, thus cannot free */
789 if (status
!= EFI_SUCCESS
)
792 status
= priv_func(sys_table_arg
, map
, priv
);
793 /* exit_boot_services() was called, thus cannot free */
794 if (status
!= EFI_SUCCESS
)
797 status
= efi_call_early(exit_boot_services
, handle
, *map
->key_ptr
);
800 /* exit_boot_services() was called, thus cannot free */
801 if (status
!= EFI_SUCCESS
)
807 efi_call_early(free_pool
, *map
->map
);