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
;
36 * Allow the platform to override the allocation granularity: this allows
37 * systems that have the capability to run with a larger page size to deal
38 * with the allocations for initrd and fdt more efficiently.
40 #ifndef EFI_ALLOC_ALIGN
41 #define EFI_ALLOC_ALIGN EFI_PAGE_SIZE
45 efi_file_handle_t
*handle
;
49 void efi_printk(efi_system_table_t
*sys_table_arg
, char *str
)
53 for (s8
= str
; *s8
; s8
++) {
54 efi_char16_t ch
[2] = { 0 };
58 efi_char16_t nl
[2] = { '\r', 0 };
59 efi_char16_printk(sys_table_arg
, nl
);
62 efi_char16_printk(sys_table_arg
, ch
);
66 efi_status_t
efi_get_memory_map(efi_system_table_t
*sys_table_arg
,
67 efi_memory_desc_t
**map
,
68 unsigned long *map_size
,
69 unsigned long *desc_size
,
71 unsigned long *key_ptr
)
73 efi_memory_desc_t
*m
= NULL
;
78 *map_size
= sizeof(*m
) * 32;
81 * Add an additional efi_memory_desc_t because we're doing an
82 * allocation which may be in a new descriptor region.
84 *map_size
+= sizeof(*m
);
85 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
86 *map_size
, (void **)&m
);
87 if (status
!= EFI_SUCCESS
)
92 status
= efi_call_early(get_memory_map
, map_size
, m
,
93 &key
, desc_size
, &desc_version
);
94 if (status
== EFI_BUFFER_TOO_SMALL
) {
95 efi_call_early(free_pool
, m
);
99 if (status
!= EFI_SUCCESS
)
100 efi_call_early(free_pool
, m
);
102 if (key_ptr
&& status
== EFI_SUCCESS
)
104 if (desc_ver
&& status
== EFI_SUCCESS
)
105 *desc_ver
= desc_version
;
113 unsigned long get_dram_base(efi_system_table_t
*sys_table_arg
)
116 unsigned long map_size
;
117 unsigned long membase
= EFI_ERROR
;
118 struct efi_memory_map map
;
119 efi_memory_desc_t
*md
;
121 status
= efi_get_memory_map(sys_table_arg
, (efi_memory_desc_t
**)&map
.map
,
122 &map_size
, &map
.desc_size
, NULL
, NULL
);
123 if (status
!= EFI_SUCCESS
)
126 map
.map_end
= map
.map
+ map_size
;
128 for_each_efi_memory_desc(&map
, md
)
129 if (md
->attribute
& EFI_MEMORY_WB
)
130 if (membase
> md
->phys_addr
)
131 membase
= md
->phys_addr
;
133 efi_call_early(free_pool
, map
.map
);
139 * Allocate at the highest possible address that is not above 'max'.
141 efi_status_t
efi_high_alloc(efi_system_table_t
*sys_table_arg
,
142 unsigned long size
, unsigned long align
,
143 unsigned long *addr
, unsigned long max
)
145 unsigned long map_size
, desc_size
;
146 efi_memory_desc_t
*map
;
148 unsigned long nr_pages
;
152 status
= efi_get_memory_map(sys_table_arg
, &map
, &map_size
, &desc_size
,
154 if (status
!= EFI_SUCCESS
)
158 * Enforce minimum alignment that EFI requires when requesting
159 * a specific address. We are doing page-based allocations,
160 * so we must be aligned to a page.
162 if (align
< EFI_ALLOC_ALIGN
)
163 align
= EFI_ALLOC_ALIGN
;
165 nr_pages
= round_up(size
, EFI_ALLOC_ALIGN
) / EFI_PAGE_SIZE
;
167 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
168 efi_memory_desc_t
*desc
;
169 unsigned long m
= (unsigned long)map
;
172 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
173 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
176 if (desc
->num_pages
< nr_pages
)
179 start
= desc
->phys_addr
;
180 end
= start
+ desc
->num_pages
* (1UL << EFI_PAGE_SHIFT
);
185 if ((start
+ size
) > end
)
188 if (round_down(end
- size
, align
) < start
)
191 start
= round_down(end
- size
, align
);
194 * Don't allocate at 0x0. It will confuse code that
195 * checks pointers against NULL.
200 if (start
> max_addr
)
205 status
= EFI_NOT_FOUND
;
207 status
= efi_call_early(allocate_pages
,
208 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
209 nr_pages
, &max_addr
);
210 if (status
!= EFI_SUCCESS
) {
219 efi_call_early(free_pool
, map
);
225 * Allocate at the lowest possible address.
227 efi_status_t
efi_low_alloc(efi_system_table_t
*sys_table_arg
,
228 unsigned long size
, unsigned long align
,
231 unsigned long map_size
, desc_size
;
232 efi_memory_desc_t
*map
;
234 unsigned long nr_pages
;
237 status
= efi_get_memory_map(sys_table_arg
, &map
, &map_size
, &desc_size
,
239 if (status
!= EFI_SUCCESS
)
243 * Enforce minimum alignment that EFI requires when requesting
244 * a specific address. We are doing page-based allocations,
245 * so we must be aligned to a page.
247 if (align
< EFI_ALLOC_ALIGN
)
248 align
= EFI_ALLOC_ALIGN
;
250 nr_pages
= round_up(size
, EFI_ALLOC_ALIGN
) / EFI_PAGE_SIZE
;
251 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
252 efi_memory_desc_t
*desc
;
253 unsigned long m
= (unsigned long)map
;
256 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
258 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
261 if (desc
->num_pages
< nr_pages
)
264 start
= desc
->phys_addr
;
265 end
= start
+ desc
->num_pages
* (1UL << EFI_PAGE_SHIFT
);
268 * Don't allocate at 0x0. It will confuse code that
269 * checks pointers against NULL. Skip the first 8
270 * bytes so we start at a nice even number.
275 start
= round_up(start
, align
);
276 if ((start
+ size
) > end
)
279 status
= efi_call_early(allocate_pages
,
280 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
282 if (status
== EFI_SUCCESS
) {
288 if (i
== map_size
/ desc_size
)
289 status
= EFI_NOT_FOUND
;
291 efi_call_early(free_pool
, map
);
296 void efi_free(efi_system_table_t
*sys_table_arg
, unsigned long size
,
299 unsigned long nr_pages
;
304 nr_pages
= round_up(size
, EFI_ALLOC_ALIGN
) / EFI_PAGE_SIZE
;
305 efi_call_early(free_pages
, addr
, nr_pages
);
309 * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
310 * option, e.g. efi=nochunk.
312 * It should be noted that efi= is parsed in two very different
313 * environments, first in the early boot environment of the EFI boot
314 * stub, and subsequently during the kernel boot.
316 efi_status_t
efi_parse_options(char *cmdline
)
321 * If no EFI parameters were specified on the cmdline we've got
324 str
= strstr(cmdline
, "efi=");
328 /* Skip ahead to first argument */
329 str
+= strlen("efi=");
332 * Remember, because efi= is also used by the kernel we need to
333 * skip over arguments we don't understand.
336 if (!strncmp(str
, "nochunk", 7)) {
337 str
+= strlen("nochunk");
341 /* Group words together, delimited by "," */
342 while (*str
&& *str
!= ',')
353 * Check the cmdline for a LILO-style file= arguments.
355 * We only support loading a file from the same filesystem as
358 efi_status_t
handle_cmdline_files(efi_system_table_t
*sys_table_arg
,
359 efi_loaded_image_t
*image
,
360 char *cmd_line
, char *option_string
,
361 unsigned long max_addr
,
362 unsigned long *load_addr
,
363 unsigned long *load_size
)
365 struct file_info
*files
;
366 unsigned long file_addr
;
368 efi_file_handle_t
*fh
= NULL
;
379 j
= 0; /* See close_handles */
381 if (!load_addr
|| !load_size
)
382 return EFI_INVALID_PARAMETER
;
390 for (nr_files
= 0; *str
; nr_files
++) {
391 str
= strstr(str
, option_string
);
395 str
+= strlen(option_string
);
397 /* Skip any leading slashes */
398 while (*str
== '/' || *str
== '\\')
401 while (*str
&& *str
!= ' ' && *str
!= '\n')
408 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
409 nr_files
* sizeof(*files
), (void **)&files
);
410 if (status
!= EFI_SUCCESS
) {
411 pr_efi_err(sys_table_arg
, "Failed to alloc mem for file handle list\n");
416 for (i
= 0; i
< nr_files
; i
++) {
417 struct file_info
*file
;
418 efi_char16_t filename_16
[256];
421 str
= strstr(str
, option_string
);
425 str
+= strlen(option_string
);
430 /* Skip any leading slashes */
431 while (*str
== '/' || *str
== '\\')
434 while (*str
&& *str
!= ' ' && *str
!= '\n') {
435 if ((u8
*)p
>= (u8
*)filename_16
+ sizeof(filename_16
))
448 /* Only open the volume once. */
450 status
= efi_open_volume(sys_table_arg
, image
,
452 if (status
!= EFI_SUCCESS
)
456 status
= efi_file_size(sys_table_arg
, fh
, filename_16
,
457 (void **)&file
->handle
, &file
->size
);
458 if (status
!= EFI_SUCCESS
)
461 file_size_total
+= file
->size
;
464 if (file_size_total
) {
468 * Multiple files need to be at consecutive addresses in memory,
469 * so allocate enough memory for all the files. This is used
470 * for loading multiple files.
472 status
= efi_high_alloc(sys_table_arg
, file_size_total
, 0x1000,
473 &file_addr
, max_addr
);
474 if (status
!= EFI_SUCCESS
) {
475 pr_efi_err(sys_table_arg
, "Failed to alloc highmem for files\n");
479 /* We've run out of free low memory. */
480 if (file_addr
> max_addr
) {
481 pr_efi_err(sys_table_arg
, "We've run out of free low memory\n");
482 status
= EFI_INVALID_PARAMETER
;
483 goto free_file_total
;
487 for (j
= 0; j
< nr_files
; j
++) {
490 size
= files
[j
].size
;
492 unsigned long chunksize
;
493 if (size
> __chunk_size
)
494 chunksize
= __chunk_size
;
498 status
= efi_file_read(files
[j
].handle
,
501 if (status
!= EFI_SUCCESS
) {
502 pr_efi_err(sys_table_arg
, "Failed to read file\n");
503 goto free_file_total
;
509 efi_file_close(files
[j
].handle
);
514 efi_call_early(free_pool
, files
);
516 *load_addr
= file_addr
;
517 *load_size
= file_size_total
;
522 efi_free(sys_table_arg
, file_size_total
, file_addr
);
525 for (k
= j
; k
< i
; k
++)
526 efi_file_close(files
[k
].handle
);
528 efi_call_early(free_pool
, files
);
536 * Relocate a kernel image, either compressed or uncompressed.
537 * In the ARM64 case, all kernel images are currently
538 * uncompressed, and as such when we relocate it we need to
539 * allocate additional space for the BSS segment. Any low
540 * memory that this function should avoid needs to be
541 * unavailable in the EFI memory map, as if the preferred
542 * address is not available the lowest available address will
545 efi_status_t
efi_relocate_kernel(efi_system_table_t
*sys_table_arg
,
546 unsigned long *image_addr
,
547 unsigned long image_size
,
548 unsigned long alloc_size
,
549 unsigned long preferred_addr
,
550 unsigned long alignment
)
552 unsigned long cur_image_addr
;
553 unsigned long new_addr
= 0;
555 unsigned long nr_pages
;
556 efi_physical_addr_t efi_addr
= preferred_addr
;
558 if (!image_addr
|| !image_size
|| !alloc_size
)
559 return EFI_INVALID_PARAMETER
;
560 if (alloc_size
< image_size
)
561 return EFI_INVALID_PARAMETER
;
563 cur_image_addr
= *image_addr
;
566 * The EFI firmware loader could have placed the kernel image
567 * anywhere in memory, but the kernel has restrictions on the
568 * max physical address it can run at. Some architectures
569 * also have a prefered address, so first try to relocate
570 * to the preferred address. If that fails, allocate as low
571 * as possible while respecting the required alignment.
573 nr_pages
= round_up(alloc_size
, EFI_ALLOC_ALIGN
) / EFI_PAGE_SIZE
;
574 status
= efi_call_early(allocate_pages
,
575 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
576 nr_pages
, &efi_addr
);
579 * If preferred address allocation failed allocate as low as
582 if (status
!= EFI_SUCCESS
) {
583 status
= efi_low_alloc(sys_table_arg
, alloc_size
, alignment
,
586 if (status
!= EFI_SUCCESS
) {
587 pr_efi_err(sys_table_arg
, "Failed to allocate usable memory for kernel.\n");
592 * We know source/dest won't overlap since both memory ranges
593 * have been allocated by UEFI, so we can safely use memcpy.
595 memcpy((void *)new_addr
, (void *)cur_image_addr
, image_size
);
597 /* Return the new address of the relocated image. */
598 *image_addr
= new_addr
;
604 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
605 * This overestimates for surrogates, but that is okay.
607 static int efi_utf8_bytes(u16 c
)
609 return 1 + (c
>= 0x80) + (c
>= 0x800);
613 * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
615 static u8
*efi_utf16_to_utf8(u8
*dst
, const u16
*src
, int n
)
621 if (n
&& c
>= 0xd800 && c
<= 0xdbff &&
622 *src
>= 0xdc00 && *src
<= 0xdfff) {
623 c
= 0x10000 + ((c
& 0x3ff) << 10) + (*src
& 0x3ff);
627 if (c
>= 0xd800 && c
<= 0xdfff)
628 c
= 0xfffd; /* Unmatched surrogate */
634 *dst
++ = 0xc0 + (c
>> 6);
638 *dst
++ = 0xe0 + (c
>> 12);
641 *dst
++ = 0xf0 + (c
>> 18);
642 *dst
++ = 0x80 + ((c
>> 12) & 0x3f);
644 *dst
++ = 0x80 + ((c
>> 6) & 0x3f);
646 *dst
++ = 0x80 + (c
& 0x3f);
653 * Convert the unicode UEFI command line to ASCII to pass to kernel.
654 * Size of memory allocated return in *cmd_line_len.
655 * Returns NULL on error.
657 char *efi_convert_cmdline(efi_system_table_t
*sys_table_arg
,
658 efi_loaded_image_t
*image
,
663 unsigned long cmdline_addr
= 0;
664 int load_options_chars
= image
->load_options_size
/ 2; /* UTF-16 */
665 const u16
*options
= image
->load_options
;
666 int options_bytes
= 0; /* UTF-8 bytes */
667 int options_chars
= 0; /* UTF-16 chars */
673 while (*s2
&& *s2
!= '\n'
674 && options_chars
< load_options_chars
) {
675 options_bytes
+= efi_utf8_bytes(*s2
++);
680 if (!options_chars
) {
681 /* No command line options, so return empty string*/
685 options_bytes
++; /* NUL termination */
687 status
= efi_low_alloc(sys_table_arg
, options_bytes
, 0, &cmdline_addr
);
688 if (status
!= EFI_SUCCESS
)
691 s1
= (u8
*)cmdline_addr
;
692 s2
= (const u16
*)options
;
694 s1
= efi_utf16_to_utf8(s1
, s2
, options_chars
);
697 *cmd_line_len
= options_bytes
;
698 return (char *)cmdline_addr
;