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 efi_file_handle_t
*handle
;
40 void efi_printk(efi_system_table_t
*sys_table_arg
, char *str
)
44 for (s8
= str
; *s8
; s8
++) {
45 efi_char16_t ch
[2] = { 0 };
49 efi_char16_t nl
[2] = { '\r', 0 };
50 efi_char16_printk(sys_table_arg
, nl
);
53 efi_char16_printk(sys_table_arg
, ch
);
57 efi_status_t
efi_get_memory_map(efi_system_table_t
*sys_table_arg
,
58 efi_memory_desc_t
**map
,
59 unsigned long *map_size
,
60 unsigned long *desc_size
,
62 unsigned long *key_ptr
)
64 efi_memory_desc_t
*m
= NULL
;
72 status
= efi_call_early(get_memory_map
, map_size
, NULL
,
73 &key
, desc_size
, &desc_version
);
74 if (status
!= EFI_BUFFER_TOO_SMALL
)
75 return EFI_LOAD_ERROR
;
78 * Add an additional efi_memory_desc_t because we're doing an
79 * allocation which may be in a new descriptor region.
81 *map_size
+= *desc_size
;
82 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
83 *map_size
, (void **)&m
);
84 if (status
!= EFI_SUCCESS
)
87 status
= efi_call_early(get_memory_map
, map_size
, m
,
88 &key
, desc_size
, &desc_version
);
89 if (status
== EFI_BUFFER_TOO_SMALL
) {
90 efi_call_early(free_pool
, m
);
91 return EFI_LOAD_ERROR
;
94 if (status
!= EFI_SUCCESS
)
95 efi_call_early(free_pool
, m
);
97 if (key_ptr
&& status
== EFI_SUCCESS
)
99 if (desc_ver
&& status
== EFI_SUCCESS
)
100 *desc_ver
= desc_version
;
108 unsigned long get_dram_base(efi_system_table_t
*sys_table_arg
)
111 unsigned long map_size
;
112 unsigned long membase
= EFI_ERROR
;
113 struct efi_memory_map map
;
114 efi_memory_desc_t
*md
;
116 status
= efi_get_memory_map(sys_table_arg
, (efi_memory_desc_t
**)&map
.map
,
117 &map_size
, &map
.desc_size
, NULL
, NULL
);
118 if (status
!= EFI_SUCCESS
)
121 map
.map_end
= map
.map
+ map_size
;
123 for_each_efi_memory_desc(&map
, md
)
124 if (md
->attribute
& EFI_MEMORY_WB
)
125 if (membase
> md
->phys_addr
)
126 membase
= md
->phys_addr
;
128 efi_call_early(free_pool
, map
.map
);
134 * Allocate at the highest possible address that is not above 'max'.
136 efi_status_t
efi_high_alloc(efi_system_table_t
*sys_table_arg
,
137 unsigned long size
, unsigned long align
,
138 unsigned long *addr
, unsigned long max
)
140 unsigned long map_size
, desc_size
;
141 efi_memory_desc_t
*map
;
143 unsigned long nr_pages
;
147 status
= efi_get_memory_map(sys_table_arg
, &map
, &map_size
, &desc_size
,
149 if (status
!= EFI_SUCCESS
)
153 * Enforce minimum alignment that EFI requires when requesting
154 * a specific address. We are doing page-based allocations,
155 * so we must be aligned to a page.
157 if (align
< EFI_PAGE_SIZE
)
158 align
= EFI_PAGE_SIZE
;
160 nr_pages
= round_up(size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
162 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
163 efi_memory_desc_t
*desc
;
164 unsigned long m
= (unsigned long)map
;
167 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
168 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
171 if (desc
->num_pages
< nr_pages
)
174 start
= desc
->phys_addr
;
175 end
= start
+ desc
->num_pages
* (1UL << EFI_PAGE_SHIFT
);
177 if ((start
+ size
) > end
|| (start
+ size
) > max
)
180 if (end
- size
> max
)
183 if (round_down(end
- size
, align
) < start
)
186 start
= round_down(end
- size
, align
);
189 * Don't allocate at 0x0. It will confuse code that
190 * checks pointers against NULL.
195 if (start
> max_addr
)
200 status
= EFI_NOT_FOUND
;
202 status
= efi_call_early(allocate_pages
,
203 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
204 nr_pages
, &max_addr
);
205 if (status
!= EFI_SUCCESS
) {
214 efi_call_early(free_pool
, map
);
220 * Allocate at the lowest possible address.
222 efi_status_t
efi_low_alloc(efi_system_table_t
*sys_table_arg
,
223 unsigned long size
, unsigned long align
,
226 unsigned long map_size
, desc_size
;
227 efi_memory_desc_t
*map
;
229 unsigned long nr_pages
;
232 status
= efi_get_memory_map(sys_table_arg
, &map
, &map_size
, &desc_size
,
234 if (status
!= EFI_SUCCESS
)
238 * Enforce minimum alignment that EFI requires when requesting
239 * a specific address. We are doing page-based allocations,
240 * so we must be aligned to a page.
242 if (align
< EFI_PAGE_SIZE
)
243 align
= EFI_PAGE_SIZE
;
245 nr_pages
= round_up(size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
246 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
247 efi_memory_desc_t
*desc
;
248 unsigned long m
= (unsigned long)map
;
251 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
253 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
256 if (desc
->num_pages
< nr_pages
)
259 start
= desc
->phys_addr
;
260 end
= start
+ desc
->num_pages
* (1UL << EFI_PAGE_SHIFT
);
263 * Don't allocate at 0x0. It will confuse code that
264 * checks pointers against NULL. Skip the first 8
265 * bytes so we start at a nice even number.
270 start
= round_up(start
, align
);
271 if ((start
+ size
) > end
)
274 status
= efi_call_early(allocate_pages
,
275 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
277 if (status
== EFI_SUCCESS
) {
283 if (i
== map_size
/ desc_size
)
284 status
= EFI_NOT_FOUND
;
286 efi_call_early(free_pool
, map
);
291 void efi_free(efi_system_table_t
*sys_table_arg
, unsigned long size
,
294 unsigned long nr_pages
;
299 nr_pages
= round_up(size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
300 efi_call_early(free_pages
, addr
, nr_pages
);
304 * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
305 * option, e.g. efi=nochunk.
307 * It should be noted that efi= is parsed in two very different
308 * environments, first in the early boot environment of the EFI boot
309 * stub, and subsequently during the kernel boot.
311 efi_status_t
efi_parse_options(char *cmdline
)
316 * If no EFI parameters were specified on the cmdline we've got
319 str
= strstr(cmdline
, "efi=");
323 /* Skip ahead to first argument */
324 str
+= strlen("efi=");
327 * Remember, because efi= is also used by the kernel we need to
328 * skip over arguments we don't understand.
331 if (!strncmp(str
, "nochunk", 7)) {
332 str
+= strlen("nochunk");
336 /* Group words together, delimited by "," */
337 while (*str
&& *str
!= ',')
348 * Check the cmdline for a LILO-style file= arguments.
350 * We only support loading a file from the same filesystem as
353 efi_status_t
handle_cmdline_files(efi_system_table_t
*sys_table_arg
,
354 efi_loaded_image_t
*image
,
355 char *cmd_line
, char *option_string
,
356 unsigned long max_addr
,
357 unsigned long *load_addr
,
358 unsigned long *load_size
)
360 struct file_info
*files
;
361 unsigned long file_addr
;
363 efi_file_handle_t
*fh
= NULL
;
374 j
= 0; /* See close_handles */
376 if (!load_addr
|| !load_size
)
377 return EFI_INVALID_PARAMETER
;
385 for (nr_files
= 0; *str
; nr_files
++) {
386 str
= strstr(str
, option_string
);
390 str
+= strlen(option_string
);
392 /* Skip any leading slashes */
393 while (*str
== '/' || *str
== '\\')
396 while (*str
&& *str
!= ' ' && *str
!= '\n')
403 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
404 nr_files
* sizeof(*files
), (void **)&files
);
405 if (status
!= EFI_SUCCESS
) {
406 pr_efi_err(sys_table_arg
, "Failed to alloc mem for file handle list\n");
411 for (i
= 0; i
< nr_files
; i
++) {
412 struct file_info
*file
;
413 efi_char16_t filename_16
[256];
416 str
= strstr(str
, option_string
);
420 str
+= strlen(option_string
);
425 /* Skip any leading slashes */
426 while (*str
== '/' || *str
== '\\')
429 while (*str
&& *str
!= ' ' && *str
!= '\n') {
430 if ((u8
*)p
>= (u8
*)filename_16
+ sizeof(filename_16
))
443 /* Only open the volume once. */
445 status
= efi_open_volume(sys_table_arg
, image
,
447 if (status
!= EFI_SUCCESS
)
451 status
= efi_file_size(sys_table_arg
, fh
, filename_16
,
452 (void **)&file
->handle
, &file
->size
);
453 if (status
!= EFI_SUCCESS
)
456 file_size_total
+= file
->size
;
459 if (file_size_total
) {
463 * Multiple files need to be at consecutive addresses in memory,
464 * so allocate enough memory for all the files. This is used
465 * for loading multiple files.
467 status
= efi_high_alloc(sys_table_arg
, file_size_total
, 0x1000,
468 &file_addr
, max_addr
);
469 if (status
!= EFI_SUCCESS
) {
470 pr_efi_err(sys_table_arg
, "Failed to alloc highmem for files\n");
474 /* We've run out of free low memory. */
475 if (file_addr
> max_addr
) {
476 pr_efi_err(sys_table_arg
, "We've run out of free low memory\n");
477 status
= EFI_INVALID_PARAMETER
;
478 goto free_file_total
;
482 for (j
= 0; j
< nr_files
; j
++) {
485 size
= files
[j
].size
;
487 unsigned long chunksize
;
488 if (size
> __chunk_size
)
489 chunksize
= __chunk_size
;
493 status
= efi_file_read(files
[j
].handle
,
496 if (status
!= EFI_SUCCESS
) {
497 pr_efi_err(sys_table_arg
, "Failed to read file\n");
498 goto free_file_total
;
504 efi_file_close(files
[j
].handle
);
509 efi_call_early(free_pool
, files
);
511 *load_addr
= file_addr
;
512 *load_size
= file_size_total
;
517 efi_free(sys_table_arg
, file_size_total
, file_addr
);
520 for (k
= j
; k
< i
; k
++)
521 efi_file_close(files
[k
].handle
);
523 efi_call_early(free_pool
, files
);
531 * Relocate a kernel image, either compressed or uncompressed.
532 * In the ARM64 case, all kernel images are currently
533 * uncompressed, and as such when we relocate it we need to
534 * allocate additional space for the BSS segment. Any low
535 * memory that this function should avoid needs to be
536 * unavailable in the EFI memory map, as if the preferred
537 * address is not available the lowest available address will
540 efi_status_t
efi_relocate_kernel(efi_system_table_t
*sys_table_arg
,
541 unsigned long *image_addr
,
542 unsigned long image_size
,
543 unsigned long alloc_size
,
544 unsigned long preferred_addr
,
545 unsigned long alignment
)
547 unsigned long cur_image_addr
;
548 unsigned long new_addr
= 0;
550 unsigned long nr_pages
;
551 efi_physical_addr_t efi_addr
= preferred_addr
;
553 if (!image_addr
|| !image_size
|| !alloc_size
)
554 return EFI_INVALID_PARAMETER
;
555 if (alloc_size
< image_size
)
556 return EFI_INVALID_PARAMETER
;
558 cur_image_addr
= *image_addr
;
561 * The EFI firmware loader could have placed the kernel image
562 * anywhere in memory, but the kernel has restrictions on the
563 * max physical address it can run at. Some architectures
564 * also have a prefered address, so first try to relocate
565 * to the preferred address. If that fails, allocate as low
566 * as possible while respecting the required alignment.
568 nr_pages
= round_up(alloc_size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
569 status
= efi_call_early(allocate_pages
,
570 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
571 nr_pages
, &efi_addr
);
574 * If preferred address allocation failed allocate as low as
577 if (status
!= EFI_SUCCESS
) {
578 status
= efi_low_alloc(sys_table_arg
, alloc_size
, alignment
,
581 if (status
!= EFI_SUCCESS
) {
582 pr_efi_err(sys_table_arg
, "Failed to allocate usable memory for kernel.\n");
587 * We know source/dest won't overlap since both memory ranges
588 * have been allocated by UEFI, so we can safely use memcpy.
590 memcpy((void *)new_addr
, (void *)cur_image_addr
, image_size
);
592 /* Return the new address of the relocated image. */
593 *image_addr
= new_addr
;
599 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
600 * This overestimates for surrogates, but that is okay.
602 static int efi_utf8_bytes(u16 c
)
604 return 1 + (c
>= 0x80) + (c
>= 0x800);
608 * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
610 static u8
*efi_utf16_to_utf8(u8
*dst
, const u16
*src
, int n
)
616 if (n
&& c
>= 0xd800 && c
<= 0xdbff &&
617 *src
>= 0xdc00 && *src
<= 0xdfff) {
618 c
= 0x10000 + ((c
& 0x3ff) << 10) + (*src
& 0x3ff);
622 if (c
>= 0xd800 && c
<= 0xdfff)
623 c
= 0xfffd; /* Unmatched surrogate */
629 *dst
++ = 0xc0 + (c
>> 6);
633 *dst
++ = 0xe0 + (c
>> 12);
636 *dst
++ = 0xf0 + (c
>> 18);
637 *dst
++ = 0x80 + ((c
>> 12) & 0x3f);
639 *dst
++ = 0x80 + ((c
>> 6) & 0x3f);
641 *dst
++ = 0x80 + (c
& 0x3f);
648 * Convert the unicode UEFI command line to ASCII to pass to kernel.
649 * Size of memory allocated return in *cmd_line_len.
650 * Returns NULL on error.
652 char *efi_convert_cmdline(efi_system_table_t
*sys_table_arg
,
653 efi_loaded_image_t
*image
,
658 unsigned long cmdline_addr
= 0;
659 int load_options_chars
= image
->load_options_size
/ 2; /* UTF-16 */
660 const u16
*options
= image
->load_options
;
661 int options_bytes
= 0; /* UTF-8 bytes */
662 int options_chars
= 0; /* UTF-16 chars */
668 while (*s2
&& *s2
!= '\n'
669 && options_chars
< load_options_chars
) {
670 options_bytes
+= efi_utf8_bytes(*s2
++);
675 if (!options_chars
) {
676 /* No command line options, so return empty string*/
680 options_bytes
++; /* NUL termination */
682 status
= efi_low_alloc(sys_table_arg
, options_bytes
, 0, &cmdline_addr
);
683 if (status
!= EFI_SUCCESS
)
686 s1
= (u8
*)cmdline_addr
;
687 s2
= (const u16
*)options
;
689 s1
= efi_utf16_to_utf8(s1
, s2
, options_chars
);
692 *cmd_line_len
= options_bytes
;
693 return (char *)cmdline_addr
;