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
;
69 *map_size
= sizeof(*m
) * 32;
72 * Add an additional efi_memory_desc_t because we're doing an
73 * allocation which may be in a new descriptor region.
75 *map_size
+= sizeof(*m
);
76 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
77 *map_size
, (void **)&m
);
78 if (status
!= EFI_SUCCESS
)
83 status
= efi_call_early(get_memory_map
, map_size
, m
,
84 &key
, desc_size
, &desc_version
);
85 if (status
== EFI_BUFFER_TOO_SMALL
) {
86 efi_call_early(free_pool
, m
);
90 if (status
!= EFI_SUCCESS
)
91 efi_call_early(free_pool
, m
);
93 if (key_ptr
&& status
== EFI_SUCCESS
)
95 if (desc_ver
&& status
== EFI_SUCCESS
)
96 *desc_ver
= desc_version
;
104 unsigned long __init
get_dram_base(efi_system_table_t
*sys_table_arg
)
107 unsigned long map_size
;
108 unsigned long membase
= EFI_ERROR
;
109 struct efi_memory_map map
;
110 efi_memory_desc_t
*md
;
112 status
= efi_get_memory_map(sys_table_arg
, (efi_memory_desc_t
**)&map
.map
,
113 &map_size
, &map
.desc_size
, NULL
, NULL
);
114 if (status
!= EFI_SUCCESS
)
117 map
.map_end
= map
.map
+ map_size
;
119 for_each_efi_memory_desc(&map
, md
)
120 if (md
->attribute
& EFI_MEMORY_WB
)
121 if (membase
> md
->phys_addr
)
122 membase
= md
->phys_addr
;
124 efi_call_early(free_pool
, map
.map
);
130 * Allocate at the highest possible address that is not above 'max'.
132 efi_status_t
efi_high_alloc(efi_system_table_t
*sys_table_arg
,
133 unsigned long size
, unsigned long align
,
134 unsigned long *addr
, unsigned long max
)
136 unsigned long map_size
, desc_size
;
137 efi_memory_desc_t
*map
;
139 unsigned long nr_pages
;
143 status
= efi_get_memory_map(sys_table_arg
, &map
, &map_size
, &desc_size
,
145 if (status
!= EFI_SUCCESS
)
149 * Enforce minimum alignment that EFI requires when requesting
150 * a specific address. We are doing page-based allocations,
151 * so we must be aligned to a page.
153 if (align
< EFI_PAGE_SIZE
)
154 align
= EFI_PAGE_SIZE
;
156 nr_pages
= round_up(size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
158 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
159 efi_memory_desc_t
*desc
;
160 unsigned long m
= (unsigned long)map
;
163 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
164 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
167 if (desc
->num_pages
< nr_pages
)
170 start
= desc
->phys_addr
;
171 end
= start
+ desc
->num_pages
* (1UL << EFI_PAGE_SHIFT
);
173 if ((start
+ size
) > end
|| (start
+ size
) > max
)
176 if (end
- size
> max
)
179 if (round_down(end
- size
, align
) < start
)
182 start
= round_down(end
- size
, align
);
185 * Don't allocate at 0x0. It will confuse code that
186 * checks pointers against NULL.
191 if (start
> max_addr
)
196 status
= EFI_NOT_FOUND
;
198 status
= efi_call_early(allocate_pages
,
199 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
200 nr_pages
, &max_addr
);
201 if (status
!= EFI_SUCCESS
) {
210 efi_call_early(free_pool
, map
);
216 * Allocate at the lowest possible address.
218 efi_status_t
efi_low_alloc(efi_system_table_t
*sys_table_arg
,
219 unsigned long size
, unsigned long align
,
222 unsigned long map_size
, desc_size
;
223 efi_memory_desc_t
*map
;
225 unsigned long nr_pages
;
228 status
= efi_get_memory_map(sys_table_arg
, &map
, &map_size
, &desc_size
,
230 if (status
!= EFI_SUCCESS
)
234 * Enforce minimum alignment that EFI requires when requesting
235 * a specific address. We are doing page-based allocations,
236 * so we must be aligned to a page.
238 if (align
< EFI_PAGE_SIZE
)
239 align
= EFI_PAGE_SIZE
;
241 nr_pages
= round_up(size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
242 for (i
= 0; i
< map_size
/ desc_size
; i
++) {
243 efi_memory_desc_t
*desc
;
244 unsigned long m
= (unsigned long)map
;
247 desc
= (efi_memory_desc_t
*)(m
+ (i
* desc_size
));
249 if (desc
->type
!= EFI_CONVENTIONAL_MEMORY
)
252 if (desc
->num_pages
< nr_pages
)
255 start
= desc
->phys_addr
;
256 end
= start
+ desc
->num_pages
* (1UL << EFI_PAGE_SHIFT
);
259 * Don't allocate at 0x0. It will confuse code that
260 * checks pointers against NULL. Skip the first 8
261 * bytes so we start at a nice even number.
266 start
= round_up(start
, align
);
267 if ((start
+ size
) > end
)
270 status
= efi_call_early(allocate_pages
,
271 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
273 if (status
== EFI_SUCCESS
) {
279 if (i
== map_size
/ desc_size
)
280 status
= EFI_NOT_FOUND
;
282 efi_call_early(free_pool
, map
);
287 void efi_free(efi_system_table_t
*sys_table_arg
, unsigned long size
,
290 unsigned long nr_pages
;
295 nr_pages
= round_up(size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
296 efi_call_early(free_pages
, addr
, nr_pages
);
300 * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
301 * option, e.g. efi=nochunk.
303 * It should be noted that efi= is parsed in two very different
304 * environments, first in the early boot environment of the EFI boot
305 * stub, and subsequently during the kernel boot.
307 efi_status_t
efi_parse_options(char *cmdline
)
312 * If no EFI parameters were specified on the cmdline we've got
315 str
= strstr(cmdline
, "efi=");
319 /* Skip ahead to first argument */
320 str
+= strlen("efi=");
323 * Remember, because efi= is also used by the kernel we need to
324 * skip over arguments we don't understand.
327 if (!strncmp(str
, "nochunk", 7)) {
328 str
+= strlen("nochunk");
332 /* Group words together, delimited by "," */
333 while (*str
&& *str
!= ',')
344 * Check the cmdline for a LILO-style file= arguments.
346 * We only support loading a file from the same filesystem as
349 efi_status_t
handle_cmdline_files(efi_system_table_t
*sys_table_arg
,
350 efi_loaded_image_t
*image
,
351 char *cmd_line
, char *option_string
,
352 unsigned long max_addr
,
353 unsigned long *load_addr
,
354 unsigned long *load_size
)
356 struct file_info
*files
;
357 unsigned long file_addr
;
359 efi_file_handle_t
*fh
= NULL
;
370 j
= 0; /* See close_handles */
372 if (!load_addr
|| !load_size
)
373 return EFI_INVALID_PARAMETER
;
381 for (nr_files
= 0; *str
; nr_files
++) {
382 str
= strstr(str
, option_string
);
386 str
+= strlen(option_string
);
388 /* Skip any leading slashes */
389 while (*str
== '/' || *str
== '\\')
392 while (*str
&& *str
!= ' ' && *str
!= '\n')
399 status
= efi_call_early(allocate_pool
, EFI_LOADER_DATA
,
400 nr_files
* sizeof(*files
), (void **)&files
);
401 if (status
!= EFI_SUCCESS
) {
402 pr_efi_err(sys_table_arg
, "Failed to alloc mem for file handle list\n");
407 for (i
= 0; i
< nr_files
; i
++) {
408 struct file_info
*file
;
409 efi_char16_t filename_16
[256];
412 str
= strstr(str
, option_string
);
416 str
+= strlen(option_string
);
421 /* Skip any leading slashes */
422 while (*str
== '/' || *str
== '\\')
425 while (*str
&& *str
!= ' ' && *str
!= '\n') {
426 if ((u8
*)p
>= (u8
*)filename_16
+ sizeof(filename_16
))
439 /* Only open the volume once. */
441 status
= efi_open_volume(sys_table_arg
, image
,
443 if (status
!= EFI_SUCCESS
)
447 status
= efi_file_size(sys_table_arg
, fh
, filename_16
,
448 (void **)&file
->handle
, &file
->size
);
449 if (status
!= EFI_SUCCESS
)
452 file_size_total
+= file
->size
;
455 if (file_size_total
) {
459 * Multiple files need to be at consecutive addresses in memory,
460 * so allocate enough memory for all the files. This is used
461 * for loading multiple files.
463 status
= efi_high_alloc(sys_table_arg
, file_size_total
, 0x1000,
464 &file_addr
, max_addr
);
465 if (status
!= EFI_SUCCESS
) {
466 pr_efi_err(sys_table_arg
, "Failed to alloc highmem for files\n");
470 /* We've run out of free low memory. */
471 if (file_addr
> max_addr
) {
472 pr_efi_err(sys_table_arg
, "We've run out of free low memory\n");
473 status
= EFI_INVALID_PARAMETER
;
474 goto free_file_total
;
478 for (j
= 0; j
< nr_files
; j
++) {
481 size
= files
[j
].size
;
483 unsigned long chunksize
;
484 if (size
> __chunk_size
)
485 chunksize
= __chunk_size
;
489 status
= efi_file_read(files
[j
].handle
,
492 if (status
!= EFI_SUCCESS
) {
493 pr_efi_err(sys_table_arg
, "Failed to read file\n");
494 goto free_file_total
;
500 efi_file_close(files
[j
].handle
);
505 efi_call_early(free_pool
, files
);
507 *load_addr
= file_addr
;
508 *load_size
= file_size_total
;
513 efi_free(sys_table_arg
, file_size_total
, file_addr
);
516 for (k
= j
; k
< i
; k
++)
517 efi_file_close(files
[k
].handle
);
519 efi_call_early(free_pool
, files
);
527 * Relocate a kernel image, either compressed or uncompressed.
528 * In the ARM64 case, all kernel images are currently
529 * uncompressed, and as such when we relocate it we need to
530 * allocate additional space for the BSS segment. Any low
531 * memory that this function should avoid needs to be
532 * unavailable in the EFI memory map, as if the preferred
533 * address is not available the lowest available address will
536 efi_status_t
efi_relocate_kernel(efi_system_table_t
*sys_table_arg
,
537 unsigned long *image_addr
,
538 unsigned long image_size
,
539 unsigned long alloc_size
,
540 unsigned long preferred_addr
,
541 unsigned long alignment
)
543 unsigned long cur_image_addr
;
544 unsigned long new_addr
= 0;
546 unsigned long nr_pages
;
547 efi_physical_addr_t efi_addr
= preferred_addr
;
549 if (!image_addr
|| !image_size
|| !alloc_size
)
550 return EFI_INVALID_PARAMETER
;
551 if (alloc_size
< image_size
)
552 return EFI_INVALID_PARAMETER
;
554 cur_image_addr
= *image_addr
;
557 * The EFI firmware loader could have placed the kernel image
558 * anywhere in memory, but the kernel has restrictions on the
559 * max physical address it can run at. Some architectures
560 * also have a prefered address, so first try to relocate
561 * to the preferred address. If that fails, allocate as low
562 * as possible while respecting the required alignment.
564 nr_pages
= round_up(alloc_size
, EFI_PAGE_SIZE
) / EFI_PAGE_SIZE
;
565 status
= efi_call_early(allocate_pages
,
566 EFI_ALLOCATE_ADDRESS
, EFI_LOADER_DATA
,
567 nr_pages
, &efi_addr
);
570 * If preferred address allocation failed allocate as low as
573 if (status
!= EFI_SUCCESS
) {
574 status
= efi_low_alloc(sys_table_arg
, alloc_size
, alignment
,
577 if (status
!= EFI_SUCCESS
) {
578 pr_efi_err(sys_table_arg
, "Failed to allocate usable memory for kernel.\n");
583 * We know source/dest won't overlap since both memory ranges
584 * have been allocated by UEFI, so we can safely use memcpy.
586 memcpy((void *)new_addr
, (void *)cur_image_addr
, image_size
);
588 /* Return the new address of the relocated image. */
589 *image_addr
= new_addr
;
595 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
596 * This overestimates for surrogates, but that is okay.
598 static int efi_utf8_bytes(u16 c
)
600 return 1 + (c
>= 0x80) + (c
>= 0x800);
604 * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
606 static u8
*efi_utf16_to_utf8(u8
*dst
, const u16
*src
, int n
)
612 if (n
&& c
>= 0xd800 && c
<= 0xdbff &&
613 *src
>= 0xdc00 && *src
<= 0xdfff) {
614 c
= 0x10000 + ((c
& 0x3ff) << 10) + (*src
& 0x3ff);
618 if (c
>= 0xd800 && c
<= 0xdfff)
619 c
= 0xfffd; /* Unmatched surrogate */
625 *dst
++ = 0xc0 + (c
>> 6);
629 *dst
++ = 0xe0 + (c
>> 12);
632 *dst
++ = 0xf0 + (c
>> 18);
633 *dst
++ = 0x80 + ((c
>> 12) & 0x3f);
635 *dst
++ = 0x80 + ((c
>> 6) & 0x3f);
637 *dst
++ = 0x80 + (c
& 0x3f);
644 * Convert the unicode UEFI command line to ASCII to pass to kernel.
645 * Size of memory allocated return in *cmd_line_len.
646 * Returns NULL on error.
648 char *efi_convert_cmdline(efi_system_table_t
*sys_table_arg
,
649 efi_loaded_image_t
*image
,
654 unsigned long cmdline_addr
= 0;
655 int load_options_chars
= image
->load_options_size
/ 2; /* UTF-16 */
656 const u16
*options
= image
->load_options
;
657 int options_bytes
= 0; /* UTF-8 bytes */
658 int options_chars
= 0; /* UTF-16 chars */
664 while (*s2
&& *s2
!= '\n'
665 && options_chars
< load_options_chars
) {
666 options_bytes
+= efi_utf8_bytes(*s2
++);
671 if (!options_chars
) {
672 /* No command line options, so return empty string*/
676 options_bytes
++; /* NUL termination */
678 status
= efi_low_alloc(sys_table_arg
, options_bytes
, 0, &cmdline_addr
);
679 if (status
!= EFI_SUCCESS
)
682 s1
= (u8
*)cmdline_addr
;
683 s2
= (const u16
*)options
;
685 s1
= efi_utf16_to_utf8(s1
, s2
, options_chars
);
688 *cmd_line_len
= options_bytes
;
689 return (char *)cmdline_addr
;