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;
81 status = efi_call_early(get_memory_map, map_size, NULL,
82 &key, desc_size, &desc_version);
83 if (status != EFI_BUFFER_TOO_SMALL)
84 return EFI_LOAD_ERROR;
87 * Add an additional efi_memory_desc_t because we're doing an
88 * allocation which may be in a new descriptor region.
90 *map_size += *desc_size;
91 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
92 *map_size, (void **)&m);
93 if (status != EFI_SUCCESS)
96 status = efi_call_early(get_memory_map, map_size, m,
97 &key, desc_size, &desc_version);
98 if (status == EFI_BUFFER_TOO_SMALL) {
99 efi_call_early(free_pool, m);
100 return EFI_LOAD_ERROR;
103 if (status != EFI_SUCCESS)
104 efi_call_early(free_pool, m);
106 if (key_ptr && status == EFI_SUCCESS)
108 if (desc_ver && status == EFI_SUCCESS)
109 *desc_ver = desc_version;
117 unsigned long get_dram_base(efi_system_table_t *sys_table_arg)
120 unsigned long map_size;
121 unsigned long membase = EFI_ERROR;
122 struct efi_memory_map map;
123 efi_memory_desc_t *md;
125 status = efi_get_memory_map(sys_table_arg, (efi_memory_desc_t **)&map.map,
126 &map_size, &map.desc_size, NULL, NULL);
127 if (status != EFI_SUCCESS)
130 map.map_end = map.map + map_size;
132 for_each_efi_memory_desc(&map, md)
133 if (md->attribute & EFI_MEMORY_WB)
134 if (membase > md->phys_addr)
135 membase = md->phys_addr;
137 efi_call_early(free_pool, map.map);
143 * Allocate at the highest possible address that is not above 'max'.
145 efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
146 unsigned long size, unsigned long align,
147 unsigned long *addr, unsigned long max)
149 unsigned long map_size, desc_size;
150 efi_memory_desc_t *map;
152 unsigned long nr_pages;
156 status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
158 if (status != EFI_SUCCESS)
162 * Enforce minimum alignment that EFI requires when requesting
163 * a specific address. We are doing page-based allocations,
164 * so we must be aligned to a page.
166 if (align < EFI_ALLOC_ALIGN)
167 align = EFI_ALLOC_ALIGN;
169 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
171 for (i = 0; i < map_size / desc_size; i++) {
172 efi_memory_desc_t *desc;
173 unsigned long m = (unsigned long)map;
176 desc = (efi_memory_desc_t *)(m + (i * desc_size));
177 if (desc->type != EFI_CONVENTIONAL_MEMORY)
180 if (desc->num_pages < nr_pages)
183 start = desc->phys_addr;
184 end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
186 if ((start + size) > end || (start + size) > max)
189 if (end - size > max)
192 if (round_down(end - size, align) < start)
195 start = round_down(end - size, align);
198 * Don't allocate at 0x0. It will confuse code that
199 * checks pointers against NULL.
204 if (start > max_addr)
209 status = EFI_NOT_FOUND;
211 status = efi_call_early(allocate_pages,
212 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
213 nr_pages, &max_addr);
214 if (status != EFI_SUCCESS) {
223 efi_call_early(free_pool, map);
229 * Allocate at the lowest possible address.
231 efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
232 unsigned long size, unsigned long align,
235 unsigned long map_size, desc_size;
236 efi_memory_desc_t *map;
238 unsigned long nr_pages;
241 status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
243 if (status != EFI_SUCCESS)
247 * Enforce minimum alignment that EFI requires when requesting
248 * a specific address. We are doing page-based allocations,
249 * so we must be aligned to a page.
251 if (align < EFI_ALLOC_ALIGN)
252 align = EFI_ALLOC_ALIGN;
254 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
255 for (i = 0; i < map_size / desc_size; i++) {
256 efi_memory_desc_t *desc;
257 unsigned long m = (unsigned long)map;
260 desc = (efi_memory_desc_t *)(m + (i * desc_size));
262 if (desc->type != EFI_CONVENTIONAL_MEMORY)
265 if (desc->num_pages < nr_pages)
268 start = desc->phys_addr;
269 end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
272 * Don't allocate at 0x0. It will confuse code that
273 * checks pointers against NULL. Skip the first 8
274 * bytes so we start at a nice even number.
279 start = round_up(start, align);
280 if ((start + size) > end)
283 status = efi_call_early(allocate_pages,
284 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
286 if (status == EFI_SUCCESS) {
292 if (i == map_size / desc_size)
293 status = EFI_NOT_FOUND;
295 efi_call_early(free_pool, map);
300 void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
303 unsigned long nr_pages;
308 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
309 efi_call_early(free_pages, addr, nr_pages);
313 * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
314 * option, e.g. efi=nochunk.
316 * It should be noted that efi= is parsed in two very different
317 * environments, first in the early boot environment of the EFI boot
318 * stub, and subsequently during the kernel boot.
320 efi_status_t efi_parse_options(char *cmdline)
325 * If no EFI parameters were specified on the cmdline we've got
328 str = strstr(cmdline, "efi=");
332 /* Skip ahead to first argument */
333 str += strlen("efi=");
336 * Remember, because efi= is also used by the kernel we need to
337 * skip over arguments we don't understand.
340 if (!strncmp(str, "nochunk", 7)) {
341 str += strlen("nochunk");
345 /* Group words together, delimited by "," */
346 while (*str && *str != ',')
357 * Check the cmdline for a LILO-style file= arguments.
359 * We only support loading a file from the same filesystem as
362 efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
363 efi_loaded_image_t *image,
364 char *cmd_line, char *option_string,
365 unsigned long max_addr,
366 unsigned long *load_addr,
367 unsigned long *load_size)
369 struct file_info *files;
370 unsigned long file_addr;
372 efi_file_handle_t *fh = NULL;
383 j = 0; /* See close_handles */
385 if (!load_addr || !load_size)
386 return EFI_INVALID_PARAMETER;
394 for (nr_files = 0; *str; nr_files++) {
395 str = strstr(str, option_string);
399 str += strlen(option_string);
401 /* Skip any leading slashes */
402 while (*str == '/' || *str == '\\')
405 while (*str && *str != ' ' && *str != '\n')
412 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
413 nr_files * sizeof(*files), (void **)&files);
414 if (status != EFI_SUCCESS) {
415 pr_efi_err(sys_table_arg, "Failed to alloc mem for file handle list\n");
420 for (i = 0; i < nr_files; i++) {
421 struct file_info *file;
422 efi_char16_t filename_16[256];
425 str = strstr(str, option_string);
429 str += strlen(option_string);
434 /* Skip any leading slashes */
435 while (*str == '/' || *str == '\\')
438 while (*str && *str != ' ' && *str != '\n') {
439 if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16))
452 /* Only open the volume once. */
454 status = efi_open_volume(sys_table_arg, image,
456 if (status != EFI_SUCCESS)
460 status = efi_file_size(sys_table_arg, fh, filename_16,
461 (void **)&file->handle, &file->size);
462 if (status != EFI_SUCCESS)
465 file_size_total += file->size;
468 if (file_size_total) {
472 * Multiple files need to be at consecutive addresses in memory,
473 * so allocate enough memory for all the files. This is used
474 * for loading multiple files.
476 status = efi_high_alloc(sys_table_arg, file_size_total, 0x1000,
477 &file_addr, max_addr);
478 if (status != EFI_SUCCESS) {
479 pr_efi_err(sys_table_arg, "Failed to alloc highmem for files\n");
483 /* We've run out of free low memory. */
484 if (file_addr > max_addr) {
485 pr_efi_err(sys_table_arg, "We've run out of free low memory\n");
486 status = EFI_INVALID_PARAMETER;
487 goto free_file_total;
491 for (j = 0; j < nr_files; j++) {
494 size = files[j].size;
496 unsigned long chunksize;
497 if (size > __chunk_size)
498 chunksize = __chunk_size;
502 status = efi_file_read(files[j].handle,
505 if (status != EFI_SUCCESS) {
506 pr_efi_err(sys_table_arg, "Failed to read file\n");
507 goto free_file_total;
513 efi_file_close(files[j].handle);
518 efi_call_early(free_pool, files);
520 *load_addr = file_addr;
521 *load_size = file_size_total;
526 efi_free(sys_table_arg, file_size_total, file_addr);
529 for (k = j; k < i; k++)
530 efi_file_close(files[k].handle);
532 efi_call_early(free_pool, files);
540 * Relocate a kernel image, either compressed or uncompressed.
541 * In the ARM64 case, all kernel images are currently
542 * uncompressed, and as such when we relocate it we need to
543 * allocate additional space for the BSS segment. Any low
544 * memory that this function should avoid needs to be
545 * unavailable in the EFI memory map, as if the preferred
546 * address is not available the lowest available address will
549 efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
550 unsigned long *image_addr,
551 unsigned long image_size,
552 unsigned long alloc_size,
553 unsigned long preferred_addr,
554 unsigned long alignment)
556 unsigned long cur_image_addr;
557 unsigned long new_addr = 0;
559 unsigned long nr_pages;
560 efi_physical_addr_t efi_addr = preferred_addr;
562 if (!image_addr || !image_size || !alloc_size)
563 return EFI_INVALID_PARAMETER;
564 if (alloc_size < image_size)
565 return EFI_INVALID_PARAMETER;
567 cur_image_addr = *image_addr;
570 * The EFI firmware loader could have placed the kernel image
571 * anywhere in memory, but the kernel has restrictions on the
572 * max physical address it can run at. Some architectures
573 * also have a prefered address, so first try to relocate
574 * to the preferred address. If that fails, allocate as low
575 * as possible while respecting the required alignment.
577 nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
578 status = efi_call_early(allocate_pages,
579 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
580 nr_pages, &efi_addr);
583 * If preferred address allocation failed allocate as low as
586 if (status != EFI_SUCCESS) {
587 status = efi_low_alloc(sys_table_arg, alloc_size, alignment,
590 if (status != EFI_SUCCESS) {
591 pr_efi_err(sys_table_arg, "Failed to allocate usable memory for kernel.\n");
596 * We know source/dest won't overlap since both memory ranges
597 * have been allocated by UEFI, so we can safely use memcpy.
599 memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
601 /* Return the new address of the relocated image. */
602 *image_addr = new_addr;
608 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
609 * This overestimates for surrogates, but that is okay.
611 static int efi_utf8_bytes(u16 c)
613 return 1 + (c >= 0x80) + (c >= 0x800);
617 * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
619 static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n)
625 if (n && c >= 0xd800 && c <= 0xdbff &&
626 *src >= 0xdc00 && *src <= 0xdfff) {
627 c = 0x10000 + ((c & 0x3ff) << 10) + (*src & 0x3ff);
631 if (c >= 0xd800 && c <= 0xdfff)
632 c = 0xfffd; /* Unmatched surrogate */
638 *dst++ = 0xc0 + (c >> 6);
642 *dst++ = 0xe0 + (c >> 12);
645 *dst++ = 0xf0 + (c >> 18);
646 *dst++ = 0x80 + ((c >> 12) & 0x3f);
648 *dst++ = 0x80 + ((c >> 6) & 0x3f);
650 *dst++ = 0x80 + (c & 0x3f);
657 * Convert the unicode UEFI command line to ASCII to pass to kernel.
658 * Size of memory allocated return in *cmd_line_len.
659 * Returns NULL on error.
661 char *efi_convert_cmdline(efi_system_table_t *sys_table_arg,
662 efi_loaded_image_t *image,
667 unsigned long cmdline_addr = 0;
668 int load_options_chars = image->load_options_size / 2; /* UTF-16 */
669 const u16 *options = image->load_options;
670 int options_bytes = 0; /* UTF-8 bytes */
671 int options_chars = 0; /* UTF-16 chars */
677 while (*s2 && *s2 != '\n'
678 && options_chars < load_options_chars) {
679 options_bytes += efi_utf8_bytes(*s2++);
684 if (!options_chars) {
685 /* No command line options, so return empty string*/
689 options_bytes++; /* NUL termination */
691 status = efi_low_alloc(sys_table_arg, options_bytes, 0, &cmdline_addr);
692 if (status != EFI_SUCCESS)
695 s1 = (u8 *)cmdline_addr;
696 s2 = (const u16 *)options;
698 s1 = efi_utf16_to_utf8(s1, s2, options_chars);
701 *cmd_line_len = options_bytes;
702 return (char *)cmdline_addr;