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
44 #define EFI_MMAP_NR_SLACK_SLOTS 8
47 efi_file_handle_t *handle;
51 void efi_printk(efi_system_table_t *sys_table_arg, char *str)
55 for (s8 = str; *s8; s8++) {
56 efi_char16_t ch[2] = { 0 };
60 efi_char16_t nl[2] = { '\r', 0 };
61 efi_char16_printk(sys_table_arg, nl);
64 efi_char16_printk(sys_table_arg, ch);
68 static inline bool mmap_has_headroom(unsigned long buff_size,
69 unsigned long map_size,
70 unsigned long desc_size)
72 unsigned long slack = buff_size - map_size;
74 return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;
77 efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
78 struct efi_boot_memmap *map)
80 efi_memory_desc_t *m = NULL;
85 *map->desc_size = sizeof(*m);
86 *map->map_size = *map->desc_size * 32;
87 *map->buff_size = *map->map_size;
89 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
90 *map->map_size, (void **)&m);
91 if (status != EFI_SUCCESS)
96 status = efi_call_early(get_memory_map, map->map_size, m,
97 &key, map->desc_size, &desc_version);
98 if (status == EFI_BUFFER_TOO_SMALL ||
99 !mmap_has_headroom(*map->buff_size, *map->map_size,
101 efi_call_early(free_pool, m);
103 * Make sure there is some entries of headroom so that the
104 * buffer can be reused for a new map after allocations are
105 * no longer permitted. Its unlikely that the map will grow to
106 * exceed this headroom once we are ready to trigger
109 *map->map_size += *map->desc_size * EFI_MMAP_NR_SLACK_SLOTS;
110 *map->buff_size = *map->map_size;
114 if (status != EFI_SUCCESS)
115 efi_call_early(free_pool, m);
117 if (map->key_ptr && status == EFI_SUCCESS)
119 if (map->desc_ver && status == EFI_SUCCESS)
120 *map->desc_ver = desc_version;
128 unsigned long get_dram_base(efi_system_table_t *sys_table_arg)
131 unsigned long map_size, buff_size;
132 unsigned long membase = EFI_ERROR;
133 struct efi_memory_map map;
134 efi_memory_desc_t *md;
135 struct efi_boot_memmap boot_map;
137 boot_map.map = (efi_memory_desc_t **)&map.map;
138 boot_map.map_size = &map_size;
139 boot_map.desc_size = &map.desc_size;
140 boot_map.desc_ver = NULL;
141 boot_map.key_ptr = NULL;
142 boot_map.buff_size = &buff_size;
144 status = efi_get_memory_map(sys_table_arg, &boot_map);
145 if (status != EFI_SUCCESS)
148 map.map_end = map.map + map_size;
150 for_each_efi_memory_desc_in_map(&map, md) {
151 if (md->attribute & EFI_MEMORY_WB) {
152 if (membase > md->phys_addr)
153 membase = md->phys_addr;
157 efi_call_early(free_pool, map.map);
163 * Allocate at the highest possible address that is not above 'max'.
165 efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
166 unsigned long size, unsigned long align,
167 unsigned long *addr, unsigned long max)
169 unsigned long map_size, desc_size, buff_size;
170 efi_memory_desc_t *map;
172 unsigned long nr_pages;
175 struct efi_boot_memmap boot_map;
178 boot_map.map_size = &map_size;
179 boot_map.desc_size = &desc_size;
180 boot_map.desc_ver = NULL;
181 boot_map.key_ptr = NULL;
182 boot_map.buff_size = &buff_size;
184 status = efi_get_memory_map(sys_table_arg, &boot_map);
185 if (status != EFI_SUCCESS)
189 * Enforce minimum alignment that EFI requires when requesting
190 * a specific address. We are doing page-based allocations,
191 * so we must be aligned to a page.
193 if (align < EFI_ALLOC_ALIGN)
194 align = EFI_ALLOC_ALIGN;
196 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
198 for (i = 0; i < map_size / desc_size; i++) {
199 efi_memory_desc_t *desc;
200 unsigned long m = (unsigned long)map;
203 desc = (efi_memory_desc_t *)(m + (i * desc_size));
204 if (desc->type != EFI_CONVENTIONAL_MEMORY)
207 if (desc->num_pages < nr_pages)
210 start = desc->phys_addr;
211 end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
216 if ((start + size) > end)
219 if (round_down(end - size, align) < start)
222 start = round_down(end - size, align);
225 * Don't allocate at 0x0. It will confuse code that
226 * checks pointers against NULL.
231 if (start > max_addr)
236 status = EFI_NOT_FOUND;
238 status = efi_call_early(allocate_pages,
239 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
240 nr_pages, &max_addr);
241 if (status != EFI_SUCCESS) {
250 efi_call_early(free_pool, map);
256 * Allocate at the lowest possible address.
258 efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
259 unsigned long size, unsigned long align,
262 unsigned long map_size, desc_size, buff_size;
263 efi_memory_desc_t *map;
265 unsigned long nr_pages;
267 struct efi_boot_memmap boot_map;
270 boot_map.map_size = &map_size;
271 boot_map.desc_size = &desc_size;
272 boot_map.desc_ver = NULL;
273 boot_map.key_ptr = NULL;
274 boot_map.buff_size = &buff_size;
276 status = efi_get_memory_map(sys_table_arg, &boot_map);
277 if (status != EFI_SUCCESS)
281 * Enforce minimum alignment that EFI requires when requesting
282 * a specific address. We are doing page-based allocations,
283 * so we must be aligned to a page.
285 if (align < EFI_ALLOC_ALIGN)
286 align = EFI_ALLOC_ALIGN;
288 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
289 for (i = 0; i < map_size / desc_size; i++) {
290 efi_memory_desc_t *desc;
291 unsigned long m = (unsigned long)map;
294 desc = (efi_memory_desc_t *)(m + (i * desc_size));
296 if (desc->type != EFI_CONVENTIONAL_MEMORY)
299 if (desc->num_pages < nr_pages)
302 start = desc->phys_addr;
303 end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
306 * Don't allocate at 0x0. It will confuse code that
307 * checks pointers against NULL. Skip the first 8
308 * bytes so we start at a nice even number.
313 start = round_up(start, align);
314 if ((start + size) > end)
317 status = efi_call_early(allocate_pages,
318 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
320 if (status == EFI_SUCCESS) {
326 if (i == map_size / desc_size)
327 status = EFI_NOT_FOUND;
329 efi_call_early(free_pool, map);
334 void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
337 unsigned long nr_pages;
342 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
343 efi_call_early(free_pages, addr, nr_pages);
347 * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
348 * option, e.g. efi=nochunk.
350 * It should be noted that efi= is parsed in two very different
351 * environments, first in the early boot environment of the EFI boot
352 * stub, and subsequently during the kernel boot.
354 efi_status_t efi_parse_options(char *cmdline)
359 * If no EFI parameters were specified on the cmdline we've got
362 str = strstr(cmdline, "efi=");
366 /* Skip ahead to first argument */
367 str += strlen("efi=");
370 * Remember, because efi= is also used by the kernel we need to
371 * skip over arguments we don't understand.
374 if (!strncmp(str, "nochunk", 7)) {
375 str += strlen("nochunk");
379 /* Group words together, delimited by "," */
380 while (*str && *str != ',')
391 * Check the cmdline for a LILO-style file= arguments.
393 * We only support loading a file from the same filesystem as
396 efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
397 efi_loaded_image_t *image,
398 char *cmd_line, char *option_string,
399 unsigned long max_addr,
400 unsigned long *load_addr,
401 unsigned long *load_size)
403 struct file_info *files;
404 unsigned long file_addr;
406 efi_file_handle_t *fh = NULL;
417 j = 0; /* See close_handles */
419 if (!load_addr || !load_size)
420 return EFI_INVALID_PARAMETER;
428 for (nr_files = 0; *str; nr_files++) {
429 str = strstr(str, option_string);
433 str += strlen(option_string);
435 /* Skip any leading slashes */
436 while (*str == '/' || *str == '\\')
439 while (*str && *str != ' ' && *str != '\n')
446 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
447 nr_files * sizeof(*files), (void **)&files);
448 if (status != EFI_SUCCESS) {
449 pr_efi_err(sys_table_arg, "Failed to alloc mem for file handle list\n");
454 for (i = 0; i < nr_files; i++) {
455 struct file_info *file;
456 efi_char16_t filename_16[256];
459 str = strstr(str, option_string);
463 str += strlen(option_string);
468 /* Skip any leading slashes */
469 while (*str == '/' || *str == '\\')
472 while (*str && *str != ' ' && *str != '\n') {
473 if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16))
486 /* Only open the volume once. */
488 status = efi_open_volume(sys_table_arg, image,
490 if (status != EFI_SUCCESS)
494 status = efi_file_size(sys_table_arg, fh, filename_16,
495 (void **)&file->handle, &file->size);
496 if (status != EFI_SUCCESS)
499 file_size_total += file->size;
502 if (file_size_total) {
506 * Multiple files need to be at consecutive addresses in memory,
507 * so allocate enough memory for all the files. This is used
508 * for loading multiple files.
510 status = efi_high_alloc(sys_table_arg, file_size_total, 0x1000,
511 &file_addr, max_addr);
512 if (status != EFI_SUCCESS) {
513 pr_efi_err(sys_table_arg, "Failed to alloc highmem for files\n");
517 /* We've run out of free low memory. */
518 if (file_addr > max_addr) {
519 pr_efi_err(sys_table_arg, "We've run out of free low memory\n");
520 status = EFI_INVALID_PARAMETER;
521 goto free_file_total;
525 for (j = 0; j < nr_files; j++) {
528 size = files[j].size;
530 unsigned long chunksize;
531 if (size > __chunk_size)
532 chunksize = __chunk_size;
536 status = efi_file_read(files[j].handle,
539 if (status != EFI_SUCCESS) {
540 pr_efi_err(sys_table_arg, "Failed to read file\n");
541 goto free_file_total;
547 efi_file_close(files[j].handle);
552 efi_call_early(free_pool, files);
554 *load_addr = file_addr;
555 *load_size = file_size_total;
560 efi_free(sys_table_arg, file_size_total, file_addr);
563 for (k = j; k < i; k++)
564 efi_file_close(files[k].handle);
566 efi_call_early(free_pool, files);
574 * Relocate a kernel image, either compressed or uncompressed.
575 * In the ARM64 case, all kernel images are currently
576 * uncompressed, and as such when we relocate it we need to
577 * allocate additional space for the BSS segment. Any low
578 * memory that this function should avoid needs to be
579 * unavailable in the EFI memory map, as if the preferred
580 * address is not available the lowest available address will
583 efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
584 unsigned long *image_addr,
585 unsigned long image_size,
586 unsigned long alloc_size,
587 unsigned long preferred_addr,
588 unsigned long alignment)
590 unsigned long cur_image_addr;
591 unsigned long new_addr = 0;
593 unsigned long nr_pages;
594 efi_physical_addr_t efi_addr = preferred_addr;
596 if (!image_addr || !image_size || !alloc_size)
597 return EFI_INVALID_PARAMETER;
598 if (alloc_size < image_size)
599 return EFI_INVALID_PARAMETER;
601 cur_image_addr = *image_addr;
604 * The EFI firmware loader could have placed the kernel image
605 * anywhere in memory, but the kernel has restrictions on the
606 * max physical address it can run at. Some architectures
607 * also have a prefered address, so first try to relocate
608 * to the preferred address. If that fails, allocate as low
609 * as possible while respecting the required alignment.
611 nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
612 status = efi_call_early(allocate_pages,
613 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
614 nr_pages, &efi_addr);
617 * If preferred address allocation failed allocate as low as
620 if (status != EFI_SUCCESS) {
621 status = efi_low_alloc(sys_table_arg, alloc_size, alignment,
624 if (status != EFI_SUCCESS) {
625 pr_efi_err(sys_table_arg, "Failed to allocate usable memory for kernel.\n");
630 * We know source/dest won't overlap since both memory ranges
631 * have been allocated by UEFI, so we can safely use memcpy.
633 memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
635 /* Return the new address of the relocated image. */
636 *image_addr = new_addr;
642 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
643 * This overestimates for surrogates, but that is okay.
645 static int efi_utf8_bytes(u16 c)
647 return 1 + (c >= 0x80) + (c >= 0x800);
651 * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
653 static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n)
659 if (n && c >= 0xd800 && c <= 0xdbff &&
660 *src >= 0xdc00 && *src <= 0xdfff) {
661 c = 0x10000 + ((c & 0x3ff) << 10) + (*src & 0x3ff);
665 if (c >= 0xd800 && c <= 0xdfff)
666 c = 0xfffd; /* Unmatched surrogate */
672 *dst++ = 0xc0 + (c >> 6);
676 *dst++ = 0xe0 + (c >> 12);
679 *dst++ = 0xf0 + (c >> 18);
680 *dst++ = 0x80 + ((c >> 12) & 0x3f);
682 *dst++ = 0x80 + ((c >> 6) & 0x3f);
684 *dst++ = 0x80 + (c & 0x3f);
690 #ifndef MAX_CMDLINE_ADDRESS
691 #define MAX_CMDLINE_ADDRESS ULONG_MAX
695 * Convert the unicode UEFI command line to ASCII to pass to kernel.
696 * Size of memory allocated return in *cmd_line_len.
697 * Returns NULL on error.
699 char *efi_convert_cmdline(efi_system_table_t *sys_table_arg,
700 efi_loaded_image_t *image,
705 unsigned long cmdline_addr = 0;
706 int load_options_chars = image->load_options_size / 2; /* UTF-16 */
707 const u16 *options = image->load_options;
708 int options_bytes = 0; /* UTF-8 bytes */
709 int options_chars = 0; /* UTF-16 chars */
715 while (*s2 && *s2 != '\n'
716 && options_chars < load_options_chars) {
717 options_bytes += efi_utf8_bytes(*s2++);
722 if (!options_chars) {
723 /* No command line options, so return empty string*/
727 options_bytes++; /* NUL termination */
729 status = efi_high_alloc(sys_table_arg, options_bytes, 0,
730 &cmdline_addr, MAX_CMDLINE_ADDRESS);
731 if (status != EFI_SUCCESS)
734 s1 = (u8 *)cmdline_addr;
735 s2 = (const u16 *)options;
737 s1 = efi_utf16_to_utf8(s1, s2, options_chars);
740 *cmd_line_len = options_bytes;
741 return (char *)cmdline_addr;
745 * Handle calling ExitBootServices according to the requirements set out by the
746 * spec. Obtains the current memory map, and returns that info after calling
747 * ExitBootServices. The client must specify a function to perform any
748 * processing of the memory map data prior to ExitBootServices. A client
749 * specific structure may be passed to the function via priv. The client
750 * function may be called multiple times.
752 efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table_arg,
754 struct efi_boot_memmap *map,
756 efi_exit_boot_map_processing priv_func)
760 status = efi_get_memory_map(sys_table_arg, map);
762 if (status != EFI_SUCCESS)
765 status = priv_func(sys_table_arg, map, priv);
766 if (status != EFI_SUCCESS)
769 status = efi_call_early(exit_boot_services, handle, *map->key_ptr);
771 if (status == EFI_INVALID_PARAMETER) {
773 * The memory map changed between efi_get_memory_map() and
774 * exit_boot_services(). Per the UEFI Spec v2.6, Section 6.4:
775 * EFI_BOOT_SERVICES.ExitBootServices we need to get the
776 * updated map, and try again. The spec implies one retry
777 * should be sufficent, which is confirmed against the EDK2
778 * implementation. Per the spec, we can only invoke
779 * get_memory_map() and exit_boot_services() - we cannot alloc
780 * so efi_get_memory_map() cannot be used, and we must reuse
781 * the buffer. For all practical purposes, the headroom in the
782 * buffer should account for any changes in the map so the call
783 * to get_memory_map() is expected to succeed here.
785 *map->map_size = *map->buff_size;
786 status = efi_call_early(get_memory_map,
793 /* exit_boot_services() was called, thus cannot free */
794 if (status != EFI_SUCCESS)
797 status = priv_func(sys_table_arg, map, priv);
798 /* exit_boot_services() was called, thus cannot free */
799 if (status != EFI_SUCCESS)
802 status = efi_call_early(exit_boot_services, handle, *map->key_ptr);
805 /* exit_boot_services() was called, thus cannot free */
806 if (status != EFI_SUCCESS)
812 efi_call_early(free_pool, *map->map);