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;