Commit | Line | Data |
---|---|---|
3c7f2550 MS |
1 | /* |
2 | * EFI stub implementation that is shared by arm and arm64 architectures. | |
3 | * This should be #included by the EFI stub implementation files. | |
4 | * | |
5 | * Copyright (C) 2013,2014 Linaro Limited | |
6 | * Roy Franz <roy.franz@linaro.org | |
7 | * Copyright (C) 2013 Red Hat, Inc. | |
8 | * Mark Salter <msalter@redhat.com> | |
9 | * | |
10 | * This file is part of the Linux kernel, and is made available under the | |
11 | * terms of the GNU General Public License version 2. | |
12 | * | |
13 | */ | |
14 | ||
bd669475 | 15 | #include <linux/efi.h> |
0ce3cc00 | 16 | #include <linux/sort.h> |
bd669475 AB |
17 | #include <asm/efi.h> |
18 | ||
19 | #include "efistub.h" | |
20 | ||
2b5fe07a AB |
21 | bool __nokaslr; |
22 | ||
73a64925 | 23 | static int efi_get_secureboot(efi_system_table_t *sys_table_arg) |
345c736e | 24 | { |
30d7bf03 | 25 | static efi_char16_t const sb_var_name[] = { |
345c736e | 26 | 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 }; |
30d7bf03 LC |
27 | static efi_char16_t const sm_var_name[] = { |
28 | 'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0 }; | |
345c736e | 29 | |
30d7bf03 | 30 | efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID; |
345c736e | 31 | efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable; |
345c736e | 32 | u8 val; |
30d7bf03 LC |
33 | unsigned long size = sizeof(val); |
34 | efi_status_t status; | |
345c736e | 35 | |
30d7bf03 | 36 | status = f_getvar((efi_char16_t *)sb_var_name, (efi_guid_t *)&var_guid, |
345c736e AB |
37 | NULL, &size, &val); |
38 | ||
30d7bf03 LC |
39 | if (status != EFI_SUCCESS) |
40 | goto out_efi_err; | |
41 | ||
42 | if (val == 0) | |
43 | return 0; | |
44 | ||
45 | status = f_getvar((efi_char16_t *)sm_var_name, (efi_guid_t *)&var_guid, | |
46 | NULL, &size, &val); | |
47 | ||
48 | if (status != EFI_SUCCESS) | |
49 | goto out_efi_err; | |
50 | ||
51 | if (val == 1) | |
52 | return 0; | |
53 | ||
54 | return 1; | |
55 | ||
56 | out_efi_err: | |
345c736e | 57 | switch (status) { |
345c736e AB |
58 | case EFI_NOT_FOUND: |
59 | return 0; | |
73a64925 LC |
60 | case EFI_DEVICE_ERROR: |
61 | return -EIO; | |
62 | case EFI_SECURITY_VIOLATION: | |
63 | return -EACCES; | |
345c736e | 64 | default: |
73a64925 | 65 | return -EINVAL; |
345c736e AB |
66 | } |
67 | } | |
68 | ||
bd669475 AB |
69 | efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, |
70 | void *__image, void **__fh) | |
3c7f2550 MS |
71 | { |
72 | efi_file_io_interface_t *io; | |
73 | efi_loaded_image_t *image = __image; | |
74 | efi_file_handle_t *fh; | |
75 | efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID; | |
76 | efi_status_t status; | |
77 | void *handle = (void *)(unsigned long)image->device_handle; | |
78 | ||
79 | status = sys_table_arg->boottime->handle_protocol(handle, | |
80 | &fs_proto, (void **)&io); | |
81 | if (status != EFI_SUCCESS) { | |
82 | efi_printk(sys_table_arg, "Failed to handle fs_proto\n"); | |
83 | return status; | |
84 | } | |
85 | ||
86 | status = io->open_volume(io, &fh); | |
87 | if (status != EFI_SUCCESS) | |
88 | efi_printk(sys_table_arg, "Failed to open volume\n"); | |
89 | ||
90 | *__fh = fh; | |
91 | return status; | |
92 | } | |
bd669475 AB |
93 | |
94 | efi_status_t efi_file_close(void *handle) | |
3c7f2550 MS |
95 | { |
96 | efi_file_handle_t *fh = handle; | |
97 | ||
98 | return fh->close(handle); | |
99 | } | |
100 | ||
bd669475 | 101 | efi_status_t |
3c7f2550 MS |
102 | efi_file_read(void *handle, unsigned long *size, void *addr) |
103 | { | |
104 | efi_file_handle_t *fh = handle; | |
105 | ||
106 | return fh->read(handle, size, addr); | |
107 | } | |
108 | ||
109 | ||
bd669475 | 110 | efi_status_t |
3c7f2550 MS |
111 | efi_file_size(efi_system_table_t *sys_table_arg, void *__fh, |
112 | efi_char16_t *filename_16, void **handle, u64 *file_sz) | |
113 | { | |
114 | efi_file_handle_t *h, *fh = __fh; | |
115 | efi_file_info_t *info; | |
116 | efi_status_t status; | |
117 | efi_guid_t info_guid = EFI_FILE_INFO_ID; | |
118 | unsigned long info_sz; | |
119 | ||
120 | status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0); | |
121 | if (status != EFI_SUCCESS) { | |
122 | efi_printk(sys_table_arg, "Failed to open file: "); | |
123 | efi_char16_printk(sys_table_arg, filename_16); | |
124 | efi_printk(sys_table_arg, "\n"); | |
125 | return status; | |
126 | } | |
127 | ||
128 | *handle = h; | |
129 | ||
130 | info_sz = 0; | |
131 | status = h->get_info(h, &info_guid, &info_sz, NULL); | |
132 | if (status != EFI_BUFFER_TOO_SMALL) { | |
133 | efi_printk(sys_table_arg, "Failed to get file info size\n"); | |
134 | return status; | |
135 | } | |
136 | ||
137 | grow: | |
138 | status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA, | |
139 | info_sz, (void **)&info); | |
140 | if (status != EFI_SUCCESS) { | |
141 | efi_printk(sys_table_arg, "Failed to alloc mem for file info\n"); | |
142 | return status; | |
143 | } | |
144 | ||
145 | status = h->get_info(h, &info_guid, &info_sz, | |
146 | info); | |
147 | if (status == EFI_BUFFER_TOO_SMALL) { | |
148 | sys_table_arg->boottime->free_pool(info); | |
149 | goto grow; | |
150 | } | |
151 | ||
152 | *file_sz = info->file_size; | |
153 | sys_table_arg->boottime->free_pool(info); | |
154 | ||
155 | if (status != EFI_SUCCESS) | |
156 | efi_printk(sys_table_arg, "Failed to get initrd info\n"); | |
157 | ||
158 | return status; | |
159 | } | |
160 | ||
161 | ||
162 | ||
bd669475 | 163 | void efi_char16_printk(efi_system_table_t *sys_table_arg, |
3c7f2550 MS |
164 | efi_char16_t *str) |
165 | { | |
166 | struct efi_simple_text_output_protocol *out; | |
167 | ||
168 | out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out; | |
169 | out->output_string(out, str); | |
170 | } | |
171 | ||
f0827e18 AB |
172 | static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg) |
173 | { | |
174 | efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; | |
175 | efi_status_t status; | |
176 | unsigned long size; | |
177 | void **gop_handle = NULL; | |
178 | struct screen_info *si = NULL; | |
179 | ||
180 | size = 0; | |
181 | status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL, | |
182 | &gop_proto, NULL, &size, gop_handle); | |
183 | if (status == EFI_BUFFER_TOO_SMALL) { | |
184 | si = alloc_screen_info(sys_table_arg); | |
185 | if (!si) | |
186 | return NULL; | |
187 | efi_setup_gop(sys_table_arg, si, &gop_proto, size); | |
188 | } | |
189 | return si; | |
190 | } | |
3c7f2550 MS |
191 | |
192 | /* | |
193 | * This function handles the architcture specific differences between arm and | |
194 | * arm64 regarding where the kernel image must be loaded and any memory that | |
195 | * must be reserved. On failure it is required to free all | |
196 | * all allocations it has made. | |
197 | */ | |
bd669475 AB |
198 | efi_status_t handle_kernel_image(efi_system_table_t *sys_table, |
199 | unsigned long *image_addr, | |
200 | unsigned long *image_size, | |
201 | unsigned long *reserve_addr, | |
202 | unsigned long *reserve_size, | |
203 | unsigned long dram_base, | |
204 | efi_loaded_image_t *image); | |
3c7f2550 MS |
205 | /* |
206 | * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint | |
207 | * that is described in the PE/COFF header. Most of the code is the same | |
208 | * for both archictectures, with the arch-specific code provided in the | |
209 | * handle_kernel_image() function. | |
210 | */ | |
ddeeefe2 | 211 | unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, |
3c7f2550 MS |
212 | unsigned long *image_addr) |
213 | { | |
214 | efi_loaded_image_t *image; | |
215 | efi_status_t status; | |
216 | unsigned long image_size = 0; | |
217 | unsigned long dram_base; | |
218 | /* addr/point and size pairs for memory management*/ | |
219 | unsigned long initrd_addr; | |
220 | u64 initrd_size = 0; | |
345c736e | 221 | unsigned long fdt_addr = 0; /* Original DTB */ |
a643375f | 222 | unsigned long fdt_size = 0; |
3c7f2550 MS |
223 | char *cmdline_ptr = NULL; |
224 | int cmdline_size = 0; | |
225 | unsigned long new_fdt_addr; | |
226 | efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID; | |
227 | unsigned long reserve_addr = 0; | |
228 | unsigned long reserve_size = 0; | |
73a64925 | 229 | int secure_boot = 0; |
f0827e18 | 230 | struct screen_info *si; |
3c7f2550 MS |
231 | |
232 | /* Check if we were booted by the EFI firmware */ | |
233 | if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) | |
234 | goto fail; | |
235 | ||
236 | pr_efi(sys_table, "Booting Linux Kernel...\n"); | |
237 | ||
b9d6769b AB |
238 | status = check_platform_features(sys_table); |
239 | if (status != EFI_SUCCESS) | |
240 | goto fail; | |
241 | ||
3c7f2550 MS |
242 | /* |
243 | * Get a handle to the loaded image protocol. This is used to get | |
244 | * information about the running image, such as size and the command | |
245 | * line. | |
246 | */ | |
247 | status = sys_table->boottime->handle_protocol(handle, | |
248 | &loaded_image_proto, (void *)&image); | |
249 | if (status != EFI_SUCCESS) { | |
250 | pr_efi_err(sys_table, "Failed to get loaded image protocol\n"); | |
251 | goto fail; | |
252 | } | |
253 | ||
254 | dram_base = get_dram_base(sys_table); | |
255 | if (dram_base == EFI_ERROR) { | |
256 | pr_efi_err(sys_table, "Failed to find DRAM base\n"); | |
257 | goto fail; | |
258 | } | |
3c7f2550 MS |
259 | |
260 | /* | |
261 | * Get the command line from EFI, using the LOADED_IMAGE | |
262 | * protocol. We are going to copy the command line into the | |
263 | * device tree, so this can be allocated anywhere. | |
264 | */ | |
265 | cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size); | |
266 | if (!cmdline_ptr) { | |
267 | pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n"); | |
2b5fe07a AB |
268 | goto fail; |
269 | } | |
270 | ||
271 | /* check whether 'nokaslr' was passed on the command line */ | |
272 | if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { | |
273 | static const u8 default_cmdline[] = CONFIG_CMDLINE; | |
274 | const u8 *str, *cmdline = cmdline_ptr; | |
275 | ||
276 | if (IS_ENABLED(CONFIG_CMDLINE_FORCE)) | |
277 | cmdline = default_cmdline; | |
278 | str = strstr(cmdline, "nokaslr"); | |
279 | if (str == cmdline || (str > cmdline && *(str - 1) == ' ')) | |
280 | __nokaslr = true; | |
281 | } | |
282 | ||
f0827e18 AB |
283 | si = setup_graphics(sys_table); |
284 | ||
2b5fe07a AB |
285 | status = handle_kernel_image(sys_table, image_addr, &image_size, |
286 | &reserve_addr, | |
287 | &reserve_size, | |
288 | dram_base, image); | |
289 | if (status != EFI_SUCCESS) { | |
290 | pr_efi_err(sys_table, "Failed to relocate kernel\n"); | |
291 | goto fail_free_cmdline; | |
3c7f2550 MS |
292 | } |
293 | ||
5a17dae4 MF |
294 | status = efi_parse_options(cmdline_ptr); |
295 | if (status != EFI_SUCCESS) | |
296 | pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n"); | |
297 | ||
73a64925 LC |
298 | secure_boot = efi_get_secureboot(sys_table); |
299 | if (secure_boot > 0) | |
300 | pr_efi(sys_table, "UEFI Secure Boot is enabled.\n"); | |
301 | ||
302 | if (secure_boot < 0) { | |
303 | pr_efi_err(sys_table, | |
304 | "could not determine UEFI Secure Boot status.\n"); | |
305 | } | |
306 | ||
345c736e AB |
307 | /* |
308 | * Unauthenticated device tree data is a security hazard, so | |
309 | * ignore 'dtb=' unless UEFI Secure Boot is disabled. | |
310 | */ | |
73a64925 LC |
311 | if (secure_boot != 0 && strstr(cmdline_ptr, "dtb=")) { |
312 | pr_efi(sys_table, "Ignoring DTB from command line.\n"); | |
345c736e | 313 | } else { |
3c7f2550 MS |
314 | status = handle_cmdline_files(sys_table, image, cmdline_ptr, |
315 | "dtb=", | |
a643375f | 316 | ~0UL, &fdt_addr, &fdt_size); |
3c7f2550 MS |
317 | |
318 | if (status != EFI_SUCCESS) { | |
319 | pr_efi_err(sys_table, "Failed to load device tree!\n"); | |
2b5fe07a | 320 | goto fail_free_image; |
3c7f2550 MS |
321 | } |
322 | } | |
0bcaa904 MR |
323 | |
324 | if (fdt_addr) { | |
325 | pr_efi(sys_table, "Using DTB from command line\n"); | |
326 | } else { | |
345c736e | 327 | /* Look for a device tree configuration table entry. */ |
a643375f | 328 | fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size); |
0bcaa904 MR |
329 | if (fdt_addr) |
330 | pr_efi(sys_table, "Using DTB from configuration table\n"); | |
331 | } | |
332 | ||
333 | if (!fdt_addr) | |
334 | pr_efi(sys_table, "Generating empty DTB\n"); | |
3c7f2550 MS |
335 | |
336 | status = handle_cmdline_files(sys_table, image, cmdline_ptr, | |
337 | "initrd=", dram_base + SZ_512M, | |
338 | (unsigned long *)&initrd_addr, | |
339 | (unsigned long *)&initrd_size); | |
340 | if (status != EFI_SUCCESS) | |
341 | pr_efi_err(sys_table, "Failed initrd from command line!\n"); | |
342 | ||
343 | new_fdt_addr = fdt_addr; | |
344 | status = allocate_new_fdt_and_exit_boot(sys_table, handle, | |
345 | &new_fdt_addr, dram_base + MAX_FDT_OFFSET, | |
346 | initrd_addr, initrd_size, cmdline_ptr, | |
347 | fdt_addr, fdt_size); | |
348 | ||
349 | /* | |
350 | * If all went well, we need to return the FDT address to the | |
351 | * calling function so it can be passed to kernel as part of | |
352 | * the kernel boot protocol. | |
353 | */ | |
354 | if (status == EFI_SUCCESS) | |
355 | return new_fdt_addr; | |
356 | ||
357 | pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n"); | |
358 | ||
359 | efi_free(sys_table, initrd_size, initrd_addr); | |
360 | efi_free(sys_table, fdt_size, fdt_addr); | |
361 | ||
3c7f2550 MS |
362 | fail_free_image: |
363 | efi_free(sys_table, image_size, *image_addr); | |
364 | efi_free(sys_table, reserve_size, reserve_addr); | |
2b5fe07a | 365 | fail_free_cmdline: |
f0827e18 | 366 | free_screen_info(sys_table, si); |
2b5fe07a | 367 | efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr); |
3c7f2550 MS |
368 | fail: |
369 | return EFI_ERROR; | |
370 | } | |
f3cdfd23 AB |
371 | |
372 | /* | |
373 | * This is the base address at which to start allocating virtual memory ranges | |
374 | * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use | |
375 | * any allocation we choose, and eliminate the risk of a conflict after kexec. | |
376 | * The value chosen is the largest non-zero power of 2 suitable for this purpose | |
377 | * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can | |
378 | * be mapped efficiently. | |
81a0bc39 RF |
379 | * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split, |
380 | * map everything below 1 GB. | |
f3cdfd23 | 381 | */ |
81a0bc39 | 382 | #define EFI_RT_VIRTUAL_BASE SZ_512M |
f3cdfd23 | 383 | |
0ce3cc00 AB |
384 | static int cmp_mem_desc(const void *l, const void *r) |
385 | { | |
386 | const efi_memory_desc_t *left = l, *right = r; | |
387 | ||
388 | return (left->phys_addr > right->phys_addr) ? 1 : -1; | |
389 | } | |
390 | ||
391 | /* | |
392 | * Returns whether region @left ends exactly where region @right starts, | |
393 | * or false if either argument is NULL. | |
394 | */ | |
395 | static bool regions_are_adjacent(efi_memory_desc_t *left, | |
396 | efi_memory_desc_t *right) | |
397 | { | |
398 | u64 left_end; | |
399 | ||
400 | if (left == NULL || right == NULL) | |
401 | return false; | |
402 | ||
403 | left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE; | |
404 | ||
405 | return left_end == right->phys_addr; | |
406 | } | |
407 | ||
408 | /* | |
409 | * Returns whether region @left and region @right have compatible memory type | |
410 | * mapping attributes, and are both EFI_MEMORY_RUNTIME regions. | |
411 | */ | |
412 | static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left, | |
413 | efi_memory_desc_t *right) | |
414 | { | |
415 | static const u64 mem_type_mask = EFI_MEMORY_WB | EFI_MEMORY_WT | | |
416 | EFI_MEMORY_WC | EFI_MEMORY_UC | | |
417 | EFI_MEMORY_RUNTIME; | |
418 | ||
419 | return ((left->attribute ^ right->attribute) & mem_type_mask) == 0; | |
420 | } | |
421 | ||
f3cdfd23 AB |
422 | /* |
423 | * efi_get_virtmap() - create a virtual mapping for the EFI memory map | |
424 | * | |
425 | * This function populates the virt_addr fields of all memory region descriptors | |
426 | * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors | |
427 | * are also copied to @runtime_map, and their total count is returned in @count. | |
428 | */ | |
429 | void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, | |
430 | unsigned long desc_size, efi_memory_desc_t *runtime_map, | |
431 | int *count) | |
432 | { | |
433 | u64 efi_virt_base = EFI_RT_VIRTUAL_BASE; | |
0ce3cc00 | 434 | efi_memory_desc_t *in, *prev = NULL, *out = runtime_map; |
f3cdfd23 AB |
435 | int l; |
436 | ||
0ce3cc00 AB |
437 | /* |
438 | * To work around potential issues with the Properties Table feature | |
439 | * introduced in UEFI 2.5, which may split PE/COFF executable images | |
440 | * in memory into several RuntimeServicesCode and RuntimeServicesData | |
441 | * regions, we need to preserve the relative offsets between adjacent | |
442 | * EFI_MEMORY_RUNTIME regions with the same memory type attributes. | |
443 | * The easiest way to find adjacent regions is to sort the memory map | |
444 | * before traversing it. | |
445 | */ | |
446 | sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc, NULL); | |
447 | ||
448 | for (l = 0; l < map_size; l += desc_size, prev = in) { | |
f3cdfd23 AB |
449 | u64 paddr, size; |
450 | ||
0ce3cc00 | 451 | in = (void *)memory_map + l; |
f3cdfd23 AB |
452 | if (!(in->attribute & EFI_MEMORY_RUNTIME)) |
453 | continue; | |
454 | ||
0ce3cc00 AB |
455 | paddr = in->phys_addr; |
456 | size = in->num_pages * EFI_PAGE_SIZE; | |
457 | ||
f3cdfd23 AB |
458 | /* |
459 | * Make the mapping compatible with 64k pages: this allows | |
460 | * a 4k page size kernel to kexec a 64k page size kernel and | |
461 | * vice versa. | |
462 | */ | |
0ce3cc00 AB |
463 | if (!regions_are_adjacent(prev, in) || |
464 | !regions_have_compatible_memory_type_attrs(prev, in)) { | |
465 | ||
466 | paddr = round_down(in->phys_addr, SZ_64K); | |
467 | size += in->phys_addr - paddr; | |
468 | ||
469 | /* | |
470 | * Avoid wasting memory on PTEs by choosing a virtual | |
471 | * base that is compatible with section mappings if this | |
472 | * region has the appropriate size and physical | |
473 | * alignment. (Sections are 2 MB on 4k granule kernels) | |
474 | */ | |
475 | if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M) | |
476 | efi_virt_base = round_up(efi_virt_base, SZ_2M); | |
477 | else | |
478 | efi_virt_base = round_up(efi_virt_base, SZ_64K); | |
479 | } | |
f3cdfd23 AB |
480 | |
481 | in->virt_addr = efi_virt_base + in->phys_addr - paddr; | |
482 | efi_virt_base += size; | |
483 | ||
484 | memcpy(out, in, desc_size); | |
485 | out = (void *)out + desc_size; | |
486 | ++*count; | |
487 | } | |
488 | } |