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12#include <linux/efi.h>
13#include <linux/libfdt.h>
14#include <asm/efi.h>
15
16#include "efistub.h"
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38#define EFI_RT_VIRTUAL_BASE SZ_512M
39#define EFI_RT_VIRTUAL_SIZE SZ_512M
40
41#ifdef CONFIG_ARM64
42# define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64
43#else
44# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
45#endif
46
47static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
48static bool flat_va_mapping;
49
50const efi_system_table_t *efi_system_table;
51
52static struct screen_info *setup_graphics(void)
53{
54 efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
55 efi_status_t status;
56 unsigned long size;
57 void **gop_handle = NULL;
58 struct screen_info *si = NULL;
59
60 size = 0;
61 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
62 &gop_proto, NULL, &size, gop_handle);
63 if (status == EFI_BUFFER_TOO_SMALL) {
64 si = alloc_screen_info();
65 if (!si)
66 return NULL;
67 status = efi_setup_gop(si, &gop_proto, size);
68 if (status != EFI_SUCCESS) {
69 free_screen_info(si);
70 return NULL;
71 }
72 }
73 return si;
74}
75
76static void install_memreserve_table(void)
77{
78 struct linux_efi_memreserve *rsv;
79 efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
80 efi_status_t status;
81
82 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
83 (void **)&rsv);
84 if (status != EFI_SUCCESS) {
85 efi_err("Failed to allocate memreserve entry!\n");
86 return;
87 }
88
89 rsv->next = 0;
90 rsv->size = 0;
91 atomic_set(&rsv->count, 0);
92
93 status = efi_bs_call(install_configuration_table,
94 &memreserve_table_guid, rsv);
95 if (status != EFI_SUCCESS)
96 efi_err("Failed to install memreserve config table!\n");
97}
98
99static u32 get_supported_rt_services(void)
100{
101 const efi_rt_properties_table_t *rt_prop_table;
102 u32 supported = EFI_RT_SUPPORTED_ALL;
103
104 rt_prop_table = get_efi_config_table(EFI_RT_PROPERTIES_TABLE_GUID);
105 if (rt_prop_table)
106 supported &= rt_prop_table->runtime_services_supported;
107
108 return supported;
109}
110
111
112
113
114
115
116
117efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
118 efi_system_table_t *sys_table_arg)
119{
120 efi_loaded_image_t *image;
121 efi_status_t status;
122 unsigned long image_addr;
123 unsigned long image_size = 0;
124
125 unsigned long initrd_addr = 0;
126 unsigned long initrd_size = 0;
127 unsigned long fdt_addr = 0;
128 unsigned long fdt_size = 0;
129 char *cmdline_ptr = NULL;
130 int cmdline_size = 0;
131 efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
132 unsigned long reserve_addr = 0;
133 unsigned long reserve_size = 0;
134 enum efi_secureboot_mode secure_boot;
135 struct screen_info *si;
136 efi_properties_table_t *prop_tbl;
137 unsigned long max_addr;
138
139 efi_system_table = sys_table_arg;
140
141
142 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
143 status = EFI_INVALID_PARAMETER;
144 goto fail;
145 }
146
147 status = check_platform_features();
148 if (status != EFI_SUCCESS)
149 goto fail;
150
151
152
153
154
155
156 status = efi_system_table->boottime->handle_protocol(handle,
157 &loaded_image_proto, (void *)&image);
158 if (status != EFI_SUCCESS) {
159 efi_err("Failed to get loaded image protocol\n");
160 goto fail;
161 }
162
163
164
165
166
167
168 cmdline_ptr = efi_convert_cmdline(image, &cmdline_size);
169 if (!cmdline_ptr) {
170 efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
171 status = EFI_OUT_OF_RESOURCES;
172 goto fail;
173 }
174
175 if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
176 IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
177 cmdline_size == 0) {
178 status = efi_parse_options(CONFIG_CMDLINE);
179 if (status != EFI_SUCCESS) {
180 efi_err("Failed to parse options\n");
181 goto fail_free_cmdline;
182 }
183 }
184
185 if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) {
186 status = efi_parse_options(cmdline_ptr);
187 if (status != EFI_SUCCESS) {
188 efi_err("Failed to parse options\n");
189 goto fail_free_cmdline;
190 }
191 }
192
193 efi_info("Booting Linux Kernel...\n");
194
195 si = setup_graphics();
196
197 status = handle_kernel_image(&image_addr, &image_size,
198 &reserve_addr,
199 &reserve_size,
200 image);
201 if (status != EFI_SUCCESS) {
202 efi_err("Failed to relocate kernel\n");
203 goto fail_free_screeninfo;
204 }
205
206 efi_retrieve_tpm2_eventlog();
207
208
209 efi_enable_reset_attack_mitigation();
210
211 secure_boot = efi_get_secureboot();
212
213
214
215
216
217
218 if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
219 secure_boot != efi_secureboot_mode_disabled) {
220 if (strstr(cmdline_ptr, "dtb="))
221 efi_err("Ignoring DTB from command line.\n");
222 } else {
223 status = efi_load_dtb(image, &fdt_addr, &fdt_size);
224
225 if (status != EFI_SUCCESS) {
226 efi_err("Failed to load device tree!\n");
227 goto fail_free_image;
228 }
229 }
230
231 if (fdt_addr) {
232 efi_info("Using DTB from command line\n");
233 } else {
234
235 fdt_addr = (uintptr_t)get_fdt(&fdt_size);
236 if (fdt_addr)
237 efi_info("Using DTB from configuration table\n");
238 }
239
240 if (!fdt_addr)
241 efi_info("Generating empty DTB\n");
242
243 if (!efi_noinitrd) {
244 max_addr = efi_get_max_initrd_addr(image_addr);
245 status = efi_load_initrd(image, &initrd_addr, &initrd_size,
246 ULONG_MAX, max_addr);
247 if (status != EFI_SUCCESS)
248 efi_err("Failed to load initrd!\n");
249 }
250
251 efi_random_get_seed();
252
253
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257
258
259
260 prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID);
261 flat_va_mapping = prop_tbl &&
262 (prop_tbl->memory_protection_attribute &
263 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA);
264
265
266 efi_novamap |= !(get_supported_rt_services() &
267 EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP);
268
269
270 if (!IS_ENABLED(CONFIG_HIBERNATION) && !efi_nokaslr && !flat_va_mapping) {
271
272
273
274
275
276
277 static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
278 EFI_RT_VIRTUAL_BASE -
279 EFI_RT_VIRTUAL_SIZE;
280 u32 rnd;
281
282 status = efi_get_random_bytes(sizeof(rnd), (u8 *)&rnd);
283 if (status == EFI_SUCCESS) {
284 virtmap_base = EFI_RT_VIRTUAL_BASE +
285 (((headroom >> 21) * rnd) >> (32 - 21));
286 }
287 }
288
289 install_memreserve_table();
290
291 status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
292 initrd_addr, initrd_size,
293 cmdline_ptr, fdt_addr, fdt_size);
294 if (status != EFI_SUCCESS)
295 goto fail_free_initrd;
296
297 if (IS_ENABLED(CONFIG_ARM))
298 efi_handle_post_ebs_state();
299
300 efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
301
302
303fail_free_initrd:
304 efi_err("Failed to update FDT and exit boot services\n");
305
306 efi_free(initrd_size, initrd_addr);
307 efi_free(fdt_size, fdt_addr);
308
309fail_free_image:
310 efi_free(image_size, image_addr);
311 efi_free(reserve_size, reserve_addr);
312fail_free_screeninfo:
313 free_screen_info(si);
314fail_free_cmdline:
315 efi_bs_call(free_pool, cmdline_ptr);
316fail:
317 return status;
318}
319
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325
326
327void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
328 unsigned long desc_size, efi_memory_desc_t *runtime_map,
329 int *count)
330{
331 u64 efi_virt_base = virtmap_base;
332 efi_memory_desc_t *in, *out = runtime_map;
333 int l;
334
335 for (l = 0; l < map_size; l += desc_size) {
336 u64 paddr, size;
337
338 in = (void *)memory_map + l;
339 if (!(in->attribute & EFI_MEMORY_RUNTIME))
340 continue;
341
342 paddr = in->phys_addr;
343 size = in->num_pages * EFI_PAGE_SIZE;
344
345 in->virt_addr = in->phys_addr;
346 if (efi_novamap) {
347 continue;
348 }
349
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353
354
355 if (!flat_va_mapping) {
356
357 paddr = round_down(in->phys_addr, SZ_64K);
358 size += in->phys_addr - paddr;
359
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363
364
365
366 if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
367 efi_virt_base = round_up(efi_virt_base, SZ_2M);
368 else
369 efi_virt_base = round_up(efi_virt_base, SZ_64K);
370
371 in->virt_addr += efi_virt_base - paddr;
372 efi_virt_base += size;
373 }
374
375 memcpy(out, in, desc_size);
376 out = (void *)out + desc_size;
377 ++*count;
378 }
379}
380