1 #include "dragonstub/elfloader.h" 2 #include "dragonstub/printk.h" 3 #include "efidef.h" 4 #include <dragonstub/dragonstub.h> 5 #include <libfdt.h> 6 #include <libfdt_internal.h> 7 8 struct exit_boot_struct { 9 struct efi_boot_memmap *boot_memmap; 10 efi_memory_desc_t *runtime_map; 11 int runtime_entry_count; 12 void *new_fdt_addr; 13 }; 14 15 #define EFI_DT_ADDR_CELLS_DEFAULT 2 16 #define EFI_DT_SIZE_CELLS_DEFAULT 2 17 18 static void fdt_update_cell_size(void *fdt) 19 { 20 int offset; 21 22 offset = fdt_path_offset(fdt, "/"); 23 /* Set the #address-cells and #size-cells values for an empty tree */ 24 25 fdt_setprop_u32(fdt, offset, "#address-cells", 26 EFI_DT_ADDR_CELLS_DEFAULT); 27 fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT); 28 } 29 30 static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) 31 { 32 int node = fdt_path_offset(fdt, "/chosen"); 33 u64 fdt_val64; 34 u32 fdt_val32; 35 int err; 36 37 if (node < 0) 38 return EFI_LOAD_ERROR; 39 40 fdt_val64 = cpu_to_fdt64((unsigned long)map->map); 41 42 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start", 43 fdt_val64); 44 if (err) 45 return EFI_LOAD_ERROR; 46 47 fdt_val32 = cpu_to_fdt32(map->map_size); 48 49 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", 50 fdt_val32); 51 if (err) 52 return EFI_LOAD_ERROR; 53 54 fdt_val32 = cpu_to_fdt32(map->desc_size); 55 56 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", 57 fdt_val32); 58 if (err) 59 return EFI_LOAD_ERROR; 60 61 fdt_val32 = cpu_to_fdt32(map->desc_ver); 62 63 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", 64 fdt_val32); 65 if (err) 66 return EFI_LOAD_ERROR; 67 68 return EFI_SUCCESS; 69 } 70 71 static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size, 72 void *fdt, int new_fdt_size, char *cmdline_ptr) 73 { 74 int node, num_rsv; 75 int status; 76 u32 fdt_val32; 77 u64 fdt_val64; 78 79 /* Do some checks on provided FDT, if it exists: */ 80 if (orig_fdt) { 81 if (fdt_check_header(orig_fdt)) { 82 efi_err("Device Tree header not valid!\n"); 83 return EFI_LOAD_ERROR; 84 } 85 /* 86 * We don't get the size of the FDT if we get if from a 87 * configuration table: 88 */ 89 if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) { 90 efi_err("Truncated device tree! foo!\n"); 91 return EFI_LOAD_ERROR; 92 } 93 } 94 95 if (orig_fdt) { 96 status = fdt_open_into(orig_fdt, fdt, new_fdt_size); 97 } else { 98 status = fdt_create_empty_tree(fdt, new_fdt_size); 99 if (status == 0) { 100 /* 101 * Any failure from the following function is 102 * non-critical: 103 */ 104 fdt_update_cell_size(fdt); 105 } 106 } 107 108 if (status != 0) 109 goto fdt_set_fail; 110 111 /* 112 * Delete all memory reserve map entries. When booting via UEFI, 113 * kernel will use the UEFI memory map to find reserved regions. 114 */ 115 num_rsv = fdt_num_mem_rsv(fdt); 116 while (num_rsv-- > 0) 117 fdt_del_mem_rsv(fdt, num_rsv); 118 119 node = fdt_subnode_offset(fdt, 0, "chosen"); 120 if (node < 0) { 121 node = fdt_add_subnode(fdt, 0, "chosen"); 122 if (node < 0) { 123 /* 'node' is an error code when negative: */ 124 status = node; 125 goto fdt_set_fail; 126 } 127 } 128 129 if (cmdline_ptr != NULL && strlen(cmdline_ptr) > 0) { 130 status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr, 131 strlen(cmdline_ptr) + 1); 132 if (status) 133 goto fdt_set_fail; 134 } 135 136 /* Add FDT entries for EFI runtime services in chosen node. */ 137 node = fdt_subnode_offset(fdt, 0, "chosen"); 138 fdt_val64 = cpu_to_fdt64((u64)(unsigned long)ST); 139 140 status = fdt_setprop_var(fdt, node, "linux,uefi-system-table", 141 fdt_val64); 142 if (status) 143 goto fdt_set_fail; 144 145 fdt_val64 = UINT64_MAX; /* placeholder */ 146 147 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64); 148 if (status) 149 goto fdt_set_fail; 150 151 fdt_val32 = UINT32_MAX; /* placeholder */ 152 153 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32); 154 if (status) 155 goto fdt_set_fail; 156 157 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size", 158 fdt_val32); 159 if (status) 160 goto fdt_set_fail; 161 162 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver", 163 fdt_val32); 164 if (status) 165 goto fdt_set_fail; 166 167 bool enalbed_ramdomize_base = false; 168 #ifdef CONFIG_RANDOMIZE_BASE 169 enalbed_ramdomize_base = true; 170 #endif 171 if (enalbed_ramdomize_base && !efi_nokaslr) { 172 efi_status_t efi_status; 173 174 efi_status = efi_get_random_bytes(sizeof(fdt_val64), 175 (u8 *)&fdt_val64); 176 if (efi_status == EFI_SUCCESS) { 177 status = fdt_setprop_var(fdt, node, "kaslr-seed", 178 fdt_val64); 179 if (status) 180 goto fdt_set_fail; 181 } 182 } 183 184 /* Shrink the FDT back to its minimum size: */ 185 fdt_pack(fdt); 186 187 return EFI_SUCCESS; 188 189 fdt_set_fail: 190 if (status == -FDT_ERR_NOSPACE) 191 return EFI_BUFFER_TOO_SMALL; 192 193 return EFI_LOAD_ERROR; 194 } 195 196 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) 197 { 198 struct exit_boot_struct *p = priv; 199 200 p->boot_memmap = map; 201 202 /* 203 * Update the memory map with virtual addresses. The function will also 204 * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME 205 * entries so that we can pass it straight to SetVirtualAddressMap() 206 */ 207 efi_get_virtmap(map->map, map->map_size, map->desc_size, p->runtime_map, 208 &p->runtime_entry_count); 209 210 return update_fdt_memmap(p->new_fdt_addr, map); 211 } 212 213 /* 214 * Allocate memory for a new FDT, then add EFI and commandline related fields 215 * to the FDT. This routine increases the FDT allocation size until the 216 * allocated memory is large enough. EFI allocations are in EFI_PAGE_SIZE 217 * granules, which are fixed at 4K bytes, so in most cases the first allocation 218 * should succeed. EFI boot services are exited at the end of this function. 219 * There must be no allocations between the get_memory_map() call and the 220 * exit_boot_services() call, so the exiting of boot services is very tightly 221 * tied to the creation of the FDT with the final memory map in it. 222 */ 223 static efi_status_t allocate_new_fdt_and_exit_boot(void *handle, 224 efi_loaded_image_t *image, 225 unsigned long *new_fdt_addr, 226 char *cmdline_ptr) 227 { 228 unsigned long desc_size; 229 u32 desc_ver; 230 efi_status_t status; 231 struct exit_boot_struct priv = { 0 }; 232 unsigned long fdt_addr = 0; 233 unsigned long fdt_size = 0; 234 if (!efi_novamap) { 235 status = efi_alloc_virtmap(&priv.runtime_map, &desc_size, 236 &desc_ver); 237 if (status != EFI_SUCCESS) { 238 efi_err("Unable to retrieve UEFI memory map.\n"); 239 return status; 240 } 241 } 242 /* 243 * Unauthenticated device tree data is a security hazard, so ignore 244 * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure 245 * boot is enabled if we can't determine its state. 246 */ 247 bool config_efi_armstub_dtb_loader = false; 248 #ifdef CONFIG_EFI_ARMSTUB_DTB_LOADER 249 config_efi_armstub_dtb_loader = true; 250 #endif 251 print_efi_secureboot_mode(efi_get_secureboot()); 252 253 if (!config_efi_armstub_dtb_loader || 254 efi_get_secureboot() != efi_secureboot_mode_disabled) { 255 if (strstr(cmdline_ptr, "dtb=")) 256 efi_err("Ignoring DTB from command line.\n"); 257 } else { 258 efi_todo("Load DTB from command line\n"); 259 // status = efi_load_dtb(image, &fdt_addr, &fdt_size); 260 261 // if (status != EFI_SUCCESS && status != EFI_NOT_READY) { 262 // efi_err("Failed to load device tree!\n"); 263 // goto fail; 264 // } 265 } 266 267 if (fdt_addr) { 268 efi_info("Using DTB from command line\n"); 269 } else { 270 /* Look for a device tree configuration table entry. */ 271 fdt_addr = (uintptr_t)get_fdt(&fdt_size); 272 if (fdt_addr) 273 efi_info("Using DTB from configuration table\n"); 274 } 275 276 if (!fdt_addr) 277 efi_info("Generating empty DTB\n"); 278 279 status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX); 280 if (status != EFI_SUCCESS) { 281 efi_err("Unable to allocate memory for new device tree.\n"); 282 goto fail; 283 } 284 efi_debug("New FDT address: 0x%lx\n", *new_fdt_addr); 285 efi_info("Generating new FDT...\n"); 286 status = update_fdt((void *)fdt_addr, fdt_size, (void *)*new_fdt_addr, 287 MAX_FDT_SIZE, cmdline_ptr); 288 289 if (status != EFI_SUCCESS) { 290 efi_err("Unable to construct new device tree.\n"); 291 goto fail_free_new_fdt; 292 } 293 294 priv.new_fdt_addr = (void *)*new_fdt_addr; 295 296 efi_info("Exiting boot services...\n"); 297 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 298 299 if (status == EFI_SUCCESS) { 300 efi_set_virtual_address_map_t *svam; 301 302 if (efi_novamap) 303 return EFI_SUCCESS; 304 305 /* Install the new virtual address map */ 306 svam = ST->RuntimeServices->SetVirtualAddressMap; 307 status = svam(priv.runtime_entry_count * desc_size, desc_size, 308 desc_ver, priv.runtime_map); 309 310 /* 311 * We are beyond the point of no return here, so if the call to 312 * SetVirtualAddressMap() failed, we need to signal that to the 313 * incoming kernel but proceed normally otherwise. 314 */ 315 if (status != EFI_SUCCESS) { 316 efi_memory_desc_t *p; 317 int l; 318 319 /* 320 * Set the virtual address field of all 321 * EFI_MEMORY_RUNTIME entries to U64_MAX. This will 322 * signal the incoming kernel that no virtual 323 * translation has been installed. 324 */ 325 for (l = 0; l < priv.boot_memmap->map_size; 326 l += priv.boot_memmap->desc_size) { 327 p = (void *)priv.boot_memmap->map + l; 328 329 if (p->Attribute & EFI_MEMORY_RUNTIME) 330 p->VirtualStart = UINT64_MAX; 331 } 332 } 333 return EFI_SUCCESS; 334 } 335 336 efi_err("Exit boot services failed.\n"); 337 338 fail_free_new_fdt: 339 efi_free(MAX_FDT_SIZE, *new_fdt_addr); 340 341 fail: 342 efi_free(fdt_size, fdt_addr); 343 344 efi_bs_call(FreePool, priv.runtime_map); 345 346 return EFI_LOAD_ERROR; 347 } 348 349 efi_status_t efi_boot_kernel(efi_handle_t handle, 350 efi_loaded_image_t *loaded_image, 351 struct payload_info *payload_info, 352 char *cmdline_ptr) 353 { 354 unsigned long fdt_addr; 355 efi_status_t status; 356 357 efi_info("Loading ELF payload...\n"); 358 // 加载ELF 359 status = load_elf(payload_info); 360 361 if (status != EFI_SUCCESS) { 362 efi_err("Failed to load ELF payload, efi error code: %d\n", 363 status); 364 return status; 365 } 366 367 efi_debug("kernel entry point: 0x%lx\n", payload_info->kernel_entry); 368 status = allocate_new_fdt_and_exit_boot(handle, loaded_image, &fdt_addr, 369 cmdline_ptr); 370 if (status != EFI_SUCCESS) { 371 efi_err("Failed to update FDT and exit boot services\n"); 372 return status; 373 } 374 #ifdef CONFIG_ARM 375 efi_handle_post_ebs_state(); 376 #endif 377 378 efi_enter_kernel(payload_info, fdt_addr, 379 fdt_totalsize((void *)fdt_addr)); 380 /* not reached */ 381 } 382 383 void *get_fdt(unsigned long *fdt_size) 384 { 385 void *fdt; 386 387 fdt = get_efi_config_table(DEVICE_TREE_GUID); 388 389 if (!fdt) 390 return NULL; 391 392 if (fdt_check_header(fdt) != 0) { 393 efi_err("Invalid header detected on UEFI supplied FDT, ignoring ...\n"); 394 return NULL; 395 } 396 *fdt_size = fdt_totalsize(fdt); 397 return fdt; 398 } 399