1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  EFI image loader
4  *
5  *  based partly on wine code
6  *
7  *  Copyright (c) 2016 Alexander Graf
8  */
9 
10 #include <common.h>
11 #include <efi_loader.h>
12 #include <pe.h>
13 
14 const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
15 const efi_guid_t efi_guid_device_path = DEVICE_PATH_GUID;
16 const efi_guid_t efi_guid_loaded_image = LOADED_IMAGE_GUID;
17 const efi_guid_t efi_simple_file_system_protocol_guid =
18 		EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
19 const efi_guid_t efi_file_info_guid = EFI_FILE_INFO_GUID;
20 
21 static int machines[] = {
22 #if defined(__aarch64__)
23 	IMAGE_FILE_MACHINE_ARM64,
24 #elif defined(__arm__)
25 	IMAGE_FILE_MACHINE_ARM,
26 	IMAGE_FILE_MACHINE_THUMB,
27 	IMAGE_FILE_MACHINE_ARMNT,
28 #endif
29 
30 #if defined(__x86_64__)
31 	IMAGE_FILE_MACHINE_AMD64,
32 #elif defined(__i386__)
33 	IMAGE_FILE_MACHINE_I386,
34 #endif
35 
36 #if defined(__riscv) && (__riscv_xlen == 32)
37 	IMAGE_FILE_MACHINE_RISCV32,
38 #endif
39 
40 #if defined(__riscv) && (__riscv_xlen == 64)
41 	IMAGE_FILE_MACHINE_RISCV64,
42 #endif
43 	0 };
44 
45 /**
46  * efi_print_image_info() - print information about a loaded image
47  *
48  * If the program counter is located within the image the offset to the base
49  * address is shown.
50  *
51  * @obj:	EFI object
52  * @image:	loaded image
53  * @pc:		program counter (use NULL to suppress offset output)
54  * Return:	status code
55  */
efi_print_image_info(struct efi_loaded_image_obj * obj,struct efi_loaded_image * image,void * pc)56 static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj,
57 					 struct efi_loaded_image *image,
58 					 void *pc)
59 {
60 	printf("UEFI image");
61 	printf(" [0x%p:0x%p]",
62 	       obj->reloc_base, obj->reloc_base + obj->reloc_size - 1);
63 	if (pc && pc >= obj->reloc_base &&
64 	    pc < obj->reloc_base + obj->reloc_size)
65 		printf(" pc=0x%zx", pc - obj->reloc_base);
66 	if (image->file_path)
67 		printf(" '%pD'", image->file_path);
68 	printf("\n");
69 	return EFI_SUCCESS;
70 }
71 
72 /**
73  * efi_print_image_infos() - print information about all loaded images
74  *
75  * @pc:		program counter (use NULL to suppress offset output)
76  */
efi_print_image_infos(void * pc)77 void efi_print_image_infos(void *pc)
78 {
79 	struct efi_object *efiobj;
80 	struct efi_handler *handler;
81 
82 	list_for_each_entry(efiobj, &efi_obj_list, link) {
83 		list_for_each_entry(handler, &efiobj->protocols, link) {
84 			if (!guidcmp(handler->guid, &efi_guid_loaded_image)) {
85 				efi_print_image_info(
86 					(struct efi_loaded_image_obj *)efiobj,
87 					handler->protocol_interface, pc);
88 			}
89 		}
90 	}
91 }
92 
93 /**
94  * efi_loader_relocate() - relocate UEFI binary
95  *
96  * @rel:		pointer to the relocation table
97  * @rel_size:		size of the relocation table in bytes
98  * @efi_reloc:		actual load address of the image
99  * @pref_address:	preferred load address of the image
100  * Return:		status code
101  */
efi_loader_relocate(const IMAGE_BASE_RELOCATION * rel,unsigned long rel_size,void * efi_reloc,unsigned long pref_address)102 static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
103 			unsigned long rel_size, void *efi_reloc,
104 			unsigned long pref_address)
105 {
106 	unsigned long delta = (unsigned long)efi_reloc - pref_address;
107 	const IMAGE_BASE_RELOCATION *end;
108 	int i;
109 
110 	if (delta == 0)
111 		return EFI_SUCCESS;
112 
113 	end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size);
114 	while (rel < end && rel->SizeOfBlock) {
115 		const uint16_t *relocs = (const uint16_t *)(rel + 1);
116 		i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t);
117 		while (i--) {
118 			uint32_t offset = (uint32_t)(*relocs & 0xfff) +
119 					  rel->VirtualAddress;
120 			int type = *relocs >> EFI_PAGE_SHIFT;
121 			uint64_t *x64 = efi_reloc + offset;
122 			uint32_t *x32 = efi_reloc + offset;
123 			uint16_t *x16 = efi_reloc + offset;
124 
125 			switch (type) {
126 			case IMAGE_REL_BASED_ABSOLUTE:
127 				break;
128 			case IMAGE_REL_BASED_HIGH:
129 				*x16 += ((uint32_t)delta) >> 16;
130 				break;
131 			case IMAGE_REL_BASED_LOW:
132 				*x16 += (uint16_t)delta;
133 				break;
134 			case IMAGE_REL_BASED_HIGHLOW:
135 				*x32 += (uint32_t)delta;
136 				break;
137 			case IMAGE_REL_BASED_DIR64:
138 				*x64 += (uint64_t)delta;
139 				break;
140 #ifdef __riscv
141 			case IMAGE_REL_BASED_RISCV_HI20:
142 				*x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) |
143 					(*x32 & 0x00000fff);
144 				break;
145 			case IMAGE_REL_BASED_RISCV_LOW12I:
146 			case IMAGE_REL_BASED_RISCV_LOW12S:
147 				/* We know that we're 4k aligned */
148 				if (delta & 0xfff) {
149 					printf("Unsupported reloc offset\n");
150 					return EFI_LOAD_ERROR;
151 				}
152 				break;
153 #endif
154 			default:
155 				printf("Unknown Relocation off %x type %x\n",
156 				       offset, type);
157 				return EFI_LOAD_ERROR;
158 			}
159 			relocs++;
160 		}
161 		rel = (const IMAGE_BASE_RELOCATION *)relocs;
162 	}
163 	return EFI_SUCCESS;
164 }
165 
invalidate_icache_all(void)166 void __weak invalidate_icache_all(void)
167 {
168 	/* If the system doesn't support icache_all flush, cross our fingers */
169 }
170 
171 /**
172  * efi_set_code_and_data_type() - determine the memory types to be used for code
173  *				  and data.
174  *
175  * @loaded_image_info:	image descriptor
176  * @image_type:		field Subsystem of the optional header for
177  *			Windows specific field
178  */
efi_set_code_and_data_type(struct efi_loaded_image * loaded_image_info,uint16_t image_type)179 static void efi_set_code_and_data_type(
180 			struct efi_loaded_image *loaded_image_info,
181 			uint16_t image_type)
182 {
183 	switch (image_type) {
184 	case IMAGE_SUBSYSTEM_EFI_APPLICATION:
185 		loaded_image_info->image_code_type = EFI_LOADER_CODE;
186 		loaded_image_info->image_data_type = EFI_LOADER_DATA;
187 		break;
188 	case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
189 		loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE;
190 		loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA;
191 		break;
192 	case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
193 	case IMAGE_SUBSYSTEM_EFI_ROM:
194 		loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE;
195 		loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA;
196 		break;
197 	default:
198 		printf("%s: invalid image type: %u\n", __func__, image_type);
199 		/* Let's assume it is an application */
200 		loaded_image_info->image_code_type = EFI_LOADER_CODE;
201 		loaded_image_info->image_data_type = EFI_LOADER_DATA;
202 		break;
203 	}
204 }
205 
206 /**
207  * efi_load_pe() - relocate EFI binary
208  *
209  * This function loads all sections from a PE binary into a newly reserved
210  * piece of memory. On success the entry point is returned as handle->entry.
211  *
212  * @handle:		loaded image handle
213  * @efi:		pointer to the EFI binary
214  * @loaded_image_info:	loaded image protocol
215  * Return:		status code
216  */
efi_load_pe(struct efi_loaded_image_obj * handle,void * efi,struct efi_loaded_image * loaded_image_info)217 efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
218 			 struct efi_loaded_image *loaded_image_info)
219 {
220 	IMAGE_NT_HEADERS32 *nt;
221 	IMAGE_DOS_HEADER *dos;
222 	IMAGE_SECTION_HEADER *sections;
223 	int num_sections;
224 	void *efi_reloc;
225 	int i;
226 	const IMAGE_BASE_RELOCATION *rel;
227 	unsigned long rel_size;
228 	int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
229 	uint64_t image_base;
230 	uint64_t image_size;
231 	unsigned long virt_size = 0;
232 	int supported = 0;
233 
234 	dos = efi;
235 	if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
236 		printf("%s: Invalid DOS Signature\n", __func__);
237 		return EFI_LOAD_ERROR;
238 	}
239 
240 	nt = (void *) ((char *)efi + dos->e_lfanew);
241 	if (nt->Signature != IMAGE_NT_SIGNATURE) {
242 		printf("%s: Invalid NT Signature\n", __func__);
243 		return EFI_LOAD_ERROR;
244 	}
245 
246 	for (i = 0; machines[i]; i++)
247 		if (machines[i] == nt->FileHeader.Machine) {
248 			supported = 1;
249 			break;
250 		}
251 
252 	if (!supported) {
253 		printf("%s: Machine type 0x%04x is not supported\n",
254 		       __func__, nt->FileHeader.Machine);
255 		return EFI_LOAD_ERROR;
256 	}
257 
258 	/* Calculate upper virtual address boundary */
259 	num_sections = nt->FileHeader.NumberOfSections;
260 	sections = (void *)&nt->OptionalHeader +
261 			    nt->FileHeader.SizeOfOptionalHeader;
262 
263 	for (i = num_sections - 1; i >= 0; i--) {
264 		IMAGE_SECTION_HEADER *sec = &sections[i];
265 		virt_size = max_t(unsigned long, virt_size,
266 				  sec->VirtualAddress + sec->Misc.VirtualSize);
267 	}
268 
269 	/* Read 32/64bit specific header bits */
270 	if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
271 		IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
272 		IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
273 		image_base = opt->ImageBase;
274 		image_size = opt->SizeOfImage;
275 		efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
276 		efi_reloc = efi_alloc(virt_size,
277 				      loaded_image_info->image_code_type);
278 		if (!efi_reloc) {
279 			printf("%s: Could not allocate %lu bytes\n",
280 			       __func__, virt_size);
281 			return EFI_OUT_OF_RESOURCES;
282 		}
283 		handle->entry = efi_reloc + opt->AddressOfEntryPoint;
284 		rel_size = opt->DataDirectory[rel_idx].Size;
285 		rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
286 		virt_size = ALIGN(virt_size, opt->SectionAlignment);
287 	} else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
288 		IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
289 		image_base = opt->ImageBase;
290 		image_size = opt->SizeOfImage;
291 		efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
292 		efi_reloc = efi_alloc(virt_size,
293 				      loaded_image_info->image_code_type);
294 		if (!efi_reloc) {
295 			printf("%s: Could not allocate %lu bytes\n",
296 			       __func__, virt_size);
297 			return EFI_OUT_OF_RESOURCES;
298 		}
299 		handle->entry = efi_reloc + opt->AddressOfEntryPoint;
300 		rel_size = opt->DataDirectory[rel_idx].Size;
301 		rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
302 		virt_size = ALIGN(virt_size, opt->SectionAlignment);
303 	} else {
304 		printf("%s: Invalid optional header magic %x\n", __func__,
305 		       nt->OptionalHeader.Magic);
306 		return EFI_LOAD_ERROR;
307 	}
308 
309 	/* Load sections into RAM */
310 	for (i = num_sections - 1; i >= 0; i--) {
311 		IMAGE_SECTION_HEADER *sec = &sections[i];
312 		memset(efi_reloc + sec->VirtualAddress, 0,
313 		       sec->Misc.VirtualSize);
314 		memcpy(efi_reloc + sec->VirtualAddress,
315 		       efi + sec->PointerToRawData,
316 		       sec->SizeOfRawData);
317 	}
318 
319 	/* Run through relocations */
320 	if (efi_loader_relocate(rel, rel_size, efi_reloc,
321 				(unsigned long)image_base) != EFI_SUCCESS) {
322 		efi_free_pages((uintptr_t) efi_reloc,
323 			       (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
324 		return EFI_LOAD_ERROR;
325 	}
326 
327 	/* Flush cache */
328 	flush_cache((ulong)efi_reloc,
329 		    ALIGN(virt_size, EFI_CACHELINE_SIZE));
330 	invalidate_icache_all();
331 
332 	/* Populate the loaded image interface bits */
333 	loaded_image_info->image_base = efi;
334 	loaded_image_info->image_size = image_size;
335 	handle->reloc_base = efi_reloc;
336 	handle->reloc_size = virt_size;
337 
338 	return EFI_SUCCESS;
339 }
340