xref: /openbmc/u-boot/cmd/bootefi.c (revision ad5b5801)
1 /*
2  *  EFI application loader
3  *
4  *  Copyright (c) 2016 Alexander Graf
5  *
6  *  SPDX-License-Identifier:     GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <command.h>
11 #include <efi_loader.h>
12 #include <errno.h>
13 #include <libfdt.h>
14 #include <libfdt_env.h>
15 #include <memalign.h>
16 #include <asm/global_data.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 /*
21  * When booting using the "bootefi" command, we don't know which
22  * physical device the file came from. So we create a pseudo-device
23  * called "bootefi" with the device path /bootefi.
24  *
25  * In addition to the originating device we also declare the file path
26  * of "bootefi" based loads to be /bootefi.
27  */
28 static struct efi_device_path_file_path bootefi_image_path[] = {
29 	{
30 		.dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE,
31 		.dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH,
32 		.dp.length = sizeof(bootefi_image_path[0]),
33 		.str = { 'b','o','o','t','e','f','i' },
34 	}, {
35 		.dp.type = DEVICE_PATH_TYPE_END,
36 		.dp.sub_type = DEVICE_PATH_SUB_TYPE_END,
37 		.dp.length = sizeof(bootefi_image_path[0]),
38 	}
39 };
40 
41 static struct efi_device_path_file_path bootefi_device_path[] = {
42 	{
43 		.dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE,
44 		.dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH,
45 		.dp.length = sizeof(bootefi_image_path[0]),
46 		.str = { 'b','o','o','t','e','f','i' },
47 	}, {
48 		.dp.type = DEVICE_PATH_TYPE_END,
49 		.dp.sub_type = DEVICE_PATH_SUB_TYPE_END,
50 		.dp.length = sizeof(bootefi_image_path[0]),
51 	}
52 };
53 
54 static efi_status_t bootefi_open_dp(void *handle, efi_guid_t *protocol,
55 			void **protocol_interface, void *agent_handle,
56 			void *controller_handle, uint32_t attributes)
57 {
58 	*protocol_interface = bootefi_device_path;
59 	return EFI_SUCCESS;
60 }
61 
62 /* The EFI loaded_image interface for the image executed via "bootefi" */
63 static struct efi_loaded_image loaded_image_info = {
64 	.device_handle = bootefi_device_path,
65 	.file_path = bootefi_image_path,
66 };
67 
68 /* The EFI object struct for the image executed via "bootefi" */
69 static struct efi_object loaded_image_info_obj = {
70 	.handle = &loaded_image_info,
71 	.protocols = {
72 		{
73 			/*
74 			 * When asking for the loaded_image interface, just
75 			 * return handle which points to loaded_image_info
76 			 */
77 			.guid = &efi_guid_loaded_image,
78 			.open = &efi_return_handle,
79 		},
80 		{
81 			/*
82 			 * When asking for the device path interface, return
83 			 * bootefi_device_path
84 			 */
85 			.guid = &efi_guid_device_path,
86 			.open = &bootefi_open_dp,
87 		},
88 	},
89 };
90 
91 /* The EFI object struct for the device the "bootefi" image was loaded from */
92 static struct efi_object bootefi_device_obj = {
93 	.handle = bootefi_device_path,
94 	.protocols = {
95 		{
96 			/* When asking for the device path interface, return
97 			 * bootefi_device_path */
98 			.guid = &efi_guid_device_path,
99 			.open = &bootefi_open_dp,
100 		}
101 	},
102 };
103 
104 static void *copy_fdt(void *fdt)
105 {
106 	u64 fdt_size = fdt_totalsize(fdt);
107 	unsigned long fdt_ram_start = -1L, fdt_pages;
108 	u64 new_fdt_addr;
109 	void *new_fdt;
110 	int i;
111 
112         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
113                 u64 ram_start = gd->bd->bi_dram[i].start;
114                 u64 ram_size = gd->bd->bi_dram[i].size;
115 
116 		if (!ram_size)
117 			continue;
118 
119 		if (ram_start < fdt_ram_start)
120 			fdt_ram_start = ram_start;
121 	}
122 
123 	/* Give us at least 4kb breathing room */
124 	fdt_size = ALIGN(fdt_size + 4096, 4096);
125 	fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
126 
127 	/* Safe fdt location is at 128MB */
128 	new_fdt_addr = fdt_ram_start + (128 * 1024 * 1024) + fdt_size;
129 	if (efi_allocate_pages(1, EFI_BOOT_SERVICES_DATA, fdt_pages,
130 			       &new_fdt_addr) != EFI_SUCCESS) {
131 		/* If we can't put it there, put it somewhere */
132 		new_fdt_addr = (ulong)memalign(4096, fdt_size);
133 	}
134 	new_fdt = (void*)(ulong)new_fdt_addr;
135 	memcpy(new_fdt, fdt, fdt_totalsize(fdt));
136 	fdt_set_totalsize(new_fdt, fdt_size);
137 
138 	return new_fdt;
139 }
140 
141 /*
142  * Load an EFI payload into a newly allocated piece of memory, register all
143  * EFI objects it would want to access and jump to it.
144  */
145 static unsigned long do_bootefi_exec(void *efi, void *fdt)
146 {
147 	ulong (*entry)(void *image_handle, struct efi_system_table *st);
148 	ulong fdt_pages, fdt_size, fdt_start, fdt_end;
149 	bootm_headers_t img = { 0 };
150 
151 	/*
152 	 * gd lives in a fixed register which may get clobbered while we execute
153 	 * the payload. So save it here and restore it on every callback entry
154 	 */
155 	efi_save_gd();
156 
157 	if (fdt && !fdt_check_header(fdt)) {
158 		/* Prepare fdt for payload */
159 		fdt = copy_fdt(fdt);
160 
161 		if (image_setup_libfdt(&img, fdt, 0, NULL)) {
162 			printf("ERROR: Failed to process device tree\n");
163 			return -EINVAL;
164 		}
165 
166 		/* Link to it in the efi tables */
167 		systab.tables[0].guid = EFI_FDT_GUID;
168 		systab.tables[0].table = fdt;
169 		systab.nr_tables = 1;
170 
171 		/* And reserve the space in the memory map */
172 		fdt_start = ((ulong)fdt) & ~EFI_PAGE_MASK;
173 		fdt_end = ((ulong)fdt) + fdt_totalsize(fdt);
174 		fdt_size = (fdt_end - fdt_start) + EFI_PAGE_MASK;
175 		fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
176 		/* Give a bootloader the chance to modify the device tree */
177 		fdt_pages += 2;
178 		efi_add_memory_map(fdt_start, fdt_pages,
179 				   EFI_BOOT_SERVICES_DATA, true);
180 	} else {
181 		printf("WARNING: Invalid device tree, expect boot to fail\n");
182 		systab.nr_tables = 0;
183 	}
184 
185 	/* Load the EFI payload */
186 	entry = efi_load_pe(efi, &loaded_image_info);
187 	if (!entry)
188 		return -ENOENT;
189 
190 	/* Initialize and populate EFI object list */
191 	INIT_LIST_HEAD(&efi_obj_list);
192 	list_add_tail(&loaded_image_info_obj.link, &efi_obj_list);
193 	list_add_tail(&bootefi_device_obj.link, &efi_obj_list);
194 #ifdef CONFIG_PARTITIONS
195 	efi_disk_register();
196 #endif
197 #ifdef CONFIG_LCD
198 	efi_gop_register();
199 #endif
200 
201 	/* Call our payload! */
202 #ifdef DEBUG_EFI
203 	printf("%s:%d Jumping to 0x%lx\n", __func__, __LINE__, (long)entry);
204 #endif
205 	return entry(&loaded_image_info, &systab);
206 }
207 
208 
209 /* Interpreter command to boot an arbitrary EFI image from memory */
210 static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
211 {
212 	char *saddr, *sfdt;
213 	unsigned long addr, fdt_addr = 0;
214 	int r = 0;
215 
216 	if (argc < 2)
217 		return 1;
218 	saddr = argv[1];
219 
220 	addr = simple_strtoul(saddr, NULL, 16);
221 
222 	if (argc > 2) {
223 		sfdt = argv[2];
224 		fdt_addr = simple_strtoul(sfdt, NULL, 16);
225 	}
226 
227 	printf("## Starting EFI application at 0x%08lx ...\n", addr);
228 	r = do_bootefi_exec((void *)addr, (void*)fdt_addr);
229 	printf("## Application terminated, r = %d\n", r);
230 
231 	if (r != 0)
232 		r = 1;
233 
234 	return r;
235 }
236 
237 #ifdef CONFIG_SYS_LONGHELP
238 static char bootefi_help_text[] =
239 	"<image address> [fdt address]\n"
240 	"  - boot EFI payload stored at address <image address>.\n"
241 	"    If specified, the device tree located at <fdt address> gets\n"
242 	"    exposed as EFI configuration table.\n";
243 #endif
244 
245 U_BOOT_CMD(
246 	bootefi, 3, 0, do_bootefi,
247 	"Boots an EFI payload from memory\n",
248 	bootefi_help_text
249 );
250 
251 void efi_set_bootdev(const char *dev, const char *devnr, const char *path)
252 {
253 	__maybe_unused struct blk_desc *desc;
254 	char devname[32] = { 0 }; /* dp->str is u16[32] long */
255 	char *colon;
256 
257 	/* Assemble the condensed device name we use in efi_disk.c */
258 	snprintf(devname, sizeof(devname), "%s%s", dev, devnr);
259 	colon = strchr(devname, ':');
260 
261 #ifdef CONFIG_ISO_PARTITION
262 	/* For ISOs we create partition block devices */
263 	desc = blk_get_dev(dev, simple_strtol(devnr, NULL, 10));
264 	if (desc && (desc->type != DEV_TYPE_UNKNOWN) &&
265 	    (desc->part_type == PART_TYPE_ISO)) {
266 		if (!colon)
267 			snprintf(devname, sizeof(devname), "%s%s:1", dev,
268 				 devnr);
269 		colon = NULL;
270 	}
271 #endif
272 
273 	if (colon)
274 		*colon = '\0';
275 
276 	/* Patch bootefi_device_path to the target device */
277 	memset(bootefi_device_path[0].str, 0, sizeof(bootefi_device_path[0].str));
278 	ascii2unicode(bootefi_device_path[0].str, devname);
279 
280 	/* Patch bootefi_image_path to the target file path */
281 	memset(bootefi_image_path[0].str, 0, sizeof(bootefi_image_path[0].str));
282 	snprintf(devname, sizeof(devname), "%s", path);
283 	ascii2unicode(bootefi_image_path[0].str, devname);
284 }
285