xref: /openbmc/u-boot/cmd/bootefi.c (revision d08957e6)
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 
16 /*
17  * When booting using the "bootefi" command, we don't know which
18  * physical device the file came from. So we create a pseudo-device
19  * called "bootefi" with the device path /bootefi.
20  *
21  * In addition to the originating device we also declare the file path
22  * of "bootefi" based loads to be /bootefi.
23  */
24 static struct efi_device_path_file_path bootefi_image_path[] = {
25 	{
26 		.dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE,
27 		.dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH,
28 		.dp.length = sizeof(bootefi_image_path[0]),
29 		.str = { 'b','o','o','t','e','f','i' },
30 	}, {
31 		.dp.type = DEVICE_PATH_TYPE_END,
32 		.dp.sub_type = DEVICE_PATH_SUB_TYPE_END,
33 		.dp.length = sizeof(bootefi_image_path[0]),
34 	}
35 };
36 
37 static efi_status_t bootefi_open_dp(void *handle, efi_guid_t *protocol,
38 			void **protocol_interface, void *agent_handle,
39 			void *controller_handle, uint32_t attributes)
40 {
41 	*protocol_interface = bootefi_image_path;
42 	return EFI_SUCCESS;
43 }
44 
45 /* The EFI loaded_image interface for the image executed via "bootefi" */
46 static struct efi_loaded_image loaded_image_info = {
47 	.device_handle = bootefi_image_path,
48 	.file_path = bootefi_image_path,
49 };
50 
51 /* The EFI object struct for the image executed via "bootefi" */
52 static struct efi_object loaded_image_info_obj = {
53 	.handle = &loaded_image_info,
54 	.protocols = {
55 		{
56 			/*
57 			 * When asking for the loaded_image interface, just
58 			 * return handle which points to loaded_image_info
59 			 */
60 			.guid = &efi_guid_loaded_image,
61 			.open = &efi_return_handle,
62 		},
63 		{
64 			/*
65 			 * When asking for the device path interface, return
66 			 * bootefi_image_path
67 			 */
68 			.guid = &efi_guid_device_path,
69 			.open = &bootefi_open_dp,
70 		},
71 	},
72 };
73 
74 /* The EFI object struct for the device the "bootefi" image was loaded from */
75 static struct efi_object bootefi_device_obj = {
76 	.handle = bootefi_image_path,
77 	.protocols = {
78 		{
79 			/* When asking for the device path interface, return
80 			 * bootefi_image_path */
81 			.guid = &efi_guid_device_path,
82 			.open = &bootefi_open_dp,
83 		}
84 	},
85 };
86 
87 /*
88  * Load an EFI payload into a newly allocated piece of memory, register all
89  * EFI objects it would want to access and jump to it.
90  */
91 static unsigned long do_bootefi_exec(void *efi)
92 {
93 	ulong (*entry)(void *image_handle, struct efi_system_table *st);
94 	ulong fdt_pages, fdt_size, fdt_start, fdt_end;
95 	bootm_headers_t img = { 0 };
96 
97 	/*
98 	 * gd lives in a fixed register which may get clobbered while we execute
99 	 * the payload. So save it here and restore it on every callback entry
100 	 */
101 	efi_save_gd();
102 
103 	/* Update system table to point to our currently loaded FDT */
104 
105 	if (working_fdt) {
106 		/* Prepare fdt for payload */
107 		if (image_setup_libfdt(&img, working_fdt, 0, NULL)) {
108 			printf("ERROR: Failed to process device tree\n");
109 			return -EINVAL;
110 		}
111 
112 		/* Link to it in the efi tables */
113 		systab.tables[0].guid = EFI_FDT_GUID;
114 		systab.tables[0].table = working_fdt;
115 		systab.nr_tables = 1;
116 
117 		/* And reserve the space in the memory map */
118 		fdt_start = ((ulong)working_fdt) & ~EFI_PAGE_MASK;
119 		fdt_end = ((ulong)working_fdt) + fdt_totalsize(working_fdt);
120 		fdt_size = (fdt_end - fdt_start) + EFI_PAGE_MASK;
121 		fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
122 		/* Give a bootloader the chance to modify the device tree */
123 		fdt_pages += 2;
124 		efi_add_memory_map(fdt_start, fdt_pages,
125 				   EFI_BOOT_SERVICES_DATA, true);
126 
127 	} else {
128 		printf("WARNING: No device tree loaded, expect boot to fail\n");
129 		systab.nr_tables = 0;
130 	}
131 
132 	/* Load the EFI payload */
133 	entry = efi_load_pe(efi, &loaded_image_info);
134 	if (!entry)
135 		return -ENOENT;
136 
137 	/* Initialize and populate EFI object list */
138 	INIT_LIST_HEAD(&efi_obj_list);
139 	list_add_tail(&loaded_image_info_obj.link, &efi_obj_list);
140 	list_add_tail(&bootefi_device_obj.link, &efi_obj_list);
141 #ifdef CONFIG_PARTITIONS
142 	efi_disk_register();
143 #endif
144 
145 	/* Call our payload! */
146 #ifdef DEBUG_EFI
147 	printf("%s:%d Jumping to 0x%lx\n", __func__, __LINE__, (long)entry);
148 #endif
149 	return entry(&loaded_image_info, &systab);
150 }
151 
152 
153 /* Interpreter command to boot an arbitrary EFI image from memory */
154 static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
155 {
156 	char *saddr;
157 	unsigned long addr;
158 	int r = 0;
159 
160 	if (argc < 2)
161 		return 1;
162 	saddr = argv[1];
163 
164 	addr = simple_strtoul(saddr, NULL, 16);
165 
166 	printf("## Starting EFI application at 0x%08lx ...\n", addr);
167 	r = do_bootefi_exec((void *)addr);
168 	printf("## Application terminated, r = %d\n", r);
169 
170 	if (r != 0)
171 		r = 1;
172 
173 	return r;
174 }
175 
176 #ifdef CONFIG_SYS_LONGHELP
177 static char bootefi_help_text[] =
178 	"<image address>\n"
179 	"  - boot EFI payload stored at address <image address>\n"
180 	"\n"
181 	"Since most EFI payloads want to have a device tree provided, please\n"
182 	"make sure you load a device tree using the fdt addr command before\n"
183 	"executing bootefi.\n";
184 #endif
185 
186 U_BOOT_CMD(
187 	bootefi, 2, 0, do_bootefi,
188 	"Boots an EFI payload from memory\n",
189 	bootefi_help_text
190 );
191 
192 void efi_set_bootdev(const char *dev, const char *devnr)
193 {
194 	char devname[16] = { 0 }; /* dp->str is u16[16] long */
195 	char *colon;
196 
197 	/* Assemble the condensed device name we use in efi_disk.c */
198 	snprintf(devname, sizeof(devname), "%s%s", dev, devnr);
199 	colon = strchr(devname, ':');
200 	if (colon)
201 		*colon = '\0';
202 
203 	/* Patch the bootefi_image_path to the target device */
204 	memset(bootefi_image_path[0].str, 0, sizeof(bootefi_image_path[0].str));
205 	ascii2unicode(bootefi_image_path[0].str, devname);
206 }
207