1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2015 Google, Inc
4  *
5  * EFI information obtained here:
6  * http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES
7  *
8  * This file implements U-Boot running as an EFI application.
9  */
10 
11 #include <common.h>
12 #include <cpu_func.h>
13 #include <debug_uart.h>
14 #include <dm.h>
15 #include <errno.h>
16 #include <init.h>
17 #include <malloc.h>
18 #include <asm/global_data.h>
19 #include <linux/err.h>
20 #include <linux/types.h>
21 #include <efi.h>
22 #include <efi_api.h>
23 #include <sysreset.h>
24 #include <dm/device-internal.h>
25 #include <dm/lists.h>
26 #include <dm/root.h>
27 
28 DECLARE_GLOBAL_DATA_PTR;
29 
efi_info_get(enum efi_entry_t type,void ** datap,int * sizep)30 int efi_info_get(enum efi_entry_t type, void **datap, int *sizep)
31 {
32 	return -ENOSYS;
33 }
34 
efi_get_mmap(struct efi_mem_desc ** descp,int * sizep,uint * keyp,int * desc_sizep,uint * versionp)35 int efi_get_mmap(struct efi_mem_desc **descp, int *sizep, uint *keyp,
36 		 int *desc_sizep, uint *versionp)
37 {
38 	struct efi_priv *priv = efi_get_priv();
39 	struct efi_boot_services *boot = priv->sys_table->boottime;
40 	efi_uintn_t size, desc_size, key;
41 	struct efi_mem_desc *desc;
42 	efi_status_t ret;
43 	u32 version;
44 
45 	/* Get the memory map so we can switch off EFI */
46 	size = 0;
47 	ret = boot->get_memory_map(&size, NULL, &key, &desc_size, &version);
48 	if (ret != EFI_BUFFER_TOO_SMALL)
49 		return log_msg_ret("get", -ENOMEM);
50 
51 	desc = malloc(size);
52 	if (!desc)
53 		return log_msg_ret("mem", -ENOMEM);
54 
55 	ret = boot->get_memory_map(&size, desc, &key, &desc_size, &version);
56 	if (ret)
57 		return log_msg_ret("get", -EINVAL);
58 
59 	*descp = desc;
60 	*sizep = size;
61 	*desc_sizep = desc_size;
62 	*versionp = version;
63 	*keyp = key;
64 
65 	return 0;
66 }
67 
68 /**
69  * efi_bind_block() - bind a new block device to an EFI device
70  *
71  * Binds a new top-level EFI_MEDIA device as well as a child block device so
72  * that the block device can be accessed in U-Boot.
73  *
74  * The device can then be accessed using 'part list efi 0', 'fat ls efi 0:1',
75  * for example, just like any other interface type.
76  *
77  * @handle: handle of the controller on which this driver is installed
78  * @blkio: block io protocol proxied by this driver
79  * @device_path: EFI device path structure for this
80  * @len: Length of @device_path in bytes
81  * @devp: Returns the bound device
82  * Return: 0 if OK, -ve on error
83  */
efi_bind_block(efi_handle_t handle,struct efi_block_io * blkio,struct efi_device_path * device_path,int len,struct udevice ** devp)84 int efi_bind_block(efi_handle_t handle, struct efi_block_io *blkio,
85 		   struct efi_device_path *device_path, int len,
86 		   struct udevice **devp)
87 {
88 	struct efi_media_plat plat;
89 	struct udevice *dev;
90 	char name[18];
91 	int ret;
92 
93 	plat.handle = handle;
94 	plat.blkio = blkio;
95 	plat.device_path = malloc(device_path->length);
96 	if (!plat.device_path)
97 		return log_msg_ret("path", -ENOMEM);
98 	memcpy(plat.device_path, device_path, device_path->length);
99 	ret = device_bind(dm_root(), DM_DRIVER_GET(efi_media), "efi_media",
100 			  &plat, ofnode_null(), &dev);
101 	if (ret)
102 		return log_msg_ret("bind", ret);
103 
104 	snprintf(name, sizeof(name), "efi_media_%x", dev_seq(dev));
105 	device_set_name(dev, name);
106 	*devp = dev;
107 
108 	return 0;
109 }
110 
setup_memory(struct efi_priv * priv)111 static efi_status_t setup_memory(struct efi_priv *priv)
112 {
113 	struct efi_boot_services *boot = priv->boot;
114 	efi_physical_addr_t addr;
115 	efi_status_t ret;
116 	int pages;
117 
118 	/*
119 	 * Use global_data_ptr instead of gd since it is an assignment. There
120 	 * are very few assignments to global_data in U-Boot and this makes
121 	 * it easier to find them.
122 	 */
123 	global_data_ptr = efi_malloc(priv, sizeof(struct global_data), &ret);
124 	if (!global_data_ptr)
125 		return ret;
126 	memset(gd, '\0', sizeof(*gd));
127 
128 	gd->malloc_base = (ulong)efi_malloc(priv, CONFIG_VAL(SYS_MALLOC_F_LEN),
129 					    &ret);
130 	if (!gd->malloc_base)
131 		return ret;
132 	pages = CONFIG_EFI_RAM_SIZE >> 12;
133 
134 	/*
135 	 * Don't allocate any memory above 4GB. U-Boot is a 32-bit application
136 	 * so we want it to load below 4GB.
137 	 */
138 	addr = 1ULL << 32;
139 	ret = boot->allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
140 				   priv->image_data_type, pages, &addr);
141 	if (ret) {
142 		log_info("(using pool %lx) ", ret);
143 		priv->ram_base = (ulong)efi_malloc(priv, CONFIG_EFI_RAM_SIZE,
144 						   &ret);
145 		if (!priv->ram_base)
146 			return ret;
147 		priv->use_pool_for_malloc = true;
148 	} else {
149 		log_info("(using allocated RAM address %lx) ", (ulong)addr);
150 		priv->ram_base = addr;
151 	}
152 	gd->ram_size = pages << 12;
153 
154 	return 0;
155 }
156 
157 /**
158  * free_memory() - Free memory used by the U-Boot app
159  *
160  * This frees memory allocated in setup_memory(), in preparation for returning
161  * to UEFI. It also zeroes the global_data pointer.
162  *
163  * @priv: Private EFI data
164  */
free_memory(struct efi_priv * priv)165 static void free_memory(struct efi_priv *priv)
166 {
167 	struct efi_boot_services *boot = priv->boot;
168 
169 	if (priv->use_pool_for_malloc)
170 		efi_free(priv, (void *)priv->ram_base);
171 	else
172 		boot->free_pages(priv->ram_base, gd->ram_size >> 12);
173 
174 	efi_free(priv, (void *)gd->malloc_base);
175 	efi_free(priv, gd);
176 	global_data_ptr = NULL;
177 }
178 
179 /**
180  * devpath_is_partition() - Figure out if a device path is a partition
181  *
182  * Checks if a device path refers to a partition on some media device. This
183  * works by checking for a valid partition number in a hard-driver media device
184  * as the final component of the device path.
185  *
186  * @path:	device path
187  * Return:	true if a partition, false if not
188  *		(e.g. it might be media which contains partitions)
189  */
devpath_is_partition(const struct efi_device_path * path)190 static bool devpath_is_partition(const struct efi_device_path *path)
191 {
192 	const struct efi_device_path *p;
193 	bool was_part = false;
194 
195 	for (p = path; p->type != DEVICE_PATH_TYPE_END;
196 	     p = (void *)p + p->length) {
197 		was_part = false;
198 		if (p->type == DEVICE_PATH_TYPE_MEDIA_DEVICE &&
199 		    p->sub_type == DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH) {
200 			struct efi_device_path_hard_drive_path *hd =
201 				(void *)path;
202 
203 			if (hd->partition_number)
204 				was_part = true;
205 		}
206 	}
207 
208 	return was_part;
209 }
210 
211 /**
212  * setup_block() - Find all block devices and setup EFI devices for them
213  *
214  * Partitions are ignored, since U-Boot has partition handling. Errors with
215  * particular devices produce a warning but execution continues to try to
216  * find others.
217  *
218  * Return: 0 if found, -ENOSYS if there is no boot-services table, -ENOTSUPP
219  *	if a required protocol is not supported
220  */
setup_block(void)221 static int setup_block(void)
222 {
223 	efi_guid_t efi_blkio_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
224 	efi_guid_t efi_devpath_guid = EFI_DEVICE_PATH_PROTOCOL_GUID;
225 	efi_guid_t efi_pathutil_guid = EFI_DEVICE_PATH_UTILITIES_PROTOCOL_GUID;
226 	efi_guid_t efi_pathtext_guid = EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
227 	struct efi_boot_services *boot = efi_get_boot();
228 	struct efi_device_path_utilities_protocol *util;
229 	struct efi_device_path_to_text_protocol *text;
230 	struct efi_device_path *path;
231 	struct efi_block_io *blkio;
232 	efi_uintn_t num_handles;
233 	efi_handle_t *handle;
234 	int ret, i;
235 
236 	if (!boot)
237 		return log_msg_ret("sys", -ENOSYS);
238 
239 	/* Find all devices which support the block I/O protocol */
240 	ret = boot->locate_handle_buffer(BY_PROTOCOL, &efi_blkio_guid, NULL,
241 				  &num_handles, &handle);
242 	if (ret)
243 		return log_msg_ret("loc", -ENOTSUPP);
244 	log_debug("Found %d handles:\n", (int)num_handles);
245 
246 	/* We need to look up the path size and convert it to text */
247 	ret = boot->locate_protocol(&efi_pathutil_guid, NULL, (void **)&util);
248 	if (ret)
249 		return log_msg_ret("util", -ENOTSUPP);
250 	ret = boot->locate_protocol(&efi_pathtext_guid, NULL, (void **)&text);
251 	if (ret)
252 		return log_msg_ret("text", -ENOTSUPP);
253 
254 	for (i = 0; i < num_handles; i++) {
255 		struct udevice *dev;
256 		const u16 *name;
257 		bool is_part;
258 		int len;
259 
260 		ret = boot->handle_protocol(handle[i], &efi_devpath_guid,
261 					    (void **)&path);
262 		if (ret) {
263 			log_warning("- devpath %d failed (ret=%d)\n", i, ret);
264 			continue;
265 		}
266 
267 		ret = boot->handle_protocol(handle[i], &efi_blkio_guid,
268 					    (void **)&blkio);
269 		if (ret) {
270 			log_warning("- blkio %d failed (ret=%d)\n", i, ret);
271 			continue;
272 		}
273 
274 		name = text->convert_device_path_to_text(path, true, false);
275 		is_part = devpath_is_partition(path);
276 
277 		if (!is_part) {
278 			len = util->get_device_path_size(path);
279 			ret = efi_bind_block(handle[i], blkio, path, len, &dev);
280 			if (ret) {
281 				log_warning("- blkio bind %d failed (ret=%d)\n",
282 					    i, ret);
283 				continue;
284 			}
285 		} else {
286 			dev = NULL;
287 		}
288 
289 		/*
290 		 * Show the device name if we created one. Otherwise indicate
291 		 * that it is a partition.
292 		 */
293 		printf("%2d: %-12s %ls\n", i, dev ? dev->name : "<partition>",
294 		       name);
295 	}
296 	boot->free_pool(handle);
297 
298 	return 0;
299 }
300 
301 /**
302  * dm_scan_other() - Scan for UEFI devices that should be available to U-Boot
303  *
304  * This sets up block devices within U-Boot for those found in UEFI. With this,
305  * U-Boot can access those devices
306  *
307  * @pre_reloc_only: true to only bind pre-relocation devices (ignored)
308  * Returns: 0 on success, -ve on error
309  */
dm_scan_other(bool pre_reloc_only)310 int dm_scan_other(bool pre_reloc_only)
311 {
312 	if (gd->flags & GD_FLG_RELOC) {
313 		int ret;
314 
315 		ret = setup_block();
316 		if (ret)
317 			return ret;
318 	}
319 
320 	return 0;
321 }
322 
323 /**
324  * efi_main() - Start an EFI image
325  *
326  * This function is called by our EFI start-up code. It handles running
327  * U-Boot. If it returns, EFI will continue. Another way to get back to EFI
328  * is via reset_cpu().
329  */
efi_main(efi_handle_t image,struct efi_system_table * sys_table)330 efi_status_t EFIAPI efi_main(efi_handle_t image,
331 			     struct efi_system_table *sys_table)
332 {
333 	struct efi_priv local_priv, *priv = &local_priv;
334 	efi_status_t ret;
335 
336 	/* Set up access to EFI data structures */
337 	ret = efi_init(priv, "App", image, sys_table);
338 	if (ret) {
339 		printf("Failed to set up U-Boot: err=%lx\n", ret);
340 		return ret;
341 	}
342 	efi_set_priv(priv);
343 
344 	/*
345 	 * Set up the EFI debug UART so that printf() works. This is
346 	 * implemented in the EFI serial driver, serial_efi.c. The application
347 	 * can use printf() freely.
348 	 */
349 	debug_uart_init();
350 
351 	ret = setup_memory(priv);
352 	if (ret) {
353 		printf("Failed to set up memory: ret=%lx\n", ret);
354 		return ret;
355 	}
356 
357 	/*
358 	 * We could store the EFI memory map here, but it changes all the time,
359 	 * so this is only useful for debugging.
360 	 *
361 	 * ret = efi_store_memory_map(priv);
362 	 * if (ret)
363 	 *	return ret;
364 	 */
365 
366 	printf("starting\n");
367 
368 	board_init_f(GD_FLG_SKIP_RELOC);
369 	board_init_r(NULL, 0);
370 	free_memory(priv);
371 
372 	return EFI_SUCCESS;
373 }
374 
efi_exit(void)375 static void efi_exit(void)
376 {
377 	struct efi_priv *priv = efi_get_priv();
378 
379 	free_memory(priv);
380 	printf("U-Boot EFI exiting\n");
381 	priv->boot->exit(priv->parent_image, EFI_SUCCESS, 0, NULL);
382 }
383 
efi_sysreset_request(struct udevice * dev,enum sysreset_t type)384 static int efi_sysreset_request(struct udevice *dev, enum sysreset_t type)
385 {
386 	efi_exit();
387 
388 	return -EINPROGRESS;
389 }
390 
391 static const struct udevice_id efi_sysreset_ids[] = {
392 	{ .compatible = "efi,reset" },
393 	{ }
394 };
395 
396 static struct sysreset_ops efi_sysreset_ops = {
397 	.request = efi_sysreset_request,
398 };
399 
400 U_BOOT_DRIVER(efi_sysreset) = {
401 	.name = "efi-sysreset",
402 	.id = UCLASS_SYSRESET,
403 	.of_match = efi_sysreset_ids,
404 	.ops = &efi_sysreset_ops,
405 };
406