xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision 8c30b571)
1 /*
2  *  EFI application runtime services
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 <dm.h>
12 #include <efi_loader.h>
13 #include <rtc.h>
14 #include <asm/global_data.h>
15 
16 /* For manual relocation support */
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void);
20 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void);
21 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void);
22 
23 #if defined(CONFIG_ARM64)
24 #define R_RELATIVE	1027
25 #define R_MASK		0xffffffffULL
26 #define IS_RELA		1
27 #elif defined(CONFIG_ARM)
28 #define R_RELATIVE	23
29 #define R_MASK		0xffULL
30 #else
31 #error Need to add relocation awareness
32 #endif
33 
34 struct elf_rel {
35 	ulong *offset;
36 	ulong info;
37 };
38 
39 struct elf_rela {
40 	ulong *offset;
41 	ulong info;
42 	long addend;
43 };
44 
45 /*
46  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
47  * payload are running concurrently at the same time. In this mode, we can
48  * handle a good number of runtime callbacks
49  */
50 
51 static void EFIAPI efi_reset_system(enum efi_reset_type reset_type,
52 				    efi_status_t reset_status,
53 				    unsigned long data_size, void *reset_data)
54 {
55 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
56 		  reset_data);
57 
58 	switch (reset_type) {
59 	case EFI_RESET_COLD:
60 	case EFI_RESET_WARM:
61 		do_reset(NULL, 0, 0, NULL);
62 		break;
63 	case EFI_RESET_SHUTDOWN:
64 		/* We don't have anything to map this to */
65 		break;
66 	}
67 
68 	EFI_EXIT(EFI_SUCCESS);
69 }
70 
71 static efi_status_t EFIAPI efi_get_time(struct efi_time *time,
72 					struct efi_time_cap *capabilities)
73 {
74 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
75 	struct rtc_time tm;
76 	int r;
77 	struct udevice *dev;
78 
79 	EFI_ENTRY("%p %p", time, capabilities);
80 
81 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
82 	if (r)
83 		return EFI_EXIT(EFI_DEVICE_ERROR);
84 
85 	r = dm_rtc_get(dev, &tm);
86 	if (r)
87 		return EFI_EXIT(EFI_DEVICE_ERROR);
88 
89 	memset(time, 0, sizeof(*time));
90 	time->year = tm.tm_year;
91 	time->month = tm.tm_mon;
92 	time->day = tm.tm_mday;
93 	time->hour = tm.tm_hour;
94 	time->minute = tm.tm_min;
95 	time->daylight = tm.tm_isdst;
96 
97 	return EFI_EXIT(EFI_SUCCESS);
98 #else
99 	return EFI_DEVICE_ERROR;
100 #endif
101 }
102 
103 struct efi_runtime_detach_list_struct {
104 	void *ptr;
105 	void *patchto;
106 };
107 
108 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
109 	{
110 		/* do_reset is gone */
111 		.ptr = &efi_runtime_services.reset_system,
112 		.patchto = NULL,
113 	}, {
114 		/* invalidate_*cache_all are gone */
115 		.ptr = &efi_runtime_services.set_virtual_address_map,
116 		.patchto = &efi_invalid_parameter,
117 	}, {
118 		/* RTC accessors are gone */
119 		.ptr = &efi_runtime_services.get_time,
120 		.patchto = &efi_device_error,
121 	},
122 };
123 
124 static bool efi_runtime_tobedetached(void *p)
125 {
126 	int i;
127 
128 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
129 		if (efi_runtime_detach_list[i].ptr == p)
130 			return true;
131 
132 	return false;
133 }
134 
135 static void efi_runtime_detach(ulong offset)
136 {
137 	int i;
138 	ulong patchoff = offset - (ulong)gd->relocaddr;
139 
140 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
141 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
142 		ulong *p = efi_runtime_detach_list[i].ptr;
143 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
144 
145 #ifdef DEBUG_EFI
146 		printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
147 #endif
148 		*p = newaddr;
149 	}
150 }
151 
152 /* Relocate EFI runtime to uboot_reloc_base = offset */
153 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
154 {
155 #ifdef IS_RELA
156 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
157 #else
158 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
159 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
160 #endif
161 
162 #ifdef DEBUG_EFI
163 	printf("%s: Relocating to offset=%lx\n", __func__, offset);
164 #endif
165 
166 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
167 		ulong base = CONFIG_SYS_TEXT_BASE;
168 		ulong *p;
169 		ulong newaddr;
170 
171 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
172 
173 		if ((rel->info & R_MASK) != R_RELATIVE) {
174 			continue;
175 		}
176 
177 #ifdef IS_RELA
178 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
179 #else
180 		newaddr = *p - lastoff + offset;
181 #endif
182 
183 		/* Check if the relocation is inside bounds */
184 		if (map && ((newaddr < map->virtual_start) ||
185 		    newaddr > (map->virtual_start + (map->num_pages << 12)))) {
186 			if (!efi_runtime_tobedetached(p))
187 				printf("U-Boot EFI: Relocation at %p is out of "
188 				       "range (%lx)\n", p, newaddr);
189 			continue;
190 		}
191 
192 #ifdef DEBUG_EFI
193 		printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
194 #endif
195 
196 		*p = newaddr;
197 		flush_dcache_range((ulong)p, (ulong)&p[1]);
198 	}
199 
200 #ifndef IS_RELA
201 	lastoff = offset;
202 #endif
203 
204         invalidate_icache_all();
205 }
206 
207 static efi_status_t EFIAPI efi_set_virtual_address_map(
208 			unsigned long memory_map_size,
209 			unsigned long descriptor_size,
210 			uint32_t descriptor_version,
211 			struct efi_mem_desc *virtmap)
212 {
213 	ulong runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL;
214 	int n = memory_map_size / descriptor_size;
215 	int i;
216 
217 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
218 		  descriptor_version, virtmap);
219 
220 	for (i = 0; i < n; i++) {
221 		struct efi_mem_desc *map;
222 
223 		map = (void*)virtmap + (descriptor_size * i);
224 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
225 			ulong new_offset = map->virtual_start - (runtime_start - gd->relocaddr);
226 
227 			efi_runtime_relocate(new_offset, map);
228 			/* Once we're virtual, we can no longer handle
229 			   complex callbacks */
230 			efi_runtime_detach(new_offset);
231 			return EFI_EXIT(EFI_SUCCESS);
232 		}
233 	}
234 
235 	return EFI_EXIT(EFI_INVALID_PARAMETER);
236 }
237 
238 /*
239  * In the second stage, U-Boot has disappeared. To isolate our runtime code
240  * that at this point still exists from the rest, we put it into a special
241  * section.
242  *
243  *        !!WARNING!!
244  *
245  * This means that we can not rely on any code outside of this file in any
246  * function or variable below this line.
247  *
248  * Please keep everything fully self-contained and annotated with
249  * EFI_RUNTIME_TEXT and EFI_RUNTIME_DATA markers.
250  */
251 
252 /*
253  * Relocate the EFI runtime stub to a different place. We need to call this
254  * the first time we expose the runtime interface to a user and on set virtual
255  * address map calls.
256  */
257 
258 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void)
259 {
260 	return EFI_UNSUPPORTED;
261 }
262 
263 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void)
264 {
265 	return EFI_DEVICE_ERROR;
266 }
267 
268 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void)
269 {
270 	return EFI_INVALID_PARAMETER;
271 }
272 
273 struct efi_runtime_services EFI_RUNTIME_DATA efi_runtime_services = {
274 	.hdr = {
275 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
276 		.revision = EFI_RUNTIME_SERVICES_REVISION,
277 		.headersize = sizeof(struct efi_table_hdr),
278 	},
279 	.get_time = &efi_get_time,
280 	.set_time = (void *)&efi_device_error,
281 	.get_wakeup_time = (void *)&efi_unimplemented,
282 	.set_wakeup_time = (void *)&efi_unimplemented,
283 	.set_virtual_address_map = &efi_set_virtual_address_map,
284 	.convert_pointer = (void *)&efi_invalid_parameter,
285 	.get_variable = (void *)&efi_device_error,
286 	.get_next_variable = (void *)&efi_device_error,
287 	.set_variable = (void *)&efi_device_error,
288 	.get_next_high_mono_count = (void *)&efi_device_error,
289 	.reset_system = &efi_reset_system,
290 };
291