xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision ad5b5801)
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 #ifdef CONFIG_SYS_CACHELINE_SIZE
24 #define EFI_CACHELINE_SIZE CONFIG_SYS_CACHELINE_SIZE
25 #else
26 /* Just use the greatest cache flush alignment requirement I'm aware of */
27 #define EFI_CACHELINE_SIZE 128
28 #endif
29 
30 #if defined(CONFIG_ARM64)
31 #define R_RELATIVE	1027
32 #define R_MASK		0xffffffffULL
33 #define IS_RELA		1
34 #elif defined(CONFIG_ARM)
35 #define R_RELATIVE	23
36 #define R_MASK		0xffULL
37 #else
38 #error Need to add relocation awareness
39 #endif
40 
41 struct elf_rel {
42 	ulong *offset;
43 	ulong info;
44 };
45 
46 struct elf_rela {
47 	ulong *offset;
48 	ulong info;
49 	long addend;
50 };
51 
52 /*
53  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
54  * payload are running concurrently at the same time. In this mode, we can
55  * handle a good number of runtime callbacks
56  */
57 
58 static void EFIAPI efi_reset_system(enum efi_reset_type reset_type,
59 				    efi_status_t reset_status,
60 				    unsigned long data_size, void *reset_data)
61 {
62 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
63 		  reset_data);
64 
65 	switch (reset_type) {
66 	case EFI_RESET_COLD:
67 	case EFI_RESET_WARM:
68 		do_reset(NULL, 0, 0, NULL);
69 		break;
70 	case EFI_RESET_SHUTDOWN:
71 		/* We don't have anything to map this to */
72 		break;
73 	}
74 
75 	EFI_EXIT(EFI_SUCCESS);
76 }
77 
78 static efi_status_t EFIAPI efi_get_time(struct efi_time *time,
79 					struct efi_time_cap *capabilities)
80 {
81 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
82 	struct rtc_time tm;
83 	int r;
84 	struct udevice *dev;
85 
86 	EFI_ENTRY("%p %p", time, capabilities);
87 
88 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
89 	if (r)
90 		return EFI_EXIT(EFI_DEVICE_ERROR);
91 
92 	r = dm_rtc_get(dev, &tm);
93 	if (r)
94 		return EFI_EXIT(EFI_DEVICE_ERROR);
95 
96 	memset(time, 0, sizeof(*time));
97 	time->year = tm.tm_year;
98 	time->month = tm.tm_mon;
99 	time->day = tm.tm_mday;
100 	time->hour = tm.tm_hour;
101 	time->minute = tm.tm_min;
102 	time->daylight = tm.tm_isdst;
103 
104 	return EFI_EXIT(EFI_SUCCESS);
105 #else
106 	return EFI_DEVICE_ERROR;
107 #endif
108 }
109 
110 struct efi_runtime_detach_list_struct {
111 	void *ptr;
112 	void *patchto;
113 };
114 
115 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
116 	{
117 		/* do_reset is gone */
118 		.ptr = &efi_runtime_services.reset_system,
119 		.patchto = NULL,
120 	}, {
121 		/* invalidate_*cache_all are gone */
122 		.ptr = &efi_runtime_services.set_virtual_address_map,
123 		.patchto = &efi_invalid_parameter,
124 	}, {
125 		/* RTC accessors are gone */
126 		.ptr = &efi_runtime_services.get_time,
127 		.patchto = &efi_device_error,
128 	},
129 };
130 
131 static bool efi_runtime_tobedetached(void *p)
132 {
133 	int i;
134 
135 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
136 		if (efi_runtime_detach_list[i].ptr == p)
137 			return true;
138 
139 	return false;
140 }
141 
142 static void efi_runtime_detach(ulong offset)
143 {
144 	int i;
145 	ulong patchoff = offset - (ulong)gd->relocaddr;
146 
147 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
148 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
149 		ulong *p = efi_runtime_detach_list[i].ptr;
150 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
151 
152 #ifdef DEBUG_EFI
153 		printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
154 #endif
155 		*p = newaddr;
156 	}
157 }
158 
159 /* Relocate EFI runtime to uboot_reloc_base = offset */
160 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
161 {
162 #ifdef IS_RELA
163 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
164 #else
165 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
166 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
167 #endif
168 
169 #ifdef DEBUG_EFI
170 	printf("%s: Relocating to offset=%lx\n", __func__, offset);
171 #endif
172 
173 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
174 		ulong base = CONFIG_SYS_TEXT_BASE;
175 		ulong *p;
176 		ulong newaddr;
177 
178 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
179 
180 		if ((rel->info & R_MASK) != R_RELATIVE) {
181 			continue;
182 		}
183 
184 #ifdef IS_RELA
185 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
186 #else
187 		newaddr = *p - lastoff + offset;
188 #endif
189 
190 		/* Check if the relocation is inside bounds */
191 		if (map && ((newaddr < map->virtual_start) ||
192 		    newaddr > (map->virtual_start + (map->num_pages << 12)))) {
193 			if (!efi_runtime_tobedetached(p))
194 				printf("U-Boot EFI: Relocation at %p is out of "
195 				       "range (%lx)\n", p, newaddr);
196 			continue;
197 		}
198 
199 #ifdef DEBUG_EFI
200 		printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
201 #endif
202 
203 		*p = newaddr;
204 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
205 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
206 	}
207 
208 #ifndef IS_RELA
209 	lastoff = offset;
210 #endif
211 
212         invalidate_icache_all();
213 }
214 
215 static efi_status_t EFIAPI efi_set_virtual_address_map(
216 			unsigned long memory_map_size,
217 			unsigned long descriptor_size,
218 			uint32_t descriptor_version,
219 			struct efi_mem_desc *virtmap)
220 {
221 	ulong runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL;
222 	int n = memory_map_size / descriptor_size;
223 	int i;
224 
225 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
226 		  descriptor_version, virtmap);
227 
228 	for (i = 0; i < n; i++) {
229 		struct efi_mem_desc *map;
230 
231 		map = (void*)virtmap + (descriptor_size * i);
232 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
233 			ulong new_offset = map->virtual_start - (runtime_start - gd->relocaddr);
234 
235 			efi_runtime_relocate(new_offset, map);
236 			/* Once we're virtual, we can no longer handle
237 			   complex callbacks */
238 			efi_runtime_detach(new_offset);
239 			return EFI_EXIT(EFI_SUCCESS);
240 		}
241 	}
242 
243 	return EFI_EXIT(EFI_INVALID_PARAMETER);
244 }
245 
246 /*
247  * In the second stage, U-Boot has disappeared. To isolate our runtime code
248  * that at this point still exists from the rest, we put it into a special
249  * section.
250  *
251  *        !!WARNING!!
252  *
253  * This means that we can not rely on any code outside of this file in any
254  * function or variable below this line.
255  *
256  * Please keep everything fully self-contained and annotated with
257  * EFI_RUNTIME_TEXT and EFI_RUNTIME_DATA markers.
258  */
259 
260 /*
261  * Relocate the EFI runtime stub to a different place. We need to call this
262  * the first time we expose the runtime interface to a user and on set virtual
263  * address map calls.
264  */
265 
266 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void)
267 {
268 	return EFI_UNSUPPORTED;
269 }
270 
271 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void)
272 {
273 	return EFI_DEVICE_ERROR;
274 }
275 
276 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void)
277 {
278 	return EFI_INVALID_PARAMETER;
279 }
280 
281 struct efi_runtime_services EFI_RUNTIME_DATA efi_runtime_services = {
282 	.hdr = {
283 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
284 		.revision = EFI_RUNTIME_SERVICES_REVISION,
285 		.headersize = sizeof(struct efi_table_hdr),
286 	},
287 	.get_time = &efi_get_time,
288 	.set_time = (void *)&efi_device_error,
289 	.get_wakeup_time = (void *)&efi_unimplemented,
290 	.set_wakeup_time = (void *)&efi_unimplemented,
291 	.set_virtual_address_map = &efi_set_virtual_address_map,
292 	.convert_pointer = (void *)&efi_invalid_parameter,
293 	.get_variable = (void *)&efi_device_error,
294 	.get_next_variable = (void *)&efi_device_error,
295 	.set_variable = (void *)&efi_device_error,
296 	.get_next_high_mono_count = (void *)&efi_device_error,
297 	.reset_system = &efi_reset_system,
298 };
299