xref: /openbmc/u-boot/arch/arm/cpu/armv8/sec_firmware.c (revision 12308b12)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2016 NXP Semiconductor, Inc.
4  */
5 
6 #include <common.h>
7 #include <errno.h>
8 #include <linux/kernel.h>
9 #include <asm/io.h>
10 #include <asm/system.h>
11 #include <asm/types.h>
12 #include <asm/macro.h>
13 #include <asm/armv8/sec_firmware.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 extern void c_runtime_cpu_setup(void);
17 
18 #define SEC_FIRMWARE_LOADED	0x1
19 #define SEC_FIRMWARE_RUNNING	0x2
20 #define SEC_FIRMWARE_ADDR_MASK	(~0x3)
21 /*
22  * Secure firmware load addr
23  * Flags used: 0x1 secure firmware has been loaded to secure memory
24  *             0x2 secure firmware is running
25  */
26 phys_addr_t sec_firmware_addr;
27 
28 #ifndef SEC_FIRMWARE_FIT_IMAGE
29 #define SEC_FIRMWARE_FIT_IMAGE		"firmware"
30 #endif
31 #ifndef SEC_FIRMEWARE_FIT_CNF_NAME
32 #define SEC_FIRMEWARE_FIT_CNF_NAME	"config-1"
33 #endif
34 #ifndef SEC_FIRMWARE_TARGET_EL
35 #define SEC_FIRMWARE_TARGET_EL		2
36 #endif
37 
38 static int sec_firmware_get_data(const void *sec_firmware_img,
39 				const void **data, size_t *size)
40 {
41 	int conf_node_off, fw_node_off;
42 	char *conf_node_name = NULL;
43 	char *desc;
44 	int ret;
45 
46 	conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
47 
48 	conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
49 	if (conf_node_off < 0) {
50 		printf("SEC Firmware: %s: no such config\n", conf_node_name);
51 		return -ENOENT;
52 	}
53 
54 	fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
55 			SEC_FIRMWARE_FIT_IMAGE);
56 	if (fw_node_off < 0) {
57 		printf("SEC Firmware: No '%s' in config\n",
58 		       SEC_FIRMWARE_FIT_IMAGE);
59 		return -ENOLINK;
60 	}
61 
62 	/* Verify secure firmware image */
63 	if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
64 		printf("SEC Firmware: Bad firmware image (bad CRC)\n");
65 		return -EINVAL;
66 	}
67 
68 	if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
69 		printf("SEC Firmware: Can't get %s subimage data/size",
70 		       SEC_FIRMWARE_FIT_IMAGE);
71 		return -ENOENT;
72 	}
73 
74 	ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
75 	if (ret)
76 		printf("SEC Firmware: Can't get description\n");
77 	else
78 		printf("%s\n", desc);
79 
80 	return ret;
81 }
82 
83 /*
84  * SEC Firmware FIT image parser checks if the image is in FIT
85  * format, verifies integrity of the image and calculates raw
86  * image address and size values.
87  *
88  * Returns 0 on success and a negative errno on error task fail.
89  */
90 static int sec_firmware_parse_image(const void *sec_firmware_img,
91 					const void **raw_image_addr,
92 					size_t *raw_image_size)
93 {
94 	int ret;
95 
96 	ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
97 					raw_image_size);
98 	if (ret)
99 		return ret;
100 
101 	debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
102 	      *raw_image_addr, *raw_image_size);
103 
104 	return 0;
105 }
106 
107 /*
108  * SEC Firmware FIT image parser to check if any loadable is
109  * present. If present, verify integrity of the loadable and
110  * copy loadable to address provided in (loadable_h, loadable_l).
111  *
112  * Returns 0 on success and a negative errno on error task fail.
113  */
114 static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
115 					    u32 *loadable_l, u32 *loadable_h)
116 {
117 	phys_addr_t sec_firmware_loadable_addr = 0;
118 	int conf_node_off, ld_node_off, images;
119 	char *conf_node_name = NULL;
120 	const void *data;
121 	size_t size;
122 	ulong load;
123 	const char *name, *str, *type;
124 	int len;
125 
126 	conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
127 
128 	conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
129 	if (conf_node_off < 0) {
130 		printf("SEC Firmware: %s: no such config\n", conf_node_name);
131 		return -ENOENT;
132 	}
133 
134 	/* find the node holding the images information */
135 	images = fdt_path_offset(sec_firmware_img, FIT_IMAGES_PATH);
136 	if (images < 0) {
137 		printf("%s: Cannot find /images node: %d\n", __func__, images);
138 		return -1;
139 	}
140 
141 	type = FIT_LOADABLE_PROP;
142 
143 	name = fdt_getprop(sec_firmware_img, conf_node_off, type, &len);
144 	if (!name) {
145 		/* Loadables not present */
146 		return 0;
147 	}
148 
149 	printf("SEC Firmware: '%s' present in config\n", type);
150 
151 	for (str = name; str && ((str - name) < len);
152 	     str = strchr(str, '\0') + 1) {
153 		printf("%s: '%s'\n", type, str);
154 		ld_node_off = fdt_subnode_offset(sec_firmware_img, images, str);
155 		if (ld_node_off < 0) {
156 			printf("cannot find image node '%s': %d\n", str,
157 			       ld_node_off);
158 			return -EINVAL;
159 		}
160 
161 		/* Verify secure firmware image */
162 		if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
163 			printf("SEC Loadable: Bad loadable image (bad CRC)\n");
164 			return -EINVAL;
165 		}
166 
167 		if (fit_image_get_data(sec_firmware_img, ld_node_off,
168 				       &data, &size)) {
169 			printf("SEC Loadable: Can't get subimage data/size");
170 			return -ENOENT;
171 		}
172 
173 		/* Get load address, treated as load offset to secure memory */
174 		if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
175 			printf("SEC Loadable: Can't get subimage load");
176 			return -ENOENT;
177 		}
178 
179 		/* Compute load address for loadable in secure memory */
180 		sec_firmware_loadable_addr = (sec_firmware_addr -
181 						gd->arch.tlb_size) + load;
182 
183 		/* Copy loadable to secure memory and flush dcache */
184 		debug("%s copied to address 0x%p\n",
185 		      FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
186 		memcpy((void *)sec_firmware_loadable_addr, data, size);
187 		flush_dcache_range(sec_firmware_loadable_addr,
188 				   sec_firmware_loadable_addr + size);
189 
190 		/* Populate loadable address only for Trusted OS */
191 		if (!strcmp(str, "trustedOS@1")) {
192 			/*
193 			 * Populate address ptrs for loadable image with
194 			 * loadbale addr
195 			 */
196 			out_le32(loadable_l, (sec_firmware_loadable_addr &
197 					      WORD_MASK));
198 			out_le32(loadable_h, (sec_firmware_loadable_addr >>
199 					      WORD_SHIFT));
200 		}
201 	}
202 
203 	return 0;
204 }
205 
206 static int sec_firmware_copy_image(const char *title,
207 			 u64 image_addr, u32 image_size, u64 sec_firmware)
208 {
209 	debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
210 	memcpy((void *)sec_firmware, (void *)image_addr, image_size);
211 	flush_dcache_range(sec_firmware, sec_firmware + image_size);
212 
213 	return 0;
214 }
215 
216 /*
217  * This function will parse the SEC Firmware image, and then load it
218  * to secure memory. Also load any loadable if present along with SEC
219  * Firmware image.
220  */
221 static int sec_firmware_load_image(const void *sec_firmware_img,
222 				   u32 *loadable_l, u32 *loadable_h)
223 {
224 	const void *raw_image_addr;
225 	size_t raw_image_size = 0;
226 	int ret;
227 
228 	/*
229 	 * The Excetpion Level must be EL3 to load and initialize
230 	 * the SEC Firmware.
231 	 */
232 	if (current_el() != 3) {
233 		ret = -EACCES;
234 		goto out;
235 	}
236 
237 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
238 	/*
239 	 * The SEC Firmware must be stored in secure memory.
240 	 * Append SEC Firmware to secure mmu table.
241 	 */
242 	if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
243 		ret = -ENXIO;
244 		goto out;
245 	}
246 
247 	sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
248 			gd->arch.tlb_size;
249 #else
250 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
251 #endif
252 
253 	/* Align SEC Firmware base address to 4K */
254 	sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
255 	debug("SEC Firmware: Load address: 0x%llx\n",
256 	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
257 
258 	ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
259 			&raw_image_size);
260 	if (ret)
261 		goto out;
262 
263 	/* TODO:
264 	 * Check if the end addr of SEC Firmware has been extend the secure
265 	 * memory.
266 	 */
267 
268 	/* Copy the secure firmware to secure memory */
269 	ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
270 			raw_image_size, sec_firmware_addr &
271 			SEC_FIRMWARE_ADDR_MASK);
272 	if (ret)
273 		goto out;
274 
275 	/*
276 	 * Check if any loadable are present along with firmware image, if
277 	 * present load them.
278 	 */
279 	ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
280 					       loadable_h);
281 	if (ret)
282 		goto out;
283 
284 	sec_firmware_addr |= SEC_FIRMWARE_LOADED;
285 	debug("SEC Firmware: Entry point: 0x%llx\n",
286 	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
287 
288 	return 0;
289 
290 out:
291 	printf("SEC Firmware: error (%d)\n", ret);
292 	sec_firmware_addr = 0;
293 
294 	return ret;
295 }
296 
297 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
298 {
299 	const void *entry = (void *)(sec_firmware_addr &
300 				SEC_FIRMWARE_ADDR_MASK);
301 
302 	return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
303 }
304 
305 /* Check the secure firmware FIT image */
306 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
307 {
308 	if (fdt_check_header(sec_firmware_img)) {
309 		printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
310 		return false;
311 	}
312 
313 	if (!fit_check_format(sec_firmware_img)) {
314 		printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
315 		return false;
316 	}
317 
318 	return true;
319 }
320 
321 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
322 /*
323  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
324  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
325  * number will be returned according to SMC Calling Conventions. But
326  * when getting the NOT_SUPPORTED error number, we cannot ensure if
327  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
328  * won't be supported by this framework.
329  * And if the secure firmware isn't running, return NOT_SUPPORTED.
330  *
331  * The return value on success is PSCI version in format
332  * major[31:16]:minor[15:0].
333  */
334 unsigned int sec_firmware_support_psci_version(void)
335 {
336 	if (current_el() == SEC_FIRMWARE_TARGET_EL)
337 		return _sec_firmware_support_psci_version();
338 
339 	return PSCI_INVALID_VER;
340 }
341 #endif
342 
343 /*
344  * Check with sec_firmware if it supports random number generation
345  * via HW RNG
346  *
347  * The return value will be true if it is supported
348  */
349 bool sec_firmware_support_hwrng(void)
350 {
351 	if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
352 			return true;
353 	}
354 
355 	return false;
356 }
357 
358 /*
359  * sec_firmware_get_random - Get a random number from SEC Firmware
360  * @rand:		random number buffer to be filled
361  * @bytes:		Number of bytes of random number to be supported
362  * @eret:		-1 in case of error, 0 for success
363  */
364 int sec_firmware_get_random(uint8_t *rand, int bytes)
365 {
366 	unsigned long long num;
367 	struct pt_regs regs;
368 	int param1;
369 
370 	if (!bytes || bytes > 8) {
371 		printf("Max Random bytes genration supported is 8\n");
372 		return -1;
373 	}
374 #define SIP_RNG_64 0xC200FF11
375 	regs.regs[0] = SIP_RNG_64;
376 
377 	if (bytes <= 4)
378 		param1 = 0;
379 	else
380 		param1 = 1;
381 	regs.regs[1] = param1;
382 
383 	smc_call(&regs);
384 
385 	if (regs.regs[0])
386 		return -1;
387 
388 	num = regs.regs[1];
389 	memcpy(rand, &num, bytes);
390 
391 	return 0;
392 }
393 
394 /*
395  * sec_firmware_init - Initialize the SEC Firmware
396  * @sec_firmware_img:	the SEC Firmware image address
397  * @eret_hold_l:	the address to hold exception return address low
398  * @eret_hold_h:	the address to hold exception return address high
399  * @loadable_l:		the address to hold loadable address low
400  * @loadable_h:		the address to hold loadable address high
401  */
402 int sec_firmware_init(const void *sec_firmware_img,
403 			u32 *eret_hold_l,
404 			u32 *eret_hold_h,
405 			u32 *loadable_l,
406 			u32 *loadable_h)
407 {
408 	int ret;
409 
410 	if (!sec_firmware_is_valid(sec_firmware_img))
411 		return -EINVAL;
412 
413 	ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
414 				      loadable_h);
415 	if (ret) {
416 		printf("SEC Firmware: Failed to load image\n");
417 		return ret;
418 	} else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
419 		ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
420 		if (ret) {
421 			printf("SEC Firmware: Failed to initialize\n");
422 			return ret;
423 		}
424 	}
425 
426 	debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
427 	      current_el());
428 
429 	/*
430 	 * The PE will be turned into target EL when returned from
431 	 * SEC Firmware.
432 	 */
433 	if (current_el() != SEC_FIRMWARE_TARGET_EL)
434 		return -EACCES;
435 
436 	sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
437 
438 	/* Set exception table and enable caches if it isn't EL3 */
439 	if (current_el() != 3) {
440 		c_runtime_cpu_setup();
441 		enable_caches();
442 	}
443 
444 	return 0;
445 }
446 
447 /*
448  * fdt_fix_kaslr - Add kalsr-seed node in Device tree
449  * @fdt:		Device tree
450  * @eret:		0 in case of error, 1 for success
451  */
452 int fdt_fixup_kaslr(void *fdt)
453 {
454 	int nodeoffset;
455 	int err, ret = 0;
456 	u8 rand[8];
457 
458 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
459 	/* Check if random seed generation is  supported */
460 	if (sec_firmware_support_hwrng() == false) {
461 		printf("WARNING: SEC firmware not running, no kaslr-seed\n");
462 		return 0;
463 	}
464 
465 	ret = sec_firmware_get_random(rand, 8);
466 	if (ret < 0) {
467 		printf("WARNING: No random number to set kaslr-seed\n");
468 		return 0;
469 	}
470 
471 	err = fdt_check_header(fdt);
472 	if (err < 0) {
473 		printf("fdt_chosen: %s\n", fdt_strerror(err));
474 		return 0;
475 	}
476 
477 	/* find or create "/chosen" node. */
478 	nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
479 	if (nodeoffset < 0)
480 		return 0;
481 
482 	err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
483 				  sizeof(rand));
484 	if (err < 0) {
485 		printf("WARNING: can't set kaslr-seed %s.\n",
486 		       fdt_strerror(err));
487 		return 0;
488 	}
489 	ret = 1;
490 #endif
491 
492 	return ret;
493 }
494