aboutsummaryrefslogtreecommitdiff
path: root/common/bl_common.c
blob: 911ad4c1299f812da68efc9d00e885f688e435fb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
/*
 * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of ARM nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch.h>
#include <arch_helpers.h>
#include <assert.h>
#include <bl_common.h>
#include <debug.h>
#include <io_storage.h>
#include <platform.h>
#include <errno.h>
#include <stdio.h>

unsigned long page_align(unsigned long value, unsigned dir)
{
	unsigned long page_size = 1 << FOUR_KB_SHIFT;

	/* Round up the limit to the next page boundary */
	if (value & (page_size - 1)) {
		value &= ~(page_size - 1);
		if (dir == UP)
			value += page_size;
	}

	return value;
}

static inline unsigned int is_page_aligned (unsigned long addr) {
	const unsigned long page_size = 1 << FOUR_KB_SHIFT;

	return (addr & (page_size - 1)) == 0;
}

void change_security_state(unsigned int target_security_state)
{
	unsigned long scr = read_scr();

	if (target_security_state == SECURE)
		scr &= ~SCR_NS_BIT;
	else if (target_security_state == NON_SECURE)
		scr |= SCR_NS_BIT;
	else
		assert(0);

	write_scr(scr);
}


/*******************************************************************************
 * The next function is a weak definition. Platform specific
 * code can override it if it wishes to.
 ******************************************************************************/

/*******************************************************************************
 * Function that takes a memory layout into which BL2 has been either top or
 * bottom loaded along with the address where BL2 has been loaded in it. Using
 * this information, it populates bl2_mem_layout to tell BL2 how much memory
 * it has access to and how much is available for use.
 ******************************************************************************/
void init_bl2_mem_layout(meminfo_t *bl1_mem_layout,
			 meminfo_t *bl2_mem_layout,
			 unsigned int load_type,
			 unsigned long bl2_base)
{
	unsigned tmp;

	if (load_type == BOT_LOAD) {
		bl2_mem_layout->total_base = bl2_base;
		tmp = bl1_mem_layout->free_base - bl2_base;
		bl2_mem_layout->total_size = bl1_mem_layout->free_size + tmp;

	} else {
		bl2_mem_layout->total_base = bl1_mem_layout->free_base;
		tmp = bl1_mem_layout->total_base + bl1_mem_layout->total_size;
		bl2_mem_layout->total_size = tmp - bl1_mem_layout->free_base;
	}

	bl2_mem_layout->free_base = bl1_mem_layout->free_base;
	bl2_mem_layout->free_size = bl1_mem_layout->free_size;
	bl2_mem_layout->attr = load_type;

	flush_dcache_range((unsigned long) bl2_mem_layout, sizeof(meminfo_t));
	return;
}

static void dump_load_info(unsigned long image_load_addr,
			   unsigned long image_size,
			   const meminfo_t *mem_layout)
{
#if DEBUG
	printf("Trying to load image at address 0x%lx, size = 0x%lx\r\n",
		image_load_addr, image_size);
	printf("Current memory layout:\r\n");
	printf("  total region = [0x%lx, 0x%lx]\r\n", mem_layout->total_base,
			mem_layout->total_base + mem_layout->total_size);
	printf("  free region = [0x%lx, 0x%lx]\r\n", mem_layout->free_base,
			mem_layout->free_base + mem_layout->free_size);
#endif
}

/* Generic function to return the size of an image */
unsigned long image_size(const char *image_name)
{
	uintptr_t dev_handle;
	uintptr_t image_handle;
	uintptr_t image_spec;
	size_t image_size = 0;
	int io_result = IO_FAIL;

	assert(image_name != NULL);

	/* Obtain a reference to the image by querying the platform layer */
	io_result = plat_get_image_source(image_name, &dev_handle, &image_spec);
	if (io_result != IO_SUCCESS) {
		WARN("Failed to obtain reference to image '%s' (%i)\n",
			image_name, io_result);
		return 0;
	}

	/* Attempt to access the image */
	io_result = io_open(dev_handle, image_spec, &image_handle);
	if (io_result != IO_SUCCESS) {
		WARN("Failed to access image '%s' (%i)\n",
			image_name, io_result);
		return 0;
	}

	/* Find the size of the image */
	io_result = io_size(image_handle, &image_size);
	if ((io_result != IO_SUCCESS) || (image_size == 0)) {
		WARN("Failed to determine the size of the image '%s' file (%i)\n",
			image_name, io_result);
	}
	io_result = io_close(image_handle);
	/* Ignore improbable/unrecoverable error in 'close' */

	/* TODO: Consider maintaining open device connection from this
	 * bootloader stage
	 */
	io_result = io_dev_close(dev_handle);
	/* Ignore improbable/unrecoverable error in 'dev_close' */

	return image_size;
}
/*******************************************************************************
 * Generic function to load an image into the trusted RAM,
 * given a name, extents of free memory & whether the image should be loaded at
 * the bottom or top of the free memory. It updates the memory layout if the
 * load is successful. It also updates the image information and the entry point
 * information in the params passed
 ******************************************************************************/
int load_image(meminfo_t *mem_layout,
			 const char *image_name,
			 unsigned int load_type,
			 unsigned long fixed_addr,
			 image_info_t *image_data,
			 entry_point_info_t *entry_point_info)
{
	uintptr_t dev_handle;
	uintptr_t image_handle;
	uintptr_t image_spec;
	unsigned long temp_image_base = 0;
	unsigned long image_base = 0;
	long offset = 0;
	size_t image_size = 0;
	size_t bytes_read = 0;
	int io_result = IO_FAIL;

	assert(mem_layout != NULL);
	assert(image_name != NULL);
	assert(image_data->h.version >= VERSION_1);

	/* Obtain a reference to the image by querying the platform layer */
	io_result = plat_get_image_source(image_name, &dev_handle, &image_spec);
	if (io_result != IO_SUCCESS) {
		WARN("Failed to obtain reference to image '%s' (%i)\n",
			image_name, io_result);
		return io_result;
	}

	/* Attempt to access the image */
	io_result = io_open(dev_handle, image_spec, &image_handle);
	if (io_result != IO_SUCCESS) {
		WARN("Failed to access image '%s' (%i)\n",
			image_name, io_result);
		return io_result;
	}

	/* Find the size of the image */
	io_result = io_size(image_handle, &image_size);
	if ((io_result != IO_SUCCESS) || (image_size == 0)) {
		WARN("Failed to determine the size of the image '%s' file (%i)\n",
			image_name, io_result);
		goto exit;
	}

	/* See if we have enough space */
	if (image_size > mem_layout->free_size) {
		WARN("Cannot load '%s' file: Not enough space.\n",
			image_name);
		dump_load_info(0, image_size, mem_layout);
		goto exit;
	}

	switch (load_type) {

	case TOP_LOAD:

	  /* Load the image in the top of free memory */
	  temp_image_base = mem_layout->free_base + mem_layout->free_size;
	  temp_image_base -= image_size;

	  /* Page align base address and check whether the image still fits */
	  image_base = page_align(temp_image_base, DOWN);
	  assert(image_base <= temp_image_base);

	  if (image_base < mem_layout->free_base) {
		WARN("Cannot load '%s' file: Not enough space.\n",
			image_name);
		dump_load_info(image_base, image_size, mem_layout);
		io_result = -ENOMEM;
		goto exit;
	  }

	  /* Calculate the amount of extra memory used due to alignment */
	  offset = temp_image_base - image_base;

	  break;

	case BOT_LOAD:

	  /* Load the BL2 image in the bottom of free memory */
	  temp_image_base = mem_layout->free_base;
	  image_base = page_align(temp_image_base, UP);
	  assert(image_base >= temp_image_base);

	  /* Page align base address and check whether the image still fits */
	  if (image_base + image_size >
	      mem_layout->free_base + mem_layout->free_size) {
		WARN("Cannot load '%s' file: Not enough space.\n",
		  image_name);
		dump_load_info(image_base, image_size, mem_layout);
		io_result = -ENOMEM;
		goto exit;
	  }

	  /* Calculate the amount of extra memory used due to alignment */
	  offset = image_base - temp_image_base;

	  break;

	default:
	  assert(0);

	}

	/*
	 * Some images must be loaded at a fixed address, not a dynamic one.
	 *
	 * This has been implemented as a hack on top of the existing dynamic
	 * loading mechanism, for the time being.  If the 'fixed_addr' function
	 * argument is different from zero, then it will force the load address.
	 * So we still have this principle of top/bottom loading but the code
	 * determining the load address is bypassed and the load address is
	 * forced to the fixed one.
	 *
	 * This can result in quite a lot of wasted space because we still use
	 * 1 sole meminfo structure to represent the extents of free memory,
	 * where we should use some sort of linked list.
	 *
	 * E.g. we want to load BL2 at address 0x04020000, the resulting memory
	 *      layout should look as follows:
	 * ------------ 0x04040000
	 * |          |  <- Free space (1)
	 * |----------|
	 * |   BL2    |
	 * |----------| 0x04020000
	 * |          |  <- Free space (2)
	 * |----------|
	 * |   BL1    |
	 * ------------ 0x04000000
	 *
	 * But in the current hacky implementation, we'll need to specify
	 * whether BL2 is loaded at the top or bottom of the free memory.
	 * E.g. if BL2 is considered as top-loaded, the meminfo structure
	 * will give the following view of the memory, hiding the chunk of
	 * free memory above BL2:
	 * ------------ 0x04040000
	 * |          |
	 * |          |
	 * |   BL2    |
	 * |----------| 0x04020000
	 * |          |  <- Free space (2)
	 * |----------|
	 * |   BL1    |
	 * ------------ 0x04000000
	 */
	if (fixed_addr != 0) {
		/* Load the image at the given address. */
		image_base = fixed_addr;

		/* Check whether the image fits. */
		if ((image_base < mem_layout->free_base) ||
		    (image_base + image_size >
		       mem_layout->free_base + mem_layout->free_size)) {
			WARN("Cannot load '%s' file: Not enough space.\n",
				image_name);
			dump_load_info(image_base, image_size, mem_layout);
			io_result = -ENOMEM;
			goto exit;
		}

		/* Check whether the fixed load address is page-aligned. */
		if (!is_page_aligned(image_base)) {
			WARN("Cannot load '%s' file at unaligned address 0x%lx\n",
				image_name, fixed_addr);
			io_result = -ENOMEM;
			goto exit;
		}

		/*
		 * Calculate the amount of extra memory used due to fixed
		 * loading.
		 */
		if (load_type == TOP_LOAD) {
			unsigned long max_addr, space_used;
			/*
			 * ------------ max_addr
			 * | /wasted/ |                 | offset
			 * |..........|..............................
			 * |  image   |                 | image_flen
			 * |----------| fixed_addr
			 * |          |
			 * |          |
			 * ------------ total_base
			 */
			max_addr = mem_layout->total_base + mem_layout->total_size;
			/*
			 * Compute the amount of memory used by the image.
			 * Corresponds to all space above the image load
			 * address.
			 */
			space_used = max_addr - fixed_addr;
			/*
			 * Calculate the amount of wasted memory within the
			 * amount of memory used by the image.
			 */
			offset = space_used - image_size;
		} else /* BOT_LOAD */
			/*
			 * ------------
			 * |          |
			 * |          |
			 * |----------|
			 * |  image   |
			 * |..........| fixed_addr
			 * | /wasted/ |                 | offset
			 * ------------ total_base
			 */
			offset = fixed_addr - mem_layout->total_base;
	}

	/* We have enough space so load the image now */
	/* TODO: Consider whether to try to recover/retry a partially successful read */
	io_result = io_read(image_handle, image_base, image_size, &bytes_read);
	if ((io_result != IO_SUCCESS) || (bytes_read < image_size)) {
		WARN("Failed to load '%s' file (%i)\n", image_name, io_result);
		goto exit;
	}

	image_data->image_base = image_base;
	image_data->image_size = image_size;

	entry_point_info->pc = image_base;

	/*
	 * File has been successfully loaded. Update the free memory
	 * data structure & flush the contents of the TZRAM so that
	 * the next EL can see it.
	 */
	/* Update the memory contents */
	flush_dcache_range(image_base, image_size);

	mem_layout->free_size -= image_size + offset;

	/* Update the base of free memory since its moved up */
	if (load_type == BOT_LOAD)
		mem_layout->free_base += offset + image_size;

exit:
	io_close(image_handle);
	/* Ignore improbable/unrecoverable error in 'close' */

	/* TODO: Consider maintaining open device connection from this bootloader stage */
	io_dev_close(dev_handle);
	/* Ignore improbable/unrecoverable error in 'dev_close' */

	return io_result;
}