1/*
2 * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <arch.h>
32#include <arch_helpers.h>
33#include <assert.h>
34#include <bl_common.h>
35#include <debug.h>
36#include <errno.h>
37#include <io_storage.h>
38#include <platform.h>
39
40unsigned long page_align(unsigned long value, unsigned dir)
41{
42	unsigned long page_size = 1 << FOUR_KB_SHIFT;
43
44	/* Round up the limit to the next page boundary */
45	if (value & (page_size - 1)) {
46		value &= ~(page_size - 1);
47		if (dir == UP)
48			value += page_size;
49	}
50
51	return value;
52}
53
54static inline unsigned int is_page_aligned (unsigned long addr) {
55	const unsigned long page_size = 1 << FOUR_KB_SHIFT;
56
57	return (addr & (page_size - 1)) == 0;
58}
59
60void change_security_state(unsigned int target_security_state)
61{
62	unsigned long scr = read_scr();
63
64	assert(sec_state_is_valid(target_security_state));
65	if (target_security_state == SECURE)
66		scr &= ~SCR_NS_BIT;
67	else
68		scr |= SCR_NS_BIT;
69
70	write_scr(scr);
71}
72
73/******************************************************************************
74 * Determine whether the memory region delimited by 'addr' and 'size' is free,
75 * given the extents of free memory.
76 * Return 1 if it is free, 0 otherwise.
77 *****************************************************************************/
78static int is_mem_free(uint64_t free_base, size_t free_size,
79		       uint64_t addr, size_t size)
80{
81	return (addr >= free_base) && (addr + size <= free_base + free_size);
82}
83
84/******************************************************************************
85 * Inside a given memory region, determine whether a sub-region of memory is
86 * closer from the top or the bottom of the encompassing region. Return the
87 * size of the smallest chunk of free memory surrounding the sub-region in
88 * 'small_chunk_size'.
89 *****************************************************************************/
90static unsigned int choose_mem_pos(uint64_t mem_start, uint64_t mem_end,
91				   uint64_t submem_start, uint64_t submem_end,
92				   size_t *small_chunk_size)
93{
94	size_t top_chunk_size, bottom_chunk_size;
95
96	assert(mem_start <= submem_start);
97	assert(submem_start <= submem_end);
98	assert(submem_end <= mem_end);
99	assert(small_chunk_size != NULL);
100
101	top_chunk_size = mem_end - submem_end;
102	bottom_chunk_size = submem_start - mem_start;
103
104	if (top_chunk_size < bottom_chunk_size) {
105		*small_chunk_size = top_chunk_size;
106		return TOP;
107	} else {
108		*small_chunk_size = bottom_chunk_size;
109		return BOTTOM;
110	}
111}
112
113/******************************************************************************
114 * Reserve the memory region delimited by 'addr' and 'size'. The extents of free
115 * memory are passed in 'free_base' and 'free_size' and they will be updated to
116 * reflect the memory usage.
117 * The caller must ensure the memory to reserve is free.
118 *****************************************************************************/
119void reserve_mem(uint64_t *free_base, size_t *free_size,
120		 uint64_t addr, size_t size)
121{
122	size_t discard_size;
123	size_t reserved_size;
124	unsigned int pos;
125
126	assert(free_base != NULL);
127	assert(free_size != NULL);
128	assert(is_mem_free(*free_base, *free_size, addr, size));
129
130	pos = choose_mem_pos(*free_base, *free_base + *free_size,
131			     addr, addr + size,
132			     &discard_size);
133
134	reserved_size = size + discard_size;
135	*free_size -= reserved_size;
136
137	if (pos == BOTTOM)
138		*free_base = addr + size;
139
140	VERBOSE("Reserved %u bytes (discarded %u bytes %s)\n",
141	     reserved_size, discard_size,
142	     pos == TOP ? "above" : "below");
143}
144
145static void dump_load_info(unsigned long image_load_addr,
146			   unsigned long image_size,
147			   const meminfo_t *mem_layout)
148{
149	INFO("Trying to load image at address 0x%lx, size = 0x%lx\n",
150		image_load_addr, image_size);
151	INFO("Current memory layout:\n");
152	INFO("  total region = [0x%lx, 0x%lx]\n", mem_layout->total_base,
153			mem_layout->total_base + mem_layout->total_size);
154	INFO("  free region = [0x%lx, 0x%lx]\n", mem_layout->free_base,
155			mem_layout->free_base + mem_layout->free_size);
156}
157
158/* Generic function to return the size of an image */
159unsigned long image_size(const char *image_name)
160{
161	uintptr_t dev_handle;
162	uintptr_t image_handle;
163	uintptr_t image_spec;
164	size_t image_size = 0;
165	int io_result = IO_FAIL;
166
167	assert(image_name != NULL);
168
169	/* Obtain a reference to the image by querying the platform layer */
170	io_result = plat_get_image_source(image_name, &dev_handle, &image_spec);
171	if (io_result != IO_SUCCESS) {
172		WARN("Failed to obtain reference to image '%s' (%i)\n",
173			image_name, io_result);
174		return 0;
175	}
176
177	/* Attempt to access the image */
178	io_result = io_open(dev_handle, image_spec, &image_handle);
179	if (io_result != IO_SUCCESS) {
180		WARN("Failed to access image '%s' (%i)\n",
181			image_name, io_result);
182		return 0;
183	}
184
185	/* Find the size of the image */
186	io_result = io_size(image_handle, &image_size);
187	if ((io_result != IO_SUCCESS) || (image_size == 0)) {
188		WARN("Failed to determine the size of the image '%s' file (%i)\n",
189			image_name, io_result);
190	}
191	io_result = io_close(image_handle);
192	/* Ignore improbable/unrecoverable error in 'close' */
193
194	/* TODO: Consider maintaining open device connection from this
195	 * bootloader stage
196	 */
197	io_result = io_dev_close(dev_handle);
198	/* Ignore improbable/unrecoverable error in 'dev_close' */
199
200	return image_size;
201}
202
203/*******************************************************************************
204 * Generic function to load an image at a specific address given a name and
205 * extents of free memory. It updates the memory layout if the load is
206 * successful, as well as the image information and the entry point information.
207 * The caller might pass a NULL pointer for the entry point if it is not
208 * interested in this information, e.g. because the image just needs to be
209 * loaded in memory but won't ever be executed.
210 * Returns 0 on success, a negative error code otherwise.
211 ******************************************************************************/
212int load_image(meminfo_t *mem_layout,
213	       const char *image_name,
214	       uint64_t image_base,
215	       image_info_t *image_data,
216	       entry_point_info_t *entry_point_info)
217{
218	uintptr_t dev_handle;
219	uintptr_t image_handle;
220	uintptr_t image_spec;
221	size_t image_size;
222	size_t bytes_read;
223	int io_result = IO_FAIL;
224
225	assert(mem_layout != NULL);
226	assert(image_name != NULL);
227	assert(image_data != NULL);
228	assert(image_data->h.version >= VERSION_1);
229
230	/* Obtain a reference to the image by querying the platform layer */
231	io_result = plat_get_image_source(image_name, &dev_handle, &image_spec);
232	if (io_result != IO_SUCCESS) {
233		WARN("Failed to obtain reference to image '%s' (%i)\n",
234			image_name, io_result);
235		return io_result;
236	}
237
238	/* Attempt to access the image */
239	io_result = io_open(dev_handle, image_spec, &image_handle);
240	if (io_result != IO_SUCCESS) {
241		WARN("Failed to access image '%s' (%i)\n",
242			image_name, io_result);
243		return io_result;
244	}
245
246	INFO("Loading file '%s' at address 0x%lx\n", image_name, image_base);
247
248	/* Find the size of the image */
249	io_result = io_size(image_handle, &image_size);
250	if ((io_result != IO_SUCCESS) || (image_size == 0)) {
251		WARN("Failed to determine the size of the image '%s' file (%i)\n",
252			image_name, io_result);
253		goto exit;
254	}
255
256	/* Check that the memory where the image will be loaded is free */
257	if (!is_mem_free(mem_layout->free_base, mem_layout->free_size,
258			 image_base, image_size)) {
259		WARN("Failed to reserve memory: 0x%lx - 0x%lx\n",
260			image_base, image_base + image_size);
261		dump_load_info(image_base, image_size, mem_layout);
262		io_result = -ENOMEM;
263		goto exit;
264	}
265
266	/* We have enough space so load the image now */
267	/* TODO: Consider whether to try to recover/retry a partially successful read */
268	io_result = io_read(image_handle, image_base, image_size, &bytes_read);
269	if ((io_result != IO_SUCCESS) || (bytes_read < image_size)) {
270		WARN("Failed to load '%s' file (%i)\n", image_name, io_result);
271		goto exit;
272	}
273
274	/*
275	 * Update the memory usage info.
276	 * This is done after the actual loading so that it is not updated when
277	 * the load is unsuccessful.
278	 * If the caller does not provide an entry point, bypass the memory
279	 * reservation.
280	 */
281	if (entry_point_info != NULL) {
282		reserve_mem(&mem_layout->free_base, &mem_layout->free_size,
283				image_base, image_size);
284	} else {
285		INFO("Skip reserving memory: 0x%lx - 0x%lx\n",
286				image_base, image_base + image_size);
287	}
288
289	image_data->image_base = image_base;
290	image_data->image_size = image_size;
291
292	if (entry_point_info != NULL)
293		entry_point_info->pc = image_base;
294
295	/*
296	 * File has been successfully loaded.
297	 * Flush the image in TZRAM so that the next EL can see it.
298	 */
299	flush_dcache_range(image_base, image_size);
300
301	INFO("File '%s' loaded: 0x%lx - 0x%lx\n", image_name, image_base,
302	     image_base + image_size);
303
304exit:
305	io_close(image_handle);
306	/* Ignore improbable/unrecoverable error in 'close' */
307
308	/* TODO: Consider maintaining open device connection from this bootloader stage */
309	io_dev_close(dev_handle);
310	/* Ignore improbable/unrecoverable error in 'dev_close' */
311
312	return io_result;
313}
314