summaryrefslogtreecommitdiff
path: root/payloads/libpayload/libcbfs/cbfs.c
blob: 44173c82f6337c647bf295ce5d2afaf9ec558bac (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
/* SPDX-License-Identifier: BSD-3-Clause */

#include <libpayload-config.h>
#include <arch/virtual.h>
#include <assert.h>
#include <cbfs.h>
#include <cbfs_glue.h>
#include <commonlib/bsd/cbfs_private.h>
#include <commonlib/bsd/fmap_serialized.h>
#include <libpayload.h>
#include <lz4.h>
#include <lzma.h>
#include <string.h>
#include <sysinfo.h>


static const struct cbfs_boot_device *cbfs_get_boot_device(bool force_ro)
{
	static struct cbfs_boot_device ro;
	static struct cbfs_boot_device rw;

	if (!force_ro) {
		if (!rw.dev.size) {
			rw.dev.offset = lib_sysinfo.cbfs_offset;
			rw.dev.size = lib_sysinfo.cbfs_size;
			rw.mcache = phys_to_virt(lib_sysinfo.cbfs_rw_mcache_offset);
			rw.mcache_size = lib_sysinfo.cbfs_rw_mcache_size;
		}
		return &rw;
	}

	if (ro.dev.size)
		return &ro;

	if (fmap_locate_area("COREBOOT", &ro.dev.offset, &ro.dev.size))
		return NULL;

	ro.mcache = phys_to_virt(lib_sysinfo.cbfs_ro_mcache_offset);
	ro.mcache_size = lib_sysinfo.cbfs_ro_mcache_size;

	return &ro;
}

ssize_t _cbfs_boot_lookup(const char *name, bool force_ro, union cbfs_mdata *mdata)
{
	const struct cbfs_boot_device *cbd = cbfs_get_boot_device(force_ro);
	if (!cbd)
		return CB_ERR;

	size_t data_offset;
	cb_err_t err = CB_CBFS_CACHE_FULL;
	if (cbd->mcache_size)
		err = cbfs_mcache_lookup(cbd->mcache, cbd->mcache_size, name, mdata,
					 &data_offset);

	if (err == CB_CBFS_CACHE_FULL)
		err = cbfs_lookup(&cbd->dev, name, mdata, &data_offset, NULL);

	/* Fallback to RO if possible. */
	if (CONFIG(LP_ENABLE_CBFS_FALLBACK) && !force_ro && err == CB_CBFS_NOT_FOUND) {
		LOG("Fall back to RO region for '%s'\n", name);
		return _cbfs_boot_lookup(name, true, mdata);
	}

	if (err) {
		if (err == CB_CBFS_NOT_FOUND)
			LOG("'%s' not found.\n", name);
		else
			ERROR("Error %d when looking up '%s'\n", err, name);
		return err;
	}

	return cbd->dev.offset + data_offset;
}

void cbfs_unmap(void *mapping)
{
	free(mapping);
}

static bool cbfs_file_hash_mismatch(const void *buffer, size_t size,
				    const union cbfs_mdata *mdata, bool skip_verification)
{
	if (!CONFIG(LP_CBFS_VERIFICATION) || skip_verification)
		return false;

	const struct vb2_hash *hash = cbfs_file_hash(mdata);
	if (!hash) {
		ERROR("'%s' does not have a file hash!\n", mdata->h.filename);
		return true;
	}
	if (vb2_hash_verify(buffer, size, hash) != VB2_SUCCESS) {
		ERROR("'%s' file hash mismatch!\n", mdata->h.filename);
		return true;
	}

	return false;
}

static size_t cbfs_load_and_decompress(size_t offset, size_t in_size, void *buffer,
				       size_t buffer_size, uint32_t compression,
				       const union cbfs_mdata *mdata, bool skip_verification)
{
	void *load = buffer;
	size_t out_size = 0;

	DEBUG("Decompressing %zu bytes from '%s' to %p with algo %d\n", in_size,
	      mdata->h.filename, buffer, compression);

	if (compression != CBFS_COMPRESS_NONE) {
		load = malloc(in_size);
		if (!load) {
			ERROR("'%s' buffer allocation failed\n", mdata->h.filename);
			return 0;
		}
	}

	if (boot_device_read(load, offset, in_size) != in_size) {
		ERROR("'%s' failed to read contents of file\n", mdata->h.filename);
		goto out;
	}

	if (cbfs_file_hash_mismatch(buffer, in_size, mdata, skip_verification))
		goto out;

	switch (compression) {
	case CBFS_COMPRESS_NONE:
		out_size = in_size;
		break;
	case CBFS_COMPRESS_LZ4:
		if (!CONFIG(LP_LZ4))
			goto out;
		out_size = ulz4fn(load, in_size, buffer, buffer_size);
		break;
	case CBFS_COMPRESS_LZMA:
		if (!CONFIG(LP_LZMA))
			goto out;
		out_size = ulzman(load, in_size, buffer, buffer_size);
		break;
	default:
		ERROR("'%s' decompression algo %d not supported\n", mdata->h.filename,
		      compression);
	}
out:
	if (load != buffer)
		free(load);
	return out_size;
}

static void *do_load(union cbfs_mdata *mdata, ssize_t offset, void *buf, size_t *size_inout,
		     bool skip_verification)
{
	bool malloced = false;
	size_t out_size;
	uint32_t compression = CBFS_COMPRESS_NONE;
	const struct cbfs_file_attr_compression *cattr =
		cbfs_find_attr(mdata, CBFS_FILE_ATTR_TAG_COMPRESSION, sizeof(*cattr));
	if (cattr) {
		compression = be32toh(cattr->compression);
		out_size = be32toh(cattr->decompressed_size);
	} else {
		out_size = be32toh(mdata->h.len);
	}

	if (buf) {
		if (!size_inout || *size_inout < out_size) {
			ERROR("'%s' buffer too small", mdata->h.filename);
			return NULL;
		}
	} else {
		buf = malloc(out_size);
		if (!buf) {
			ERROR("'%s' allocation failure", mdata->h.filename);
			return NULL;
		}
		malloced = true;
	}

	if (cbfs_load_and_decompress(offset, be32toh(mdata->h.len), buf, out_size, compression,
				     mdata, skip_verification)
	    != out_size) {
		if (malloced)
			free(buf);
		return NULL;
	}
	if (size_inout)
		*size_inout = out_size;

	return buf;
}

void *_cbfs_load(const char *name, void *buf, size_t *size_inout, bool force_ro)
{
	ssize_t offset;
	union cbfs_mdata mdata;

	DEBUG("%s(name='%s', buf=%p, force_ro=%s)\n", __func__, name, buf,
	      force_ro ? "true" : "false");

	offset = _cbfs_boot_lookup(name, force_ro, &mdata);
	if (offset < 0)
		return NULL;

	return do_load(&mdata, offset, buf, size_inout, false);
}

void *_cbfs_unverified_area_load(const char *area, const char *name, void *buf,
				 size_t *size_inout)
{
	struct cbfs_dev dev;
	union cbfs_mdata mdata;
	size_t data_offset;

	DEBUG("%s(area='%s', name='%s', buf=%p)\n", __func__, area, name, buf);

	if (fmap_locate_area(area, &dev.offset, &dev.size) != CB_SUCCESS)
		return NULL;

	if (cbfs_lookup(&dev, name, &mdata, &data_offset, NULL)) {
		ERROR("'%s' not found in '%s'\n", name, area);
		return NULL;
	}

	return do_load(&mdata, dev.offset + data_offset, buf, size_inout, true);
}