summaryrefslogtreecommitdiff
path: root/boot/vbe_simple.c
blob: 12682abd3996c54eb7d01b2dc4e33c4b62833e10 (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Verified Boot for Embedded (VBE) 'simple' method
 *
 * Copyright 2022 Google LLC
 * Written by Simon Glass <sjg@chromium.org>
 */

#define LOG_CATEGORY LOGC_BOOT

#include <common.h>
#include <bootdev.h>
#include <bootflow.h>
#include <bootmeth.h>
#include <dm.h>
#include <log.h>
#include <memalign.h>
#include <mmc.h>
#include <vbe.h>
#include <dm/device-internal.h>
#include <dm/ofnode.h>
#include <u-boot/crc.h>
#include "vbe_simple.h"

/** struct simple_nvdata - storage format for non-volatile data */
struct simple_nvdata {
	u8 crc8;
	u8 hdr;
	u16 spare1;
	u32 fw_vernum;
	u8 spare2[0x38];
};

static int simple_read_version(struct udevice *dev, struct blk_desc *desc,
			       u8 *buf, struct simple_state *state)
{
	struct simple_priv *priv = dev_get_priv(dev);
	int start;

	if (priv->version_size > MMC_MAX_BLOCK_LEN)
		return log_msg_ret("ver", -E2BIG);

	start = priv->area_start + priv->version_offset;
	if (start & (MMC_MAX_BLOCK_LEN - 1))
		return log_msg_ret("get", -EBADF);
	start /= MMC_MAX_BLOCK_LEN;

	if (blk_dread(desc, start, 1, buf) != 1)
		return log_msg_ret("read", -EIO);
	strlcpy(state->fw_version, buf, MAX_VERSION_LEN);
	log_debug("version=%s\n", state->fw_version);

	return 0;
}

static int simple_read_nvdata(struct udevice *dev, struct blk_desc *desc,
			      u8 *buf, struct simple_state *state)
{
	struct simple_priv *priv = dev_get_priv(dev);
	uint hdr_ver, hdr_size, size, crc;
	const struct simple_nvdata *nvd;
	int start;

	if (priv->state_size > MMC_MAX_BLOCK_LEN)
		return log_msg_ret("state", -E2BIG);

	start = priv->area_start + priv->state_offset;
	if (start & (MMC_MAX_BLOCK_LEN - 1))
		return log_msg_ret("get", -EBADF);
	start /= MMC_MAX_BLOCK_LEN;

	if (blk_dread(desc, start, 1, buf) != 1)
		return log_msg_ret("read", -EIO);
	nvd = (struct simple_nvdata *)buf;
	hdr_ver = (nvd->hdr & NVD_HDR_VER_MASK) >> NVD_HDR_VER_SHIFT;
	hdr_size = (nvd->hdr & NVD_HDR_SIZE_MASK) >> NVD_HDR_SIZE_SHIFT;
	if (hdr_ver != NVD_HDR_VER_CUR)
		return log_msg_ret("hdr", -EPERM);
	size = 1 << hdr_size;
	if (size > sizeof(*nvd))
		return log_msg_ret("sz", -ENOEXEC);

	crc = crc8(0, buf + 1, size - 1);
	if (crc != nvd->crc8)
		return log_msg_ret("crc", -EPERM);
	state->fw_vernum = nvd->fw_vernum;

	log_debug("version=%s\n", state->fw_version);

	return 0;
}

int vbe_simple_read_state(struct udevice *dev, struct simple_state *state)
{
	ALLOC_CACHE_ALIGN_BUFFER(u8, buf, MMC_MAX_BLOCK_LEN);
	struct simple_priv *priv = dev_get_priv(dev);
	struct blk_desc *desc;
	char devname[16];
	const char *end;
	int devnum;
	int ret;

	/* First figure out the block device */
	log_debug("storage=%s\n", priv->storage);
	devnum = trailing_strtoln_end(priv->storage, NULL, &end);
	if (devnum == -1)
		return log_msg_ret("num", -ENODEV);
	if (end - priv->storage >= sizeof(devname))
		return log_msg_ret("end", -E2BIG);
	strlcpy(devname, priv->storage, end - priv->storage + 1);
	log_debug("dev=%s, %x\n", devname, devnum);

	desc = blk_get_dev(devname, devnum);
	if (!desc)
		return log_msg_ret("get", -ENXIO);

	ret = simple_read_version(dev, desc, buf, state);
	if (ret)
		return log_msg_ret("ver", ret);

	ret = simple_read_nvdata(dev, desc, buf, state);
	if (ret)
		return log_msg_ret("nvd", ret);

	return 0;
}

static int vbe_simple_get_state_desc(struct udevice *dev, char *buf,
				     int maxsize)
{
	struct simple_state state;
	int ret;

	ret = vbe_simple_read_state(dev, &state);
	if (ret)
		return log_msg_ret("read", ret);

	if (maxsize < 30)
		return -ENOSPC;
	snprintf(buf, maxsize, "Version: %s\nVernum: %x/%x", state.fw_version,
		 state.fw_vernum >> FWVER_KEY_SHIFT,
		 state.fw_vernum & FWVER_FW_MASK);

	return 0;
}

static int vbe_simple_read_bootflow(struct udevice *dev, struct bootflow *bflow)
{
	int ret;

	if (CONFIG_IS_ENABLED(BOOTMETH_VBE_SIMPLE_FW)) {
		if (vbe_phase() == VBE_PHASE_FIRMWARE) {
			ret = vbe_simple_read_bootflow_fw(dev, bflow);
			if (ret)
				return log_msg_ret("fw", ret);
			return 0;
		}
	}

	return -EINVAL;
}

static int vbe_simple_read_file(struct udevice *dev, struct bootflow *bflow,
				const char *file_path, ulong addr, ulong *sizep)
{
	int ret;

	if (vbe_phase() == VBE_PHASE_OS) {
		ret = bootmeth_common_read_file(dev, bflow, file_path, addr,
						sizep);
		if (ret)
			return log_msg_ret("os", ret);
	}

	/* To be implemented */
	return -EINVAL;
}

static struct bootmeth_ops bootmeth_vbe_simple_ops = {
	.get_state_desc	= vbe_simple_get_state_desc,
	.read_bootflow	= vbe_simple_read_bootflow,
	.read_file	= vbe_simple_read_file,
};

static int bootmeth_vbe_simple_probe(struct udevice *dev)
{
	struct simple_priv *priv = dev_get_priv(dev);

	memset(priv, '\0', sizeof(*priv));
	if (dev_read_u32(dev, "area-start", &priv->area_start) ||
	    dev_read_u32(dev, "area-size", &priv->area_size) ||
	    dev_read_u32(dev, "version-offset", &priv->version_offset) ||
	    dev_read_u32(dev, "version-size", &priv->version_size) ||
	    dev_read_u32(dev, "state-offset", &priv->state_offset) ||
	    dev_read_u32(dev, "state-size", &priv->state_size))
		return log_msg_ret("read", -EINVAL);
	dev_read_u32(dev, "skip-offset", &priv->skip_offset);
	priv->storage = strdup(dev_read_string(dev, "storage"));
	if (!priv->storage)
		return log_msg_ret("str", -EINVAL);

	return 0;
}

static int bootmeth_vbe_simple_bind(struct udevice *dev)
{
	struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);

	plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
		"VBE simple" : "vbe-simple";
	plat->flags = BOOTMETHF_GLOBAL;

	return 0;
}

#if CONFIG_IS_ENABLED(OF_REAL)
static const struct udevice_id generic_simple_vbe_simple_ids[] = {
	{ .compatible = "fwupd,vbe-simple" },
	{ }
};
#endif

U_BOOT_DRIVER(vbe_simple) = {
	.name	= "vbe_simple",
	.id	= UCLASS_BOOTMETH,
	.of_match = of_match_ptr(generic_simple_vbe_simple_ids),
	.ops	= &bootmeth_vbe_simple_ops,
	.bind	= bootmeth_vbe_simple_bind,
	.probe	= bootmeth_vbe_simple_probe,
	.flags	= DM_FLAG_PRE_RELOC,
	.priv_auto	= sizeof(struct simple_priv),
};