1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Verified Boot for Embedded (VBE) 'simple' method
4  *
5  * Copyright 2022 Google LLC
6  * Written by Simon Glass <sjg@chromium.org>
7  */
8 
9 #define LOG_CATEGORY LOGC_BOOT
10 
11 #include <bootdev.h>
12 #include <bootflow.h>
13 #include <bootmeth.h>
14 #include <dm.h>
15 #include <log.h>
16 #include <memalign.h>
17 #include <mmc.h>
18 #include <vbe.h>
19 #include <dm/device-internal.h>
20 #include <dm/ofnode.h>
21 #include "vbe_simple.h"
22 
simple_read_nvdata(const struct simple_priv * priv,struct udevice * blk,struct simple_state * state)23 static int simple_read_nvdata(const struct simple_priv *priv,
24 			      struct udevice *blk, struct simple_state *state)
25 {
26 	ALLOC_CACHE_ALIGN_BUFFER(u8, buf, MMC_MAX_BLOCK_LEN);
27 	const struct vbe_nvdata *nvd;
28 	int ret;
29 
30 	ret = vbe_read_nvdata(blk, priv->area_start + priv->state_offset,
31 			      priv->state_size, buf);
32 	if (ret)
33 		return log_msg_ret("nv", ret);
34 
35 	nvd = (struct vbe_nvdata *)buf;
36 	state->fw_vernum = nvd->fw_vernum;
37 
38 	log_debug("version=%s\n", state->fw_version);
39 
40 	return 0;
41 }
42 
vbe_simple_read_state(struct udevice * dev,struct simple_state * state)43 int vbe_simple_read_state(struct udevice *dev, struct simple_state *state)
44 {
45 	struct simple_priv *priv = dev_get_priv(dev);
46 	struct udevice *blk;
47 	int ret;
48 
49 	ret = vbe_get_blk(priv->storage, &blk);
50 	if (ret)
51 		return log_msg_ret("blk", ret);
52 
53 	ret = vbe_read_version(blk, priv->area_start + priv->version_offset,
54 			       state->fw_version, MAX_VERSION_LEN);
55 	if (ret)
56 		return log_msg_ret("ver", ret);
57 
58 	ret = simple_read_nvdata(priv, blk, state);
59 	if (ret)
60 		return log_msg_ret("nvd", ret);
61 
62 	return 0;
63 }
64 
vbe_simple_get_state_desc(struct udevice * dev,char * buf,int maxsize)65 static int vbe_simple_get_state_desc(struct udevice *dev, char *buf,
66 				     int maxsize)
67 {
68 	struct simple_state state;
69 	int ret;
70 
71 	ret = vbe_simple_read_state(dev, &state);
72 	if (ret)
73 		return log_msg_ret("read", ret);
74 
75 	if (maxsize < 30)
76 		return -ENOSPC;
77 	snprintf(buf, maxsize, "Version: %s\nVernum: %x/%x", state.fw_version,
78 		 state.fw_vernum >> FWVER_KEY_SHIFT,
79 		 state.fw_vernum & FWVER_FW_MASK);
80 
81 	return 0;
82 }
83 
vbe_simple_read_bootflow(struct udevice * dev,struct bootflow * bflow)84 static int vbe_simple_read_bootflow(struct udevice *dev, struct bootflow *bflow)
85 {
86 	int ret;
87 
88 	if (CONFIG_IS_ENABLED(BOOTMETH_VBE_SIMPLE_FW)) {
89 		if (vbe_phase() == VBE_PHASE_FIRMWARE) {
90 			ret = vbe_simple_read_bootflow_fw(dev, bflow);
91 			if (ret)
92 				return log_msg_ret("fw", ret);
93 			return 0;
94 		}
95 	}
96 
97 	return -EINVAL;
98 }
99 
vbe_simple_read_file(struct udevice * dev,struct bootflow * bflow,const char * file_path,ulong addr,enum bootflow_img_t type,ulong * sizep)100 static int vbe_simple_read_file(struct udevice *dev, struct bootflow *bflow,
101 				const char *file_path, ulong addr,
102 				enum bootflow_img_t type, ulong *sizep)
103 {
104 	int ret;
105 
106 	if (vbe_phase() == VBE_PHASE_OS) {
107 		ret = bootmeth_common_read_file(dev, bflow, file_path, addr,
108 						type, sizep);
109 		if (ret)
110 			return log_msg_ret("os", ret);
111 	}
112 
113 	/* To be implemented */
114 	return -EINVAL;
115 }
116 
117 static struct bootmeth_ops bootmeth_vbe_simple_ops = {
118 	.get_state_desc	= vbe_simple_get_state_desc,
119 	.read_bootflow	= vbe_simple_read_bootflow,
120 	.read_file	= vbe_simple_read_file,
121 };
122 
bootmeth_vbe_simple_probe(struct udevice * dev)123 static int bootmeth_vbe_simple_probe(struct udevice *dev)
124 {
125 	struct simple_priv *priv = dev_get_priv(dev);
126 
127 	memset(priv, '\0', sizeof(*priv));
128 	if (dev_read_u32(dev, "area-start", &priv->area_start) ||
129 	    dev_read_u32(dev, "area-size", &priv->area_size) ||
130 	    dev_read_u32(dev, "version-offset", &priv->version_offset) ||
131 	    dev_read_u32(dev, "version-size", &priv->version_size) ||
132 	    dev_read_u32(dev, "state-offset", &priv->state_offset) ||
133 	    dev_read_u32(dev, "state-size", &priv->state_size))
134 		return log_msg_ret("read", -EINVAL);
135 	dev_read_u32(dev, "skip-offset", &priv->skip_offset);
136 	priv->storage = strdup(dev_read_string(dev, "storage"));
137 	if (!priv->storage)
138 		return log_msg_ret("str", -EINVAL);
139 
140 	return 0;
141 }
142 
bootmeth_vbe_simple_bind(struct udevice * dev)143 static int bootmeth_vbe_simple_bind(struct udevice *dev)
144 {
145 	struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
146 
147 	plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
148 		"VBE simple" : "vbe-simple";
149 	plat->flags = BOOTMETHF_GLOBAL;
150 
151 	return 0;
152 }
153 
154 #if CONFIG_IS_ENABLED(OF_REAL)
155 static const struct udevice_id generic_simple_vbe_simple_ids[] = {
156 	{ .compatible = "fwupd,vbe-simple" },
157 	{ }
158 };
159 #endif
160 
161 U_BOOT_DRIVER(vbe_simple) = {
162 	.name	= "vbe_simple",
163 	.id	= UCLASS_BOOTMETH,
164 	.of_match = of_match_ptr(generic_simple_vbe_simple_ids),
165 	.ops	= &bootmeth_vbe_simple_ops,
166 	.bind	= bootmeth_vbe_simple_bind,
167 	.probe	= bootmeth_vbe_simple_probe,
168 	.flags	= DM_FLAG_PRE_RELOC,
169 	.priv_auto	= sizeof(struct simple_priv),
170 };
171