1 // SPDX-License-Identifier: GPL-2.0+
3 * Verified Boot for Embedded (VBE) 'simple' method
5 * Copyright 2022 Google LLC
6 * Written by Simon Glass <sjg@chromium.org>
18 #include <version_string.h>
19 #include <dm/device-internal.h>
20 #include <dm/ofnode.h>
21 #include <u-boot/crc.h>
24 MAX_VERSION_LEN = 256,
26 NVD_HDR_VER_SHIFT = 0,
27 NVD_HDR_VER_MASK = 0xf,
28 NVD_HDR_SIZE_SHIFT = 4,
29 NVD_HDR_SIZE_MASK = 0xf << NVD_HDR_SIZE_SHIFT,
31 /* Firmware key-version is in the top 16 bits of fw_ver */
33 FWVER_FW_MASK = 0xffff,
35 NVD_HDR_VER_CUR = 1, /* current version */
38 /** struct simple_priv - information read from the device tree */
50 /** struct simple_state - state information read from media
52 * @fw_version: Firmware version string
53 * @fw_vernum: Firmware version number
56 char fw_version[MAX_VERSION_LEN];
60 /** struct simple_nvdata - storage format for non-volatile data */
61 struct simple_nvdata {
69 static int simple_read_version(struct udevice *dev, struct blk_desc *desc,
70 u8 *buf, struct simple_state *state)
72 struct simple_priv *priv = dev_get_priv(dev);
75 if (priv->version_size > MMC_MAX_BLOCK_LEN)
76 return log_msg_ret("ver", -E2BIG);
78 start = priv->area_start + priv->version_offset;
79 if (start & (MMC_MAX_BLOCK_LEN - 1))
80 return log_msg_ret("get", -EBADF);
81 start /= MMC_MAX_BLOCK_LEN;
83 if (blk_dread(desc, start, 1, buf) != 1)
84 return log_msg_ret("read", -EIO);
85 strlcpy(state->fw_version, buf, MAX_VERSION_LEN);
86 log_debug("version=%s\n", state->fw_version);
91 static int simple_read_nvdata(struct udevice *dev, struct blk_desc *desc,
92 u8 *buf, struct simple_state *state)
94 struct simple_priv *priv = dev_get_priv(dev);
95 uint hdr_ver, hdr_size, size, crc;
96 const struct simple_nvdata *nvd;
99 if (priv->state_size > MMC_MAX_BLOCK_LEN)
100 return log_msg_ret("state", -E2BIG);
102 start = priv->area_start + priv->state_offset;
103 if (start & (MMC_MAX_BLOCK_LEN - 1))
104 return log_msg_ret("get", -EBADF);
105 start /= MMC_MAX_BLOCK_LEN;
107 if (blk_dread(desc, start, 1, buf) != 1)
108 return log_msg_ret("read", -EIO);
109 nvd = (struct simple_nvdata *)buf;
110 hdr_ver = (nvd->hdr & NVD_HDR_VER_MASK) >> NVD_HDR_VER_SHIFT;
111 hdr_size = (nvd->hdr & NVD_HDR_SIZE_MASK) >> NVD_HDR_SIZE_SHIFT;
112 if (hdr_ver != NVD_HDR_VER_CUR)
113 return log_msg_ret("hdr", -EPERM);
114 size = 1 << hdr_size;
115 if (size > sizeof(*nvd))
116 return log_msg_ret("sz", -ENOEXEC);
118 crc = crc8(0, buf + 1, size - 1);
119 if (crc != nvd->crc8)
120 return log_msg_ret("crc", -EPERM);
121 state->fw_vernum = nvd->fw_vernum;
123 log_debug("version=%s\n", state->fw_version);
128 static int simple_read_state(struct udevice *dev, struct simple_state *state)
130 ALLOC_CACHE_ALIGN_BUFFER(u8, buf, MMC_MAX_BLOCK_LEN);
131 struct simple_priv *priv = dev_get_priv(dev);
132 struct blk_desc *desc;
138 /* First figure out the block device */
139 log_debug("storage=%s\n", priv->storage);
140 devnum = trailing_strtoln_end(priv->storage, NULL, &end);
142 return log_msg_ret("num", -ENODEV);
143 if (end - priv->storage >= sizeof(devname))
144 return log_msg_ret("end", -E2BIG);
145 strlcpy(devname, priv->storage, end - priv->storage + 1);
146 log_debug("dev=%s, %x\n", devname, devnum);
148 desc = blk_get_dev(devname, devnum);
150 return log_msg_ret("get", -ENXIO);
152 ret = simple_read_version(dev, desc, buf, state);
154 return log_msg_ret("ver", ret);
156 ret = simple_read_nvdata(dev, desc, buf, state);
158 return log_msg_ret("nvd", ret);
163 static int vbe_simple_get_state_desc(struct udevice *dev, char *buf,
166 struct simple_state state;
169 ret = simple_read_state(dev, &state);
171 return log_msg_ret("read", ret);
175 snprintf(buf, maxsize, "Version: %s\nVernum: %x/%x", state.fw_version,
176 state.fw_vernum >> FWVER_KEY_SHIFT,
177 state.fw_vernum & FWVER_FW_MASK);
182 static int vbe_simple_read_bootflow(struct udevice *dev, struct bootflow *bflow)
184 /* To be implemented */
189 static struct bootmeth_ops bootmeth_vbe_simple_ops = {
190 .get_state_desc = vbe_simple_get_state_desc,
191 .read_bootflow = vbe_simple_read_bootflow,
192 .read_file = bootmeth_common_read_file,
195 int vbe_simple_fixup_node(ofnode node, struct simple_state *state)
200 version = strdup(state->fw_version);
202 return log_msg_ret("ver", -ENOMEM);
204 ret = ofnode_write_string(node, "cur-version", version);
206 return log_msg_ret("ver", ret);
207 ret = ofnode_write_u32(node, "cur-vernum", state->fw_vernum);
209 return log_msg_ret("ver", ret);
210 ret = ofnode_write_string(node, "bootloader-version", version_string);
212 return log_msg_ret("fix", ret);
218 * bootmeth_vbe_simple_ft_fixup() - Write out all VBE simple data to the DT
220 * @ctx: Context for event
221 * @event: Event to process
222 * @return 0 if OK, -ve on error
224 static int bootmeth_vbe_simple_ft_fixup(void *ctx, struct event *event)
226 oftree tree = event->data.ft_fixup.tree;
232 * Ideally we would have driver model support for fixups, but that does
233 * not exist yet. It is a step too far to try to do this before VBE is
236 for (ret = vbe_find_first_device(&dev); dev;
237 ret = vbe_find_next_device(&dev)) {
238 struct simple_state state;
240 if (strcmp("vbe_simple", dev->driver->name))
243 /* Check if there is a node to fix up */
244 node = ofnode_path_root(tree, "/chosen/fwupd");
245 if (!ofnode_valid(node))
247 node = ofnode_find_subnode(node, dev->name);
248 if (!ofnode_valid(node))
251 log_debug("Fixing up: %s\n", dev->name);
252 ret = device_probe(dev);
254 return log_msg_ret("probe", ret);
255 ret = simple_read_state(dev, &state);
257 return log_msg_ret("read", ret);
259 ret = vbe_simple_fixup_node(node, &state);
261 return log_msg_ret("fix", ret);
266 EVENT_SPY(EVT_FT_FIXUP, bootmeth_vbe_simple_ft_fixup);
268 static int bootmeth_vbe_simple_probe(struct udevice *dev)
270 struct simple_priv *priv = dev_get_priv(dev);
272 memset(priv, '\0', sizeof(*priv));
273 if (dev_read_u32(dev, "area-start", &priv->area_start) ||
274 dev_read_u32(dev, "area-size", &priv->area_size) ||
275 dev_read_u32(dev, "version-offset", &priv->version_offset) ||
276 dev_read_u32(dev, "version-size", &priv->version_size) ||
277 dev_read_u32(dev, "state-offset", &priv->state_offset) ||
278 dev_read_u32(dev, "state-size", &priv->state_size))
279 return log_msg_ret("read", -EINVAL);
280 dev_read_u32(dev, "skip-offset", &priv->skip_offset);
281 priv->storage = strdup(dev_read_string(dev, "storage"));
283 return log_msg_ret("str", -EINVAL);
288 static int bootmeth_vbe_simple_bind(struct udevice *dev)
290 struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
292 plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
293 "VBE simple" : "vbe-simple";
294 plat->flags = BOOTMETHF_GLOBAL;
299 #if CONFIG_IS_ENABLED(OF_REAL)
300 static const struct udevice_id generic_simple_vbe_simple_ids[] = {
301 { .compatible = "fwupd,vbe-simple" },
306 U_BOOT_DRIVER(vbe_simple) = {
307 .name = "vbe_simple",
308 .id = UCLASS_BOOTMETH,
309 .of_match = of_match_ptr(generic_simple_vbe_simple_ids),
310 .ops = &bootmeth_vbe_simple_ops,
311 .bind = bootmeth_vbe_simple_bind,
312 .probe = bootmeth_vbe_simple_probe,
313 .flags = DM_FLAG_PRE_RELOC,
314 .priv_auto = sizeof(struct simple_priv),