1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Verified Boot for Embedded (VBE) loading firmware phases
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 <dm.h>
12 #include <bootflow.h>
13 #include <vbe.h>
14 #include <version_string.h>
15 #include <dm/device-internal.h>
16 #include "vbe_simple.h"
17 
vbe_simple_fixup_node(ofnode node,struct simple_state * state)18 int vbe_simple_fixup_node(ofnode node, struct simple_state *state)
19 {
20 	const char *version, *str;
21 	int ret;
22 
23 	version = strdup(state->fw_version);
24 	if (!version)
25 		return log_msg_ret("dup", -ENOMEM);
26 
27 	ret = ofnode_write_string(node, "cur-version", version);
28 	if (ret)
29 		return log_msg_ret("ver", ret);
30 	ret = ofnode_write_u32(node, "cur-vernum", state->fw_vernum);
31 	if (ret)
32 		return log_msg_ret("num", ret);
33 
34 	/* Drop the 'U-Boot ' at the start */
35 	str = version_string;
36 	if (!strncmp("U-Boot ", str, 7))
37 		str += 7;
38 	ret = ofnode_write_string(node, "bootloader-version", str);
39 	if (ret)
40 		return log_msg_ret("bl", ret);
41 
42 	return 0;
43 }
44 
45 /**
46  * bootmeth_vbe_simple_ft_fixup() - Write out all VBE simple data to the DT
47  *
48  * @ctx: Context for event
49  * @event: Event to process
50  * @return 0 if OK, -ve on error
51  */
bootmeth_vbe_simple_ft_fixup(void * ctx,struct event * event)52 static int bootmeth_vbe_simple_ft_fixup(void *ctx, struct event *event)
53 {
54 	oftree tree = event->data.ft_fixup.tree;
55 	struct udevice *dev;
56 
57 	/*
58 	 * Ideally we would have driver model support for fixups, but that does
59 	 * not exist yet. It is a step too far to try to do this before VBE is
60 	 * in place.
61 	 */
62 	for (vbe_find_first_device(&dev); dev; vbe_find_next_device(&dev)) {
63 		struct simple_state state;
64 		ofnode node, subnode, chosen;
65 		int ret;
66 
67 		if (strcmp("vbe_simple", dev->driver->name))
68 			continue;
69 
70 		/* Check if there is a node to fix up, adding if not */
71 		chosen = oftree_path(tree, "/chosen");
72 		if (!ofnode_valid(chosen))
73 			continue;
74 
75 		ret = device_probe(dev);
76 		if (ret) {
77 			/*
78 			 * This should become an error when VBE is updated to
79 			 * only bind this device when a node exists
80 			 */
81 			log_debug("VBE device '%s' failed to probe (err=%d)",
82 				  dev->name, ret);
83 			return 0;
84 		}
85 
86 		ret = ofnode_add_subnode(chosen, "fwupd", &node);
87 		if (ret && ret != -EEXIST)
88 			return log_msg_ret("fwu", ret);
89 
90 		ret = ofnode_add_subnode(node, dev->name, &subnode);
91 		if (ret && ret != -EEXIST)
92 			return log_msg_ret("dev", ret);
93 
94 		/* Copy over the vbe properties for fwupd */
95 		log_debug("Fixing up: %s\n", dev->name);
96 		ret = ofnode_copy_props(subnode, dev_ofnode(dev));
97 		if (ret)
98 			return log_msg_ret("cp", ret);
99 
100 		ret = vbe_simple_read_state(dev, &state);
101 		if (ret)
102 			return log_msg_ret("read", ret);
103 
104 		ret = vbe_simple_fixup_node(subnode, &state);
105 		if (ret)
106 			return log_msg_ret("fix", ret);
107 	}
108 
109 	return 0;
110 }
111 EVENT_SPY_FULL(EVT_FT_FIXUP, bootmeth_vbe_simple_ft_fixup);
112