1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 2018 The FreeBSD Foundation.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <err.h>
29 #include <fcntl.h>
30 #include <stdbool.h>
31 #include <stdint.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
36 
37 static const size_t bufsize = 65536;
38 
39 /* SDM vol 3 9.11.1 Intel microcode header. */
40 struct microcode_update_header {
41 	uint32_t header_version;
42 	uint32_t update_revision;
43 	uint32_t date;			/* BCD mmddyyyy */
44 	uint32_t processor_signature;
45 	uint32_t checksum;		/* Over update data and header */
46 	uint32_t loader_revision;
47 	uint32_t processor_flags;
48 	uint32_t data_size;
49 	uint32_t total_size;
50 	uint32_t reserved[3];
51 };
52 
53 /*
54  * SDM vol 2A CPUID EAX = 01h Returns Model, Family, Stepping Information.
55  * Caller must free the returned string.
56  */
57 
58 static char *
format_signature(uint32_t signature)59 format_signature(uint32_t signature)
60 {
61 	char *buf;
62 	unsigned family, model, stepping;
63 
64 	family = (signature & 0xf00) >> 8;
65 	model = (signature & 0xf0) >> 4;
66 	stepping = signature & 0xf;
67 	if (family == 0x06 || family == 0x0f)
68 		model += (signature & 0xf0000) >> 12;
69 	if (family == 0x0f)
70 		family += (signature & 0xff00000) >> 20;
71 	asprintf(&buf, "%02x-%02x-%02x", family, model, stepping);
72 	if (buf == NULL)
73 		err(1, "asprintf");
74 	return (buf);
75 }
76 
77 static void
dump_header(const struct microcode_update_header * hdr)78 dump_header(const struct microcode_update_header *hdr)
79 {
80 	char *sig_str;
81 	int i;
82 	bool platformid_printed;
83 
84 	sig_str = format_signature(hdr->processor_signature);
85 	printf("header version\t0x%x\n", hdr->header_version);
86 	printf("revision\t0x%x\n", hdr->update_revision);
87 	printf("date\t\t0x%x\t%04x-%02x-%02x\n", hdr->date,
88 	    hdr->date & 0xffff, (hdr->date & 0xff000000) >> 24,
89 	    (hdr->date & 0xff0000) >> 16);
90 	printf("signature\t0x%x\t\t%s\n", hdr->processor_signature, sig_str);
91 	printf("checksum\t0x%x\n", hdr->checksum);
92 	printf("loader revision\t0x%x\n", hdr->loader_revision);
93 	printf("processor flags\t0x%x", hdr->processor_flags);
94 	platformid_printed = false;
95 	for (i = 0; i < 8; i++) {
96 		if (hdr->processor_flags & 1 << i) {
97 			printf("%s%d", platformid_printed ? ", " : "\t\t", i);
98 			platformid_printed = true;
99 		}
100 	}
101 	printf("\n");
102 	printf("datasize\t0x%x\t\t0x%x\n", hdr->data_size,
103 	    hdr->data_size != 0 ? hdr->data_size : 2000);
104 	printf("size\t\t0x%x\t\t0x%x\n", hdr->total_size,
105 	    hdr->total_size != 0 ? hdr->total_size : 2048);
106 	free(sig_str);
107 }
108 
109 static void
usage(void)110 usage(void)
111 {
112 
113 	printf("ucode-split [-v] microcode_file\n");
114 	exit(1);
115 }
116 
117 int
main(int argc,char * argv[])118 main(int argc, char *argv[])
119 {
120 	struct microcode_update_header hdr;
121 	char *buf, *output_file, *sig_str;
122 	size_t len, resid;
123 	ssize_t rv;
124 	int c, ifd, ofd;
125 	bool vflag;
126 
127 	vflag = false;
128 	while ((c = getopt(argc, argv, "v")) != -1) {
129 		switch (c) {
130 		case 'v':
131 			vflag = true;
132 			break;
133 		default:
134 			usage();
135 		}
136 	}
137 	argc -= optind;
138 	argv += optind;
139 
140 	if (argc != 1)
141 		usage();
142 
143 	ifd = open(argv[0], O_RDONLY);
144 	if (ifd < 0)
145 		err(1, "open");
146 
147 	buf = malloc(bufsize);
148 	if (buf == NULL)
149 		err(1, "malloc");
150 
151 	for (;;) {
152 		/* Read header. */
153 		rv = read(ifd, &hdr, sizeof(hdr));
154 		if (rv < 0) {
155 			err(1, "read");
156 		} else if (rv == 0) {
157 			break;
158 		} else if (rv < (ssize_t)sizeof(hdr)) {
159 			errx(1, "invalid microcode header");
160 		}
161 		if (hdr.header_version != 1)
162 			errx(1, "invalid header version");
163 
164 		if (vflag)
165 			dump_header(&hdr);
166 
167 		sig_str = format_signature(hdr.processor_signature);
168 		asprintf(&output_file, "%s.%02x", sig_str,
169 		    hdr.processor_flags & 0xff);
170 		free(sig_str);
171 		if (output_file == NULL)
172 			err(1, "asprintf");
173 		ofd = open(output_file, O_WRONLY | O_CREAT | O_TRUNC, 0600);
174 		if (ofd < 0)
175 			err(1, "open");
176 
177 		/* Write header. */
178 		rv = write(ofd, &hdr, sizeof(hdr));
179 		if (rv < (ssize_t)sizeof(hdr))
180 			err(1, "write");
181 
182 		/* Copy data. */
183 		resid = (hdr.total_size != 0 ? hdr.total_size : 2048) -
184 		    sizeof(hdr);
185 		if (resid > 1 << 24) /* Arbitrary chosen maximum size. */
186 			errx(1, "header total_size too large");
187 		while (resid > 0) {
188 			len = resid < bufsize ? resid : bufsize;
189 			rv = read(ifd, buf, len);
190 			if (rv < 0)
191 				err(1, "read");
192 			else if (rv < (ssize_t)len)
193 				errx(1, "truncated microcode data");
194 			if (write(ofd, buf, len) < (ssize_t)len)
195 				err(1, "write");
196 			resid -= len;
197 		}
198 		if (vflag)
199 			printf("written to %s\n\n", output_file);
200 		close(ofd);
201 		free(output_file);
202 	}
203 }
204