xref: /freebsd/usr.sbin/bhyve/bootrom.c (revision 65b71c48d226f3ef3eb1c4452dccc678a7d2ac96)
1 /*-
2  * Copyright (c) 2015 Neel Natu <neel@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/types.h>
31 #include <sys/mman.h>
32 #include <sys/stat.h>
33 
34 #include <machine/vmm.h>
35 
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <unistd.h>
41 #include <stdbool.h>
42 
43 #include <vmmapi.h>
44 #include "bhyverun.h"
45 #include "bootrom.h"
46 
47 #define	MAX_BOOTROM_SIZE	(16 * 1024 * 1024)	/* 16 MB */
48 
49 int
50 bootrom_init(struct vmctx *ctx, const char *romfile)
51 {
52 	struct stat sbuf;
53 	vm_paddr_t gpa;
54 	ssize_t rlen;
55 	char *ptr;
56 	int fd, i, rv, prot;
57 
58 	rv = -1;
59 	fd = open(romfile, O_RDONLY);
60 	if (fd < 0) {
61 		fprintf(stderr, "Error opening bootrom \"%s\": %s\n",
62 		    romfile, strerror(errno));
63 		goto done;
64 	}
65 
66         if (fstat(fd, &sbuf) < 0) {
67 		fprintf(stderr, "Could not fstat bootrom file \"%s\": %s\n",
68 		    romfile, strerror(errno));
69 		goto done;
70         }
71 
72 	/*
73 	 * Limit bootrom size to 16MB so it doesn't encroach into reserved
74 	 * MMIO space (e.g. APIC, HPET, MSI).
75 	 */
76 	if (sbuf.st_size > MAX_BOOTROM_SIZE || sbuf.st_size < PAGE_SIZE) {
77 		fprintf(stderr, "Invalid bootrom size %ld\n", sbuf.st_size);
78 		goto done;
79 	}
80 
81 	if (sbuf.st_size & PAGE_MASK) {
82 		fprintf(stderr, "Bootrom size %ld is not a multiple of the "
83 		    "page size\n", sbuf.st_size);
84 		goto done;
85 	}
86 
87 	ptr = vm_create_devmem(ctx, VM_BOOTROM, "bootrom", sbuf.st_size);
88 	if (ptr == MAP_FAILED)
89 		goto done;
90 
91 	/* Map the bootrom into the guest address space */
92 	prot = PROT_READ | PROT_EXEC;
93 	gpa = (1ULL << 32) - sbuf.st_size;
94 	if (vm_mmap_memseg(ctx, gpa, VM_BOOTROM, 0, sbuf.st_size, prot) != 0)
95 		goto done;
96 
97 	/* Read 'romfile' into the guest address space */
98 	for (i = 0; i < sbuf.st_size / PAGE_SIZE; i++) {
99 		rlen = read(fd, ptr + i * PAGE_SIZE, PAGE_SIZE);
100 		if (rlen != PAGE_SIZE) {
101 			fprintf(stderr, "Incomplete read of page %d of bootrom "
102 			    "file %s: %ld bytes\n", i, romfile, rlen);
103 			goto done;
104 		}
105 	}
106 	rv = 0;
107 done:
108 	if (fd >= 0)
109 		close(fd);
110 	return (rv);
111 }
112