xref: /freebsd/usr.sbin/bhyve/bootrom.c (revision 2f513db7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2015 Neel Natu <neel@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/types.h>
33 #include <sys/mman.h>
34 #include <sys/stat.h>
35 
36 #include <machine/vmm.h>
37 
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <stdio.h>
41 #include <string.h>
42 #include <unistd.h>
43 #include <stdbool.h>
44 
45 #include <vmmapi.h>
46 #include "bhyverun.h"
47 #include "bootrom.h"
48 #include "debug.h"
49 
50 #define	MAX_BOOTROM_SIZE	(16 * 1024 * 1024)	/* 16 MB */
51 
52 int
53 bootrom_init(struct vmctx *ctx, const char *romfile)
54 {
55 	struct stat sbuf;
56 	vm_paddr_t gpa;
57 	ssize_t rlen;
58 	char *ptr;
59 	int fd, i, rv, prot;
60 
61 	rv = -1;
62 	fd = open(romfile, O_RDONLY);
63 	if (fd < 0) {
64 		EPRINTLN("Error opening bootrom \"%s\": %s",
65 		    romfile, strerror(errno));
66 		goto done;
67 	}
68 
69         if (fstat(fd, &sbuf) < 0) {
70 		EPRINTLN("Could not fstat bootrom file \"%s\": %s",
71 		    romfile, strerror(errno));
72 		goto done;
73         }
74 
75 	/*
76 	 * Limit bootrom size to 16MB so it doesn't encroach into reserved
77 	 * MMIO space (e.g. APIC, HPET, MSI).
78 	 */
79 	if (sbuf.st_size > MAX_BOOTROM_SIZE || sbuf.st_size < PAGE_SIZE) {
80 		EPRINTLN("Invalid bootrom size %ld", sbuf.st_size);
81 		goto done;
82 	}
83 
84 	if (sbuf.st_size & PAGE_MASK) {
85 		EPRINTLN("Bootrom size %ld is not a multiple of the "
86 		    "page size", sbuf.st_size);
87 		goto done;
88 	}
89 
90 	ptr = vm_create_devmem(ctx, VM_BOOTROM, "bootrom", sbuf.st_size);
91 	if (ptr == MAP_FAILED)
92 		goto done;
93 
94 	/* Map the bootrom into the guest address space */
95 	prot = PROT_READ | PROT_EXEC;
96 	gpa = (1ULL << 32) - sbuf.st_size;
97 	if (vm_mmap_memseg(ctx, gpa, VM_BOOTROM, 0, sbuf.st_size, prot) != 0)
98 		goto done;
99 
100 	/* Read 'romfile' into the guest address space */
101 	for (i = 0; i < sbuf.st_size / PAGE_SIZE; i++) {
102 		rlen = read(fd, ptr + i * PAGE_SIZE, PAGE_SIZE);
103 		if (rlen != PAGE_SIZE) {
104 			EPRINTLN("Incomplete read of page %d of bootrom "
105 			    "file %s: %ld bytes", i, romfile, rlen);
106 			goto done;
107 		}
108 	}
109 	rv = 0;
110 done:
111 	if (fd >= 0)
112 		close(fd);
113 	return (rv);
114 }
115