1 /*
2 * Dump DMI information in a way hopefully compatible with dmidecode
3 */
4
5 #include <stdio.h>
6 #include <string.h>
7 #include <stdlib.h>
8 #include "sysdump.h"
9
10 struct dmi_header {
11 char signature[5];
12 uint8_t csum;
13 uint16_t tbllen;
14 uint32_t tbladdr;
15 uint16_t nstruc;
16 uint8_t revision;
17 uint8_t reserved;
18 };
19
20 struct smbios_header {
21 char signature[4];
22 uint8_t csum;
23 uint8_t len;
24 uint8_t major;
25 uint8_t minor;
26 uint16_t maxsize;
27 uint8_t revision;
28 uint8_t fmt[5];
29
30 struct dmi_header dmi;
31 };
32
checksum(const void * buf,size_t len)33 static uint8_t checksum(const void *buf, size_t len)
34 {
35 const uint8_t *p = buf;
36 uint8_t csum = 0;
37
38 while (len--)
39 csum += *p++;
40
41 return csum;
42 }
43
is_old_dmi(size_t dptr)44 static bool is_old_dmi(size_t dptr)
45 {
46 const struct dmi_header *dmi = (void *)dptr;
47
48 return !memcmp(dmi->signature, "_DMI_", 5) &&
49 !checksum(dmi, 0x0f);
50 return false;
51 }
52
is_smbios(size_t dptr)53 static bool is_smbios(size_t dptr)
54 {
55 const struct smbios_header *smb = (void *)dptr;
56
57 return !memcmp(smb->signature, "_SM_", 4) &&
58 !checksum(smb, smb->len) &&
59 is_old_dmi(dptr+16);
60 }
61
dump_smbios(struct upload_backend * be,size_t dptr)62 static void dump_smbios(struct upload_backend *be, size_t dptr)
63 {
64 const struct smbios_header *smb = (void *)dptr;
65 struct smbios_header smx = *smb;
66 char filename[32];
67
68 snprintf(filename, sizeof filename, "dmi/%05x.%08x",
69 dptr, smb->dmi.tbladdr);
70 cpio_hdr(be, MODE_FILE, smb->dmi.tbllen + 32, filename);
71
72 /*
73 * Adjust the address of the smbios table to be 32, to
74 * make dmidecode happy. The checksum on the smbios table is unchanged,
75 * since it includes the checksum on the dmi table.
76 */
77 smx.dmi.tbladdr = sizeof smx;
78 smx.dmi.csum -= checksum(&smx.dmi, 0x0f);
79
80 write_data(be, &smx, sizeof smx);
81 write_data(be, (const void *)smb->dmi.tbladdr, smb->dmi.tbllen);
82 }
83
dump_old_dmi(struct upload_backend * be,size_t dptr)84 static void dump_old_dmi(struct upload_backend *be, size_t dptr)
85 {
86 const struct dmi_header *dmi = (void *)dptr;
87 struct fake {
88 struct dmi_header dmi;
89 char pad[16];
90 } fake;
91 char filename[32];
92
93 snprintf(filename, sizeof filename, "dmi/%05x.%08x",
94 dptr, dmi->tbladdr);
95 cpio_hdr(be, MODE_FILE, dmi->tbllen + 32, filename);
96
97 /*
98 * Adjust the address of the smbios table to be 32, to
99 * make dmidecode happy.
100 */
101 fake.dmi = *dmi;
102 memset(&fake.pad, 0, sizeof fake.pad);
103 fake.dmi.tbladdr = sizeof fake;
104 fake.dmi.csum -= checksum(&fake.dmi, 0x0f);
105
106 write_data(be, &fake, sizeof fake);
107 write_data(be, (const void *)dmi->tbladdr, dmi->tbllen);
108 }
109
dump_dmi(struct upload_backend * be)110 void dump_dmi(struct upload_backend *be)
111 {
112 size_t dptr;
113
114 cpio_mkdir(be, "dmi");
115
116 /* Search for _SM_ or _DMI_ structure */
117 for (dptr = 0xf0000 ; dptr < 0x100000 ; dptr += 16) {
118 if (is_smbios(dptr)) {
119 dump_smbios(be, dptr);
120 dptr += 16; /* Skip the subsequent DMI header */
121 } else if (is_old_dmi(dptr)) {
122 dump_old_dmi(be, dptr);
123 }
124 }
125 }
126