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/*
* Dump DMI information in a way hopefully compatible with dmidecode
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "sysdump.h"
#include "backend.h"
struct dmi_header {
char signature[5];
uint8_t csum;
uint16_t tbllen;
uint32_t tbladdr;
uint16_t nstruc;
uint8_t revision;
uint8_t reserved;
};
struct smbios_header {
char signature[4];
uint8_t csum;
uint8_t len;
uint8_t major;
uint8_t minor;
uint16_t maxsize;
uint8_t revision;
uint8_t fmt[5];
struct dmi_header dmi;
};
static uint8_t checksum(const void *buf, size_t len)
{
const uint8_t *p = buf;
uint8_t csum = 0;
while (len--)
csum += *p++;
return csum;
}
static bool is_old_dmi(size_t dptr)
{
const struct dmi_header *dmi = (void *)dptr;
return !memcmp(dmi->signature, "_DMI_", 5) &&
!checksum(dmi, 0x0f);
return false;
}
static bool is_smbios(size_t dptr)
{
const struct smbios_header *smb = (void *)dptr;
return !memcmp(smb->signature, "_SM_", 4) &&
!checksum(smb, smb->len) &&
is_old_dmi(dptr+16);
}
static void dump_smbios(struct backend *be, size_t dptr)
{
const struct smbios_header *smb = (void *)dptr;
struct smbios_header smx = *smb;
cpio_hdr(be, MODE_FILE, smb->dmi.tbllen + 32, "dmidata");
/*
* Adjust the address of the smbios table to be 32, to
* make dmidecode happy. According to dmidecode, the checksum on
* the smbios structure doesn't need to be adjusted, for whatever
* reason...
*/
smx.dmi.tbladdr = sizeof smx;
smx.dmi.csum -= checksum(&smb->dmi, 0x0f);
write_data(be, &smx, sizeof smx, false);
write_data(be, (const void *)smb->dmi.tbladdr, smb->dmi.tbllen, false);
}
static void dump_old_dmi(struct backend *be, size_t dptr)
{
const struct dmi_header *dmi = (void *)dptr;
struct fake {
struct dmi_header dmi;
char pad[16];
} fake;
cpio_hdr(be, MODE_FILE, dmi->tbllen + 32, "dmidata");
/*
* Adjust the address of the smbios table to be 32, to
* make dmidecode happy. According to dmidecode, the checksum on
* the smbios structure doesn't need to be adjusted, for whatever
* reason...
*/
fake.dmi = *dmi;
memset(&fake.pad, 0, sizeof fake.pad);
fake.dmi.tbladdr = sizeof fake;
fake.dmi.csum -= checksum(&fake.dmi, 0x0f);
write_data(be, &fake, sizeof fake, false);
write_data(be, (const void *)dmi->tbladdr, dmi->tbllen, false);
}
void dump_dmi(struct backend *be)
{
size_t dptr;
/* Search for _SM_ or _DMI_ structure */
for (dptr = 0xf0000 ; dptr < 0x100000 ; dptr += 16) {
if (is_smbios(dptr)) {
dump_smbios(be, dptr);
break;
} else if (is_old_dmi(dptr)) {
dump_old_dmi(be, dptr);
break;
}
}
}
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