Merge pull request #21 from mjg59/smbios

Add smbios command

docs/grub.texi

@@ -3848,6 +3848,7 @@ you forget a command, you can run the command @command{help}
 * sha256sum::                   Compute or check SHA256 hash
 * sha512sum::                   Compute or check SHA512 hash
 * sleep::                       Wait for a specified number of seconds
+* smbios::                      Retrieve SMBIOS information
 * source::                      Read a configuration file in same context
 * test::                        Check file types and compare values
 * true::                        Do nothing, successfully
@@ -4967,6 +4968,74 @@ if timeout was interrupted by @key{ESC}.
 @end deffn
 
 
+@node smbios
+@subsection smbios
+
+@deffn Command smbios @
+ [@option{--type} @var{type}] @
+ [@option{--handle} @var{handle}] @
+ [@option{--match} @var{match}] @
+ (@option{--get-byte} | @option{--get-word} | @option{--get-dword} | @
+  @option{--get-qword} | @option{--get-string} | @option{--get-uuid}) @
+ @var{offset} @
+ [@option{--set} @var{variable}]
+Retrieve SMBIOS information.
+
+The @command{smbios} command returns the value of a field in an SMBIOS
+structure.  The following options determine which structure to select.
+
+@itemize @bullet
+@item
+Specifying @option{--type} will select structures with a matching
+@var{type}.  The type can be any integer from 0 to 255.
+@item
+Specifying @option{--handle} will select structures with a matching
+@var{handle}.  The handle can be any integer from 0 to 65535.
+@item
+Specifying @option{--match} will select structure number @var{match} in the
+filtered list of structures; e.g. @code{smbios --type 4 --match 2} will select
+the second Process Information (Type 4) structure.  The list is always ordered
+the same as the hardware's SMBIOS table.  The match number must be a positive
+integer.  If unspecified, the first matching structure will be selected.
+@end itemize
+
+The remaining options determine which field in the selected SMBIOS structure to
+return.  Only one of these options may be specified at a time.
+
+@itemize @bullet
+@item
+When given @option{--get-byte}, return the value of the byte
+at @var{offset} bytes into the selected SMBIOS structure.
+@item
+When given @option{--get-word}, return the value of the word (two bytes)
+at @var{offset} bytes into the selected SMBIOS structure.
+@item
+When given @option{--get-dword}, return the value of the dword (four bytes)
+at @var{offset} bytes into the selected SMBIOS structure.
+@item
+When given @option{--get-qword}, return the value of the qword (eight bytes)
+at @var{offset} bytes into the selected SMBIOS structure.
+@item
+When given @option{--get-string}, return the string with its index found
+at @var{offset} bytes into the selected SMBIOS structure.
+@item
+When given @option{--get-uuid}, return the value of the UUID (sixteen bytes)
+at @var{offset} bytes into the selected SMBIOS structure.
+@end itemize
+
+The default action is to print the value of the requested field to the console,
+but a variable name can be specified with @option{--set} to store the value
+instead of printing it.
+
+For example, this will store and then display the system manufacturer's name.
+
+@example
+smbios --type 1 --get-string 4 --set system_manufacturer
+echo $system_manufacturer
+@end example
+@end deffn
+
+
 @node source
 @subsection source
 

grub-core/Makefile.core.def

@@ -1053,6 +1053,21 @@ module = {
   common = commands/sleep.c;
 };
 
+module = {
+  name = smbios;
+
+  common = commands/smbios.c;
+  efi = commands/efi/smbios.c;
+  i386_pc = commands/i386/pc/smbios.c;
+  i386_coreboot = commands/i386/pc/smbios.c;
+  i386_multiboot = commands/i386/pc/smbios.c;
+
+  enable = efi;
+  enable = i386_pc;
+  enable = i386_coreboot;
+  enable = i386_multiboot;
+};
+
 module = {
   name = suspend;
   ieee1275 = commands/ieee1275/suspend.c;

grub-core/commands/efi/loadbios.c

@@ -30,6 +30,7 @@ GRUB_MOD_LICENSE ("GPLv3+");
 static grub_efi_guid_t acpi_guid = GRUB_EFI_ACPI_TABLE_GUID;
 static grub_efi_guid_t acpi2_guid = GRUB_EFI_ACPI_20_TABLE_GUID;
 static grub_efi_guid_t smbios_guid = GRUB_EFI_SMBIOS_TABLE_GUID;
+static grub_efi_guid_t smbios3_guid = GRUB_EFI_SMBIOS3_TABLE_GUID;
 
 #define EBDA_SEG_ADDR	0x40e
 #define LOW_MEM_ADDR	0x413
@@ -93,7 +94,7 @@ static void
 fake_bios_data (int use_rom)
 {
   unsigned i;
-  void *acpi, *smbios;
+  void *acpi, *smbios, *smbios3;
   grub_uint16_t *ebda_seg_ptr, *low_mem_ptr;
 
   ebda_seg_ptr = (grub_uint16_t *) EBDA_SEG_ADDR;
@@ -103,6 +104,7 @@ fake_bios_data (int use_rom)
 
   acpi = 0;
   smbios = 0;
+  smbios3 = 0;
   for (i = 0; i < grub_efi_system_table->num_table_entries; i++)
     {
       grub_efi_packed_guid_t *guid =
@@ -127,6 +129,11 @@ fake_bios_data (int use_rom)
 	  smbios = grub_efi_system_table->configuration_table[i].vendor_table;
 	  grub_dprintf ("efi", "SMBIOS: %p\n", smbios);
 	}
+      else if (! grub_memcmp (guid, &smbios3_guid, sizeof (grub_efi_guid_t)))
+	{
+	  smbios3 = grub_efi_system_table->configuration_table[i].vendor_table;
+	  grub_dprintf ("efi", "SMBIOS3: %p\n", smbios3);
+	}
     }
 
   *ebda_seg_ptr = FAKE_EBDA_SEG;
@@ -137,8 +144,13 @@ fake_bios_data (int use_rom)
   if (acpi)
     grub_memcpy ((char *) ((FAKE_EBDA_SEG << 4) + 16), acpi, 1024 - 16);
 
-  if ((use_rom) && (smbios))
+  if (use_rom)
-    grub_memcpy ((char *) SBIOS_ADDR, (char *) smbios + 16, 16);
+    {
+      if (smbios)
+	grub_memcpy ((char *) SBIOS_ADDR, (char *) smbios, 31);
+      if (smbios3)
+	grub_memcpy ((char *) SBIOS_ADDR + 32, (char *) smbios3, 24);
+    }
 }
 
 static grub_err_t

grub-core/commands/efi/lsefisystab.c

@@ -48,6 +48,7 @@ static const struct guid_mapping guid_mappings[] =
     { GRUB_EFI_MPS_TABLE_GUID, "MPS"},
     { GRUB_EFI_SAL_TABLE_GUID, "SAL"},
     { GRUB_EFI_SMBIOS_TABLE_GUID, "SMBIOS"},
+    { GRUB_EFI_SMBIOS3_TABLE_GUID, "SMBIOS3"},
     { GRUB_EFI_SYSTEM_RESOURCE_TABLE_GUID, "SYSTEM RESOURCE TABLE"},
     { GRUB_EFI_TIANO_CUSTOM_DECOMPRESS_GUID, "TIANO CUSTOM DECOMPRESS"},
     { GRUB_EFI_TSC_FREQUENCY_GUID, "TSC FREQUENCY"},

grub-core/commands/efi/smbios.c

@@ -0,0 +1,59 @@
+/* smbios.c - get smbios tables. */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2015  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/smbios.h>
+#include <grub/misc.h>
+#include <grub/efi/efi.h>
+#include <grub/efi/api.h>
+
+struct grub_smbios_eps *
+grub_machine_smbios_get_eps (void)
+{
+  unsigned i;
+  static grub_efi_packed_guid_t smbios_guid = GRUB_EFI_SMBIOS_TABLE_GUID;
+
+  for (i = 0; i < grub_efi_system_table->num_table_entries; i++)
+    {
+      grub_efi_packed_guid_t *guid =
+	&grub_efi_system_table->configuration_table[i].vendor_guid;
+
+      if (! grub_memcmp (guid, &smbios_guid, sizeof (grub_efi_packed_guid_t)))
+	return (struct grub_smbios_eps *)
+	  grub_efi_system_table->configuration_table[i].vendor_table;
+    }
+  return 0;
+}
+
+struct grub_smbios_eps3 *
+grub_machine_smbios_get_eps3 (void)
+{
+  unsigned i;
+  static grub_efi_packed_guid_t smbios3_guid = GRUB_EFI_SMBIOS3_TABLE_GUID;
+
+  for (i = 0; i < grub_efi_system_table->num_table_entries; i++)
+    {
+      grub_efi_packed_guid_t *guid =
+	&grub_efi_system_table->configuration_table[i].vendor_guid;
+
+      if (! grub_memcmp (guid, &smbios3_guid, sizeof (grub_efi_packed_guid_t)))
+	return (struct grub_smbios_eps3 *)
+	  grub_efi_system_table->configuration_table[i].vendor_table;
+    }
+  return 0;
+}

grub-core/commands/i386/pc/smbios.c

@@ -0,0 +1,50 @@
+/* smbios.c - get smbios tables. */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2015  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/acpi.h>
+#include <grub/smbios.h>
+#include <grub/misc.h>
+
+struct grub_smbios_eps *
+grub_machine_smbios_get_eps (void)
+{
+  grub_uint8_t *ptr;
+
+  grub_dprintf ("smbios", "Looking for SMBIOS EPS. Scanning BIOS\n");
+  for (ptr = (grub_uint8_t *) 0xf0000; ptr < (grub_uint8_t *) 0x100000;
+       ptr += 16)
+    if (grub_memcmp (ptr, "_SM_", 4) == 0
+	&& grub_byte_checksum (ptr, sizeof (struct grub_smbios_eps)) == 0)
+      return (struct grub_smbios_eps *) ptr;
+  return 0;
+}
+
+struct grub_smbios_eps3 *
+grub_machine_smbios_get_eps3 (void)
+{
+  grub_uint8_t *ptr;
+
+  grub_dprintf ("smbios", "Looking for SMBIOS3 EPS. Scanning BIOS\n");
+  for (ptr = (grub_uint8_t *) 0xf0000; ptr < (grub_uint8_t *) 0x100000;
+       ptr += 16)
+    if (grub_memcmp (ptr, "_SM3_", 5) == 0
+	&& grub_byte_checksum (ptr, sizeof (struct grub_smbios_eps3)) == 0)
+      return (struct grub_smbios_eps3 *) ptr;
+  return 0;
+}

grub-core/commands/smbios.c

@@ -0,0 +1,372 @@
+/* smbios.c - retrieve smbios information. */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2013,2014,2015  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/dl.h>
+#include <grub/env.h>
+#include <grub/extcmd.h>
+#include <grub/i18n.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/smbios.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+
+/* Locate the SMBIOS entry point structure depending on the hardware. */
+struct grub_smbios_eps *
+grub_smbios_get_eps (void)
+{
+  static struct grub_smbios_eps *eps = NULL;
+  if (eps != NULL)
+    return eps;
+  eps = grub_machine_smbios_get_eps ();
+  return eps;
+}
+
+/* Locate the SMBIOS3 entry point structure depending on the hardware. */
+struct grub_smbios_eps3 *
+grub_smbios_get_eps3 (void)
+{
+  static struct grub_smbios_eps3 *eps = NULL;
+  if (eps != NULL)
+    return eps;
+  eps = grub_machine_smbios_get_eps3 ();
+  return eps;
+}
+
+/* Abstract useful values found in either the SMBIOS3 or SMBIOS EPS. */
+static struct {
+  grub_addr_t start;
+  grub_addr_t end;
+  grub_uint16_t structures;
+} table_desc = {0, 0, 0};
+
+
+/*
+ * These functions convert values from the various SMBIOS structure field types
+ * into a string formatted to be returned to the user.  They expect that the
+ * structure and offset were already validated.  The given buffer stores the
+ * newly formatted string if needed.  When the requested data is successfully
+ * retrieved and formatted, the pointer to the string is returned; otherwise,
+ * NULL is returned on failure.
+ */
+
+static const char *
+grub_smbios_format_byte (char *buffer, grub_size_t size,
+                         const grub_uint8_t *structure, grub_uint8_t offset)
+{
+  grub_snprintf (buffer, size, "%u", structure[offset]);
+  return (const char *)buffer;
+}
+
+static const char *
+grub_smbios_format_word (char *buffer, grub_size_t size,
+                         const grub_uint8_t *structure, grub_uint8_t offset)
+{
+  grub_uint16_t value = grub_get_unaligned16 (structure + offset);
+  grub_snprintf (buffer, size, "%u", value);
+  return (const char *)buffer;
+}
+
+static const char *
+grub_smbios_format_dword (char *buffer, grub_size_t size,
+                          const grub_uint8_t *structure, grub_uint8_t offset)
+{
+  grub_uint32_t value = grub_get_unaligned32 (structure + offset);
+  grub_snprintf (buffer, size, "%" PRIuGRUB_UINT32_T, value);
+  return (const char *)buffer;
+}
+
+static const char *
+grub_smbios_format_qword (char *buffer, grub_size_t size,
+                          const grub_uint8_t *structure, grub_uint8_t offset)
+{
+  grub_uint64_t value = grub_get_unaligned64 (structure + offset);
+  grub_snprintf (buffer, size, "%" PRIuGRUB_UINT64_T, value);
+  return (const char *)buffer;
+}
+
+/* The matching string pointer is returned directly to avoid extra copying. */
+static const char *
+grub_smbios_get_string (char *buffer __attribute__ ((unused)),
+                        grub_size_t size __attribute__ ((unused)),
+                        const grub_uint8_t *structure, grub_uint8_t offset)
+{
+  const grub_uint8_t *ptr = structure + structure[1];
+  const grub_uint8_t *table_end = (const grub_uint8_t *)table_desc.end;
+  const grub_uint8_t referenced_string_number = structure[offset];
+  grub_uint8_t i;
+
+  /* A string referenced with zero is interpreted as unset. */
+  if (referenced_string_number == 0)
+    return NULL;
+
+  /* Search the string set. */
+  for (i = 1; *ptr != 0 && ptr < table_end; i++)
+    if (i == referenced_string_number)
+      {
+        const char *str = (const char *)ptr;
+        while (*ptr++ != 0)
+          if (ptr >= table_end)
+            return NULL; /* The string isn't terminated. */
+        return str;
+      }
+    else
+      while (*ptr++ != 0 && ptr < table_end);
+
+  /* The string number is greater than the number of strings in the set. */
+  return NULL;
+}
+
+static const char *
+grub_smbios_format_uuid (char *buffer, grub_size_t size,
+                         const grub_uint8_t *structure, grub_uint8_t offset)
+{
+  const grub_uint8_t *f = structure + offset; /* little-endian fields */
+  const grub_uint8_t *g = f + 8; /* byte-by-byte fields */
+  grub_snprintf (buffer, size,
+                 "%02x%02x%02x%02x-%02x%02x-%02x%02x-"
+                 "%02x%02x-%02x%02x%02x%02x%02x%02x",
+                 f[3], f[2], f[1], f[0], f[5], f[4], f[7], f[6],
+                 g[0], g[1], g[2], g[3], g[4], g[5], g[6], g[7]);
+  return (const char *)buffer;
+}
+
+
+/* List the field formatting functions and the number of bytes they need. */
+#define MAXIMUM_FORMAT_LENGTH (sizeof ("ffffffff-ffff-ffff-ffff-ffffffffffff"))
+static const struct {
+  const char *(*format) (char *buffer, grub_size_t size,
+                         const grub_uint8_t *structure, grub_uint8_t offset);
+  grub_uint8_t field_length;
+} field_extractors[] = {
+  {grub_smbios_format_byte, 1},
+  {grub_smbios_format_word, 2},
+  {grub_smbios_format_dword, 4},
+  {grub_smbios_format_qword, 8},
+  {grub_smbios_get_string, 1},
+  {grub_smbios_format_uuid, 16}
+};
+
+/* List command options, with structure field getters ordered as above. */
+#define FIRST_GETTER_OPT (3)
+#define SETTER_OPT (FIRST_GETTER_OPT + ARRAY_SIZE(field_extractors))
+static const struct grub_arg_option options[] = {
+  {"type",       't', 0, N_("Match entries with the given type."),
+                         N_("type"), ARG_TYPE_INT},
+  {"handle",     'h', 0, N_("Match entries with the given handle."),
+                         N_("handle"), ARG_TYPE_INT},
+  {"match",      'm', 0, N_("Select a structure when several match."),
+                         N_("match"), ARG_TYPE_INT},
+  {"get-byte",   'b', 0, N_("Get the byte's value at the given offset."),
+                         N_("offset"), ARG_TYPE_INT},
+  {"get-word",   'w', 0, N_("Get two bytes' value at the given offset."),
+                         N_("offset"), ARG_TYPE_INT},
+  {"get-dword",  'd', 0, N_("Get four bytes' value at the given offset."),
+                         N_("offset"), ARG_TYPE_INT},
+  {"get-qword",  'q', 0, N_("Get eight bytes' value at the given offset."),
+                         N_("offset"), ARG_TYPE_INT},
+  {"get-string", 's', 0, N_("Get the string specified at the given offset."),
+                         N_("offset"), ARG_TYPE_INT},
+  {"get-uuid",   'u', 0, N_("Get the UUID's value at the given offset."),
+                         N_("offset"), ARG_TYPE_INT},
+  {"set",       '\0', 0, N_("Store the value in the given variable name."),
+                         N_("variable"), ARG_TYPE_STRING},
+  {0, 0, 0, 0, 0, 0}
+};
+
+
+/*
+ * Return a matching SMBIOS structure.
+ *
+ * This method can use up to three criteria for selecting a structure:
+ *   - The "type" field                  (use -1 to ignore)
+ *   - The "handle" field                (use -1 to ignore)
+ *   - Which to return if several match  (use  0 to ignore)
+ *
+ * The return value is a pointer to the first matching structure.  If no
+ * structures match the given parameters, NULL is returned.
+ */
+static const grub_uint8_t *
+grub_smbios_match_structure (const grub_int16_t type,
+                             const grub_int32_t handle,
+                             const grub_uint16_t match)
+{
+  const grub_uint8_t *ptr = (const grub_uint8_t *)table_desc.start;
+  const grub_uint8_t *table_end = (const grub_uint8_t *)table_desc.end;
+  grub_uint16_t structures = table_desc.structures;
+  grub_uint16_t structure_count = 0;
+  grub_uint16_t matches = 0;
+
+  while (ptr < table_end
+         && ptr[1] >= 4 /* Valid structures include the 4-byte header. */
+         && (structure_count++ < structures || structures == 0))
+    {
+      grub_uint16_t structure_handle = grub_get_unaligned16 (ptr + 2);
+      grub_uint8_t structure_type = ptr[0];
+
+      if ((handle < 0 || handle == structure_handle)
+          && (type < 0 || type == structure_type)
+          && (match == 0 || match == ++matches))
+        return ptr;
+
+      else
+        {
+          ptr += ptr[1];
+          while ((*ptr++ != 0 || *ptr++ != 0) && ptr < table_end);
+        }
+
+      if (structure_type == GRUB_SMBIOS_TYPE_END_OF_TABLE)
+        break;
+    }
+
+  return NULL;
+}
+
+
+static grub_err_t
+grub_cmd_smbios (grub_extcmd_context_t ctxt,
+                 int argc __attribute__ ((unused)),
+                 char **argv __attribute__ ((unused)))
+{
+  struct grub_arg_list *state = ctxt->state;
+
+  grub_int16_t type = -1;
+  grub_int32_t handle = -1;
+  grub_uint16_t match = 0;
+  grub_uint8_t offset = 0;
+
+  const grub_uint8_t *structure;
+  const char *value;
+  char buffer[MAXIMUM_FORMAT_LENGTH];
+  grub_int32_t option;
+  grub_int8_t field_type = -1;
+  grub_uint8_t i;
+
+  if (table_desc.start == 0)
+    return grub_error (GRUB_ERR_IO,
+                       N_("the SMBIOS entry point structure was not found"));
+
+  /* Read the given filtering options. */
+  if (state[0].set)
+    {
+      option = grub_strtol (state[0].arg, NULL, 0);
+      if (option < 0 || option > 255)
+        return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                           N_("the type must be between 0 and 255"));
+      type = (grub_int16_t)option;
+    }
+  if (state[1].set)
+    {
+      option = grub_strtol (state[1].arg, NULL, 0);
+      if (option < 0 || option > 65535)
+        return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                           N_("the handle must be between 0 and 65535"));
+      handle = (grub_int32_t)option;
+    }
+  if (state[2].set)
+    {
+      option = grub_strtol (state[2].arg, NULL, 0);
+      if (option <= 0)
+        return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                           N_("the match must be a positive integer"));
+      match = (grub_uint16_t)option;
+    }
+
+  /* Determine the data type of the structure field to retrieve. */
+  for (i = 0; i < ARRAY_SIZE(field_extractors); i++)
+    if (state[FIRST_GETTER_OPT + i].set)
+      {
+        if (field_type >= 0)
+          return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                             N_("only one --get option is usable at a time"));
+        field_type = i;
+      }
+
+  /* Require a choice of a structure field to return. */
+  if (field_type < 0)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                       N_("one of the --get options is required"));
+
+  /* Locate a matching SMBIOS structure. */
+  structure = grub_smbios_match_structure (type, handle, match);
+  if (structure == NULL)
+    return grub_error (GRUB_ERR_IO,
+                       N_("no structure matched the given options"));
+
+  /* Ensure the requested byte offset is inside the structure. */
+  option = grub_strtol (state[FIRST_GETTER_OPT + field_type].arg, NULL, 0);
+  if (option < 0 || option >= structure[1])
+    return grub_error (GRUB_ERR_OUT_OF_RANGE,
+                       N_("the given offset is outside the structure"));
+
+  /* Ensure the requested data type at the offset is inside the structure. */
+  offset = (grub_uint8_t)option;
+  if (offset + field_extractors[field_type].field_length > structure[1])
+    return grub_error (GRUB_ERR_OUT_OF_RANGE,
+                       N_("the field ends outside the structure"));
+
+  /* Format the requested structure field into a readable string. */
+  value = field_extractors[field_type].format (buffer, sizeof (buffer),
+                                               structure, offset);
+  if (value == NULL)
+    return grub_error (GRUB_ERR_IO,
+                       N_("failed to retrieve the structure field"));
+
+  /* Store or print the formatted value. */
+  if (state[SETTER_OPT].set)
+    grub_env_set (state[SETTER_OPT].arg, value);
+  else
+    grub_printf ("%s\n", value);
+
+  return GRUB_ERR_NONE;
+}
+
+
+static grub_extcmd_t cmd;
+
+GRUB_MOD_INIT(smbios)
+{
+  struct grub_smbios_eps3 *eps3;
+  struct grub_smbios_eps *eps;
+
+  if ((eps3 = grub_smbios_get_eps3 ()))
+    {
+      table_desc.start = (grub_addr_t)eps3->table_address;
+      table_desc.end = table_desc.start + eps3->maximum_table_length;
+      table_desc.structures = 0; /* SMBIOS3 drops the structure count. */
+    }
+  else if ((eps = grub_smbios_get_eps ()))
+    {
+      table_desc.start = (grub_addr_t)eps->intermediate.table_address;
+      table_desc.end = table_desc.start + eps->intermediate.table_length;
+      table_desc.structures = eps->intermediate.structures;
+    }
+
+  cmd = grub_register_extcmd ("smbios", grub_cmd_smbios, 0,
+                              N_("[-t type] [-h handle] [-m match] "
+                                 "(-b|-w|-d|-q|-s|-u) offset "
+                                 "[--set variable]"),
+                              N_("Retrieve SMBIOS information."), options);
+}
+
+GRUB_MOD_FINI(smbios)
+{
+  grub_unregister_extcmd (cmd);
+}

grub-core/efiemu/i386/pc/cfgtables.c

@@ -22,18 +22,22 @@
 #include <grub/misc.h>
 #include <grub/mm.h>
 #include <grub/acpi.h>
+#include <grub/smbios.h>
 
 grub_err_t
 grub_machine_efiemu_init_tables (void)
 {
-  grub_uint8_t *ptr;
   void *table;
   grub_err_t err;
   grub_efi_guid_t smbios = GRUB_EFI_SMBIOS_TABLE_GUID;
+  grub_efi_guid_t smbios3 = GRUB_EFI_SMBIOS3_TABLE_GUID;
   grub_efi_guid_t acpi20 = GRUB_EFI_ACPI_20_TABLE_GUID;
   grub_efi_guid_t acpi = GRUB_EFI_ACPI_TABLE_GUID;
 
   err = grub_efiemu_unregister_configuration_table (smbios);
+  if (err)
+    return err;
+  err = grub_efiemu_unregister_configuration_table (smbios3);
   if (err)
     return err;
   err = grub_efiemu_unregister_configuration_table (acpi);
@@ -43,6 +47,20 @@ grub_machine_efiemu_init_tables (void)
   if (err)
     return err;
 
+  table = grub_smbios_get_eps ();
+  if (table)
+    {
+      err = grub_efiemu_register_configuration_table (smbios, 0, 0, table);
+      if (err)
+	return err;
+    }
+  table = grub_smbios_get_eps3 ();
+  if (table)
+    {
+      err = grub_efiemu_register_configuration_table (smbios3, 0, 0, table);
+      if (err)
+	return err;
+    }
   table = grub_acpi_get_rsdpv1 ();
   if (table)
     {
@@ -58,19 +76,5 @@ grub_machine_efiemu_init_tables (void)
 	return err;
     }
 
-  for (ptr = (grub_uint8_t *) 0xf0000; ptr < (grub_uint8_t *) 0x100000;
-       ptr += 16)
-    if (grub_memcmp (ptr, "_SM_", 4) == 0
-	&& grub_byte_checksum (ptr, *(ptr + 5)) == 0)
-      break;
-
-  if (ptr < (grub_uint8_t *) 0x100000)
-    {
-      grub_dprintf ("efiemu", "Registering SMBIOS\n");
-      err = grub_efiemu_register_configuration_table (smbios, 0, 0, ptr);
-      if (err)
-	return err;
-    }
-
   return GRUB_ERR_NONE;
 }

include/grub/efi/api.h

@@ -314,6 +314,11 @@
     { 0x9a, 0x16, 0x0, 0x90, 0x27, 0x3f, 0xc1, 0x4d } \
   }
 
+#define GRUB_EFI_SMBIOS3_TABLE_GUID	\
+  { 0xf2fd1544, 0x9794, 0x4a2c, \
+    { 0x99, 0x2e, 0xe5, 0xbb, 0xcf, 0x20, 0xe3, 0x94 } \
+  }
+
 #define GRUB_EFI_SAL_TABLE_GUID \
   { 0xeb9d2d32, 0x2d88, 0x11d3, \
       { 0x9a, 0x16, 0x0, 0x90, 0x27, 0x3f, 0xc1, 0x4d } \

include/grub/smbios.h

@@ -0,0 +1,68 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2015  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_SMBIOS_HEADER
+#define GRUB_SMBIOS_HEADER	1
+
+#include <grub/types.h>
+
+#define GRUB_SMBIOS_TYPE_END_OF_TABLE ((grub_uint8_t)127)
+
+struct grub_smbios_ieps
+{
+  grub_uint8_t anchor[5]; /* "_DMI_" */
+  grub_uint8_t checksum;
+  grub_uint16_t table_length;
+  grub_uint32_t table_address;
+  grub_uint16_t structures;
+  grub_uint8_t revision;
+} GRUB_PACKED;
+
+struct grub_smbios_eps
+{
+  grub_uint8_t anchor[4]; /* "_SM_" */
+  grub_uint8_t checksum;
+  grub_uint8_t length; /* 0x1f */
+  grub_uint8_t version_major;
+  grub_uint8_t version_minor;
+  grub_uint16_t maximum_structure_size;
+  grub_uint8_t revision;
+  grub_uint8_t formatted[5];
+  struct grub_smbios_ieps intermediate;
+} GRUB_PACKED;
+
+struct grub_smbios_eps3
+{
+  grub_uint8_t anchor[5]; /* "_SM3_" */
+  grub_uint8_t checksum;
+  grub_uint8_t length; /* 0x18 */
+  grub_uint8_t version_major;
+  grub_uint8_t version_minor;
+  grub_uint8_t docrev;
+  grub_uint8_t revision;
+  grub_uint8_t reserved;
+  grub_uint32_t maximum_table_length;
+  grub_uint64_t table_address;
+} GRUB_PACKED;
+
+struct grub_smbios_eps *grub_smbios_get_eps (void);
+struct grub_smbios_eps3 *grub_smbios_get_eps3 (void);
+struct grub_smbios_eps *grub_machine_smbios_get_eps (void);
+struct grub_smbios_eps3 *grub_machine_smbios_get_eps3 (void);
+
+#endif /* ! GRUB_SMBIOS_HEADER */