В Sun, 08 Feb 2015 13:54:46 -0500
David Michael <fedora....@gmail.com> пишет:
> The following are two use cases from Rajat Jain <rajatj...@juniper.net>:
>
> 1) We have a board that boots Linux and this board itself can be plugged into
> one of different chassis types. We need to pass different parameters to the
> kernel based on the "CHASSIS_TYPE" information that is passed by the bios in
> the DMI / SMBIOS tables.
>
> 2) We may have a USB stick that can go into multiple boards, and the exact
> kernel to be loaded depends on the machine information (PRODUCT_NAME etc)
> passed via the DMI.
>
> * grub-core/commands/smbios.c: New file.
> * grub-core/Makefile.core.def (smbios): New module.
> * docs/grub.texi (smbios): New node.
> (Command-line and menu entry commands): Add a menu entry for smbios.
That's not needed. ChangeLog is now generated from GIT commits.
> ---
>
> Changes since v1:
>
> * Removed formfeeds and quoted use cases in the commit messages as
> suggested by Prarit Bhargava.
>
> * Enabled building the module on all EFI platforms as suggested by Leif
> Lindholm.
>
> docs/grub.texi | 67 ++++++++
> grub-core/Makefile.core.def | 7 +
> grub-core/commands/smbios.c | 361
> ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 435 insertions(+)
> create mode 100644 grub-core/commands/smbios.c
>
> diff --git a/docs/grub.texi b/docs/grub.texi
> index 46b9e7f..f4e187f 100644
> --- a/docs/grub.texi
> +++ b/docs/grub.texi
> @@ -3830,6 +3830,7 @@ 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
> @@ -4944,6 +4945,72 @@ if timeout was interrupted by @key{ESC}.
> @end deffn
>
>
> +@node smbios
> +@subsection smbios
> +
> +@deffn Command smbios @
> + [@option{-t} @var{type}] @
> + [@option{-h} @var{handle}] @
> + [@option{-m} @var{match}] @
> + [ (@option{-b} | @option{-w} | @option{-d} | @option{-q} | @option{-s}) @
> + @var{offset} [@option{-v} @var{variable}] ]
I think that in general we should endorse and advertise long options -
they make scripts much more readable - and mention single letter
options in description (if at all) or help output. Look e.g. at search
command description.
In other places we use "--set var" to set variable. Let's remain
consistent with this usage. If you want to spare some typing, make it
optional, like
smbios offset [[--set] var]
> +Retrieve SMBIOS information. This command is only available on x86 and EFI
> +systems.
> +
> +When run with no options, @command{smbios} will print the SMBIOS table
> entries
> +to the console as the header values, a hex dump, and a string list. The
> +following options can filter which table entries are printed.
> +
> +@itemize @bullet
> +@item
> +Specifying @option{-t} will only print entries with a matching @var{type}.
> The
> +type can be any value from 0 to 255. Specify a value outside this range to
> +match entries with any type. The default is -1.
I think out of range value should result in error.
> +@item
> +Specifying @option{-h} will only print entries with a matching @var{handle}.
> +The handle can be any value from 0 to 65535. Specify a value outside this
> +range to match entries with any handle. The default is -1.
ditto.
> +@item
> +Specifying @option{-m} will only print number @var{match} in the list of all
> +filtered entries; e.g. @code{smbios -m 3} will print the third entry. The
> list
> +is always ordered the same as the hardware's SMBIOS table. The match number
> +can be any positive value. Specify 0 to match all entries. The default is
> 0.
> +@end itemize
> +
> +The remaining options print the value of a field in the matched SMBIOS table
> +entry. Only one of these options may be specified. When they are used, the
> +option @code{-m 0} is synonymous with @code{-m 1} to match the first entry.
If user provides conflicting options this should really be an error.
> +
> +@itemize @bullet
> +@item
> +When given @option{-b}, print the value of the byte
> +at @var{offset} bytes into the matched SMBIOS table entry.
> +@item
> +When given @option{-w}, print the value of the word (two bytes)
> +at @var{offset} bytes into the matched SMBIOS table entry.
> +@item
> +When given @option{-d}, print the value of the dword (four bytes)
> +at @var{offset} bytes into the matched SMBIOS table entry.
> +@item
> +When given @option{-q}, print the value of the qword (eight bytes)
> +at @var{offset} bytes into the matched SMBIOS table entry.
> +@item
> +When given @option{-s}, print the string table entry with its index found
> +at @var{offset} bytes into the matched SMBIOS table entry.
> +@end itemize
> +
> +If any of the options in the above list were given, a variable name can be
> +specified with @option{-v} to store the value instead of printing it.
> +
> +For example, this will store and display the system manufacturer string.
> +
> +@example
> +smbios -t 1 -s 4 -v system_manufacturer
> +echo $system_manufacturer
> +@end example
> +@end deffn
> +
> +
> @node source
> @subsection source
>
> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> index 42443bc..f87de70 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -1023,6 +1023,13 @@ module = {
> };
>
> module = {
> + name = smbios;
> + common = commands/smbios.c;
> + enable = efi;
> + enable = x86;
> +};
> +
> +module = {
> name = suspend;
> ieee1275 = commands/ieee1275/suspend.c;
> enable = i386_ieee1275;
> diff --git a/grub-core/commands/smbios.c b/grub-core/commands/smbios.c
> new file mode 100644
> index 0000000..d8edeea
> --- /dev/null
> +++ b/grub-core/commands/smbios.c
> @@ -0,0 +1,361 @@
> +/* Expose SMBIOS data to the console and configuration files */
> +/*
> + * 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/extcmd.h>
> +#include <grub/env.h>
> +#include <grub/i18n.h>
> +#include <grub/misc.h>
> +#include <grub/mm.h>
> +
> +#ifdef GRUB_MACHINE_EFI
> +#include <grub/efi/efi.h>
> +#else
> +#include <grub/acpi.h>
> +#endif
> +
> +GRUB_MOD_LICENSE ("GPLv3+");
> +
> +/* Reference: DMTF Standard DSP0134 2.7.1 Table 1 */
> +
> +struct __attribute__ ((packed)) 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;
> + };
> +
> +struct __attribute__ ((packed)) grub_smbios_eps
> + {
> + grub_uint8_t anchor[4]; /* "_SM_" */
> + grub_uint8_t checksum;
> + grub_uint8_t length;
> + 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;
> + };
> +
> +static const struct grub_smbios_eps *eps = NULL;
> +
> +/* Reference: DMTF Standard DSP0134 2.7.1 Section 5.2.1 */
> +
> +/*
> + * In order for any of this module to function, it needs to find an entry
> point
> + * structure. This returns a pointer to a struct that identifies the fields
> of
> + * the EPS, or NULL if it cannot be located.
> + */
> +static const struct grub_smbios_eps *
> +grub_smbios_locate_eps (void)
> +{
> +#ifdef GRUB_MACHINE_EFI
> + static const grub_efi_guid_t smbios_guid = GRUB_EFI_SMBIOS_TABLE_GUID;
> + const grub_efi_system_table_t *st = grub_efi_system_table;
> + const grub_efi_configuration_table_t *t = st->configuration_table;
> + unsigned int i;
> +
> + for (i = 0; i < st->num_table_entries; i++)
> + if (grub_memcmp (&smbios_guid, &t->vendor_guid, sizeof (smbios_guid)) ==
> 0)
> + {
> + grub_dprintf ("smbios", "Found entry point structure at %p\n",
> + t->vendor_table);
> + return (const struct grub_smbios_eps *)t->vendor_table;
> + }
> + else
> + t++;
> +#else
> + grub_uint8_t *ptr;
> +
> + for (ptr = (grub_uint8_t *)0x000F0000;
> + ptr < (grub_uint8_t *)0x00100000;
> + ptr += 16)
> + if (grub_memcmp (ptr, "_SM_", 4) == 0
> + && grub_byte_checksum (ptr, ptr[5]) == 0)
> + {
> + grub_dprintf ("smbios", "Found entry point structure at %p\n", ptr);
> + return (const struct grub_smbios_eps *)ptr;
> + }
> +#endif
> +
> + grub_dprintf ("smbios", "Failed to locate entry point structure\n");
> + return NULL;
> +}
> +
> +/* Reference: DMTF Standard DSP0134 2.7.1 Sections 6.1.2-6.1.3 */
> +
> +/*
> + * Given a pointer to the first bytes of an entry, print its contents in a
> + * semi-human-readable format. Return the size of the entry printed.
> + */
> +static grub_uint16_t
> +grub_smbios_dump_entry (const grub_uint8_t *entry)
> +{
> + const grub_uint8_t *ptr = entry;
> + grub_uint8_t newstr = 1;
> + grub_uint8_t length;
> +
> + /* Write the entry's mandatory four header bytes. */
> + length = ptr[1];
> + grub_printf ("Entry: Type=0x%02x Length=0x%02x Handle=0x%04x\n",
> + ptr[0], length, *(1 + (grub_uint16_t *)ptr));
Could you reverse the order in 1 + (grub_uint16_t *)ptr and in other
places too?
> +
> + /* Dump of the formatted area (including the header) in hex. */
> + grub_printf (" Hex Dump: ");
> + while (length-- > 0)
> + grub_printf ("%02x", *ptr++);
> + grub_printf ("\n");
> +
> + /* Print each string found in the appended string list. */
> + while (ptr[0] != 0 || ptr[1] != 0)
I wonder do we have any ad hoc way to limit it? It looks like Linux
kernel does more sanity checks and does not blindly trust data.
> + {
> + if (newstr)
> + grub_printf (" String: %s\n", ptr);
> + newstr = *ptr++ == 0;
> + }
> + ptr += 2;
> +
> + /* Return the total number of bytes covered. */
> + return ptr - entry;
> +}
> +
> +/* Reference: DMTF Standard DSP0134 2.7.1 Sections 6.1.2-6.1.3 */
> +
> +/*
> + * Return or print a matched table entry. Multiple entries can be matched if
> + * they are being printed.
> + *
> + * This method can handle up to three criteria for selecting an entry:
> + * - The entry's "type" field (use outside [0,0xFF] to ignore)
> + * - The entry's "handle" field (use outside [0,0xFFFF] to
> ignore)
> + * - The entry to return if several match (use 0 to print all matches)
> + *
> + * The parameter "print" was added for verbose debugging. When non-zero, the
> + * matched entries are printed to the console instead of returned.
> + */
> +static const grub_uint8_t *
> +grub_smbios_match_entry (const struct grub_smbios_eps *ep,
> + const grub_int16_t type,
> + const grub_int32_t handle,
> + const grub_uint16_t match,
> + const grub_uint8_t print)
> +{
> + grub_addr_t table_address = (grub_addr_t)ep->intermediate.table_address;
> + grub_uint16_t table_length = ep->intermediate.table_length;
> + grub_uint16_t structures = ep->intermediate.structures;
> + grub_uint16_t structure = 0;
> + grub_uint16_t matches = 0;
> + const grub_uint8_t *table = (const grub_uint8_t *)table_address;
> + const grub_uint8_t *ptr = table;
> +
> + while (ptr - table < table_length && structure++ < structures)
> +
> + /* Test if the current entry matches the given parameters. */
> + if ((handle < 0 || 65535 < handle || handle == *(1 + (grub_uint16_t
> *)ptr))
> + && (type < 0 || 255 < type || type == ptr[0])
> + && (match == 0 || match == ++matches))
As said it is better to validate on input, so handle > 65535 etc can be
omitted.
> + {
> + if (print)
> + {
> + ptr += grub_smbios_dump_entry (ptr);
> + if (match > 0)
> + break;
> + }
> + else
> + return ptr;
> + }
> +
> + /* If the entry didn't match, skip it (formatted area and string list).
> */
> + else
> + {
> + ptr += ptr[1];
> + while (*ptr++ != 0 || *ptr++ != 0);
Same here about more checks for table end.
> + }
> +
> + return NULL;
> +}
> +
> +/* Reference: DMTF Standard DSP0134 2.7.1 Section 6.1.3 */
> +
> +/*
> + * Given a pointer to a string list and a number, iterate over each of the
> + * strings until the desired item is reached. (The value of 1 indicates the
> + * first string, etc.)
> + */
> +static const char *
> +grub_smbios_get_string (const grub_uint8_t *strings, const grub_uint8_t
> number)
> +{
> + const char *ptr = (const char *)strings;
> + grub_uint8_t newstr = 1;
> + grub_uint8_t index = 1;
> +
> + /* A string referenced with zero is interpreted as unset. */
> + if (number == 0)
> + return NULL;
> +
> + /* Search the string table, incrementing the counter as each null passes.
> */
> + while (ptr[0] != 0 || ptr[1] != 0)
And here.
> + {
> + if (newstr && number == index++)
> + return ptr;
> + newstr = *ptr++ == 0;
> + }
> +
> + /* The requested string index is greater than the number of table entries.
> */
> + 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 *entry;
> + grub_uint8_t accessors;
> + grub_uint8_t i;
> + char buffer[24]; /* 64-bit number -> maximum 20 decimal digits */
> + const char *value = buffer;
> +
> + if (eps == NULL)
> + return grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("missing entry point"));
"SMBIOS table not found" or something like this, so it is more
understandable.
> +
> + /* Only one value can be returned at a time; reject multiple selections. */
> + accessors = !!state[3].set + !!state[4].set + !!state[5].set +
> + !!state[6].set + !!state[7].set;
> + if (accessors > 1)
> + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("too many -b|-w|-d|-q|-s"));
Only one of ... can be specified
> +
> + /* Reject the environment variable if no value was selected. */
> + if (accessors == 0 && state[8].set)
> + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("-v without
> -b|-w|-d|-q|-s"));
--set requires explicit value type.
> +
> + /* Read the given matching parameters. */
> + if (state[0].set)
> + type = grub_strtol (state[0].arg, NULL, 0);
> + if (state[1].set)
> + handle = grub_strtol (state[1].arg, NULL, 0);
> + if (state[2].set)
> + match = grub_strtoul (state[2].arg, NULL, 0);
> +
> + /* When not selecting a value, print all matching entries and quit. */
> + if (accessors == 0)
> + {
> + grub_smbios_match_entry (eps, type, handle, match, 1);
> + return GRUB_ERR_NONE;
> + }
> +
> + /* Select a single entry from the matching parameters. */
> + entry = grub_smbios_match_entry (eps, type, handle, match, 0);
> + if (entry == NULL)
> + return grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("no such entry"));
> +
> + /* Ensure the specified offset+length is within the matched entry. */
> + for (i = 3; i <= 7; i++)
> + if (state[i].set)
> + {
> + offset = grub_strtoul (state[i].arg, NULL, 0);
> + if (offset + (1 << (i == 7 ? 0 : i - 3)) > entry[1])
Such optimizations will really strike back in future, as soon as options
are changed and make code confusing. Just explicitly set entry size when
parsing arguments.
> + return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("value outside
> entry"));
> + break;
> + }
> +
> + /* If a string was requested, try to find its pointer. */
> + if (state[7].set)
> + {
> + value = grub_smbios_get_string (entry + entry[1], entry[offset]);
> + if (value == NULL)
> + return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("string not defined"));
> + }
> +
> + /* Create a string from a numeric value suitable for printing. */
> + else if (state[3].set)
> + grub_snprintf (buffer, sizeof (buffer), "%u", entry[offset]);
> + else if (state[4].set)
> + grub_snprintf (buffer, sizeof (buffer), "%u",
> + *(grub_uint16_t *)(entry + offset));
Will it also work on other platforms (alignment)?
> + else if (state[5].set)
> + grub_snprintf (buffer, sizeof (buffer), "%" PRIuGRUB_UINT32_T,
> + *(grub_uint32_t *)(entry + offset));
Ditto.
> + else if (state[6].set)
> + grub_snprintf (buffer, sizeof (buffer), "%" PRIuGRUB_UINT64_T,
> + *(grub_uint64_t *)(entry + offset));
> +
Ditto.
> + /* Store or print the requested value. */
> + if (state[8].set)
> + {
> + grub_env_set (state[8].arg, value);
> + grub_env_export (state[8].arg);
> + }
> + else
> + grub_printf ("%s\n", value);
> +
> + return GRUB_ERR_NONE;
> +}
> +
> +static grub_extcmd_t cmd;
> +
> +static const struct grub_arg_option options[] =
> + {
> + {"type", 't', 0, N_("Match entries with the given type."),
> + N_("byte"), ARG_TYPE_INT},
> + {"handle", 'h', 0, N_("Match entries with the given handle."),
> + N_("word"), ARG_TYPE_INT},
> + {"match", 'm', 0, N_("Select the entry to use when several match."),
> + N_("number"), 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},
> + {"variable", 'v', 0, N_("Store the value in the given variable name."),
> + N_("name"), ARG_TYPE_STRING},
> + {0, 0, 0, 0, 0, 0}
> + };
> +
> +GRUB_MOD_INIT(smbios)
> +{
> + /* SMBIOS data is supposed to be static, so find it only once during init.
> */
> + eps = grub_smbios_locate_eps ();
> +
> + cmd = grub_register_extcmd ("smbios", grub_cmd_smbios, 0,
> + N_("[-t byte] [-h word] [-m number] "
> + "[(-b|-w|-d|-q|-s) offset [-v name]]"),
> + N_("Retrieve SMBIOS information."), options);
> +}
> +
> +GRUB_MOD_FINI(smbios)
> +{
> + grub_unregister_extcmd (cmd);
> +}
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