lint

Synopsis

opendmi [global options] lint [command options]

Description

The lint command checks the SMBIOS data against the rules of the specification and reports what it finds, from the checksum of the entry point down to the values of individual fields.

The checks cover the entry point, the table as a whole, and every structure in it. Rules which apply to any structure look at its length, its strings, the values of its fields, the references it makes and the additional information entries pointing at it. Rules which belong to a particular type look at what that type means: that the enabled cores of a processor fit the ones it has, that the mapped address ranges of the memory arrays do not overlap, that a cooling device points at a temperature probe rather than at a voltage one.

Since the data is decoded before it is checked, the rules see fields rather than bytes, and a report names the structure and the attribute the issue belongs to. Some rules read the raw bytes as well, to catch what the decoder discards.

Output

Every issue is reported the way a compiler reports a diagnostic, so that the output is readable by the tools which are used to that format:

0x0009: warning: firmware@0x0000.rom-size (Platform firmware information): ROM size refers to the extended one, which the structure does not carry [firmware.rom-size]
0x00F3: note: baseboard@0x0002 (Baseboard or module information): string 4 holds whitespace only [string.blank]
0x103C: note: <table>: table has 290 bytes past the end-of-table structure [table.trailing-data]
9 issues: 0 errors, 1 warning, 8 notes

The line starts with the offset of the issue within the data, followed by its severity. The location which comes next is the code of the structure type and the handle of the structure, and the attribute the issue belongs to if it has one; the translated name of the type follows in parentheses. Issues of the entry point and of the table itself have no offset and are located at <entry> and <table> instead. The rule which has found the issue is named in brackets at the end of the line.

Issues have three severities. An error means a requirement of the specification is violated, and the data cannot be trusted. A warning means a recommendation is not followed. A note points out a peculiarity of the data which is not a defect in itself.

Selecting the rules

Rules are named group.rule, e.g. entry.checksum or processor.cores. The groups which apply to any structure are entry, table, entity, string, value, link, overlay and quality; the rest of the groups are named after the structure types the rules belong to. Every rule is described in the Rules section below.

--enable and --disable take either a full name or a group name, which stands for every rule in it. Naming rules with --enable leaves the rest of them out, and a rule named explicitly is checked even if it is disabled by default. Use --list-rules to see the rules along with their severities; the ones which are only checked with --all-checks say so.

Rules of the structure types belong to the specifications of those types, which is how an extension module can bring rules of its own along with the structures it describes.

Profiles

Severity depends on the profile the data is checked against. By default the data is assumed to have been read from a platform, where the defects of the firmware are nothing the reader can fix, and where a peculiarity is worth a note rather than a complaint. With --producer the same data is checked as data being written, where it is expected to conform to the specification because it is authored rather than observed, and several rules become errors.

Options

-?, -h, --help: Print help and exit.
-A, --all-checks: Check the rules which are disabled by default, either because they are a matter of taste rather than of the specification, or because they report what is unusual rather than what is wrong.
-e rule, --enable=rule: Check the named rule or group of rules, and nothing else. The option may be given several times, and a rule named here is checked even if it is disabled by default.
-d rule, --disable=rule: Skip the named rule or group of rules. The option may be given several times, and takes precedence over --enable.
-P, --producer: Check the data as if it was produced, not read, which makes the rules as strict as the specification is.
-S, --strict: Treat warnings as errors, so that the command fails on a warning as well.
-q, --quiet: Report the errors only, leaving the warnings and the notes out. They are still counted in the summary.
-R, --list-rules: List the rules with their descriptions and their severities in the profile --producer selects, and exit without checking anything. Listing the rules reads no SMBIOS data, so it works without access to the platform; the rules of the structure types are the ones of the modules which are enabled.

Rules

Rules are listed by their groups, in the order --list-rules lists them. Every rule is stated as what the data is expected to be, and an issue is reported where the data is not. The severity of a rule is given for the default profile and for --producer.

Entry point

entry.checksum: Severity: warning, or error with --producer.

Bytes of the entry point add up to zero, which is what its checksum is for. The entry point of SMBIOS 2.1 is checked twice, as a whole and for the intermediate anchor it carries, which has a checksum of its own.
entry.length: Severity: warning, or error with --producer.

Length the entry point declares is at least the length of its format, and is no longer than the data the entry point has been read from.
entry.table-address: Severity: warning, or error with --producer.

Entry point declares the address of the table, rather than an address of zero.
entry.table-size: Severity: warning, or error with --producer.

Table is as long as the entry point declares it. The entry point of SMBIOS 3.0 declares the maximum size of the table rather than its size, and the table is then no longer than that.
entry.entity-count: Severity: warning, or error with --producer.

Table holds as many structures as the entry point declares. Only the entry points of SMBIOS 2.1 and earlier declare the number.
entry.entity-max-size: Severity: warning, or error with --producer.

No structure is longer than the size of the largest structure the entry point declares.

Table

table.truncated: Severity: error.

Table ends after a whole structure, rather than in the middle of one.
table.invalid-header: Severity: error.

Headers of the structures have valid lengths, so that the table is read to its end. Structures are located by the lengths of the ones before them, so a header of an invalid length stops the reading: a header of no length, which stands for the end of the table, of another type than the end-of-table structure while data follows it, or a header of a length shorter than itself. The issue tells the offset of the header and how many bytes of the table are left unread.
table.terminator: Severity: warning, or error with --producer.

Table ends with an end-of-table structure.
table.trailing-data: Severity: note, or error with --producer.

No data follows the end-of-table structure within the table. The issue tells how many bytes follow it.
table.missing-required: Severity: warning, or error with --producer.

Table has a structure of every type the specification requires for the version the entry point declares. Since SMBIOS 2.3, these are the platform firmware information, the system information, the system enclosure, the processor, the cache, the physical memory array, the memory device, the memory array mapped address and the system boot information.
table.missing-recommended: Severity: note, or warning with --producer. Checked with --all-checks only.

Table has a structure of every type the specification recommends for the version the entry point declares. Since SMBIOS 2.3, these are the port connector information and the system slots.
table.duplicate-singleton: Severity: warning, or error with --producer.

Table has one structure at most of every type the specification allows only one of, which are the platform firmware information and the system information.
table.reserved-handle: Severity: warning, or error with --producer.

No structure has a handle of the range from 0xFF00 to 0xFFFF, which the specification reserves. The end-of-table structure is left out, since firmware commonly gives it a handle of that range.

Structures

entity.below-minimum: Severity: error.

Structure is at least as long as the minimum length of its type. A structure which is shorter is not decoded.
entity.unknown-length: Severity: warning, or error with --producer.

Structure ends where a version of the specification of its type ends it, rather than in the middle of a set of fields. The fields of such a structure are decoded up to where it ends.
entity.undecoded: Severity: warning, or error with --producer.

Structure of a type which has fields to decode has been decoded.
entity.newer-fields: Severity: note, or error with --producer.

Structure has no fields added by a version of the specification newer than the one the entry point declares.
entity.newer-type: Severity: warning, or error with --producer.

Type of the structure is defined by the version of the specification the entry point declares, or by an earlier one.
entity.unknown-type: Severity: note, or warning with --producer. Checked with --all-checks only.

Type of the structure is described by the specification or by an enabled module. The type of an OEM-specific structure, from 128 to 255, is known to the module of its vendor only, which may be disabled rather than missing.
entity.obsolete: Severity: note, or warning with --producer. Checked with --all-checks only.

Structure is not of a type the specification has made obsolete, which are the memory controller information, the memory module information and the on board devices information.

Strings

string.too-long: Severity: warning, or error with --producer.

No string is longer than 64 characters.
string.non-printable: Severity: warning, or error with --producer.

Strings hold printable characters only. A control character is data which has ended up in the strings rather than text. Characters above 0x7F are taken for text in an encoding other than ASCII.
string.blank: Severity: note, or warning with --producer.

No string holds whitespace only.
string.padded: Severity: note, or warning with --producer. Checked with --all-checks only.

No string has leading or trailing whitespace.
string.unreferenced: Severity: note, or warning with --producer. Checked with --all-checks only.

Every string of a decoded structure is referenced by one of its fields, rather than taking up space nothing reads.

Values

Rules of the values check the fields of the decoded structures, including the ones of the nested structures and of the arrays. Values which stand for an unknown or an unspecified one are left out.

value.invalid-enum: Severity: warning, or error with --producer.

Fields of enumerated values hold values defined by a version of the specification. Enumerations which name some of the values only, e.g. the ones established by reverse engineering, are not checked.
value.reserved: Severity: note, or error with --producer.

Fields of enumerated values hold no values the specification reserves.
value.reserved-bits: Severity: note, or error with --producer.

Bit fields have no bits set which the specification reserves between the ones it defines. Bits above the highest one it defines are left to the vendors, e.g. the bits 32 to 63 of the firmware characteristics, and are not reported.
value.bcd: Severity: warning, or error with --producer.

Fields the specification encodes as binary-coded decimals hold a decimal digit in every nibble.
value.range: Severity: warning, or error with --producer.

Fields hold values within the limits the specification sets for them.
value.jep106: Severity: warning, or error with --producer.

Manufacturer identification codes of JEDEC lead to one of the nine banks JEP106 defines, and have an odd number of bits set in their identifier byte, whose highest bit is a parity bit. Codes copied from the SPD carry a parity bit in the number of continuation bytes as well, which is not counted.
value.uuid: Severity: note, or warning with --producer. Checked with --all-checks only.

UUIDs identify something. A UUID of all zeroes stands for one which is not set, and a UUID of all ones for one which is not present: the specification allows both, but they identify nothing.

References

Rules of the references check the fields holding the handles of other structures. Handles 0xFFFE and 0xFFFF stand for no reference, and are left out.

link.dangling: Severity: warning, or error with --producer.

References point to structures of the table.
link.wrong-type: Severity: warning, or error with --producer.

References point to structures of the types the fields expect, e.g. the cache handles of a processor to caches.
link.self: Severity: warning, or error with --producer.

No structure references itself.
link.orphan: Severity: note. Checked with --all-checks only.

Structures which describe a part of another one are referenced by a structure of the table. These are the caches, the voltage, temperature and current probes, the management devices and the thresholds of the management devices.

Additional information

Rules of the additional information check the entries of the additional information structures, which put values in place of the fields of other structures.

overlay.dangling: Severity: warning, or error with --producer.

Entries refer to structures of the table.
overlay.out-of-bounds: Severity: warning, or error with --producer.

Entries refer to fields of the structures: the offset they refer to is past the header of the structure, and the value they carry ends within it.
overlay.empty: Severity: note, or warning with --producer. Checked with --all-checks only.

Entries carry a value or a string.

Data quality

quality.placeholder: Severity: note, or warning with --producer. Checked with --all-checks only.

Strings hold data rather than the placeholders firmware vendors leave in place, e.g. To Be Filled By O.E.M., Default string, System Serial Number or N/A, which are compared regardless of case.

Structure types

Rules of the structure types are named after the codes of the types they belong to.

firmware.rom-size: Severity: warning, or error with --producer.

ROM size of 0xFF, which refers to the extended ROM size, is used only by the structures of SMBIOS 3.1 and later, which carry it.
firmware.release-date: Severity: note, or warning with --producer.

Release date is written as mm/dd/yyyy, the way the specification requires since SMBIOS 2.3, rather than with a year of two digits.
processor.family: Severity: warning, or error with --producer.

Processor family of 0xFE, which refers to the second processor family field, is used only by the structures of SMBIOS 2.6 and later, which carry it.
processor.id: Severity: note, or error with --producer.

Signature and feature flags of the identifier of an x86 processor are stored in the order of the specification, the signature first. Firmware of some vendors stores them the other way round, which the decoder puts back in place, and which is told by the bits the signature reserves.
processor.cores: Severity: warning, or error with --producer.

Enabled cores and threads are no more than the ones the processor has, and the processor has at least as many threads as cores.
processor.speed: Severity: note, or warning with --producer.

Current speed of the processor is no higher than its maximum speed.
processor.cache: Severity: warning, or error with --producer.

L1, L2 and L3 cache handles of the processor refer to caches of those levels.
memory-controller.module-size: Severity: warning, or error with --producer.

Installed and enabled sizes of the memory modules of the controller are no larger than the largest module the controller supports.
cache.size: Severity: warning, or error with --producer.

Installed size of the cache is no larger than its maximum size.
cache.sram: Severity: warning, or error with --producer.

Current SRAM type of the cache is one of the SRAM types it supports.
slot.width: Severity: warning, or error with --producer.

Physical width of the slot is at least the width of its bus, since a card as wide as the bus has to fit the slot.
group-assoc.member: Severity: note, or warning with --producer.

Members of the groups of well-known names are the structures the groups list, e.g. the members of the Firmware Version Info group are Intel firmware version information. A member which is not is placed by the vendor at a type number no enabled module knows of, or is listed by mistake. Checked for the groups of the enabled modules.
system-event-log.area: Severity: warning, or error with --producer.

Header and data of the log start within the area of the log.
system-event-log.descriptors: Severity: warning, or error with --producer.

Descriptors of the supported log types are 2 bytes long, which is the length the specification defines.
memory-array.extended-capacity: Severity: warning, or error with --producer.

Maximum capacity of 0x80000000, which refers to the extended maximum capacity, is used only by the structures long enough to carry it.
memory-array.device-count: Severity: warning, or error with --producer.

Number of the memory devices the array declares matches the number of the memory device structures referring to it, which are counted whether they are populated or not.
memory-array.capacity: Severity: warning, or error with --producer.

Sizes of the memory devices of the array add up to no more than its maximum capacity.
memory-device.extended-size: Severity: warning, or error with --producer.

Size of 0x7FFF, which refers to the extended size, is used only by the structures long enough to carry it.
memory-device.width: Severity: warning, or error with --producer.

Total width of the device, which covers the data bits and the bits of error correction, is at least its data width.
memory-device.speed: Severity: note, or warning with --producer.

Configured speed of the device is no higher than its maximum speed.
memory-device.voltage: Severity: warning, or error with --producer.

Configured voltage of the device is within its minimum and maximum voltages.
memory-device.sizes: Severity: warning, or error with --producer.

Volatile and non-volatile sizes of the device add up to no more than its size.
memory-device.attributes: Severity: note, or error with --producer.

Attributes of the device have none of the bits the specification reserves set: bits 7-4 up to SMBIOS 3.10, and bit 7 from it, which widens the rank to five bits and defines the flags of a disabled and of an unmapped device.
memory-device.disabled: Severity: warning, or error with --producer.

Device disabled because of an error, as SMBIOS 3.10 and later flag it, is not said to have no error: neither by the error information handle of 0xFFFF, nor by the memory error information structure it refers to reporting the OK kind of error, which is meant for the devices left out of the memory map.
memory-array-address.range: Severity: error.

Mapped address range starts no later than it ends.
memory-array-address.overlap: Severity: warning, or error with --producer.

Mapped address ranges of the memory arrays do not overlap, since they describe the physical address space of the system. Every pair of the ranges is reported once, by the structure of the higher handle.
memory-device-address.range: Severity: error.

Mapped address range starts no later than it ends.
memory-device-address.bounds: Severity: warning, or error with --producer.

Mapped address range of the device lies within the mapped address range of the memory array it belongs to.
portable-battery.sbds: Severity: note, or warning with --producer.

Battery carries either its own serial number and chemistry or the SBDS ones, rather than both, since the specification puts the SBDS values in place of the others.
system-reset.limit: Severity: warning, or error with --producer.

Number of the resets is no higher than the limit of them.
power-controls.bcd: Severity: warning, or error with --producer.

Month, day, hour, minute and second of the next scheduled power-on are binary-coded decimals. Fields which are not set hold 0xFF, and are left out.
voltage-probe.range: Severity: warning, or error with --producer.

Minimum value of the probe is no higher than its maximum value, and its nominal value is within them.
cooling-device.probe: Severity: warning, or error with --producer.

Temperature probe handle of the cooling device refers to a temperature probe.
temperature-probe.range: Severity: warning, or error with --producer.

Minimum value of the probe is no higher than its maximum value, and its nominal value is within them.
current-probe.range: Severity: warning, or error with --producer.

Minimum value of the probe is no higher than its maximum value, and its nominal value is within them.
mgmt-device-threshold.order: Severity: warning, or error with --producer.

Lower thresholds grow from the non-recoverable one to the critical and the non-critical ones, and the upper ones grow from the non-critical one to the critical and the non-recoverable ones. Thresholds left as a template are reported by mgmt-device-threshold.template instead.
mgmt-device-threshold.template: Severity: note, or error with --producer.

Thresholds hold values rather than the ordinals of the fields holding them, which firmware leaves in place from the template of the structure.
memory-channel.load: Severity: warning, or error with --producer.

Loads of the memory devices of the channel add up to no more than the maximum load it supports.
ipmi-device.revision: Severity: warning, or error with --producer.

Revision of the IPMI specification is a binary-coded decimal, e.g. 0x20 for IPMI 2.0.
power-supply.probes: Severity: warning, or error with --producer.

Voltage probe, cooling device and current probe handles of the power supply refer to structures of those types.
onboard-device-ex.instance: Severity: warning, or error with --producer.

No two onboard devices of the same type share an instance number, which is what tells them apart. Every pair is reported once, by the structure of the higher handle.
mgmt-controller.records: Severity: warning, or error with --producer.

Interface-specific data leaves room for the protocol records, and every protocol record fits the structure.
tpm-device.vendor: Severity: note, or error with --producer.

Vendor identifier is stored in the order of the specification, rather than as a little-endian double word, which starts with the terminating zero, e.g. \0XFI for IFX. The decoder puts the identifier back in place.
tpm-device.version: Severity: warning, or error with --producer.

Specification version of the device is a version of the TPM specifications the TCG has published, 1.x or 2.x.
firmware-inventory.version: Severity: warning, or error with --producer.

Version of the firmware is no older than the lowest supported version, when both are written in the same format other than a free-form one.
intel-rsd-cabled-pcie.start-lane: Severity: warning, or error with --producer.

Cable indices of an Intel RSD cabled PCIe port start at lane 0, 4, 8 or 12, since every cable carries a group of four lanes. Checked with the intel-rsd module enabled.
intel-rsd-cabled-pcie.cable-count: Severity: warning, or error with --producer.

Intel RSD cabled PCIe port declares no more than the four cable indices the specification lays out. Checked with the intel-rsd module enabled.

Exit status

0: Data has been checked and no error has been found.
1: An error has been found, or a warning in strict mode, or the data could not be read.
2: Command line is invalid.

Examples

Check the data of the local platform:

$ opendmi lint

Check a dump, which is how the data of another machine is checked:

$ opendmi -i smbios.bin lint

Check everything, reporting the peculiarities of the data along with its defects:

$ opendmi lint -A

Check the references between the structures only:

$ opendmi lint -e link -e overlay

Check everything except the complaints about the strings:

$ opendmi lint -A -d string

Check the data as if it was being written, and fail on anything the specification does not allow:

$ opendmi -i smbios.bin lint -P -S

List the rules and what they check:

$ opendmi lint -R

List the rules with the severities they have for the data being written:

$ opendmi lint -R -P