IUCODE_TOOL(8) iucode_tool manual IUCODE_TOOL(8)
NAME
iucode_tool - Tool to manipulate Intel(R) IA-32/X86-64 microcode bun-
dles
SYNOPSIS
iucode_tool [options] [[-ttype] filename|dirname] ...
DESCRIPTION
iucode_tool is an utility that can load Intel(R) processor microcode
data from files in both text and binary microcode bundle formats.
It can output a list of the microcodes in these files, merge them,
upload them to the kernel (to upgrade the microcode in the system pro-
cessor cores) or write some of them out to a file in binary format for
later use.
iucode_tool will load all microcodes in the specified files and direc-
tories to memory, in order to process them. Duplicated and outdated
microcodes will be discarded. It can read microcode data from standard
input (stdin), by specifying a file name of "-" (minus sign).
Microcode data files are assumed to be in .dat text format if they have
a .dat suffix, and to be in binary format otherwise. Standard input
(stdin) is assumed to be in .dat text format. The -t option can be
used to change the type of the files specified after it, including for
stdin.
If a directory is specified, all files whose names do not begin with a
dot will be loaded, in unspecified order. Nested directories are
skipped.
Empty files and directories are ignored, and will be skipped.
You can select which microcodes should be written out, listed or
uploaded to the kernel using the -S, -s, --date-before and --date-after
options. Should none of those options be specified, all microcodes
will be selected.
You can upload the selected microcodes to the kernel, write them out to
a file (in binary format), to a Linux early initramfs archive, to per-
processor-signature files in a directory, or to per-microcode files in
a directory using the -w, --write-earlyfw, -k, -K, and -W options.
For more information about Intel processor microcodes, please read the
included documentation and the Intel manuals listed in the SEE ALSO
section.
OPTIONS
iucode_tool accepts the following options:
-q, --quiet
Inhibit usual output.
-v, --verbose
Print more information. Use more than once for added verbosity.
-h, -?, --help
List all available options and their meanings.
--usage
Show summary of options.
-V, --version
Show version of program.
-t type
Sets the file type of the following files. type can be:
b binary format. This is the same format used by the ker-
nel driver and the BIOS/EFI, which is described in detail
by the Intel 64 and IA-32 Architectures Software Devel-
oper's Manual, Volume 3A, section 9.11.
d Intel microcode .dat text format. This is the format
normally used by Intel to distribute microcode data
files.
a (default) iucode_tool will use the suffix of the file
name to select the file type: .dat text format for files
that have a .dat suffix, and binary type otherwise. Note
that for stdin, .dat text format is assumed.
--downgrade
When multiple versions of the microcode for a specific processor
are available from different files, keep the one from the file
loaded last, regardless of revision levels. Files are always
loaded in the order they were specified in the command line.
This option has no effect when just one file has been loaded.
--no-downgrade
When multiple versions of the microcode for a specific processor
are available from different files, keep the one with the high-
est revision level. This is the default mode of operation.
--strict-checks
Perform strict checks on the microcode data. It will refuse to
load microcodes and microcode data files with unexpected size
and metadata. It will also refuse to load microcode entries
that have the same metadata, but different payload. This is the
default mode of operation.
--no-strict-checks
Perform less strict checks on the microcode data. Use only if
you happen to come across a microcode data file that has
microcodes with weird sizes or incorrect non-critical metadata
(such as invalid dates), which you want to retain. If you just
want to skip those, use the --ignore-broken option.
--ignore-broken
Skip broken microcode entries when loading a microcode data
file, instead of aborting program execution. If the microcode
entry has an unknown format or had its header severely cor-
rupted, all remaining data in the file will be ignored. This
option is also useful to process data files with extra padding
at the end (the padding will be reported as an invalid microcode
entry), as well as to salvage microcodes from an incomplete data
file.
--no-ignore-broken
Abort program execution if a broken microcode is found while
loading a microcode data file. This is the default mode of
operation.
-s ! | [!]signature[,pf_mask]
Select microcodes by the specified signature and processor flags
mask (pf_mask). If pf_mask is specified, it will select only
microcodes that are suitable for at least one of the processor
flag combinations in the mask.
Specify more than once to select more microcodes. This option
can be combined with the --scan-system option to select more
microcodes. If signature is prefixed with a "!" (exclamation
mark), it will unselect microcodes instead. Ordering matters,
with later -s options overriding earlier ones.
The special notation -s! (with no signature parameter) instructs
iucode_tool to require explicit inclusion of microcode signa-
tures (using the non-negated form of -s, or using --scan-sys-
tem).
The --scan-system option has precedence, therefore the
microcodes it selects cannot be unselected.
-S, --scan-system
Select microcodes by scanning all online processors on this sys-
tem for their signatures.
This option can be combined with the -s option to select more
microcodes.
Should the signature scan fail on all online processors, the
program will print a warning to the user and continue as if
--scan-system had not been specified. This is a fail-safe con-
dition when iucode_tool is used to install microcode updates for
the next boot.
--date-before=YYYY-MM-DD and --date-after=YYYY-MM-DD
Limit the selected microcodes by a date range. The date must be
given in ISO format, with four digits for the year and two dig-
its for the month and day and "-" (minus sign) for the separa-
tor. Dates are not range-checked, so you can use
--date-after=2000-00-00 to select all microcodes dated since
January 1st, 2000.
--loose-date-filtering
When a date range is specified, all revisions of the microcode
will be considered for selection (ignoring just the date range,
all other filters still apply) should any of the microcode's
revisions be within the date range.
--strict-date-filtering
When a date range is specified, select only microcodes which are
within the date range. This is the default mode of operation.
-l, --list
List selected microcode signatures.
-L, --list-all
List all microcode signatures while they're being processed.
-k[device], --kernel[=device]
Upload selected microcodes to the kernel. Optionally, the
device path can be specified (default: /dev/cpu/microcode).
This update method is being deprecated.
-K[directory], --write-firmware[=directory]
Write selected microcodes with the file names expected by the
Linux kernel firmware loader. Optionally, the destination
directory can be specified (default: /lib/firmware/intel-ucode).
-wfile, --write-to=file
Write selected microcodes to a file in binary format.
--write-earlyfw=file
Write selected microcodes to an early initramfs archive, which
should be prepended to the regular initramfs to allow the kernel
to update processor microcode very early during system boot.
-Wdirectory, --write-named-to=file
Write selected microcodes to the specified directory, one
microcode per file, in binary format. The file names reflect
the microcode signature, mask and revision.
--overwrite
Remove the destination file before writing, if it exists and is
not a directory. The destination file is not overwritten in-
place. Hardlinks will be severed, and any existing access per-
missions, ACLs and other extended attributes of the old destina-
tion file will be lost.
--no-overwrite
Abort if the destination file already exists. This is the
default mode of operation. Do note that iucode_tool does not
follow non-directory symlinks when writing files.
NOTES
iucode_tool reads all data to memory before doing any processing.
iucode_tool creates files with permissions 0644 (rw-r--r--), modified
by the current umask.
iucode_tool's selected microcode listing and microcode output files are
sorted by cpu signature, however the ordering inside a group of
microcodes that share the same cpu signature is undefined: it is deter-
ministic, but it is sensitive to command line parameters and their
ordering, and also depends on the ordering of the individual microcodes
inside each loaded data file.
When multiple revisions of a microcode are selected, the older ones
will be skipped. Only the newest selected revision of a microcode (or
the last one in load order when the --downgrade option is active) will
be written to a file or uploaded to the kernel.
Intel microcode data files, both in binary and text formats, can be
concatenated to generate a bigger and still valid microcode data file.
iucode_tool does not follow symlinks when writing microcode data files.
It will either refuse to write the file and abort (default mode of
operation), or (when the --overwrite option is active) it will remove
the target symlink or file (and therefore breaking hardlinks) before
writing the new file.
iucode_tool does follow directory symlinks to locate the directory to
write files into.
Linux Notes
The cpuid kernel driver is required for the --scan-system functionality
to work.
Early initramfs support for microcode updates is available since Linux
v3.9. Kernels without early initramfs support will just make the
microcode file available to the initramfs environment at /ker-
nel/x86/microcode/GenuineIntel.bin.
The early initramfs image with microcode update data must be aligned to
a 16-byte boundary relative to the start of the initramfs file to work
around a bug in some versions of the Linux kernel.
Each Intel processor microcode must be uploaded through a single write
syscall to /dev/cpu/microcode, but more than one microcode can be
uploaded per write syscall. Writing the microcode to the kernel device
will update all system processor cores at once. This method is being
deprecated and does not work on other system processor types.
The old Linux firmware interface for microcode updates needs to be
triggered on a per-core basis, by writing the number 1 to
/sys/devices/system/cpu/*/microcode/reload. Depending on kernel ver-
sion, you must either trigger it on every core to avoid a dangerous
situation where some cores are using outdated microcode, or the kernel
will accept the request only for the boot processor and use it to trig-
ger an update on all system processor cores.
Since Linux v3.6, the per-core interface has been replaced with a new
interface that explicitly triggers an update for every core at once
when the number 1 is written to /sys/devices/sys-
tem/cpu/microcode/reload.
The microcode driver should not be unloaded unless you are sure it is
not going to be needed. Depending on kernel version and configuration,
the driver needs to be loaded for the kernel to be able to reapply the
microcode updates after the system resumes from suspend or hibernation,
and also to update any system processor cores that were offline at the
time the update was applied.
EXAMPLES
Updating files in /lib/firmware/intel-ucode:
iucode_tool -K/lib/firmware/intel-ucode /lib/firmware/intel-
ucode/* /tmp/file-with-new-microcodes.bin
Processing several compressed files at once:
zcat intel-microcode*.dat.gz | iucode_tool -k -
zcat intel-microcode*.bin.gz | iucode_tool -k -tb -
BUGS
Microcode with negative revision numbers is not special-cased, and will
not be preferred over regular microcode.
Files are not replaced atomically: if iucode_tool is interrupted while
writing to a file, that file will be corrupted.
SEE ALSO
The Intel 64 and IA-32 Architectures Software Developer's Manual, Vol-
ume 3A: System Programming Guide, Part 1 (order number 253668), section
9.11.
AUTHOR
Henrique de Moraes Holschuh <hmh@hmh.eng.br>
IUCODE_TOOL 1.1.1 September 9th, 2014 IUCODE_TOOL(8)
Czas wygenerowania: 0.00055 sek.
Created with the man page lookup class by Andrew Collington.
Based on a C man page viewer by Vadim Pavlov
Unicode soft-hyphen fix (as used by RedHat) by Dan Edwards
Some optimisations by Eli Argon
Caching idea and code contribution by James Richardson
Copyright © 2003-2023 Linux.pl
Hosted by Hosting Linux.pl