Provided by: flashrom_1.6.0-2ubuntu1_amd64 
NAME
flashrom - detect, read, write, verify and erase flash chips
SYNOPSIS
flashrom [-h|-R|-L|
-p <programmername>[:<parameters>] [-c <chipname>]
(--flash-name|--flash-size|
[-E|-x|-r [<file>]|-w [<file>]|-v [<file>]]
[(-l <file>|--ifd|--fmap|--fmap-file <file>)
[-i <include>[:<file>]]]
[--wp-status] [--wp-list] [--wp-enable|--wp-disable]
[--wp-range <start>,<length>|--wp-region <region>]
[-n] [-N] [-f]
[--rpmc-root-key <keyfile>] [--key-data <value>]
[--counter-address <address>]
[--get-rpmc-status] [--write-root-key] [--update-hmac-key]
[--increment-counter <current>] [--get-counter])]
[-V[V[V]]] [-o <logfile>] [--progress] [--sacrifice-ratio <ratio>]
DESCRIPTION
flashrom is a utility for detecting, reading, writing, verifying and erasing flash chips. It's often
used to flash BIOS/EFI/coreboot/firmware images in-system using a supported mainboard. However, it also
supports various external PCI/USB/parallel-port/serial-port based devices which can program flash chips,
including some network cards (NICs), SATA/IDE controller cards, graphics cards, the Bus Pirate device,
various FTDI FT2232/FT4232H/FT4233H/FT232H based USB devices, and more.
It supports a wide range of DIP32, PLCC32, DIP8, SO8/SOIC8, TSOP32, TSOP40, TSOP48, and BGA chips, which
use various protocols such as LPC, FWH, parallel flash, or SPI.
OPTIONS
You can specify one of -h, -R, -L, -E, -r, -w, -v, a RPMC command or no operation. If no operation is
specified, flashrom will only probe for flash chips. It is recommended that if you try flashrom the first
time on a system, you run it in probe-only mode and check the output. Also you are advised to make a
backup of your current ROM contents with -r before you try to write a new image. All operations
involving any chip access (probe/read/write/...) require the -p/--programmer option to be used (please
see below).
-r, --read [<file>]
Read flash ROM contents and save them into the given <file>. If the file already exists, it will
be overwritten.
The <file> parameter is required here unless reading is restricted to one or more flash regions
via the -i/--include parameter and the file is specified there. See the --include section below
for examples.
-w, --write (<file>|-)
Write <file> into flash ROM. If - is provided instead, contents will be read from stdin. This
will first automatically erase the chip, then write to it.
In the process the chip is also read several times. First an in-memory backup is made for disaster
recovery and to be able to skip regions that are already equal to the image file. This copy is
updated along with the write operation. In case of erase errors it is even re-read completely.
After writing has finished and if verification is enabled, the whole flash chip is read out and
compared with the input image.
The <file> parameter is required here unless writing is restricted to one or more flash regions
via the -i/--include parameter and the file is specified there. See the --include section below
for examples.
-n, --noverify
Skip the automatic verification of flash ROM contents after writing. Using this option is not
recommended, you should only use it if you know what you are doing and if you feel that the time
for verification takes too long.
Typical usage is:
flashrom -p prog -n -w <file>
This option is only useful in combination with --write.
-N, --noverify-all
Skip not included regions during automatic verification after writing (cf. -l and -i). You should
only use this option if you are sure that communication with the flash chip is reliable (e.g. when
using the internal programmer). Even if flashrom is instructed not to touch parts of the flash
chip, their contents could be damaged (e.g. due to misunderstood erase commands).
This option is required to flash an Intel system with locked ME flash region using the internal
programmer. It may be enabled by default in this case in the future.
-v, --verify (<file>|-)
Verify the flash ROM contents against the given <file>. If - is provided instead, contents will
be written to the stdout.
The <file> parameter is required here unless verification is restricted to one or more flash
regions via the -i/--include parameter and the file is specified there. See the --include section
below for examples.
-E, --erase
Erase the flash ROM chip.
-x, --extract
Extract every region defined on the layout from flash ROM chip to a file with the same name as the
extracted region (replacing spaces with underscores).
-V, --verbose
More verbose output. This option can be supplied multiple times (max. 3 times, i.e. -VVV ) for
even more debug output.
-c, --chip <chipname>
Probe only for the specified flash ROM chip. This option takes the chip name as printed by
flashrom -L without the vendor name as parameter. Please note that the chip name is case
sensitive.
-f, --force
Force one or more of the following actions:
• Force chip read and pretend the chip is there.
• Force chip access even if the chip is bigger than the maximum supported size for the flash bus.
• Force erase even if erase is known bad.
• Force write even if write is known bad.
-l, --layout <file>
Read ROM layout from <file>.
flashrom supports ROM layouts. This allows you to flash certain parts of the flash chip only. A
ROM layout file contains multiple lines with the following syntax:
startaddr:endaddr imagename
startaddr and endaddr are hexadecimal addresses within the ROM file and do not refer to any
physical address. Please note that using a 0x prefix for those hexadecimal numbers is not
necessary, but you can't specify decimal/octal numbers. imagename is an arbitrary name for the
region/image from startaddr to endaddr (both addresses included).
Example:
00000000:00008fff gfxrom
00009000:0003ffff normal
00040000:0007ffff fallback
If you only want to update the image named normal in a ROM based on the layout above, run:
flashrom -p prog --layout rom.layout --image normal -w some.rom
To update only the images named normal and fallback, run:
flashrom -p prog -l rom.layout -i normal -i fallback -w some.rom
Overlapping sections are not supported.
--fmap Read layout from fmap in flash chip.
flashrom supports the fmap binary format which is commonly used by coreboot for partitioning a
flash chip. The on-chip fmap will be read and used to generate the layout.
If you only want to update the COREBOOT region defined in the fmap, run:
flashrom -p prog --fmap --image COREBOOT -w some.rom
--fmap-file <file>
Read layout from a <file> containing binary fmap (e.g. coreboot roms).
flashrom supports the fmap binary format which is commonly used by coreboot for partitioning a
flash chip. The fmap in the specified file will be read and used to generate the layout.
If you only want to update the COREBOOT region defined in the binary fmap file, run:
flashrom -p prog --fmap-file some.rom --image COREBOOT -w some.rom
--ifd Read ROM layout from Intel Firmware Descriptor.
flashrom supports ROM layouts given by an Intel Firmware Descriptor (IFD). The on-chip descriptor
will be read and used to generate the layout. If you need to change the layout, you have to update
the IFD only first.
The following ROM images may be present in an IFD:
fd - the IFD itself
bios - the host firmware aka. BIOS
me - Intel Management Engine firmware
gbe - gigabit ethernet firmware
pd - platform specific data
-i, --include <region>[:<file>]
Read, write, or verify only <region> to or from ROM. The -i option may be used multiple times if
the user wishes to read, write, or verify multiple regions using a single command.
The user may optionally specify a corresponding <file> for any region they wish to read or write.
A read operation will read the corresponding regions from ROM and write individual files for each
one. A write option will read file(s) and write to the corresponding region(s) in ROM.
For all read/write/verify operations, the <file> parameter following those operations becomes
optional and will be ignored if present whenever the <file> is specified following the region.
Common rules for -r/-w/-v syntax parsing:
• If no filename is specified at all, quit.
• If a file is specified for -r/-w/-v and no files are specified with -i args (or -i is not
used), then that file will be used for reading/ writing/verifying the entire ROM.
• If no filename is specified for -r/-w/-v, but files are specified for -i, then the number of
file arguments for -i options must be equal to the total number of -i options.
Rules for reading:
• If files are specified for -i args but not -r, do partial reads for each -i arg, creating a
new file for each region. Each -i option must specify a filename.
• If filenames are specified for -r and -i args, then:
• Do partial read for each -i arg, creating a new file for each region where a filename
is provided (-i region:filename).
• Create a ROM-sized file with partially filled content. For each -i arg, fill the
corresponding offset with content from ROM.
Rules for writing and verifying:
• If files are specified for both -w/-v and -i args, -i files take priority (files specified
for -w/-v are unused).
• If files are specified for -i args but not -w, do partial writes for each -i arg. Likewise
for -v and -i args. All -i args must supply a filename. Any omission is considered ambiguous.
• Regions with a filename associated must not overlap. This is also considered ambiguous. Note:
This is checked later since it requires processing the layout/fmap first.
Examples:
To read regions named foo and bar in layout file <layout> into region-sized files foo.bin
and bar.bin, run:
flashrom -p prog -r -l <layout> -i foo:foo.bin -i bar:bar.bin
To write files foo.bin and bar.bin into regions named foo and bar in layout file <layout>
to the ROM, run:
flashrom -p prog -w -l <layout> -i foo:foo.bin -i bar:bar.bin
To verify regions named foo and bar using layout file <layout> and files foo.bin and
bar.bin, run:
flashrom -p prog -v -l <layout> -i foo:foo.bin -i bar:bar.bin
--wp-status
Prints the flash's current status register protection mode and write protection range.
--wp-list
Prints a list of all protection ranges that the flash supports.
--wp-enable
Enables hardware status register protection (SRP) if the flash supports it. Once SRP is enabled,
operations that change the flash's status registers (including --wp-disable and --wp-range) can
only be performed if the flash's #WP pin is at an inactive logic level.
--wp-disable
Disables status register protection if the flash allows it.
--wp-range <start>,<length>
Configures the flash to protect a range of addresses from <start> to (<start> + <length> - 1),
bounds inclusive. The range must be supported by the flash, see --wp-list.
--wp-region <region>
Same as --wp-range but protects the range occupied by an image region. This option requires a
image layout to be specified, see --layout. The region must be supported by the flash, see
--wp-list.
--flash-name
Prints out the detected flash chip's name.
--flash-size
Prints out the detected flash chip's size.
--flash-contents <ref-file>
The file contents of <ref-file> will be used to decide which parts of the flash need to be
written. Providing this saves an initial read of the full flash chip. Be careful, if the
provided data doesn't actually match the flash contents, results are undefined.
-L, --list-supported
List the flash chips, chipsets, mainboards, and external programmers (including PCI, USB, parallel
port, and serial port based devices) supported by flashrom.
There are many unlisted boards which will work out of the box, without special support in
flashrom. Please let us know if you can verify that other boards work or do not work out of the
box.
IMPORTANT: For verification you have to test an ERASE and/or WRITE operation, so make sure you
only do that if you have proper means to recover from failure!
-p, --programmer <name>[:parameter[,parameter[,parameter]]]
Specify the programmer device. This is mandatory for all operations involving any chip access
(probe/read/write/...). Currently supported are:
• internal (for in-system flashing in the mainboard)
• dummy (virtual programmer for testing flashrom)
• nic3com (for flash ROMs on 3COM network cards)
• nicrealtek (for flash ROMs on Realtek and SMC 1211 network cards)
• nicnatsemi (for flash ROMs on National Semiconductor DP838* network cards)
• nicintel (for parallel flash ROMs on Intel 10/100Mbit network cards)
• gfxnvidia (for flash ROMs on NVIDIA graphics cards)
• drkaiser (for flash ROMs on Dr. Kaiser PC-Waechter PCI cards)
• satasii (for flash ROMs on Silicon Image SATA/IDE controllers)
• satamv (for flash ROMs on Marvell SATA controllers)
• atahpt (for flash ROMs on Highpoint ATA/RAID controllers)
• atavia (for flash ROMs on VIA VT6421A SATA controllers)
• atapromise (for flash ROMs on Promise PDC2026x ATA/RAID controllers)
• it8212 (for flash ROMs on ITE IT8212F ATA/RAID controller)
• ft2232_spi (for SPI flash ROMs attached to an FT2232/FT4232H/FT232H family based USB
SPI programmer)
• serprog (for flash ROMs attached to a programmer speaking serprog, including some
Arduino-based devices)
• buspirate_spi (for SPI flash ROMs attached to a Bus Pirate)
• dediprog (for SPI flash ROMs attached to a Dediprog SF100)
• rayer_spi (for SPI flash ROMs attached to a parallel port by one of various cable
types)
• raiden_debug_spi (For Chrome EC based debug tools - SuzyQable, Servo V4, C2D2 & uServo)
• pony_spi (for SPI flash ROMs attached to a SI-Prog serial port bitbanging adapter)
• nicintel_spi (for SPI flash ROMs on Intel Gigabit network cards)
• ogp_spi (for SPI flash ROMs on Open Graphics Project graphics card)
• linux_mtd (for SPI flash ROMs accessible via /dev/mtdX on Linux)
• linux_spi (for SPI flash ROMs accessible via /dev/spidevX.Y on Linux)
• usbblaster_spi (for SPI flash ROMs attached to an Altera USB-Blaster compatible cable)
• nicintel_eeprom (for SPI EEPROMs on Intel Gigabit network cards)
• mstarddc_spi (for SPI flash ROMs accessible through DDC in MSTAR-equipped displays)
• pickit2_spi (for SPI flash ROMs accessible via Microchip PICkit2)
• ch341a_spi (for SPI flash ROMs attached to WCH CH341A)
• ch347_api (for SPI flash ROMs attached to WHC CH347)
• digilent_spi (for SPI flash ROMs attached to iCEblink40 development boards)
• jlink_spi (for SPI flash ROMs attached to SEGGER J-Link and compatible devices)
• ni845x_spi (for SPI flash ROMs attached to National Instruments USB-8451 or USB-8452)
• stlinkv3_spi (for SPI flash ROMs attached to STMicroelectronics STLINK V3 devices)
• realtek_mst_i2c_spi (for SPI flash ROMs attached to Realtek DisplayPort hubs accessible through
I2C)
• parade_lspcon (for SPI flash ROMs attached to Parade Technologies LSPCONs (PS175))
• mediatek_i2c_spi (for SPI flash ROMs attached to some Mediatek display devices accessible
over I2C)
• dirtyjtag_spi (for SPI flash ROMs attached to DirtyJTAG-compatible devices)
• asm106x (for SPI flash ROMs attached to asm106x PCI SATA controllers)
• spidriver (for SPI flash ROMs attached to an Excamera Labs SPIDriver)
Some programmers have optional or mandatory parameters which are described in detail in the
PROGRAMMER-SPECIFIC INFORMATION section. Support for some programmers can be disabled at compile
time. flashrom -h lists all supported programmers.
-h, --help
Show a help text and exit.
-o, --output <logfile>
Save the full debug log to <logfile>. If the file already exists, it will be overwritten. This is
the recommended way to gather logs from flashrom because they will be verbose even if the
on-screen messages are not verbose and don't require output redirection.
--progress
Show progress percentage of operations on the standard output.
--sacrifice-ratio <ratio>
Fraction (as a percentage, 0-50) of an erase block that may be erased even if unmodified. Larger
values may complete programming faster, but may also hurt chip longevity by erasing cells
unnecessarily.
Default is 0, S+1 size block only selected if all the S size blocks inside it need to be erased in
full. 50 means that if more than a half of the area needs to be erased, a S+1 size block can be
selected to cover all the area with one erase. The tradeoff is the speed of programming operation
VS the longevity of the chip. Default is longevity.
DANGEROUS! It wears your chip faster!
-R, --version
Show version information and exit.
RPMC commands
This section describes the commands added in JESD260. They are only supported on specific chip models.
If the chip is detected correctly but you still get Error: RPMC commands are not supported on this
device, try using -c "SFDP-capable chip" for automatic feature detection.
--get-rpmc-status
Read the extended RPMC status by issuing a OP2 command
Example:
flashrom -p prog --get-rpmc-status
--write-root-key
Write new root key from --rpmc-root-key file for --counter-address.
Example:
flashrom -p prog --rpmc-root-key <keyfile> --counter-address <address> --write-root-key
--update-hmac-key
Update the hmac key register for --counter-address with the provided --key-data. Requires valid
--rpmc-root-key.
Example:
flashrom -p prog --rpmc-root-key <keyfile> --counter-address <address> --key-data <value> --update-hmac-key
--increment-counter <current>
Increments the counter at --counter-address by one above the <current>. Requires previously
updated --key-data and valid --rpmc-root-key.
Examples:
flashrom -p prog --rpmc-root-key <keyfile> --counter-address <address> --key-data <value> --increment-counter 12
flashrom -p prog --rpmc-root-key <keyfile> --counter-address <address> --key-data <value> -w rom.bin --update-hmac-key --increment-counter 25
--get-counter
Get the current counter value for --counter-address. Requires previously updated --key-data and
valid --rpmc-root-key.
Examples:
flashrom -p prog --rpmc-root-key <keyfile> --counter-address <address> --key-data <value> --get-counter
flashrom -p prog --rpmc-root-key <keyfile> --counter-address <address> --key-data <value> --update-hmac-key --get-counter
RPMC options
--counter-address <address>
Target the counter at <address> for any RPMC operations. Addressing starts at 0. Defaults to 0.
Example:
flashrom --counter-address 2
--rpmc-root-key <keyfile>
Use <keyfile> as location of 32-byte root key.
Example:
flashrom --rpmc-root-key /home/user/some_key.bin
--key-data <value>
Hexadecimal <value> will be used as 4-byte key data in RPMC operations. Defaults to 0.
Example:
flashrom --key-data 12abc
PROGRAMMER-SPECIFIC INFORMATION
Some programmer drivers accept further parameters to set programmer-specific parameters. These parameters
are separated from the programmer name by a colon. While some programmers take arguments atfixed
positions, other programmers use a key/value interface in which the key and value is separated by an
equal sign and different pairs are separated by a comma or a colon.
internal programmer
Board Enables
Some mainboards require to run mainboard specific code to enable flash erase and write support
(and probe support on old systems with parallel flash). The mainboard brand and model (if it
requires specific code) is usually autodetected using one of the following mechanisms: If your
system is running coreboot, the mainboard type is determined from the coreboot table. Otherwise,
the mainboard is detected by examining the onboard PCI devices and possibly DMI info. If PCI and
DMI do not contain information to uniquely identify the mainboard (which is the exception), or if
you want to override the detected mainboard model, you can specify the mainboard using the:
flashrom -p internal:mainboard=<vendor>:<board>
syntax.
See the Known boards or Known laptops section in the output of flashrom -L for a list of boards
which require the specification of the board name, if no coreboot table is found.
Some of these board-specific flash enabling functions (called board enables ) in flashrom have not
yet been tested. If your mainboard is detected needing an untested board enable function, a
warning message is printed and the board enableis not executed, because a wrong board enable
function might cause the system to behave erratically, as board enable functions touch the
low-level internals of a mainboard. Not executing a board enable function (if one is needed)
might cause detection or erasing failure. If your board protects only part of the flash (commonly
the top end, called boot block), flashrom might encounter an error only after erasing the
unprotected part, so running without the board-enable function might be dangerous for erase and
write (which includes erase).
The suggested procedure for a mainboard with untested board specific code is to first try to probe
the ROM (just invoke flashrom and check that it detects your flash chip type) without running the
board enable code (i.e. without any parameters). If it finds your chip, fine. Otherwise, retry
probing your chip with the board-enable code running, using:
flashrom -p internal:boardenable=force
If your chip is still not detected, the board enable code seems to be broken or the flash chip
unsupported. Otherwise, make a backup of your current ROM contents (using -r) and store it to a
medium outside of your computer, like a USB drive or a network share. If you needed to run the
board enable code already for probing, use it for reading too. If reading succeeds and the
contents of the read file look legit you can try to write the new image. You should enable the
board enable code in any case now, as it has been written because it is known that writing/erasing
without the board enable is going to fail. In any case (success or failure), please report to the
flashrom mailing list, see below.
Coreboot
On systems running coreboot, flashrom checks whether the desired image matches your mainboard.
This needs some special board ID to be present in the image. If flashrom detects that the image
you want to write and the current board do not match, it will refuse to write the image unless you
specify:
flashrom -p internal:boardmismatch=force
ITE IT87 Super I/O
If your mainboard is manufactured by GIGABYTE and supports DualBIOS it is very likely that it uses
an ITE IT87 series Super I/O to switch between the two flash chips. Only one of them can be
accessed at a time and you can manually select which one to use with the:
flashrom -p internal:dualbiosindex=chip
syntax where chip is the index of the chip to use (0 = main, 1 = backup). You can check which one
is currently selected by leaving out the chip parameter.
If your mainboard uses an ITE IT87 series Super I/O for LPC<->SPI flash bus translation, flashrom
should autodetect that configuration. If you want to set the I/O base port of the IT87 series SPI
controller manually instead of using the value provided by the BIOS, use the:
flashrom -p internal:it87spiport=portnum
syntax where portnum is the I/O port number (must be a multiple of 8). In the unlikely case
flashrom doesn't detect an active IT87 LPC<->SPI bridge, please send a bug report so we can
diagnose the problem.
AMD chipsets
Beginning with the SB700 chipset there is an integrated microcontroller (IMC) based on the 8051
embedded in every AMD southbridge. Its firmware resides in the same flash chip as the host's
which makes writing to the flash risky if the IMC is active. Flashrom tries to temporarily
disable the IMC but even then changing the contents of the flash can have unwanted effects: when
the IMC continues (at the latest after a reboot) it will continue executing code from the flash.
If the code was removed or changed in an unfortunate way it is unpredictable what the IMC will do.
Therefore, if flashrom detects an active IMC it will disable write support unless the user forces
it with the:
flashrom -p internal:amd_imc_force=yes
syntax. The user is responsible for supplying a suitable image or leaving out the IMC region with
the help of a layout file. This limitation might be removed in the future when we understand the
details better and have received enough feedback from users. Please report the outcome if you had
to use this option to write a chip.
An optional spispeed parameter specifies the frequency of the SPI bus where applicable (i.e.SB600
or later with an SPI flash chip directly attached to the chipset). Syntax is:
flashrom -p internal:spispeed=frequency
where frequency can be '16.5 MHz', '22 MHz', '33 MHz', '66 MHz', '100 MHZ', or '800 kHz'. Support
of individual frequencies depends on the generation of the chipset:
• SB6xx, SB7xx, SP5xxx: from 16.5 MHz up to and including 33 MHz. The default is to use 16.5 MHz
and disable Fast Reads.
• SB8xx, SB9xx, Hudson: from 16.5 MHz up to and including 66 MHz. The default is to use 16.5 MHz
and disable Fast Reads.
• Yangtze (with SPI 100 engine as found in Kabini and Tamesh): all of them. The default is to use
the frequency that is currently configured.
An optional spireadmode parameter specifies the read mode of the SPI bus where applicable (Bolton
or later). Syntax is:
flashrom -p internal:spireadmode=mode
where mode can be 'Normal (up to 33 MHz)', 'Normal (up to 66 MHz)', 'Dual IO (1-1-2)', 'Quad IO
(1-1-4)', 'Dual IO (1-2-2)', 'Quad IO (1-4-4)', or 'Fast Read'.
The default is to use the read mode that is currently configured.
Intel chipsets
If you have an Intel chipset with an ICH8 or later southbridge with SPI flash attached, and if a
valid descriptor was written to it (e.g. by the vendor), the chipset provides an alternative way
to access the flash chip(s) named Hardware Sequencing. It is much simpler than the normal access
method (called Software Sequencing), but does not allow the software to choose the SPI commands to
be sent. You can use the:
flashrom -p internal:ich_spi_mode=value
syntax where value can be auto, swseq or hwseq. By default (or when setting ich_spi_mode=auto) the
module tries to use swseq and only activates hwseq if need be (e.g. if important opcodes are
inaccessible due to lockdown; or if more than one flash chip is attached). The other options
(swseq, hwseq) select the respective mode (if possible).
ICH8 and later southbridges may also have locked address ranges of different kinds if a valid
descriptor was written to it. The flash address space is then partitioned in multiple so called
"Flash Regions" containing the host firmware, the ME firmware and so on respectively. The flash
descriptor can also specify up to 5 so called Protected Regions, which are freely chosen address
ranges independent from the aforementioned Flash Regions. All of them can be write and/or read
protected individually.
If you have an Intel chipset with an ICH2 or later southbridge and if you want to set specific
IDSEL values for a non-default flash chip or an embedded controller (EC), you can use the:
flashrom -p internal:fwh_idsel=value
syntax where value is the 48-bit hexadecimal raw value to be written in the IDSEL registers of the
Intel southbridge. The upper 32 bits use one hex digit each per 512 kB range between 0xffc00000
and 0xffffffff, and the lower 16 bits use one hex digit each per 1024 kB range between 0xff400000
and 0xff7fffff. The rightmost hex digit corresponds with the lowest address range. All address
ranges have a corresponding sister range 4 MB below with identical IDSEL settings. The default
value for ICH7 is given in the example below.
Example:
flashrom -p internal:fwh_idsel=0x001122334567
Laptops
Using flashrom on older laptops that don't boot from the SPI bus is dangerous and may easily make
your hardware unusable (see also the BUGS section). The embedded controller (EC) in some machines
may interact badly with flashing. More information is at Info on laptops and EC <>. Problems
occur when the flash chip is shared between BIOS and EC firmware, and the latter does not expect
flashrom to access the chip. While flashrom tries to change the contents of that memory the EC
might need to fetch new instructions or data from it and could stop working correctly. Probing for
and reading from the chip may also irritate your EC and cause fan failure, backlight failure,
sudden poweroff, and other nasty effects. flashrom will attempt to detect if it is running on such
a laptop and limit probing to SPI buses. If you want to probe the LPC bus anyway at your own risk,
use:
flashrom -p internal:laptop=force_I_want_a_brick
We will not help you if you force flashing on a laptop because this is a really dumb idea.
You have been warned.
Currently we rely on the chassis type encoded in the DMI/SMBIOS data to detect laptops. Some
vendors did not implement those bits correctly or set them to generic and/or dummy values.
flashrom will then issue a warning and restrict buses like above. In this case you can use:
flashrom -p internal:laptop=this_is_not_a_laptop
to tell flashrom (at your own risk) that it is not running on a laptop.
dummy programmer
The dummy programmer operates on a buffer in memory only. It provides a safe and fast way to test various
aspects of flashrom and is mainly used in development and while debugging. It is able to emulate some
chips to a certain degree (basic identify/read/erase/write operations work).
An optional parameter specifies the bus types it should support. For that you have to use the:
flashrom -p dummy:bus=[type[+type[+type]]]
syntax where type can be parallel, lpc, fwh, spi in any order. If you specify bus without type, all buses
will be disabled. If you do not specify bus, all buses will be enabled.
Example:
flashrom -p dummy:bus=lpc+fwh
The dummy programmer supports flash chip emulation for automated self-tests without hardware access. If
you want to emulate a flash chip, use the:
flashrom -p dummy:emulate=chip
syntax where chip is one of the following chips (please specify only the chip name, not the vendor):
• ST M25P10.RES SPI flash chip (128 kB, RES, page write)
• SST SST25VF040.REMS SPI flash chip (512 kB, REMS, byte write)
• SST SST25VF032B SPI flash chip (4096 kB, RDID, AAI write)
• Macronix MX25L6436 SPI flash chip (8192 kB, RDID, SFDP)
• Winbond W25Q128FV SPI flash chip (16384 kB, RDID)
• Spansion S25FL128L SPI flash chip (16384 kB, RDID)
• Dummy vendor VARIABLE_SIZE SPI flash chip (configurable size, page write)
Example:
flashrom -p dummy:emulate=SST25VF040.REMS
To use VARIABLE_SIZE chip, size must be specified to configure the size of the flash chip as a power of
two.
Example:
flashrom -p dummy:emulate=VARIABLE_SIZE,size=16777216,image=dummy.bin
Persistent images
If you use flash chip emulation, flash image persistence is available as well by using the:
flashrom -p dummy:emulate=chip,image=image.rom
syntax where image.rom is the file where the simulated chip contents are read on flashrom startup
and where the chip contents on flashrom shutdown are written to.
Example:
flashrom -p dummy:emulate=M25P10.RES,image=dummy.bin
SPI write chunk size
If you use SPI flash chip emulation for a chip which supports SPI page write with the default
opcode, you can set the maximum allowed write chunk size with the:
flashrom -p dummy:emulate=chip,spi_write_256_chunksize=size
syntax where size is the number of bytes (min.& 1, max.& 256). Example:
flashrom -p dummy:emulate=M25P10.RES,spi_write_256_chunksize=5
SPI blacklist
To simulate a programmer which refuses to send certain SPI commands to the flash chip, you can
specify a blacklist of SPI commands with the:
flashrom -p dummy:spi_blacklist=commandlist
syntax where ommandlist is a list of two-digit hexadecimal representations of SPI commands. If
commandlist is e.g. 0302, flashrom will behave as if the SPI controller refuses to run command
0x03 (READ) and command 0x02 (WRITE). commandlist may be up to 512 characters (256 commands)
long. Implementation note: flashrom will detect an error during command execution.
SPI ignorelist
To simulate a flash chip which ignores (doesn't support) certain SPI commands, you can specify an
ignorelist of SPI commands with the:
flashrom -p dummy:spi_ignorelist=commandlist
syntax where commandlist is a list of two-digit hexadecimal representations of SPI commands. If
commandlist is e.g. 0302, the emulated flash chip will ignore command 0x03 (READ) and command 0x02
(WRITE). commandlist may be up to 512 characters (256 commands) long. Implementation note:
flashrom won't detect an error during command execution.
SPI status register
You can specify the initial content of the chip's status register with the:
flashrom -p dummy:spi_status=content"
syntax where content is a hexadecimal value of up to 24 bits. For example, 0x332211 assigns 0x11
to SR1, 0x22 to SR2 and 0x33 to SR3. Shorter value is padded to 24 bits with zeroes on the left.
See datasheet for chosen chip for details about the registers content.
Write protection
Chips with emulated WP: W25Q128FV, S25FL128L.
You can simulate state of hardware protection pin (WP) with the:
flashrom -p dummy:hwwp=state
syntax where state is yes or no (default value). yes means active state of the pin implies that
chip is write-protected (on real hardware the pin is usually negated, but not here).
Frequency
Frequency can be specified in Hz (default), KHz, or MHz (not case sensitive). If freq parameter
is passed in from command line, commands will delay for certain time before returning, so that to
emulate the requested frequency.
Valid range is [1Hz, 8000Mhz] and there is no delay by default.
The delay of an SPI command is proportional to the number of bits send over SPI bus in both
directions and is calculated based on the assumption that we transfer at 1 bit/Hz:
flashrom -p dummy:emulate=W25Q128FV,freq=64mhz
nic3com, nicrealtek, nicnatsemi, nicintel, nicintel_eeprom, nicintel_spi, gfxnvidia, ogp_spi, drkaiser,
satasii, satamv, atahpt, atavia, atapromise, it8212 programmers
These programmers have an option to specify the PCI address of the card your want to use, which must be
specified if more than one card supported by the selected programmer is installed in your system. The
syntax is:
flashrom -p xxxx:pci=bb:dd.f
where xxxx is the name of the programmer, bb is the PCI bus number, dd is the PCI device number, and b is
the PCI function number of the desired device. Example:
flashrom -p nic3com:pci=05:04.0
Some of these programmers have more info below.
atavia programmer
The VT6421A is a PATA/SATA PCI controller that can be found on various cheap PCI cards. Currently there
is a datasheet <http://spacehopper.org/mirrors/ftp.vtbridge.org/Docs/Storage/DS_VT6421A_100_CCPL.PDF>.
There exists a patch for flashrom that makes it possible to access the attached flash chip, but it has
problems with some cards. They seem to need an offset added to the chip address for unknown reasons.
Due to the mysterious address handling of the VIA VT6421A controller the user can specify an offset with
the:
flashrom -p atavia:offset=addr
syntax where addr will be interpreted as usual (leading 0x (0) for hexadecimal (octal) values, or else
decimal).
Cards found in the wild:
┌──────────┬─────────────┬────────┬─────────┬────────────┬─────────────┬──────────┬─────────────┬───────┐
│ Vendor │ Model │ rev. │ country │ lot code │ Chip │ Size [B] │ Offset │ lspci │
├──────────┼─────────────┼────────┼─────────┼────────────┼─────────────┼──────────┼─────────────┼───────┤
│ │ │ │ │ │ W39V040BPZ │ 512k │ │ │
├──────────┼─────────────┼────────┼─────────┼────────────┼─────────────┼──────────┼─────────────┼───────┤
│ Eminent │ EM2001 │ 0910CD │ Taiwan │ 2IA0022481 │ SST49LF020A │ 256k │ 0xfff00000 │ [2] │
├──────────┼─────────────┼────────┼─────────┼────────────┼─────────────┼──────────┼─────────────┼───────┤
│ "SATA │ "High speed │ 0901CD │ Taiwan │ 2IA0022471 │ Pm49FL004 │ 512k │ 0xfff80000 │ [3] │
│ CONNECT" │ 2/4-port │ │ │ │ │ │ = │ │
│ │ Serial ATA │ │ │ │ │ │ 0xffffffff │ │
│ │ card" │ │ │ │ │ │ - size + 1 │ │
│ │ │ │ │ │ │ │ (aka │ │
│ │ │ │ │ │ │ │ phys_addr) │ │
├──────────┼─────────────┼────────┼─────────┼────────────┼─────────────┼──────────┼─────────────┼───────┤
│ Gembird │ SATA-3 │ │ │ │ W39V040C │ 512k │ │ │
├──────────┼─────────────┼────────┼─────────┼────────────┼─────────────┼──────────┼─────────────┼───────┤
│ │ HZ-006 │ │ │ │ Pm39LV512 │ 64k │ │ [4] │
└──────────┴─────────────┴────────┴─────────┴────────────┴─────────────┴──────────┴─────────────┴───────┘
• [2] <http://paste.flashrom.org/view.php?id=1369>
• [3] <http://www.flashrom.org/pipermail/flashrom/2012-September/009992.html>
• [4] <http://www.flashrom.org/pipermail/flashrom/2012-December/010318.html>
The revision consists of two characters that are printed below the "VT6421A" string on the chip prefixed
by 4 numbers that encode the production year and week. The country is noted right of the revision.
atapromise programmer
This programmer is currently limited to 32 kB, regardless of the actual size of the flash chip. This
stems from the fact that, on the tested device (a Promise Ultra100), not all of the chip's address lines
were actually connected. You may use this programmer to flash firmware updates, since these are only 16
kB in size (padding to 32 kB is required).
nic3com programmer
flashrom supports some 3Com network cards to reflash the (parallel) flash attached to these cards, but it
is also possible to use these cards to reflash other chips which fit in there electrically. Please note
that the small number of address lines connected to the chip may make accessing large chips impossible.
The maximum supported chip size is 128KB.
nicintel_spi programmer
Programmer for SPI flash ROMs on Intel Gigabit network cards. Tested on 32-bit hardware/PCI only.
nicintel_eeprom programmer
This is the first programmer module in flashrom that does not provide access to NOR flash chips but
EEPROMs mounted on gigabit Ethernet cards based on Intel's 82580 NIC. Because EEPROMs normally do not
announce their size nor allow themselves to be identified, the controller relies on correct size values
written to predefined addresses within the chip. Flashrom follows this scheme but assumes the minimum
size of 16 kB (128 kb) if an unprogrammed EEPROM/card is detected. Intel specifies following EEPROMs to
be compatible: Atmel AT25128, AT25256, Micron (ST) M95128, M95256 and OnSemi (Catalyst) CAT25CS128.
gfxnvidia programmer
Flashrom supports some Nvidia graphic cards to reflash the (parallel) flash attached to these cards, but
it is also possible to use these cards to reflash other chips which fit in there electrically.
satasii programmer
Flashrom supports some SiI ATA/SATA controllers to reflash the flash attached to these controller cards,
but it is also possible to use these cards to reflash other chips which fit in there electrically.
Please note that the small number of address lines connected to the chip may make accessing large chips
impossible.
ft2232_spi programmer
This module supports various programmers based on FTDI FT2232/FT4232H/FT232H chips including the DLP
Design DLP-USB1232H, openbiosprog-spi, Amontec JTAGkey/JTAGkey-tiny/JTAGkey-2, Dangerous Prototypes Bus
Blaster, Olimex ARM-USB-TINY/-H, Olimex ARM-USB-OCD/-H, OpenMoko Neo1973 Debug board (V2+),
TIAO/DIYGADGET USB Multi-Protocol Adapter (TUMPA), TUMPA Lite, GOEPEL PicoTAP, Google Servo v1/v2, Tin
Can Tools Flyswatter/Flyswatter 2 and Kristech KT-LINK.
An optional parameter specifies the controller type, channel/interface/port it should support. For that
you have to use the:
flashrom \-p ft2232_spi:type=model,port=interface
syntax where model can be 2232H, 4232H, 232H, jtagkey, busblaster, openmoko, arm-usb-tiny,
arm-usb-tiny-h, arm-usb-ocd, arm-usb-ocd-h, tumpa, tumpalite, picotap, google-servo, ``google-servo-v2,
google-servo-v2-legacy or kt-link. interface can be A, B, C, or D. The default model is 4232H, the
default interface is A and GPIO is not used by default.
If there is more than one ft2232_spi-compatible device connected, you can select which one should be used
by specifying its serial number with the:
flashrom -p ft2232_spi:serial=number
syntax where number is the serial number of the device (which can be found for example in the output of
lsusb -v).
All models supported by the ft2232_spi driver can configure the SPI clock rate by setting a divisor. The
expressible divisors are all even numbers between 2 and 2^17 (=131072) resulting in SPI clock frequencies
of 6 MHz down to about 92 Hz for 12 MHz inputs (non-H chips) and 30 MHz down to about 458 Hz for 60 MHz
inputs ('H' chips). The default divisor is set to 2, but you can use another one by specifying the
optional divisor parameter with the:
flashrom -p ft2232_spi:divisor=div
syntax. Using the parameter csgpiol (DEPRECATED - use gpiol instead) an additional CS# pin can be chosen,
where the value can be a number between 0 and 3, denoting GPIOL0-GPIOL3 correspondingly. Example:
flashrom -p ft2232_spi:csgpiol=3
The parameter gpiolX=[HLC] allows use of the GPIOL pins either as generic gpios with a fixed value during
flashing or as additional CS# signal, where X can be a number between 0 and 3, denoting GPIOL0-GPIOL3
correspondingly. The parameter may be specified multiple times, one time per GPIOL pin. Valid values are
H, L and C:
• H - Set GPIOL output high
• L - Set GPIOL output low
• C - Use GPIOL as additional CS# output
Example:
flashrom -p ft2232_spi:gpiol0=H
Note that not all GPIOL pins are freely usable with all programmers as some have special functionality.
serprog programmer
This module supports all programmers speaking the serprog protocol. This includes some Arduino-based
devices as well as various programmers by Urja Rannikko, Juhana Helovuo, Stefan Tauner, Chi Zhang and
many others.
A mandatory parameter specifies either a serial device (and baud rate) or an IP/port combination for
communicating with the programmer. The device/baud combination has to start with dev= and separate the
optional baud rate with a colon. For example:
flashrom -p serprog:dev=/dev/ttyS0:115200
If no baud rate is given the default values by the operating system/hardware will be used. For IP
connections you have to use the:
flashrom -p serprog:ip=ipaddr:port
syntax. In case the device supports it, you can set the SPI clock frequency with the optional spispeed
parameter. The frequency is parsed as hertz, unless an M, or k suffix is given, then megahertz or
kilohertz are used respectively. Example that sets the frequency to 2 MHz:
flashrom -p serprog:dev=/dev/device:baud,spispeed=2M
Optional cs parameter can be used to switch which chip select number is used. This allows connecting
multiple chips at once and selecting which one to flash by software means (rather than rewiring):
flashrom -p serprog:dev=/dev/device:baud,cs=0
The particular programmer implementation needs to support this feature, for it to work. If the requested
chip select isn't available, flashrom will fail safely.
More information about serprog is available in this document: Serial Flasher Protocol Specification <>.
buspirate_spi programmer
A required dev parameter specifies the Bus Pirate device node and an optional spispeed parameter
specifies the frequency of the SPI bus. The parameter delimiter is a comma. Syntax is:
flashrom -p buspirate_spi:dev=/dev/device,spispeed=frequency
where frequency can be 30k, 125k, 250k, 1M, 2M, 2.6M, 4M or 8M (in Hz). The default is the maximum
frequency of 8 MHz.
The baud rate for communication between the host and the Bus Pirate can be specified with the optional
serialspeed parameter. Syntax is:
flashrom -p buspirate_spi:serialspeed=baud
where baud can be 115200, 230400, 250000 or 2000000 (2M). The default is 2M baud for Bus Pirate hardware
version 3.0 and greater, and 115200 otherwise.
An optional pullups parameter specifies the use of the Bus Pirate internal pull-up resistors. This may be
needed if you are working with a flash ROM chip that you have physically removed from the board. Syntax
is:
flashrom -p buspirate_spi:pullups=state
where state can be on or off. More information about the Bus Pirate pull-up resistors and their purpose
is available in a guide by dangerousprototypes <http://dangerousprototypes.com/docs/
Practical_guide_to_Bus_Pirate_pull-up_resistors>.
When working with low-voltage chips, the internal 10k pull-ups of the Bus Pirate might be too high. In
such cases, it's necessary to create an external pull-up using lower-value resistors.
For this, you can use the hiz parameter. This way, the Bus Pirate will operate as an open drain. Syntax
is:
flashrom -p buspirate_spi:hiz=state
where state can be on or off.
The state of the Bus Pirate power supply pins is controllable through an optional psus parameter. Syntax
is:
flashrom -p buspirate_spi:psus=state
where state can be on or off. This allows the bus pirate to power the ROM chip directly. This may also
be used to provide the required pullup voltage (when using the pullups option), by connecting the Bus
Pirate's Vpu input to the appropriate Vcc pin.
An optional aux parameter specifies the state of the Bus Pirate auxiliary pin. This may be used to drive
the auxiliary pin high or low before a transfer. Syntax is:
flashrom -p buspirate_spi:aux=state
where state can be high or low. The default state is high.
pickit2_spi programmer
An optional voltage parameter specifies the voltage the PICkit2 should use. The default unit is Volt if
no unit is specified. You can use mV, millivolt, V or Volt as unit specifier. Syntax is:
flashrom \-p pickit2_spi:voltage=value
where value can be 0V, 1.8V, 2.5V, 3.5V or the equivalent in mV.
An optional spispeed parameter specifies the frequency of the SPI bus. Syntax is:
flashrom -p pickit2_spi:spispeed=frequency
where frequency can be 250k, 333k, 500k or 1M (in Hz). The default is a frequency of 1 MHz.
dediprog programmer
An optional voltage parameter specifies the voltage the Dediprog should use. The default unit is Volt if
no unit is specified. You can use mV, milliVolt, V or Volt as unit specifier. Syntax is:
flashrom -p dediprog:voltage=value
where value can be 0V, 1.8V, 2.5V, 3.5V or the equivalent in mV.
An optional device parameter specifies which of multiple connected Dediprog devices should be used.
Please be aware that the order depends on libusb's usb_get_busses() function and that the numbering
starts at 0. Usage example to select the second device:
flashrom -p dediprog:device=1
An optional spispeed parameter specifies the frequency of the SPI bus. The firmware on the device needs
to be 5.0.0 or newer. Syntax is:
flashrom -p dediprog:spispeed=frequency
where frequency can be 375k, 750k, 1.5M, 2.18M, 3M, 8M, 12M or 24M (in Hz). The default is a frequency
of 12 MHz.
An optional target parameter specifies which target chip should be used. Syntax is:
flashrom -p dediprog:target=value
where value can be 1 or 2 to select target chip 1 or 2 respectively. The default is target chip 1.
rayer_spi programmer
The default I/O base address used for the parallel port is 0x378 and you can use the optional iobase
parameter to specify an alternate base I/O address with the:
flashrom -p rayer_spi:iobase=baseaddr
syntax where baseaddr is base I/O port address of the parallel port, which must be a multiple of four.
Make sure to not forget the "0x" prefix for hexadecimal port addresses.
The default cable type is the RayeR cable. You can use the optional type parameter to specify the cable
type with the:
flashrom -p rayer_spi:type=model
syntax where model can be rayer for the RayeR cable, byteblastermv for the Altera ByteBlasterMV, stk200
for the Atmel, STK200/300, wiggler for the Macraigor Wiggler, xilinx for the Xilinx Parallel Cable III
(DLC 5), or spi_tt for SPI Tiny Tools-compatible hardware.
More information about the RayeR hardware is available at RayeR's website <http://rayer.g6.cz/elektro/
spipgm.htm>. The Altera ByteBlasterMV datasheet can be obtained from Altera <http://www.altera.co.jp/
literature/ds/dsbytemv.pdf>. For more information about the Macraigor Wiggler see their company homepage
<http://www.macraigor.com/wiggler.htm>. The schematic of the Xilinx DLC 5 was published in a Xilinx
guide <http://www.xilinx.com/support/documentation/user_guides/xtp029.pdf>.
raiden_debug_spi programmer
Some devices such as the GSC knows how it is wired to AP and EC flash chips, and can be told which
specific device to talk to using the target parameter:
flashrom -p raiden_debug_spi:target={ap,ec}
Other devices such as Servo Micro and HyperDebug are generic, and do not know how they are wired, the
caller is responsible for first configure the appropriate MUXes or buffers, and then tell the debugger
which port to use (Servo Micro has just one SPI port, HyperDebug is the first of this kind to have
multiple):
flashrom -p raiden_debug_spi:target=N
where N is an non-negative integer (default 0).
The default is to use the first available servo. You can use the optional serial parameter to specify the
servo USB device serial number to use specifically with:
flashrom -p raiden_debug_spi:serial=XXX
The servo device serial number can be found via lsusb. Raiden will poll the ap target waiting for the
system power to settle on the AP and EC flash devices.
The optional custom_rst=true parameter alters the behavior of the reset process:
flashrom -p raiden_debug_spi:custom_rst=<true|false>
syntax, where:
custom_rst=false is the implicit default timeout of 3ms
and custom_rst=true set RAIDEN_DEBUG_SPI_REQ_ENABLE_AP_CUSTOM instead of RAIDEN_DEBUG_SPI_REQ_ENABLE_AP.
This custom reset will modify the timeout from 3ms to 10ms and will not set EC_RST_L, meaning neither the
EC nor the AP will be reset. With this setting, it's the user's responsibility to manage the reset signal
manually or by configuring the GPIO. Failure to handle the reset signal appropriately will likely result
in flashing errors.
More information about the ChromiumOS servo hardware is available at servos website <https://chromium
.googlesource.com/chromiumos/third_party/hdctools/+/HEAD/docs/servo_v4.md>.
pony_spi programmer
The serial port (like /dev/ttyS0, /dev/ttyUSB0 on Linux or COM3 on windows) is specified using the
mandatory dev parameter. The adapter type is selectable between SI-Prog (used for SPI devices with
PonyProg 2000) or a custom made serial bitbanging programmer named "serbang". The optional type parameter
accepts the values si_prog (default) or serbang.
Information about the SI-Prog adapter can be found at its website <http://www.lancos.com/siprogsch.html>.
An example call to flashrom is:
flashrom -p pony_spi:dev=/dev/ttyS0,type=serbang
Please note that while USB-to-serial adapters work under certain circumstances, this slows down operation
considerably.
ogp_spi programmer
The flash ROM chip to access must be specified with the rom parameter:
flashrom -p ogp_spi:rom=name
Where name is either cprom or s3 for the configuration ROM and bprom or bios for the BIOS ROM. If more
than one card supported by the ogp_spi programmer is installed in your system, you have to specify the
PCI address of the card you want to use with the pci= parameter as explained in the nic3com et al.
section above.
linux_mtd programmer
You may specify the MTD device to use with the:
flashrom -p linux_mtd:dev=/dev/mtdX
syntax where /dev/mtdX is the Linux device node for your MTD device. If left unspecified the first MTD
device found (e.g. /dev/mtd0) will be used by default.
Please note that the linux_mtd driver only works on Linux.
linux_spi programmer
You have to specify the SPI controller to use with the:
flashrom -p linux_spi:dev=/dev/spidevX.Y
syntax where /dev/spidevX.Y is the Linux device node for your SPI controller.
In case the device supports it, you can set the SPI clock frequency with the optional spispeed parameter.
The frequency is parsed as kilohertz. Example that sets the frequency to 8 MHz:
flashrom -p linux_spi:dev=/dev/spidevX.Y,spispeed=8000
Please note that the linux_spi driver only works on Linux.
mstarddc_spi programmer
The Display Data Channel (DDC) is an I2C bus present on VGA and DVI connectors, that allows exchanging
information between a computer and attached displays. Its most common uses are getting display
capabilities through EDID (at I2C address 0x50) and sending commands to the display using the DDC/CI
protocol (at address 0x37). On displays driven by MSTAR SoCs, it is also possible to access the SoC
firmware flash (connected to the Soc through another SPI bus) using an In-System Programming (ISP) port,
usually at address 0x49. This flashrom module allows the latter via Linux's I2C driver.
IMPORTANT: Before using this programmer, the display MUST be in standby mode, and only connected to the
computer that will run flashrom using a VGA cable, to an inactive VGA output. It absolutely MUST NOT be
used as a display during the procedure!
You have to specify the DDC/I2C controller and I2C address to use with the:
flashrom -p mstarddc_spi:dev=/dev/i2c-X:YY
syntax where /dev/i2c-X is the Linux device node for your I2C controller connected to the display's DDC
channel, and YY is the (hexadecimal) address of the MSTAR ISP port (address 0x49 is usually used).
Example that uses I2C controller /dev/i2c-1 and address 0x49:
flashrom -p mstarddc_spi:dev=/dev/i2c-1:49
It is also possible to inhibit the reset command that is normally sent to the display once the flashrom
operation is completed using the optional noreset parameter. A value of 1 prevents flashrom from sending
the reset command. Example that does not reset the display at the end of the operation:
flashrom -p mstarddc_spi:dev=/dev/i2c-1:49,noreset=1
Please note that sending the reset command is also inhibited if an error occurred during the operation.
To send the reset command afterwards, you can simply run flashrom once more, in chip probe mode (not
specifying an operation), without the noreset parameter, once the flash read/write operation you intended
to perform has completed successfully.
Please also note that the mstarddc_spi driver only works on Linux.
ch341a_spi programmer
The WCH CH341A programmer does not support any parameters currently. SPI frequency is fixed at 2 MHz, and
CS0 is used as per the device.
ch347_spi programmer
An optional spispeed parameter could be used to specify the SPI speed. This parameter is available for
the CH347T and CH347F device. The default SPI speed is 15MHz if no value is specified. Syntax is:
flashrom -p ch347_spi:spispeed=value
where value can be 60M, 30M, 15M, 7.5M, 3.75M, 1.875M, 937.5K, 468.75K.
ni845x_spi programmer
An optional voltage parameter could be used to specify the IO voltage. This parameter is available for
the NI USB-8452 device. The default unit is Volt if no unit is specified. You can use mV, milliVolt, V
or Volt as unit specifier. Syntax is:
flashrom -p ni845x_spi:voltage=value
where value can be 1.2V, 1.5V, 1.8V, 2.5V, 3.3V or the equivalent in mV.
In the case if none of the programmer's supported IO voltage is within the supported voltage range of the
detected flash chip the flashrom will abort the operation (to prevent damaging the flash chip). You can
override this behaviour by passing yes to the ignore_io_voltage_limits parameter (for e.g. if you are
using an external voltage translator circuit). Syntax is:
flashrom -p ni845x_spi:ignore_io_voltage_limits=yes
You can use the serial parameter to explicitly specify which connected NI USB-845x device should be used.
You should use your device's 7 digit hexadecimal serial number. Usage example to select the device with
1230A12 serial number:
flashrom -p ni845x_spi:serial=1230A12
An optional spispeed parameter specifies the frequency of the SPI bus. Syntax is:
flashrom -p ni845x_spi:spispeed=frequency
where frequency should a number corresponding to the desired frequency in kHz. The maximum frequency is
12 MHz (12000 kHz) for the USB-8451 and 50 MHz (50000 kHz) for the USB-8452. The default is a frequency
of 1 MHz (1000 kHz).
An optional cs parameter specifies which target chip select line should be used. Syntax is:
flashrom -p ni845x_spi:csnumber=value
where value should be between 0 and 7. By default the CS0 is used.
digilent_spi programmer
An optional spispeed parameter specifies the frequency of the SPI bus. Syntax is:
flashrom -p digilent_spi:spispeed=frequency
where frequency can be 62.5k, 125k, 250k, 500k, 1M, 2M or 4M (in Hz). The default is a frequency of 4
MHz.
dirtyjtag_spi programmer
An optional freq parameter specifies the frequency of the SPI bus. Syntax is:
flashrom -p dirtyjtag_spi:spispeed=frequency
where spispeed can be any value in hertz, kilohertz or megahertz supported by the programmer. The
default is a frequency of 100 KHz.
jlink_spi programmer
This module supports SEGGER J-Link and compatible devices.
The MOSI signal of the flash chip must be attached to TDI pin of the programmer, MISO to TDO and SCK to
TCK. The chip select (CS) signal of the flash chip can be attached to different pins of the programmer
which can be selected with the:
flashrom -p jlink_spi:cs=pin
syntax where pin can be either TRST, RESET or TMS. The default pin for chip select is RESET. Note that,
when using RESET, it is normal that the indicator LED blinks orange or red.
Additionally, the Tref pin of the programmer must be attached to the logic level of the flash chip. The
programmer measures the voltage on this pin and generates the reference voltage for its input comparators
and adapts its output voltages to it.
Pinout for devices with 20-pin JTAG connector:
+-------+
| 1 2 | 1: VTref 2:
| 3 4 | 3: TRST 4: GND
| 5 6 | 5: TDI 6: GND
+-+ 7 8 | 7: TMS 8: GND
| 9 10 | 9: TCK 10: GND
| 11 12 | 11: 12: GND
+-+ 13 14 | 13: TDO 14:
| 15 16 | 15: RESET 16:
| 17 18 | 17: 18:
| 19 20 | 19: PWR_5V 20:
+-------+
If there is more than one compatible device connected, you can select which one should be used by
specifying its serial number with the:
flashrom -p jlink_spi:serial=number
syntax where number is the serial number of the device (which can be found for example in the output of
lsusb -v).
The SPI speed can be selected by using the:
flashrom -p jlink_spi:spispeed=frequency
syntax where frequency is the SPI clock frequency in kHz. The maximum speed depends on the device in use.
The power=on option can be used to activate the 5 V power supply (PWR_5V) of the J-Link during a flash
operation.
stlinkv3_spi programmer
This module supports SPI flash programming through the STMicroelectronics STLINK V3 programmer/debugger's
SPI bridge interface:
flashrom -p stlinkv3_spi
If there is more than one compatible device connected, you can select which one should be used by
specifying its serial number with the:
flashrom -p stlinkv3_spi:serial=number
syntax where number is the serial number of the device (which can be found for example in the output of
lsusb -v).
The SPI speed can be selected by using the:
flashrom -p stlinkv3_spi:spispeed=frequency
syntax where frequency is the SPI clock frequency in kHz. If the passed frequency is not supported by the
adapter the nearest lower supported frequency will be used.
realtek_mst_i2c_spi, parade_lspcon and mediatek_i2c_spi programmers
These programmers tunnel SPI commands through I2C-connected devices. The I2C bus over which communication
occurs must be specified either by device path with the devpath option:
flashrom -p realtek_mst_i2c_spi:devpath=/dev/i2c-8
or by a bus number with the bus option, which implies a device path like /dev/i2c-N where N is the
specified bus number:
flashrom -p parade_lspcon:bus=8
realtek_mst_i2c_spi programmer
This programmer supports SPI flash programming for chips attached to Realtek DisplayPort MST hubs,
themselves accessed through I2C (tunneling SPI flash commands through the MST hub's I2C connection with
the host).
In-system programming (ISP) mode
The reset_mcu and enter_isp options provide control over device mode changes, where each can be set to 0
or 1 to enable or disable the corresponding mode transition.
enter_isp defaults to 1, and if enabled will issue commands to the MST hub when beginning operation to
put it into ISP mode.
reset_mcu defaults to 0, and if enabled will issue a reset command to the MST hub on programming
completion, causing it to exit ISP mode and to reload its own firmware from flash.
allow_brick defaults to no, however must be set explicitly to yes to allow the driver to run if you are
sure you have a MST chip.
The hub must be in ISP mode for SPI flash access to be possible, so it is usually only useful to disable
enter_isp if an earlier invocation avoided resetting it on completion. For instance, to erase the flash
and rewrite it with the contents of a file without resetting in between (which could render it
nonfunctional if attempting to load firmware from a blank flash):
flashrom -p realtek_mst_i2c_spi:bus=0,enter_isp=1,reset_mcu=0 -E
flashrom -p realtek_mst_i2c_spi:bus=0,enter_isp=0,reset_mcu=1 -w new.bin
parade_lspcon programmer
This programmer supports SPI flash programming for chips attached to Parade Technologies
DisplayPort-to-HDMI level shifter/protocol converters (LSPCONs), e.g. the PS175. Communication to the SPI
flash is tunneled through the LSPCON over I2C.
mediatek_i2c_spi programmer
This programmer supports SPI flash programming for chips attached to some Mediatek display controllers,
themselves accessed through I2C (tunneling SPI flash commands through an I2C connection with the host).
The programmer is designed to support the TSUMOP82JUQ integrated display driver and scaler as used in the
Google Meet Series One Desk 27 (which runs a version of ChromeOS and uses flashrom in its
tsum-scaler-updater scripts that ship with the OS). Other chips may use compatible protocols but have not
been tested with this programmer, and external chip IOs may need to be controlled through other non-
flashrom means to configure the chip in order for it to operate as expected.
devpath and bus options select the I2C bus to use, as described previously. allow_brick defaults to no,
and must explicitly be set to yes in order for the programmer to operate. This is required because there
is no mechanism in the driver to positively identify that a given I2C bus is actually connected to a
supported device.
spidriver programmer
This is a SPI hardware interface with a display (<https://spidriver.com/>), connected as an FT230X USB
serial device at a fixed baud rate of 460800.
Firmware: <https://github.com/jamesbowman/spidriver>
A required dev parameter specifies the Excamera Labs SPIDriver device node and an optional mode parameter
specifies the mode of the SPI bus. The parameter delimiter is a comma. Syntax is:
flashrom -p spidriver:dev=/dev/device,mode=0
where mode can be 0, 1, 2 or 3. The default is mode 0. Setting the SPI mode requires version 2 of the
device firmware.
An optional A and/or B parameter specifies the state of the SPIDriver A and B pins. This may be used to
drive the A or B pins high or low before a transfer. Syntax is:
flashrom -p spidriver:a=state,b=state
where state can be high or low. The default state is high.
EXAMPLES
To back up and update your BIOS, run:
flashrom -p internal -r backup.rom -o backuplog.txt
flashrom -p internal -w newbios.rom -o writelog.txt
Please make sure to copy backup.rom to some external media before you try to write. That makes offline
recovery easier.
If writing fails and flashrom complains about the chip being in an unknown state, you can try to restore
the backup by running:
flashrom -p internal -w backup.rom -o restorelog.txt
If you encounter any problems, please contact us and supply backuplog.txt, writelog.txt and
restorelog.txt. See section BUGS for contact info.
EXIT STATUS
flashrom exits with 0 on success, 1 on most failures but with 3 if a call to mmap() fails.
REQUIREMENTS
flashrom needs different access permissions for different programmers.
• internal
• needs raw memory access
• PCI configuration space access
• raw I/O port access (x86)
• MSR access (x86)
• atavia
• needs PCI configuration space access
• nic3com, nicrealtek, nicnatsemi
• need PCI configuration space read access
• raw I/O port access
• atahpt
• needs PCI configuration space access
• raw I/O port access
• gfxnvidia, drkaiser, it8212
• need PCI configuration space access
• raw memory access
• rayer_spi
• needs raw I/O port access
• raiden_debug_spi
• needs access to the respective USB device via libusb API version 1.0
• satasii, nicintel, nicintel_eeprom, nicintel_spi
• need PCI configuration space read access
• raw memory access
• satamv, atapromise
• need PCI configuration space read access
• raw I/O port access
• raw memory access
• serprog
• needs TCP access to the network or userspace access to a serial port
• buspirate_spi, spidriver
• needs userspace access to a serial port
• ft2232_spi, usbblaster_spi, pickit2_spi
• need access to the respective USB device via libusb API version 1.0
• ch341a_spi, dediprog
• need access to the respective USB device via libusb API version 1.0
• dummy
• needs no access permissions at all
• internal, nic3com, nicrealtek, nicnatsemi, gfxnvidia, drkaiser, satasii, satamv, atahpt, atavia,
atapromise, asm106x
• have to be run as superuser/root
• need raw access permission
• serprog, buspirate_spi, dediprog, usbblaster_spi, ft2232_spi, pickit2_spi, ch341a_spi, digilent_spi,
dirtyjtag_spi, spidriver
• can be run as normal user on most operating systems if appropriate device permissions are set
• ogp
• needs PCI configuration space read access and raw memory access
• realtek_mst_i2c_spi, parade_lspcon
• need userspace access to the selected I2C bus
On OpenBSD, you can obtain raw access permission by setting:
securelevel=-1
in /etc/rc.securelevel and rebooting, or rebooting into single user mode.
BUGS
You can report bugs, ask us questions or send success reports via our communication channels listed here:
Contact <https://www.flashrom.org/Contact>
Also, we provide a pastebin service <https://paste.flashrom.org> that is very useful to share logs
without spamming the communication channels.
LAPTOPS
Using flashrom on older laptops is dangerous and may easily make your hardware unusable. flashrom will
attempt to detect if it is running on a susceptible laptop and restrict flash-chip probing for safety
reasons. Please see the detailed discussion of this topic and associated flashrom options in the Laptops
paragraph in the internal programmer subsection of the PROGRAMMER-SPECIFIC INFORMATION section and the
information at Info on laptops and EC <>.
One-time programmable (OTP) memory and unique IDs
Some flash chips contain OTP memory often denoted as security registers. They usually have a capacity in
the range of some bytes to a few hundred bytes and can be used to give devices unique IDs etc. flashrom
is not able to read or write these memories and may therefore not be able to duplicate a chip completely.
For chip types known to include OTP memories a warning is printed when they are detected.
Similar to OTP memories are unique, factory programmed, unforgeable IDs. They are not modifiable by the
user at all.
LICENSE
flashrom is covered by the GNU General Public License (GPL), version 2. Some files are additionally
available under any later version of the GPL.
COPYRIGHT
Please see the individual files.
AUTHORS
More than 350 authors have contributed to Flashrom over its life. Each individual is credited in the hall
of fame <https://flashrom.org/about_flashrom/hall_of_fame.html>, or author metadata can be found in the
git history.
All still active authors can be reached via the mailing list <mailto:flashrom@flashrom.org>.
This manual page was written by Uwe Hermann <mailto:uwe@hermann-uwe.de>, Carl-Daniel Hailfinger, Stefan
Tauner and others. It is licensed under the terms of the GNU GPL (version 2 or later).
Nov 05, 2025 FLASHROM(8)