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 enable is 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 contens 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

* SB8xx, SB9xx, Hudson: from 16.5 MHz up to and including 66 MHz

* Yangtze (with SPI 100 engine as found in Kabini and Tamesh): all of them

The default is to use 16.5 MHz and disable Fast Reads.

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 in the wiki ⟨https://flashrom.org/Laptops⟩. 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)

Example: flashrom -p dummy:emulate=SST25VF040.REMS

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 commandlist 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 an 8-bit hexadecimal value.

nic3com, nicrealtek, nicnatsemi, nicintel, nicintel_eeprom, nicintel_spi, gfxnvidia, ogp_spi, drkaiser, satasii, satamv, atahpt, atavia , atapromise and 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 f is the PCI function number of the desired device.

Example: flashrom -p nic3com:pci=05:04.0

atavia programmer

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). For more information please see its wiki page ⟨https://flashrom.org/VT6421A⟩.

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).

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.

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 and Tin Can Tools Flyswatter/Flyswatter 2.

An optional parameter specifies the controller type, channel/interface/port and GPIO-based chip select it should support. For that you have to use the

flashrom -p ft2232_spi:type=model,port=interface,csgpiol=gpio

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 or google-servo-v2-legacy interface can be A, B, C, or D and csgpiol can be a number between 0 and 3, denoting GPIOL0-GPIOL3 correspondingly. 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. 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.

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

More information about serprog is available in serprog-protocol.txt in the source distribution.

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⟩. Only the external supply voltage (Vpu) is supported as of this writing.

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 user guide ⟨http://www.xilinx.com/support/documentation/user_guides/xtp029.pdf⟩.

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.

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.

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 or RESET. 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 VTref 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: 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.

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.

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 in our wiki ⟨https://flashrom.org/Laptops⟩.

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.