Flashrom, help with unresponsive winbond w25q32 flash

[julian1]

First time using flashrom/ft232.

With so many W25 variants I attempted to buy the most generic part I could, a Winbond W25Q32JV SSIMTR .

But during probing flashrom appears to only recognizes the manufacturer,

$ /sbin/flashrom  -p ft2232_spi:type=232H,divisor=32
> [...]
> Found Winbond flash chip "unknown Winbond (ex Nexcom) SPI chip" (0 kB, SPI) on ft2232_spi.
> [...]
> This flash part has status NOT WORKING for operations: PROBE READ ERASE WRITE

I get the same result for flashrom version 1 and 1.1,


Trying to force the chip id to somehting close (suggested by internet search), looks like it *might* work for read
$ /sbin/flashrom   -p ft2232_spi:type=232H,divisor=32  --chip W25Q32.V -f   --read modem.bin

gets me file full of 0xff. Either it's working, but maybe spi MISO line is being held high. I would half expect  an unprogrammed nor flash return garbage.

Trying to write, with forced chip id fails,
$ flashrom   -p ft2232_spi:type=232H,divisor=32  --chip W25Q32.V -f   --write modem.bin
> No EEPROM/flash device found.

eg. rejected, perhaps by flashrom, not accepting the chip id override

Any ideas?

[julian1]

Resolved by substituting a Micron N25Q032 part. Supports read,write,verify etc out of the box.

[woofy]

Did you include the "Release Power Down" command (ABh) in your initialisation?

[julian1]

Did you include the "Release Power Down" command (ABh) in your initialisation?

That's a good command to be aware of. I think flashrom is a bit limited in not exposing a user modifiable configuration script. Instead all configuration options for each product id gets compiled into the binary. When I get a chance to try with a mcu spi, rather than flashrom/ft232h, I will test it.

[amyk]

gets me file full of 0xff. Either it's working, but maybe spi MISO line is being held high. I would half expect  an unprogrammed nor flash return garbage.

With few exceptions, unprogrammed flash is all 1s.

[SiliconWizard]

gets me file full of 0xff. Either it's working, but maybe spi MISO line is being held high. I would half expect  an unprogrammed nor flash return garbage.

With few exceptions, unprogrammed flash is all 1s.

Indeed.
Unless the Flash chip has been messed with, there's no reason that I know of it should contain "random" data.

Usually Flash chips have ID registers? So one way to figure out for sure if communication with the chip (and chip itself) is fine is to read its ID.

[julian1]

Usually Flash chips have ID registers? So one way to figure out for sure if communication with the chip (and chip itself) is fine is to read its ID.

I concluded that spi/comms was probably Ok, because flashrom correctly identified the manufacturer by reading the id. The specific part number/id however was not in flashrom's db/cache of known parts, so it refused to proceed with any risky command (erase or write). Alternatively, as woofy suggests it may have been a poor init sequence, eg. missing 'release power down', from the generic sequence when using the chip override feature of flashrom. Unfortunately the verbose trace doesn't provide a lot more info. 

[SiliconWizard]

Well, if it's not supported by the tool you use (flashrom), then there's nothing much you can do. Sorry if I missed it, but is there a way to force flashrom to proceed with a write, for instance? And then see how it goes?