Having a 64Mbit IS25LP064A and using flashrom 1.0, when calling sudo flashrom -p ft2232_spi:type=2232H,port=A,divisor=100
I get: flashrom v1.0 on Linux 4.15.0-33-generic (x86_64) ... Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns). Found Generic flash chip "unknown SPI chip (RDID)" (0 kB, SPI) on ft2232_spi. ...
:( Writing and reading commands break with the same message.
So I checked the table at https://www.flashrom.org/Supported_hardware The chip is not supported yet. But it says that chips supporting JESD216 should work.
Measuring the signal I got that the command given above does first a RDJDID Operation and later the RDSFDP operation (which should be according to JESD216). I attach the signals. You can see the the operations and what is done. According to the datasheet is MF7-MF0: 9Dh and Memory Type + Capacity (ID15 - ID0): 6017h. Which you can see on the RDJDID signals image.
I know the signal quality is not the best but doing real improves would cost a lot of time. As I already successfully programmed another supported chip and because the Flash chip response the right way I think that it´s not a signal integrity problem.
So my questions are: 1) Does "unknown SPI chip (RDID)" mean "it´s not in the database" or does it mean "RDID could not be read successfully"? 2) If it means "RDID could not be read successfully": Is there any other possibility than signal integrity why flashrom does not show the right RDID? 3) If it means "it´s not in the database": Would adding it to the database solve the problem or is that not crucial? 4) Does flashrom supports flashs with memory of 64Mbit? As I can´t find any in the supported hardware list.
The datasheet of the flash can be obtained from: https://www.mouser.de/datasheet/2/198/25LP032-64A-B-737452.pdf
Btw: the JESD216 link at https://www.flashrom.org/Supported_hardware does not work. May be https://www.jedec.org/standards-documents/docs/jesd216b is what should be linked?