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 itīs not a signal integrity problem.
So my questions are:
  1. Does “unknown SPI chip (RDID)” mean “itīs 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 “itīs 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 canīt find any in the supported hardware list.
The datasheet of the flash can be obtained from:
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?