Posts: 44
Joined: Sat Sep 29, 2018 11:27 am

SPI Serial FLASH --> File system

Sun Jun 16, 2019 10:15 pm

Hi there,

I have an ISSI IS25LP128F SPI 128Mbit FLASH chip attached to SPI bus 0 on nCS0 (GPIO8 pin 24 nCS_FLASH) This shows up as /dev/spidev0.0 on the Pi

I would like to put a file system on this device allowing me to leave the SD card mounted RO (except for the all important security updates).

I realise that I will need to use a file system that will handle wear levelling for me - JFFS should do the trick. But before I can mount the file system I will need (I think) the MTD layer to take /dev/spi0.0 and present it as /dev/mtd0

Does anyone have a simple, worked through example of how to setup an MTD node on the Pi?

-- 8< --

I can access this using the flashroom tool

Code: Select all

RPi$ flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=60000

flashrom v1.1-rc1-14-gee13d0c on Linux 4.19.42-v7+ (armv7l)
flashrom is free software, get the source code at https://flashrom.org

Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
Found ISSI flash chip "IS25LP128" (16384 kB, SPI) on linux_spi.
No operations were specified.
So clearly the hardware is correctly connected and working correctly :-)

Many thanks

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