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Altera_Forum's avatar
Altera_Forum
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20 years ago

EPCS Driver and Filesystem

Just a heads up.. I started work on an EPCS Driver for uClinux, going through the MTD Layer. I can get the new driver to probe and install itself, and catch the read/write routines, so it's just a matter of actually reading/writing to the chip now, which shouldn't be too hard.

I will post relevant updates.

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    20 years ago

    I was wondering if I should use the 'readl' or 'writel' macros to basically emulate IORDs and IOWRs, or should I just initialize pointers to the correct memory locations? I had the driver detecting a chip successfully, but it's very erratic; I can add some printks and functionality completely changes, but that was using pointers. I took a look at u-boots EPCS code, and that uses readl/writel, so I was thinking of that...

  • Altera_Forum's avatar
    Altera_Forum
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    20 years ago

    Good news!

    I have a preliminary driver that supports partitions, the different EPCS chips (ideally) and a read-only filesystem (ROMFS for example). Writing to the chip isn't supported yet, but that will be done shortly... it would help if a couple of people could test this out; I am using a 64Mbit flash, so ideally, other chips would help.

    Note: this driver can very easily be ported to any SPI Flash Chip, notably ones made by ST Micro. Very few modifications would be required, so it's not restricted to EPCS.

    If anyone is interested, reply to the thread or send a PM.

    J
  • Altera_Forum's avatar
    Altera_Forum
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    20 years ago

    Ok, now I have a R/W driver, and I did a couple of tests with JFFS2 - pagesize=erasesize=64K (for EPCS 64). I will continue to fix it up, but let me know if you are interested in trying it out...

    It's nice getting rid of that damn CFI interface, the serial devices are much cleaner.