[ECOS] Need uncached memory for USB - Redboot IXP435

mukund jampala mukund.redboot@gmail.com
Sat Jul 11 07:29:00 GMT 2009


Hi Guys,

I am having problems finding the uncached buffers on Redboot on IXP435.
I need these buffers to setup HW descriptors for USB EHCI controller.

I found no means of getting an uncached buffer. Let me know if there is one?
So, I resolved to start using the flush/invalidate MACROS.
HAL_DCACHE_FLUSH / HAL_DCACHE_INVALIDATE.
But it does not work some how? Strangely, it does not flush the
buffers completely.
And the controller gets confused.

The same code works perfectly if I disable the CACHING by placing the
following code in hal_hardware_init(void).
file: "hal/arm/xscale/ixp425/current/src/ixp425_misc.c".

    HAL_DISABLE_INTERRUPTS(oldints);
    HAL_DCACHE_SYNC();
    // HAL_ICACHE_DISABLE();
    HAL_DCACHE_DISABLE();
    HAL_DCACHE_SYNC();
    // HAL_ICACHE_INVALIDATE_ALL();
    HAL_DCACHE_INVALIDATE_ALL();
    HAL_RESTORE_INTERRUPTS(oldints);

I have developed a complete USB EHCI Host stack /drivers for Redboot.
I am this close to completion and I am struck here.

Please help reslove this issue. Any clues would help.

- Mukund Jampala

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