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Re: Strataflash mapping problem
- From: Jonathan Larmour <jifl at eCosCentric dot com>
- To: Enric Bel Prim <ebp at dimat dot es>
- Cc: "'ecos-devel at sources dot redhat dot com'" <ecos-devel at sources dot redhat dot com>
- Date: Mon, 16 Feb 2004 21:15:44 +0000
- Subject: Re: Strataflash mapping problem
- References: <01C3F48E.BB02C480.ebp@dimat.es>
Enric Bel Prim wrote:
Hi, again.
Yes, I agree with Jeffrey Daly that CYGNUM_FLASH_DEVICES should be the real
number of flash devices (4 in my platform), and CYGNUM_FLASH_WIDTH should
be the number of bits in each device (16 in my platform). But
CYGNUM_FLASH_INTERLEAVE should be 1 for my platform (16 bits devices
located in a 16 bit expansion bus of IXP425) and never equal to
CYGNUM_FLASH_DEVICES (as is defined in line 95 in strata.h)....
Finally I'm considering using the generic driver for the Intel 28fXXX
devices instead of the Intel strata to acces the Intel Strata Flash devices
of my platform.
The 28fXXX driver requires the following settings:
// Platform code must define the below
// #define CYGNUM_FLASH_INTERLEAVE : Number of interleaved devices (in
parallel)
// #define CYGNUM_FLASH_SERIES : Number of devices in series
// #define CYGNUM_FLASH_WIDTH : Width of devices on platform
// #define CYGNUM_FLASH_BASE : Address of first device
For my platform I will set: (CYGNUM_FLASH_INTERLEAVE = 1,
CYGNUM_FLASH_SERIES = 4, CYGNUM_FLASH_WIDTH = 16, CYGNUM_FLASH_BASE =
0x50000000)
I think CYGNUM_FLASH_SERIES will solve my flash mapping problems??? I
wonder why the strata flash driver doesn't allow this setting!!.
Because no-one has implemented it :-).
Does anybody know if I can use the 28fXXX driver to acces Intel Strata
Flash devices? I mean, will I loose some functionality/feature of the
Strata devices if I use the generic 28fXXX driver?
I don't know, but if you look at where CYGNUM_FLASH_SERIES is mentioned in
the 28fxxx driver, you'll see it should be pretty easy to bring the same
ideas over into the strata driver if you needed to.
Given the buffered write support is broken, I don't perceive any real
difference in functionality between the drivers, but I haven't looked in
detail.
Jifl
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