Re: [ECOS] Atmel DataFlash Driver and EB55

[Sebastian Block <SebastianBlock at gmx dot net>]

Am Donnerstag, 7. Oktober 2004 09:46 schrieb Andrew Lunn:
> On Thu, Oct 07, 2004 at 08:45:54AM +0200, Sebastian Block wrote:
> > Hi,
> >
> > I've got a new problem, when building redboot.
> > It compile all ok, but when building the redboot.elf it tells :
> >
> >  arm-elf-gcc -c  -I/tmp/eb/install/include
> >  -I/tmp/ecos/packages/redboot/current
> >  -I/tmp/ecos/packages/redboot/current/src
> >  -I/tmp/ecos/packages/redboot/current/tests -I. -finline-limit=7000
> >  -mcpu=arm7tdmi -mno-short-load-words -Wall -Wpointer-arith
> >  -Wstrict-prototypes -Winline -Wundef -Woverloaded-virtual -g -O2
> >  -ffunction-sections -fdata-sections -fno-rtti -fno-exceptions
> >  -o /tmp/eb/install/lib/version.o
> > /tmp/ecos/packages/redboot/current/src/version.c arm-elf-gcc
> > -mcpu=arm7tdmi -mno-short-load-words -Wl,--gc-sections -Wl,-static -g
> > -nostdlib -L/tmp/eb/install/lib -Ttarget.ld
> >  -o /tmp/eb/install/bin/redboot.elf /tmp/eb/install/lib/version.o
> >  /tmp/eb/install/lib/extras.o: In function `do_load':
> >  /tmp/ecos/packages/redboot/current/src/load.c:569: undefined reference
> > to `flash_read_buf'
> >  collect2: ld returned 1 exit status
> >  make[1]: *** [/tmp/eb/install/bin/redboot.elf] Fehler 1
> >  make[1]: Leaving directory `/tmp/eb/redboot/current'
> >  make: *** [build] Fehler 2
> >
> > Did I forget something to add to the target !?
> > I'm sorry that I've got no idea where the comes from.
>
> I never tried building redboot on the eb55 with DataFlash before. I
> can reproduce your problem and understand what is going on.
>
> The DataFLASH driver does not allow reads of flash by doing a
> memcpy. There is no memory mapping for a DataFlash device. It needs to
> get the data from over the SPI buffer. With the old flash API you had
> to define CYGSEM_IO_FLASH_READ_INDIRECT which told io/flash to call
> flash_read_buf to read the flash rather than do a memcpy.
>
> With the new API this is done differently. If the strucutre of
> functions contains a NULL pointer for the read function, io/flash will
> do a memcpy. If a read function has been provided it will use
> it. CYGSEM_IO_FLASH_READ_INDIRECT is not used by version 2 flash
> drivers. However the DataFlash cdl are incorrectly defined it. This is
> causing problems with the legacy device interface code. The legacy
> flash interface code allows an old device driver to be used with the
> new io/flash API. It puts a wrapper around the old driver API which
> makes it look like its a new driver. The legacy wrapper uses
> CYGSEM_IO_FLASH_READ_INDIRECT to determine if it should call memcpy to
> perform a read from flash or call the legacy function
> flash_read_buf. The legacy device driver the eb55 uses,
> CYGPKG_DEVS_FLASH_ATMEL_AT49XXXX, allows memcpy to access the flash
> and so does not define the function flash_read_buf. Hence the linker
> error.
>
> So in summary:
>
> V2 device drivers should set flash_read in the device structure is
> reading is to be perfored by a function.
>
> Legacy devices should define CYGSEM_IO_FLASH_READ_INDIRECT and provide
> a function flash_read_buf.
>
> Attached is a patch which fixes your problem and allows RedBoot to
> link. I don't have the hardware so i have no idea if it actually runs.
>
>         Andrew

Thank you for that nice explanation. now I understand something more even with 
my flash-driver.
Now it compile correctly :)
But there is no chance to write / read .. but I'll debug it myself .. 
hopefully I find the bug.

Thank you

Sebastian

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