[U-Boot] Flag -mno-cache-volatile to bypass the cache

[ivanchuklist ivanchu]

I'd like to add mmc/spi support to u-boot for nios2 processors but i don't
receive any response about this. Anyway, thanks you all.
Regards,
Ivan Llopard

2009/2/6 ivanchuklist ivanchu <ivanchuklist at gmail.com>

> I feel like a fool :S. If i didn't miss anything spi_xfer is defined in
> include/spi.h and that function is implemented in cpu related code. I see
> also that atmel has put their code in drivers/spi and drivers/mmc. Finally i
> took as example cpu/pxa/mmc.c where i found functions (defined in
> include/mmc.h) to provide access to the mmc card with the commands cp and
> mmc (if CONFIG_CMD_MMC is defined). Then, i chose to put my code in
> cpu/nios2/mmc_spi.c to implement the following functions,
>
> Functions used in common/cmd_mmc.c,
> mmc_read: return -1 (cp error)
> mmc_write: return -1 (cp error)
> mmc2info: return -1 (cp error)
> mmc_init: it initializes the card in spi mode and it fills the
> block_dev_desc_t structure (mmc command).
>
> Functions used to access the block device,
> mmc_block_read: it reads a block in spi mode and its passed as a pointer in
> the field block_read in block_dev_desc_t (used in fs/fat/fat.c to access the
> partition table)
> mmc_get_dev: to give a pointer to the block_dev_desc_t variable (needed by
> disk/part.c because CONFIG_MMC is defined).
>
> Because i had to write functions to manage the spi core, i thought that
> spi_xfer() should be used to access the core in mmc_block_read.
> I'm a little lost because there are some implementations that places the
> code in cpu/ and others in drivers/. Is the code well placed in cpu/?. I
> would like to write the code as it should be written and i wouldn't like to
> mess up the code tree.
>
> Regards,
> Ivan Llopard.
>
> 2009/2/5 Wolfgang Denk <wd at denx.de>
>
>> Dear ivanchuklist ivanchu,
>>
>>
>> In message <51a313240902051201k1977196cu314e60a1cfcd0e11 at mail.gmail.com>
>> you wrote:
>> >
>> > I see also in cpu/nios an implementation of the spi core, it uses
>> volatiles
>> > variables to access hardware, so it will not work. Nevertheless the
>> > implementation is correct.
>>
>> I'm not a NIOS expert - but if it doesn't work, this should be fixed.
>> Patches welcome.
>>
>> > I'm adding sd access by spi protocol to u-boot, so i created a new file
>> > called mmc_spi.c in cpu/nios2. I faced many problems. I just want to
>> have
>> > access to the fat partition, then i wrote mmc_get_dev and mmc_read_block
>> but
>> > i need to initialize the card so i implemented mmc_init (which add mmc
>> > command) and i don't want to write mmc_read/write/2info. Should i
>> implement
>> > those functions?. In the other hand, should i use spi_xfer() to do spi
>> > transactions?.
>>
>> Sorry, I don't know any of this code,
>>
>> Best regards,
>>
>> Wolfgang Denk
>>
>> --
>> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
>> "What terrible way to die."
>> "There are no good ways."
>>        -- Sulu and Kirk, "That Which Survives", stardate unknown
>>
>
>