Dear Richard Retanubun,
In message <4d515d06.7020...@ruggedcom.com> you wrote:
>
> If by "how NOR flash in handled" you mean cmd_flash.c::flash_sect_roundb()
> then yes, I do want to do this
> but I need to know what number to round it to, no?
The code needs to know that, you don't ;-)
> In the context of cmd_flash, it has access to flash_info_t
> which contains the sector_size information. Also cfi_flash.c also provides a
> function called flash_sector_size()
> that is called by other components that needs to know. If I have
> misunderstood what you mean, sorry, please clarify.
You are right.
> To have SPI flash do this, for example; stmicro.c::stmicro_erase() function
> will auto round up to the nearest sector_size.
> Which is indeed the simpler way. Right now, most drivers/mtd/spi/*.c just
> does this check:
>
> <quoted_code>
> sector_size = stm->params->page_size * stm->params->pages_per_sector;
>
> if (offset % sector_size || len % sector_size) {
> debug("SF: Erase offset/length not multiple of sector size\n");
> return -1;
> }
> </quoted_code>
This is ok if an explicit size is given - you will se ethe same
behaviour on NOR flash when trying something like
erase 40000000 40002345
> I am worried about unintentionally erasing more than what the caller
> requested.
> Would it be better to round up manually and then calls the erase?
No. If the caller uses the "+<size>" notation he explictly requests
to round up. He is supposed to know what he is doing.
Being able to use "+${filesize}" allows for many powerful solutions
to standard tasks that without this would result in cumbersome
manipulation of the size - which would then probably break if you
issue a new revision of your hardware with different flash chips fit.
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: w...@denx.de
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Houston July 20, 1969, 7:27 P.M.
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