[U-Boot] [PATCH] cmd_sf: add handler for +len arg for all commands

Marek Vasut marex at denx.de
Sun Oct 5 21:45:33 CEST 2014


On Sunday, October 05, 2014 at 09:27:00 PM, Maxime Hadjinlian wrote:
> On Sun, Oct 5, 2014 at 9:19 PM,  <thomas.langer at lantiq.com> wrote:
> >> On Sunday, October 05, 2014 at 08:40:26 PM, Maxime Hadjinlian wrote:
> >> > Hi Thomas, all,
> >> > 
> >> > On Sun, Oct 5, 2014 at 7:43 PM,  <thomas.langer at lantiq.com> wrote:
> >> > > Hello Maxime,
> >> > > 
> >> > > can you explain the usecase?
> >> > > I think, only the erase is executed per sector, all other commands
> >> > > are working fine with a byte oriented length.
> >> > 
> >> > I need to write a file that is downloaded through TFTP. So I can get
> >> > the filesize through the variable of the same name, but if it's not
> >> > rounded, the write command may fail.
> >> > I can save the filesize in another variable, but at next boot, when I
> >> > need to read this file, I can't read the file, since I only know it's
> >> > size in byte, I need to be able to round it again.
> >> 
> >> I wonder, do all SPI flashes need to do sector-aligned writes ?
> > 
> > All the serial flashes I have seen so far do support reading and writing
> > with any length, independent from the erase size.
> > Otherwise the current implementation of env_sf.c would also not work.
> 
> Well the QSPI, I used, does not. Every read and write has to be
> aligned. That's why I needed that in the first place.

Aligned how exactly?

Best regards,
Marek Vasut


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