lkml.org 
[lkml]   [2008]   [Aug]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 00/10] AXFS: Advanced XIP filesystem
> I like the general approach of it. It's much more flexible than the ext2
> extension I've done, and the possibility to select XIP vs. compression per
> page is really really neat. I can imagine that people will prefer this over
> the ext2 implementation on s390. It is unclear to me how the "secondary
> block device" thing is supposed to work. Could you elaborate a bit on that?

First off we don't yet support direct_access(), but I am planning on that soon.

Sure. For a system that has say a NOR Flash and a NAND or a embedded
MMC, one can split a filesystem image such that only the XIP parts of
the image are on the NOR while the compressed bits are on the NAND /
eMMC. The NOR part is accessed as directly addressable memory, while
the NAND would use mtd->read() and the eMMC would use block device
access API's. In this case I would call this NAND or eMMC the
"secondary device" because the primary device is the NOR.

Assuming my NOR was at /dev//mtd2 and my NAND at /dev/mtd5. I would
call the following to mount such a system:

mount -t axfs -o second_dev=/dev/mtd5 /dev/mtd2 /mnt/axfs


\
 
 \ /
  Last update: 2008-08-21 16:33    [W:0.262 / U:3.616 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site