I have maintained, on and off, a patch to crafms that supports traditional
cramfs decompress-and-read/run-from-RAM, plus direct mmaping with no
decompression and read/run straight out of ROM:
It includes a modification to mkcramfs to compress or not compress
individual files based on their +t mode setting. Mkcramfs will leave +t
uncompressed in the cramfs image and cramfs will directly mmap them.
Please note that the patch is against 2.4.9. I haven't tried to use it
----- Original Message -----
From: "Thomas Capricelli" <firstname.lastname@example.org>
Sent: Thursday, December 13, 2001 11:02 AM
Subject: Mounting a in-ROM filesystem efficiently
> I'm looking for a way to put a filesystem into ROM.
> Seems pretty trivial, isn't it ?
> My understanding is (the way initrd does, and the way I do as of today)
> * create a RAMDISK
> * loads the data into ramdisk
> * mount the ramdisk
> problem is that I don't want to waste the RAM as the data in the ROM is
> already in the address space. (it's an embedded system, btw)
> Speed is not an issue here. ROM access might be slower than RAM, it will
> always be so much quicker than a disk access. (wrong?)
> Ideally, i would give address/length of the fs in ROM to a function, and I
> would get a ramdisk configured to read its data exactly there, and not in
> Any hint ?
> I've tried to look in the different options from mainstream kernels and
> embedded-oriented kernels whithout success.
> ps : i'm subscribed to lkml, no need to cc:
> Thomas Capricelli <email@example.com>
> boson.eu.org, kvim, zetalinux-
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to firstname.lastname@example.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to email@example.com
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Dec 15 2001 - 21:00:26 EST