Hi Jonathan, Jonathan Pratt wrote:
I'm working on an ixp425 board which was something like the MonteJade. The prototype boards have 32MB SDRAM populated like the MonteJade but we'd like to drop that down to 16MB. To test this I've altered the specified amount of available memory on the kernel commandline. We plan to implement JFFS2 sometime, but are currently using the CRAMFS instead. The size of the CRAMFS is 2.8MB compressed, just over 6 uncompressed with the stuff we currently have in it.
(That strikes me as odd. A cramfs stores its files compressed, I am surpised you get such good compression of a cramfs fs...)
This means that I can alter the size of the RAM disk on the kernel command line to 7MB leaving 9MB for the kernel (again this is a temporary measure). This is specified as 16M of memory at 0x00000000, and a RAM disk of 7M at 0x00900000. Unfortuantely linux dies after the decompression of the kernel (I get nothing out the terminal at all). If I give Linux 10MB it will uncompress and run normally. The system dies when the filesystem is mounted if I give it less than 7MB. I've tried putting the zImage into various RAM locations prior to executing it but it hasn't helped.
What address do you load the kernel at?
When I run uClinux with 32M available (on the command line) and cat /proc/meminfo, I see that there's 20MB available, with about 2M allocated to the kernel, 3M in buffers, and the other 7M (I presume) used by the RAM disk.
Seems reasonable.
Does anyone know what's going on? Will uClinux always require 10MB
Well, its not "uClinux" that is using 10MB. The linux kernel will need some space to decompress itself, and it will copy the ramdisk in its entirety at startup before freeing the startup image. (And this latter step is probably what is causing you problems).
during the boot process? Is there any (easy) way to limit this or is it just regarded as unimportant since the memory is apparantly freed up afterwards anyway?
I have run 16MB images before on the ixp425. With smaller cramfs images though (IIRC of the order of 4 to 5 MB). Regards Greg ------------------------------------------------------------------------ Greg Ungerer -- Chief Software Dude EMAIL: [EMAIL PROTECTED] Secure Computing Corporation PHONE: +61 7 3435 2888 825 Stanley St, FAX: +61 7 3891 3630 Woolloongabba, QLD, 4102, Australia WEB: http://www.SnapGear.com _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
