On 01/30/2003 03:44 AM leeyang wrote:

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• Minimum Flash Size if I don't use NFS ( full embeded application )

4MB. For a resonable 'standard' Embedded Linux runtime environment for PowerPC including basic network support you need approx. the following space in Flash:

U-Boot : 120 KB Linux kernel : 600 KB RAMDisk image : 1 MB Root file-system on JFFS2: 2.5 MB

My embedded fs are ppcboot+kernel+ramdisk(rootfs),However ramdisk will take 4.5M ram.

I am going to switch to jffs2, but could you tell me the function of your 1M ramdisk?

The size is for a RAMdisk image built with SELF, our "Simple Embedded Linux Framework" (see ftp://ftp.denx.de/pub/LinuxPPC/usr/src/SELF). The size of the root filesystem is approx. 2.5MB resulting in a compressed RAMdisk image of 1MB. You may want to put this root filesystem on a JFFS2 or better CRAMFS partition but usually there is no real benefit. Actually you waste flash memory space for saving little RAM space.

Would you please check http://lists.infradead.org/pipermail/linux-mtd/2003-January/006836.html and I state my situation there.

About flash partitioning: You can define a static partition table in the Linux kernel e.g. drivers/mtd/maps/tqm8xxl.c for the TQM8xxL modules. With the DENX kernel you can also define the partitioning via Linux bootargs if the kernel option CONFIG_MTD_CMDLINE_PARTS is defined. See http://www.denx.de/doc/TQM8xxL/dplg.html#FLASH-FILESYSTEMS for further information.

Good luck,

Wolfgang.