Hi, On Wed, Mar 07, 2012 at 03:50:32PM +0000, Christian Gagneraud wrote: > I would like to know how people do to generate their kernel config > file (which are usually very small).
Did you look at 'make kernel_menuconfig' ? > Should I do a kernel_menuconfig manually and select the very minimum > that allow to boot the board, or is there any "magic script" that > could extract this file for me given a "generic" config? I think that the goal is to keep config-default as small as possible... > I would like to know as well, what is the strategy concerning the > partitioning of the (NAND) flash. Should I try to get OpenWRT to > reuse the existing partioning or is it common to redefine a new > partioning that fits the OpenWRT requirements (especially concerning > the squahfs over jffs2). > > This is the out-of-factory layout of my NAND flash (32MB): > mtd0: "at91bootstrap" > mtd1: "uboot" > mtd2: "env1" > mtd3: "env2" > mtd4: "Linux" > mtd5: "rootfs" (JFFS2) > > And I was thinking of going for something like this: > mtd0: "at91bootstrap" Ok. > mtd1: "uboot" Ok. > mtd2: "env" I would suggest uboot_env. > mtd6: "firmware" No need for this. > mtd3: +- "kernel" Ok. > mtd4 +- "rootfs" mounted as / type mini_fo Ok. > +- mounted as /rom type squasfs > mtd5: +- "rootfs_data" mounted as /overlay type jffs2 No. Because that is created on the fly. Look at: target/linux/generic/patches-3.2/400-rootfs_split.patchtarget/linux/generic/patches-3.2/400-rootfs_split.patch You could also merge kernel and rootfs into linux (only lantiq target): target/linux/lantiq/patches/201-owrt-mtd_uimage_split.patch target/linux/lantiq/files-3.1/arch/mips/lantiq/xway/mach-gigasx76x.c Example of booting lantiq board: Creating 4 MTD partitions on "ltq_nor": 0x000000000000-0x000000010000 : "uboot" 0x000000010000-0x000000020000 : "uboot_env" 0x000000020000-0x0000007f0000 : "linux" Creating 2 MTD partitions on "ltq_nor": 0x000000020000-0x0000001066af : "kernel" mtd: partition "kernel" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only 0x0000001066af-0x0000007f0000 : "rootfs" mtd: partition "rootfs" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only mtd: partition "rootfs" set to be root filesystem mtd: partition "rootfs_data" created automatically, ofs=440000, len=3B0000 0x000000440000-0x0000007f0000 : "rootfs_data" 0x0000007f0000-0x000000800000 : "board_config" > I like this idea of having a firmware.bin for kernel+rootfs on one > hand and then having the /rom ro and /overlay rw. Thought I'm > surprised that /etc/config doesn't have it's own partition There is no need for that. > Still concerning a bit the partitioning, I'm now moving to the image > format of the final "firmware.bin". Especially concerning the > splitting of rootfs into /rom and /overlay. For what I understood, > there's a magic value "0xdeadc0de" that needs to be placed at "the > right place". Is it something handled by OpenWRT or do I have to > write the boiler plate myself in the target/at91 directory? It's handled by OpenWrt: target/linux/generic/patches-3.2/400-rootfs_split.patchtarget/linux/generic/patches-3.2/400-rootfs_split.patch > Last but not least, I had a look at the target/linux subdirectory > and I'm having difficulties to find several "good" candidates to > mimic. IMHO the at91 is not bad. A quick look at it: * remove execute flag on target/linux/at91/patches/805-free_some_portc_pins.patch * probably move dfboot and u-boot to package: * target/linux/at91/image/dfboot/ * target/linux/at91/image/u-boot/ Hope that helps. Luka _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
