From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnout Vandecappelle Date: Fri, 27 Apr 2012 22:37:44 +0200 Subject: [Buildroot] Using buildroot images (iso/ext2) in real target device (flash drive) In-Reply-To: References: Message-ID: <201204272237.44841.arnout@mind.be> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On Friday 27 April 2012 16:23:20 Willy wrote: > So I've deleted the output/ folder, made some modifications and rebuilt > all obtaining a smaller kernel and a smaller fs. > Now it boot, but always using the bzImage (I've only /boot/grub/* and > bzImage on my flash usb). So where did the rest of your rootfs.ext2 go? > Every modifications does not survive to reboot. Maybe you changed the rootfs to an initramfs? > So I've built the vmlinux image and tar fs, but I got > "Grub Error 13: Invalid or unsupported executable format" vmlinux is not executable by grub, and a tar file is not readable by the kernel. The proper approach is the following: - Create a /boot/grub/menu.lst in your rootfs skeleton. - Make sure you have the grub boot loader configured. - Build kernel and rootfs.ext2. Make sure BR2_LINUX_KERNEL_INSTALL_TARGET is selected, so the kernel is inside the rootfs.ext2. If you want extra space in your rootfs to write files to it, set the BR2_TARGET_ROOTFS_EXT2_BLOCKS variable to the size of the root partition. Note, though, that genext2fs creates that whole size in memory, so you need to have enough RAM. - Write rootfs.ext2 to the root partition: 'cat rootfs.ext2 > /dev/hdc1' - Run 'grub --device-map=/dev/null --no-floppy' and give the following commands interactively: device (hd0) /dev/hdc root (hd0,0) setup (hd0) quit This installs grub on /dev/hdc and makes it bootable. Regards, Arnout -- Arnout Vandecappelle arnout at mind be Senior Embedded Software Architect +32-16-286540 Essensium/Mind http://www.mind.be G.Geenslaan 9, 3001 Leuven, Belgium BE 872 984 063 RPR Leuven LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle GPG fingerprint: 7CB5 E4CC 6C2E EFD4 6E3D A754 F963 ECAB 2450 2F1F