Changes between Version 11 and Version 12 of buildroot

Timestamp:

11/28/2019 12:31:03 AM (6 years ago)

Author:

Cale Collins

Comment:

Created 'Building .ext4 filesystem and compressed disk image' for Newport.

buildroot

@@ -145 +145 @@
  * disk partitioning tools
 
+
+=== Building .ext4 filesystem and compressed disk image
+
+In the event you choose to use Buildroot but wish to avoid the drawbacks of a ramdisk you can install it to a block storage device. For this you will need to create a .ext4 filesystem image.  This example will utilize the Linux-Newport branch of the mainline 4.14.4 kernel. 
+
+Prerequisite for this procedure you will need to have:
+
+* Downloaded and configured the [wiki:/newport/bsp Newport BSP], many of the tools used will be provided by it.
+* The [http://dev.gateworks.com/newport/kernel/linux-newport.tar.xz linux-newport.tar.xz] kernel tarball.  
+* The latest [http://dev.gateworks.com/newport/boot_firmware/firmware-newport.img firmware-newport.img] boot firmware if you would like to create a compressed disk image.
+
+With the Newport BSP installed, and Buildroot cloned, configure Buildroot in make menuconfig with the two following options:
+{{{#!bash
+cd buildroot
+make menuconfig
+}}}
+* Target options -> Target Architecture -> AArch64 (little endian) (BR2_aarch64)
+* Filesystem images -> tar the root filesystem -> Compression method (xz) (BR2_TARGET_ROOTFS_CPIO_XZ)
+
+Save the .config and exit.  
+
+Now:
+{{{#!bash
+make -j8
+}}}
+
+After the build completes:
+* Export the location of the rootfs.tar located in your buildroot/output/images folder.
+{{{#!bash
+ROOTFS=${PWD}/output/images/rootfs.tar
+}}}
+* Create a tmp_mnt directory at a location of your discression, this is your temporary mounting point for compiling the filesystem.
+{{{#!bash
+mkdir tmp_mnt
+TMP_MNT=${PWD}/tmp_mnt  
+}}}
+* Create a filesystem of a specific size. It will be expandable later using resize2fs, make it large enough to fit what you have in your current build.   
+{{{#!bash
+OUT=buildroot-newport.ext4
+SIZEMB=1536 # 1.5GB
+truncate -s ${SIZEMB}M ${OUT}
+mkfs.ext4 -q -F -L rootfs ${OUT}
+}}}
+* Mount this file to your 'tmp_mnt' directory
+{{{#!bash
+sudo mount ${OUT} ${TMP_MNT}
+}}}
+* Extract the Buildroot rootfs.tar and linux-newport.tar.xz which was downloaded to this mount point.
+{{{#!bash
+sudo tar -C ${TMP_MNT} -xf ${ROOTFS}
+sudo tar -C ${TMP_MNT} -xf linux-newport.tar.xz
+}}}
+* Convert the kernel 'Image' (uncompressed Kernel) to a fit image.  For this you will need a tool from your Newport BSP directory, in this example the path to the BSP directory is named ${NEWPORT_BSP}.
+{{{#!bash
+mv ${TMP_MNT}/boot/Image vmlinux
+gzip -f vmlinux
+${NEWPORT_BSP}/newport/mkits.sh -o kernel.its -k vmlinux.gz -C gzip -v "buldroot-newport"
+mkimage -f kernel.its tmp_mnt/boot/kernel.itb #adds header
+}}}
+* Create U-Boot bootscript using the existing Ubuntu one from the Newport BSP, use mkimage to add the u-boot header.
+{{{#!bash
+mkimage -A arm64 -T script -C none -d ${NEWPORT_BSP}/newport/ubuntu.scr ${TMP_MNT}/boot/newport.scr
+}}}
+* Unmount temporary mount point, and compress the .ext4 file to be used with the u-boot command 'gzwrite'.
+{{{#!bash
+umount ${TMP_MNT}
+sync
+gzip -k -f ${OUT}
+}}}
+
+To load this root file system without disturbing the existing boot firmware tftpboot can be used:
+
+* Boot your Newport SBC, at the prompt "Hit any key to stop autoboot" press a key. 
+* Execute the following commands.
+{{{#!bash
+setenv ipaddr <your boards IP>
+setenv serverip <your TFTP server IP>
+setenv dev 0
+setenv image buildroot-newport.ext4.gz
+run update_rootfs
+}}}
+
+To create a disk image from the .ext4 file:
+
+* Creating a disk image is useful if you would like to overwrite the existing boot firmware when the image is flashed.  
+{{{#!bash
+# http://dev.gateworks.com/newport/boot_firmware/firmware-newport.img
+cp firmware-newport.img buildroot-newport.img
+# copy buildroot rootfs .ext4 filesystem to image with an offset 
+dd if=buildroot-newport.ext4 of=buildroot-newport.img bs=16M seek=1
+# compress it
+gzip -k -f buildroot-newport.img
+}}}
+
+
 [=#ventana]
 == Ventana (IMX6)