A38X Kernel

Official release of the Clearfog board is with Linux kernel 3.10.70 which is supplied by Marvell.

Most of the support for the chip and the platform is already upstreamed mainline and future releases will be based on LTS kernels that are almost identical to the mainline kernel.

To main differences between Marvell kernel and mainline are in the network drivers, noticeably -

• Interrupts spreading to SMP
• RSS support
• Hardware buffer management

As of writing this page, patches to support first item are already queued to LK 4.4, and patches are ready to be submitted for the second and third features.

To build the kernel perform the following on a Linux PC -

• git clone –branch linux-4.9.y https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable.git
• export ARCH=arm CROSS_COMPILE=<External ARM toolchain prefix>
• make mvebu_v7_defconfig
• # optionally modify the default configuration
• make zImage dtbs modules

To build the kernel perform the following on a Linux PC -

• git clone https://github.com/SolidRun/linux-armada38x.git
• export CROSS_COMPILE=<External ARM toolchain prefix>
• export ARCH=arm
• make mvebu_lsp_defconfig
• # optionally modify the default configuration
• make zImage dtbs modules

If extended kernel features is requested to be included by the build then you can replace

• make mvebu_lsp_defconfig

by

• ./scripts/kconfig/merge_config.sh -m arch/arm/configs/mvebu_lsp_defconfig arch/arm/configs/mvebu_extra_defconfig
• make olddefconfig

The merge_config.sh is a Linux kernel tool that combines different defconfig fragments into a single .config. In this case it combines mvebu_lsp_defconfig and mvebu_extra_defconfig

Many recent Linux distributions are using systemd, which requires these additional configuration options:

CONFIG_CGROUPS=y
CONFIG_FHANDLE=y
CONFIG_EXPERT=y
CONFIG_EPOLL=y
CONFIG_SIGNALFD=y
CONFIG_TIMERFD=y
CONFIG_NET=y
CONFIG_DEVTMPFS=y
CONFIG_INOTIFY_USER=y
CONFIG_PROC_FS=y
CONFIG_SYSFS=y