• Stefan Agner's avatar
    ARM: vf610: enable Cortex-M4 configuration on Vybrid SoC · 8064887e
    Stefan Agner authored
    This patch allows to build the Kernel for Vybrid (VF6xx) SoC
    when ARMv7-M CPU is selected. The resulting image runs on the
    secondary Cortex-M4 core. This core has equally access to all
    peripherals as the main Cortex-A5 core. However, there is no
    resource control mechanism, hence when both cores are used
    simultaneously, orthogonal device tree's are required.
    
    The boot CPU is dependent on the SoC variant. The available
    boards use mostly variants where the Cortex-A5 is the primary
    and hence the boot CPU. Booting the secondary Cortex-M4 CPU
    needs SoC specific registers written. There is no in kernel
    support for this right now, a external userspace utility
    called "m4boot" can be used to boot the kernel:
    
    m4boot xipImage initramfs.cpio.lzo vf610m4-colibri.dtb
    Signed-off-by: default avatarStefan Agner <stefan@agner.ch>
    Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
    8064887e
Kconfig 16.4 KB