Kernel

This is a linux 5.4-rt kernel intended for SoftBank Robotics NAO V6 with some of the changes ported from SoftBank's 4.4 kernel.

The modifications (compared to the standard 5.4-rt kernel) are:

• a workaround by SoftBank in arch/x86/mm/ioremap.c for the congatec board
• the CGOS driver 1.03.029 by congatec
  • including a patch by SoftBank to enable 32-bit compat ioctls (which is only necessary as long as 32-bit SoftBank executables are used)
• the SoftBank driver cgos-sbr that exports some data as sysfs files
  • modified for 5.4 due to removal of a crypto API
• the SoftBank driver sbre-usb-i2c for an STM32 that provides a USB-I2C bridge
  • modified for 5.4 because USB transfers cannot use stack memory
• the SoftBank driver sbre-dfuse that manages the firmware upload process of the USB-I2C bridge
  • modified for 5.4 because USB transfers cannot use stack memory
• add a quirk flag for a SDHCI device (by SoftBank)
• the SoftBank patch for the audio device WM8860

Furthermore, we include a configuration (.config) that seems to work.

Compiling

On Linux, assuming ${installPath} has been set to a directory where the built kernel shall be placed:

LOCALVERSION="" make ARCH=x86_64 -j$(nproc)
mkdir -p "${installPath}"
INSTALL_PATH="${installPath}" make ARCH=x86_64 install
make INSTALL_MOD_PATH="${installPath}" ARCH=x86_64 modules_install
rm "${installPath}"/lib/modules/*/source
rm "${installPath}"/lib/modules/*/build

Known Issues

With this kernel, the root device is called /dev/mmcblk1 instead of /dev/mmcblk0 (as there are two SDIO controllers in the system). This is almost no problem because most parts of the system use UUIDs, but it breaks the kexec call after flashing the robot, as that passes root=/dev/mmcblk0p3 to the kernel. This means you either need to patch the installer in the .opn image to do a proper reboot or set the "halt after upgrade" flag in order to shut the robot down.