Steps to Rebuild the Toolchain

Obtain buildroot-toolchains_toolchains.bootlin.com-stable-2020.08-1.tar.gz and toolchain-sources_stable-2020.08-1_src.tar.gz after installing nv-driveos-foundation-oss-src-<release>_<GCID>_amd64.deb

The files are under <top>/drive-foundation_src/bootlin/

Common

1. mkdir build
2. tar -C build -xpf toolchain-sources_stable-2020.08-1_src.tar.gz

aarch64-glibc-stable-2022.03-1

1. tar -C build -xpf buildroot-toolchains_toolchains.bootlin.com-stable-2022.03-1.tar.gz
2. tar -C build -xpf toolchain-sources_stable-2022.03-1_src.tar.gz
3. Add the following lines to build/aarch64-glibc-stable-2022.03-1.defconfig:
   1. BR2_GCC_ENABLE_OPENMP=y
   2. BR2_HOST_DIR="$(TOPDIR)/build"
4. cp build/aarch64-glibc-stable-2022.03-1.defconfig build/.config
5. cd build && make olddefconfig && make sdk && cd -
6. Toolchain is available in build/output/images/aarch64-buildroot-linux-gnu_sdk-buildroot.tar.gz

armv5-eabi-glibc-stable-2020.08-1

1. tar -C build -xpf buildroot-toolchains_toolchains.bootlin.com-stable-2020.08-1.tar.gz
2. cp build/armv5-eabi-glibc-stable-2020.08-1.defconfig build/.config
3. cd build && make olddefconfig && make sdk && cd -
4. Toolchain is available in build/output/images/armv5-eabi-buildroot-linux-gnu_sdk-buildroot.tar.gz

armv7-eabihf-glibc-stable-2020.08-1

1. tar -C build -xpf buildroot-toolchains_toolchains.bootlin.com-stable-2020.08-1.tar.gz
2. cp build/armv7-eabihf-glibc-stable-2020.08-1.defconfig build/.config
3. cd build && make olddefconfig && make sdk && cd -
4. Toolchain is available in build/output/images/armv7-eabihf-buildroot-linux-gnu_sdk-buildroot.tar.gz