Thanks @ThorGroup for RedPill, and @haydibe for simple way to create image for bootloader with Docker.   A little instruction how to use last version toolchain in macOS Big Sur 11.5.2 :   1. Install Xcode, Xcode command line tools, and Docker on Mac. Run Docker. Download last version toolchain, moved to Desktop and unzip.   2.  Install HomeBrew in Terminal /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"   3
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