For a description of the hardware, go to https://developer.arm.com/tools-and-software/development-boards/iot-test-chips-and-boards/musca-b-test-chip-board
For emulated hardware, go to https://www.qemu.org/docs/master/system/arm/musca.html
In the local.conf file, MACHINE should be set as follows: MACHINE ?= "musca-b1"
To build the trusted firmware-m: bash$ bitbake trusted-firmware-m