2.4. TC0 Total Compute Platform

Some of the features of TC0 platform referenced in TF-A include:

  • A System Control Processor to abstract power and system management tasks away from application processors. The RAM firmware for SCP is included in the TF-A FIP and is loaded by AP BL2 from FIP in flash to SRAM for copying by SCP (SCP has access to AP SRAM).

  • GICv4

  • Trusted Board Boot

  • SCMI

  • MHUv2

2.4.1. Boot Sequence

The execution begins from SCP_BL1. SCP_BL1 powers up the AP which starts executing AP_BL1 and then executes AP_BL2 which loads the SCP_BL2 from FIP to SRAM. The SCP has access to AP SRAM. The address and size of SCP_BL2 is communicated to SCP using SDS. SCP copies SCP_BL2 from SRAM to its own RAM and starts executing it. The AP then continues executing the rest of TF-A stages including BL31 runtime stage and hands off executing to Non-secure world (u-boot). Build Procedure (TF-A only)

  • Obtain arm toolchain. Set the CROSS_COMPILE environment variable to point to the toolchain folder.

  • Build TF-A:

    make PLAT=tc0 BL33=<path_to_uboot.bin> \
    SCP_BL2=<path_to_scp_ramfw.bin>  all fip

    Enable TBBR by adding the following options to the make command:

    MBEDTLS_DIR=<path_to_mbedtls_directory>  \
    ARM_ROTPK_LOCATION=devel_rsa  \

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