pal_baremetal

Baremetal README

Please Note: The code in the "pal_baremetal" directory is only a reference code for implementation of PAL API's and it has not been verified on any model or SoC's. The directory pal_baremetal consists of the reference code of the PAL API's specific to a platform. Description of each directory are as follows:

Directory Structure

1. common: The implementation common to all the baremetal platforms for all modules are in this directory.
     1.1 include:
       - pal_common_support.h: Implementation that is common to all platforms.
       - pal_pcie_enum.h: Implementation needed for enumeration.
       - pal_pl011_uart.h: Implementation needed for PL011 UART driver.
       - pal_pmu.h: Implementation needed for PMU specific data structures.
     1.2. src:
       Source files common to all baremetal platforms which do not require user modification.
       Eg: Info tables parsing, PCIe enumeration code, etc.  
2. RDN2: Contains Platform specific code. The details in this folder need to be modified w.r.t the platform.

Build Steps

Reference Cmake file is present at CMakeLists.txt. To compile SBSA, perform following steps.

1. cd sbsa-acs
2. export CROSS_COMPILE=<path_to_the_toolchain>/bin/aarch64-none-elf-
3. mkdir build
4. cd build
5. cmake ../ -G"Unix Makefiles" -DCROSS_COMPILE=$CROSS_COMPILE -DTARGET="Target platform"
6. make

Recommended: CMake v3.17, GCC v12.2

CMake Command Line Options:
 -DARM_ARCH_MAJOR = Arch major version. Default value is 9.
 -DARM_ARCH_MINOR = Arch minor version. Default value is 0.
 -DCROSS_COMPILE  = Cross compiler path
 -DTARGET         = Target platform. Should be same as folder under pal_baremetal

On a successful build, *.bin, *.elf, *.img and debug binaries are generated at build/output directory. The output library files will be generated at build/tools/cmake/acs_host of the sbsa-acs directory.

Running SBSA ACS with Bootwrapper on RDN2

1. In RDN2 software stack make following change:

In <rdn2_path>/build-scripts/build-target-bins.sh - replace uefi.bin with acs_latest.bin

  if [ "${!tfa_tbbr_enabled}" == "1" ]; then
      $TOP_DIR/$TF_A_PATH/tools/cert_create/cert_create  \
      ${cert_tool_param} \
-     ${bl33_param_id} ${OUTDIR}/${!uefi_out}/uefi.bin
+     ${bl33_param_id} ${OUTDIR}/${!uefi_out}/acs_latest.bin
  fi

  ${fip_tool} update \
  ${fip_param} \
- ${bl33_param_id} ${OUTDIR}/${!uefi_out}/uefi.bin \
+ ${bl33_param_id} ${OUTDIR}/${!uefi_out}/acs_latest.bin \
  ${PLATDIR}/${!target_name}/fip-uefi.bin

2. Repackage the FIP image with this new binary

• cp <sbsa_acs>/build/output/acs_host.bin <rdn2_path>/output/rdn2/components/css-common/acs_latest.bin

• cd <rdn2_path>

• ./build-scripts/rdinfra/build-test-acs.sh -p rdn2 package

• export MODEL=<path_to_FVP_RDN2_model>

• cd /model-scripts/rdinfra/platforms/rdn2

• ./run_model.sh

Note: Any platform specific changes can be done by using TARGET_BM_BOOT macro defintion. The pal_baremetal reference code is located in pal_baremetal. To customize the bare-metal code for different platforms, create a directory <platform_name> in pal_baremetal folder and copy the reference code from include and source folders from RDN2 to <platform_name>.

For more details on how to port the reference code to a specific platform and for further customisation please refer to the User Guide

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