Arm Development Studio Platinum 2021.a is required to debug RD_N2 FVP. 

Download Software Stack

Select a Reference Design (RD) platform. There is a list of platforms here. For this guide we are using RD-N2 release tag RD-INFRA-2021.05.27.

For this guide, we have installed the software stack to ~/rd-infra.

Download the software stack using the guide here.

Setup Software Stack for Debugging

Make sure model-scripts/sgi/uefi.sh contains platforms_rdinfra[rdn2]=1

~/rd-infra$ grep "platforms_rdinfra\[rdn2\]" model-scripts/sgi/uefi.sh
platforms_rdinfra[rdn2]=1

Modify PlatformDxe.inf

In uefi/edk2/edk2-platforms/Platform/ARM/SgiPkg/Drivers/PlatformDxe/PlatformDxe.inf under section Protocols add gHestTableProtocolGuid.

[Protocols] 
  gEfiAcpiTableProtocolGuid          ## CONSUMES 
  gEfiAcpiSdtProtocolGuid            ## CONSUMES 
  gHestTableProtocolGuid             ## SOMETIMES CONSUMES 

Build UEFI edk2 

Now build the software stack. This generates the config files we need to modify. 

~/rd-infra$ ./build-scripts/build-test-uefi.sh -p rdn2 all

Modify tools_def 

In uefi/edk2/Conf/tools_def.txt and uefi/edk2/BaseTool/Conf/tools_def.template remove -Os from line DEFINE GCC_ALL_CC_FLAGS. This makes debugging much easier by not space optimising the firmware. 

uefi/edk2/Conf/tools_def.txt: 

DEFINE GCC_ALL_CC_FLAGS         = -g -fshort-wchar -fno-builtin -fno-strict-aliasing -Wall -Werror -Wno-array-bounds -include AutoGen.h -fno-common

Add –g to DEFINE_GCC_ASM_FLAGS to generate debug information. 

DEFINE GCC_ASM_FLAGS              = -g -c -x assembler -imacros AutoGen.h

Optional: Update tools_def.template to reflect these changes in the future. 

~/rd-infra$ cp uefi/edk2/Conf/tools_def.txt uefi/edk2/BaseTools/Conf/tools_def.template

Disable SPM. The build will fail unless it’s disabled. 

In build-scripts/configs/rdn2/rdn2 make ARM_TF_ENABLE_SPM=0

Set DebugPrintErrorLevel 

In uefi/edk2/edk2-platforms/Platform/ARM/SgiPkg/RdN2/RdN2.dsc add the following line in section PcdsFixedAtBuild.common to enable verbose printing. 

gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel|0x00400000

Set 0x00400000 to a combination of these flags: 

#define DEBUG_INIT      0x00000001  // Initialization
#define DEBUG_WARN      0x00000002  // Warnings
#define DEBUG_LOAD      0x00000004  // Load events
#define DEBUG_FS        0x00000008  // EFI File system
#define DEBUG_POOL      0x00000010  // Alloc & Free (pool)
#define DEBUG_PAGE      0x00000020  // Alloc & Free (page)
#define DEBUG_INFO      0x00000040  // Informational debug messages
#define DEBUG_DISPATCH  0x00000080  // PEI/DXE/SMM Dispatchers
#define DEBUG_VARIABLE  0x00000100  // Variable
#define DEBUG_BM        0x00000400  // Boot Manager
#define DEBUG_BLKIO     0x00001000  // BlkIo Driver
#define DEBUG_NET       0x00004000  // Network Io Driver
#define DEBUG_UNDI      0x00010000  // UNDI Driver
#define DEBUG_LOADFILE  0x00020000  // LoadFile
#define DEBUG_EVENT     0x00080000  // Event messages
#define DEBUG_GCD       0x00100000  // Global Coherency Database changes
#define DEBUG_CACHE     0x00200000  // Memory range cachability changes
#define DEBUG_VERBOSE   0x00400000  // Detailed debug messages that may
                                    // significantly impact boot performance
#define DEBUG_ERROR     0x80000000  // Error

from uefi/edk2/MdePkg/Include/Library/DebugLib.h 

Install FVP 

Download the correct FVP version for the platform and version you selected. 

For RD-N2 version RD-INFRA-2021.05.27 navigate to Neoverse N2 Reference Design FVP and click Download RD-N2. 

Run the installer FVP_RD_N2.sh. 

Modify FVP start script 

Modify model-scripts/rdinfra/platforms/rdn2/run_model.sh: 

remove -R parameter from PARAMS= section. This stops the model from running as soon as a debug server is connected. 

PARAMS="--data css.scp.armcortexm7ct=$OUTDIR/scp_ramfw.bin@0x0BD80000 \
	--data css.mcp.armcortexm7ct=$OUTDIR/mcp_ramfw.bin@0x0BF80000 \
	-C css.mcp.ROMloader.fname=$OUTDIR/mcp_romfw.bin \
	-C css.scp.ROMloader.fname=$OUTDIR/scp_romfw.bin \
	-C css.trustedBootROMloader.fname=$OUTDIR/$BL1_IMAGE \
	-C board.flashloader0.fname=$OUTDIR/$FIP_IMAGE \
	-C board.flashloader1.fname=$PWD/nor1_flash.img \
	-C board.flashloader1.fnameWrite=$PWD/nor1_flash.img \
	-C board.flashloader2.fname=$PWD/nor2_flash.img \
	-C board.flashloader2.fnameWrite=$PWD/nor2_flash.img \
	-S \
	-C css.scp.pl011_uart_scp.out_file=${MODEL_TYPE,,}/${UART0_SCP_OUTPUT_FILE_NAME} \
	-C css.scp.pl011_uart_scp.unbuffered_output=1 \
	-C css.scp.pl011_uart_scp.uart_enable=true \

Rebuild: 

~/rd-infra$ ./build-scripts/build-test-uefi.sh -p rdn2 all

Debug RDN2 

Find the start address of UEFI module 

TF-A loads BL33_AP_UEFI binary (the UEFI firmware) to the address specified by PLAT_ARM_NS_IMAGE_BASE in arm-tf/include/plat/arm/css/common/css_dev.h 

~/rd-infra$ grep PLAT_ARM_NS_IMAGE_BASE arm-tf/include/plat/arm/css/common/css_def.h

#define PLAT_ARM_NS_IMAGE_BASE U(0xE0000000)

The start address is 0xE0000000 

Start FVP 

Update MODEL environment variable with your FVP_RD_N2 model executable. 

export MODEL=~/FVP_RD_N2/models/Linux64_GCC-6.4/FVP_RD_N2

Go to model-scripts/rdinfra and run uefi.sh -p rdn2 

~/rd-infra$ cd model-scripts/rdinfra/ 

~/rd-infra/model-scripts/rdinfra$ ./uefi.sh -p rdn2 

The FVP will now start and wait for a debugger to connect.