1Porting UEFI to a ARM platform : 2-------------------------------- 31. Create the new platform directory under ArmPlatformPkg 4 52. Create its DSC and FDF files into this new directory. These files can be copied from ArmVExpress-CTA9x4.dsc and ArmVExpress-CTA9x4.fdf; and adapted following the requirement of your platform. 6 73. Set up the PCDs required by ArmPlatformPkg in your FDF or DSC files 8 94. Implement 'ArmPlatformLib' for your platform following the interface defined by ArmPlatformPkg\Include\Library\ArmPlatformLib.h. 10 11 12PCDs Description : 13------------------- 14 15# Firmware Device / Volume 16gArmTokenSpaceGuid.PcdSecureFdBaseAddress : Base address of your Secure Firmware Device 17gArmTokenSpaceGuid.PcdSecureFdSize : Size in byte of your Secure Firmware Device. 18gArmTokenSpaceGuid.PcdFdBaseAddress : Base Address of your Non-Secure/Normal World Firmware Device. 19gArmTokenSpaceGuid.PcdFdSize : Size in bytes of your Non-Secure/Normal World Firmware Device 20 21# Stacks 22gArmPlatformTokenSpaceGuid.PcdCPUCoresSecStackBase : Base of Secure Stack for Secure World 23gArmPlatformTokenSpaceGuid.PcdCPUCoreSecPrimaryStackSize : Size of the stack for the Primary Core in Secure World 24gArmPlatformTokenSpaceGuid.PcdCPUCoreSecSecondaryStackSize : Size of the stack for the Secondary Cores in Secure World 25gArmPlatformTokenSpaceGuid.PcdCPUCoresSecMonStackBase : Base of Stack for Monitor World 26gArmPlatformTokenSpaceGuid.PcdCPUCoreSecMonStackSize : Size of the stack for each cores 27gArmPlatformTokenSpaceGuid.PcdCPUCoresStackBase : Base of SEC Stack for Normal World 28gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize : Size of the stack for the Primary Core 29gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize : Size of the stack for the Secondary Core 30 31# CPU / Architectural controllers 32gArmTokenSpaceGuid.PcdGicDistributorBase : Base address of the Distributor of your General Interrupt Controller 33gArmTokenSpaceGuid.PcdGicInterruptInterfaceBase : Base address of the Interface of your General Interrupt Controller 34 35# Memory Regions 36gArmPlatformTokenSpaceGuid.PcdSystemMemoryUefiRegionSize : Size of the region reserve for PI & UEFI 37gArmTokenSpaceGuid.PcdSystemMemoryBase : Base Address of the System Memory (DRAM) 38gArmTokenSpaceGuid.PcdSystemMemorySize : Size of the System Memory (DRAM) 39 40# Features 41gArmPlatformTokenSpaceGuid.PcdSystemMemoryInitializeInSec : TRUE if System Memory initialized by the SEC phase 42gArmPlatformTokenSpaceGuid.PcdSendSgiToBringUpSecondaryCores : TRUE if the PrePi or PrePeiCore modules have to send an SGI to resume the excution of the secondary cores 43 44# Boot Manager 45gArmPlatformTokenSpaceGuid.PcdDefaultBootDescription : Description of the Default Boot Entry 46gArmPlatformTokenSpaceGuid.PcdDefaultBootDevicePath : DevicePath of the Default Boot Entry 47gArmPlatformTokenSpaceGuid.PcdDefaultBootArgument : Argument for the Default Boot Entry 48gArmPlatformTokenSpaceGuid.PcdDefaultBootType : Define the binary type of the Default Boot Entry (0=EFI application, 1=Linux kernel with ATAG support, 2=Linux Kernel with FDT support) 49gArmPlatformTokenSpaceGuid.PcdPlatformBootTimeOut : Timeout before booting on the Device Boot entry (by default the auto boot is skipped) 50gArmPlatformTokenSpaceGuid.PcdDefaultConInPaths : List of Device Path use for the Console Input 51gArmPlatformTokenSpaceGuid.PcdDefaultConOutPaths : List of Device Path use for the Console Output 52 53 54FAQ : 55----- 56# When to use PrePi or PrePeiCore ? 57- PrePi: when the memory has already been initialized by the first stage boot loader 58 Boot sequence: PlatformFirmware/PrePi/Dxe/Bds 59 Example: Beagle Board 60 61- PrePeiCore: when the firmware is started from XIP memory and in Secure world. The PeiCore shadows the firmware itself in System Memory (DRAM) 62 Boot sequence: Sec/PrePiCore/PeiCore/Dxe/Bds 63 Example: ARM Versatile Express 64 65See: 66- ArmPlatformPkg/Documentation/ARM-EDK2-Overview.png 67- ArmPlatformPkg/Documentation/ArmPlatformLib-Full-Boot.png 68- ArmPlatformPkg/Documentation/ArmPlatformLib-2nd-Stage.png 69 70# What is the PcdStandalone 71gArmPlatformTokenSpaceGuid.PcdStandalone=FALSE is used on ARM Development Platforms during the development stage. 72To avoid to reflash the NOR Flash after each build, the SEC (in NOR Flash) intializes thd DRAM and wait until the Normal World firmware is copied into the DRAM. 73Copying the firmware in DRAM is much faster than reflashing the NOR Flash. It is also more convenient to debug the firmware form DRAM than NOR Flash (eg: use of software breakpoint) 74 75
