1 Introduction to ARM A15 Linux DSP Platform Software Apps Team 04/19/2013 1TI Confidential - NDA Restrictions

2 Outline 1.ARM Cortex-A15 Overview 2.ARM A15 Linux Overview  U-boot  Two Stage Bootloading  Boot Monitor  SMP Boot Sequence  LPAE  Linux Drivers 2 TI Confidential - NDA Restrictions

3 ARM A15 Overview  ARMv7-A Cortex - the latest member of the Cortex-A series of processors  1-4x SMP within a single processor cluster and low power consumption  Thumb-2 Technology  TrustZone Security  Floating Point  NEON  Hardware Virtualization  Large Physical Address Extension (LPAE) 3 TI Confidential - NDA Restrictions

4 Thumb-2 Technology  Thumb Mode  16-bit Thumb instructions vs 32-bit ARM instructions  Thumb-2 extends with additional 32-bit instructions  Code density similar to Thumb  up to a 30% reduction in memory to store instructions  Performance similar to the ARM instruction set on 32-bit memory

5 TrustZone Security  2 virtual processors backed by hardware based access control  Enable application core to switch between 2 states (worlds)  Each world can operate independently while using the same core.  Memory and peripherals are made aware of the operating world and provide access control  Secure Monitor is code that runs in secure Monitor mode and processes switches to and from the secure world

6 Floating Point  Vector Floating Point (VFP) is an FPU coprocessor extension to the ARM architecture  Hardware support for FP operations in half-, single- and double-precision floating point arithmetic.

7 NEON Linux version: 3.6.0, GCC version: Linaro  Advanced SIMD extension, or Media Processing Engine (MPE)  A combined 64- and 128-bit SIMD instruction set  Provides acceleration for media and signal application  NEON hardware shares the same floating-point registers as used in VFP.

8 Hardware Virtualization  Hardware support for multiple software environments available on the same physical processor  Software applications can access the system capabilities simultaneously  Virtual envrionments are isolated from each other

9 LPAE  64-bit “long-descriptor” format for page tables  Supports 40-bit physical address – up to 1TB of memory

10 ARM A15 Linux Overview  U-boot  Two Stage Bootloading  Boot Monitor  SMP Boot Sequence  LPAE  Linux Drivers

11 U-Boot  Based on the Universal Boot Loader public project  Program that moves executable from non-volatile memory to memory and then transfers CPU control to the newly “loaded” executable  Minimal drivers  SPI  I2C  UART  NAND  ETH  USB

12 Two Stage Bootloading  ROM Boot Loader(RBL) loads Secondary Program Loader (SPL) from SPI NOR flash  SPL loads and run the second stage boot loader, a full version of U-Boot) from NOR or NAND  Keystone II – SPI boot mode  The first 64K of the SPI NOR flash is flashed with SPL  Followed by U-Boot image

13 Boot Monitor  ARM Cortex A15 requires certain functions to be executed in the PL1 privilege level  Provides secure privilege level execution service for Linux Kernel code through SMC calls

14 Boot Monitor – High level architecture

Boot Sequence – Primary Core TI Confidential - NDA Restrictions 15  RBL is run on Power On reset  After completion, load and run u-boot in non-secure mode  Boot Monitor gets installed  As part of non-secure entry, boot monitor calls the RBL API through SMC call (SMC #0) passing _init() entry point address.  RBL enters monitor mode, _init() inits the monitor vector and calls init() to init Core/CPU specific inits, set the primary/secondary flag, the Set the secondary core non-secure entry point address  Back to non-secure mode and booting of linux kernel  At linux start up, primary core make SMC call to power on each of the secondary cores  Primary core waits for secondary cores to boot up and then proceeds to rest of booting sequence

16 Boot Sequence – Secondary Core  On Power On reset, RBL initializes and enters the secondary entry point address of the Boot Monitor core through SMC call (SMC #0)  RBL enters monitor mode, _init() inits the monitor vector and calls init() to init Core/CPU specific inits.  On return from _init(), it jumps to secondary kernel entry point address and start booting 2 nd instance of Linux kernel

17 LPAE  DDR3A memory address space 0x – 0x09 FFFF FFFF  Cortex-A15 LPAE with 40-bit address bus may access if MMU is on  ARM has only 32-bit effective address bus if MMU is off  To access DDR3A when MMU is off  MSMC maps first 2GB to 0x – 0x00 FFFF FFFF  The aliased address space can be used when MMU is on or off  Keystone II does not support cache coherency for the aliased address space  Default memory property of TCI6638 is 0x size 0x  When U-boot boots the kernel, it can modify the default start address.  If mem_lpae=0, U-boot does not modify  If mem_lpae=1, U-boot sets the start address to 0x

18 Linux Drivers  GIC IRQ chip driver  Keystone IPC IRQ chip driver  SMP  AEMIF driver  NAND driver  SPI and SPI NOR flash drivers  I2C and EEPROM drivers  Keystone GPIO driver  Keystone IPC GPIO driver  Network driver (NetCP), PktDMA, Packet Accelerator  SGMII driver  QoS driver  USB driver  10Gig Ethernet driver (not validated due to test hardware)  PCIe driver

19 Getting Started with MCSDK

20 Prerequisite  K2EVM-HK (Follow Hardware setup guide to make sure you have the latest BMC updates)  User guide: (getting started guide & exploring as well)  Download MCSDK:  Ubuntu Linux LTS machine, set up Proxy (consult IT)

21 Install CCS & MCSDK  1. Install CCSv5.3.0 at. For processor architecture, make sure "C6x DSP + ARM processors" is selected.  2. Install TI KeyStone2 Emupack, ti_emupack_keystone2_setup_ If installed on Linux, replace \ with / in this file /opt/ti/ccsv5/ccs_base/common/targetdb/devices/TCI6638.xml  3. Install MCSDK , same directory as CCS, e.g.: /opt/ti  4. copy the file tci6638-evm.ccxml from mcsdk_linux_3_00_00_09/host-tools/loadlin folder to ~/ /ti/CCSTargetConfiguration folder where the CCS saves the user specific configuration file.

22 Build Prerequisite  Toolchain installation: Download the gcc-linaro-arm-linux-gnueabi _linux.tar.bz2 from cd ~/ tar xjf gcc-linaro-arm-linux-gnueabi _linux.tar.bz2 export CROSS_COMPILE=arm-linux-gnueabi- export ARCH=arm PATH=$HOME/gcc-linaro-arm-linux-gnueabi _linux/bin:$PATH  Configure git and install packages needed at build time: sudo apt-get install git-core sudo apt-get install build-essential subversion ccache sed wget cvs coreutils unzip texinfo docbook-utils gawk help2man diffstat file g++ texi2html bison flex htmldoc chrpath libxext-dev xserver-xorg-dev doxygen bitbake uboot-mkimage libncurses5-dev

23 Getting started with MCSDK  Either use prebuilt images or build Uboot, boot monitor, kernel & file system on your own.  File systems supported: ramfs, Net mounted file system, UBIFS. Configure environment variable as per user’s guide.  Getting Kernel & file system to boot  Run applications