U-Boot for UniPhier SoC family
  ==============================

  Recommended toolchains
  ----------------------

  The UniPhier platform is well tested with Linaro toolchains.

  You can download pre-built toolchains from:

  
      http://www.linaro.org/downloads/

  
  Compile the source
  ------------------

  The source can be configured and built with the following commands:

      $ make <defconfig>
      $ make CROSS_COMPILE=<toolchain-prefix> DEVICE_TREE=<device-tree>

  The recommended <toolchain-prefix> is `arm-linux-gnueabihf-` for 32bit SoCs,
  `aarch64-linux-gnu-` for 64bit SoCs, but you may wish to change it to use your
  favorite compiler.

  The following tables show <defconfig> and <device-tree> for each board.

  32bit SoC boards:

   Board         | <defconfig>                 | <device-tree>
  ---------------|-----------------------------|------------------------------
  LD4 reference  | uniphier_ld4_sld8_defconfig | uniphier-ld4-ref (default)
  sld8 reference | uniphier_ld4_sld8_defconfig | uniphier-sld8-def
  Pro4 reference | uniphier_v7_defconfig       | uniphier-pro4-ref
  Pro4 Ace       | uniphier_v7_defconfig       | uniphier-pro4-ace
  Pro4 Sanji     | uniphier_v7_defconfig       | uniphier-pro4-sanji
  Pro5 4KBOX     | uniphier_v7_defconfig       | uniphier-pro5-4kbox
  PXs2 Gentil    | uniphier_v7_defconfig       | uniphier-pxs2-gentil
  PXs2 Vodka     | uniphier_v7_defconfig       | uniphier-pxs2-vodka (default)
  LD6b reference | uniphier_v7_defconfig       | uniphier-ld6b-ref

  64bit SoC boards:

   Board         | <defconfig>           | <device-tree>
  ---------------|-----------------------|----------------------------
  LD11 reference | uniphier_v8_defconfig | uniphier-ld11-ref
  LD11 Global    | uniphier_v8_defconfig | uniphier-ld11-global
  LD20 reference | uniphier_v8_defconfig | uniphier-ld20-ref (default)
  LD20 Global    | uniphier_v8_defconfig | uniphier-ld20-global

  PXs3 reference | uniphier_v8_defconfig | uniphier-pxs3-ref

  For example, to compile the source for PXs2 Vodka board, run the following:

      $ make uniphier_v7_defconfig

      $ make CROSS_COMPILE=arm-linux-gnueabihf- DEVICE_TREE=uniphier-pxs2-vodka

  The device tree marked as (default) can be omitted.  `uniphier-pxs2-vodka` is

  the default device tree for the configuration `uniphier_v7_defconfig`, so the
  following gives the same result.

      $ make uniphier_v7_defconfig

      $ make CROSS_COMPILE=arm-linux-gnueabihf-

  Booting 32bit SoC boards
  ------------------------

  The build command will generate the following:
  - u-boot.bin
  - spl/u-boot.bin

  U-Boot can boot UniPhier 32bit SoC boards by itself.  Flash the generated images
  to the storage device (NAND or eMMC) on your board.

   - spl/u-boot-spl.bin at the offset address 0x00000000

   - u-boot.bin         at the offset address 0x00020000

  The `u-boot-with-spl.bin` is the concatenation of the two (with appropriate
  padding), so you can also do:

  
   - u-boot-with-spl.bin at the offset address 0x00000000

  
  If a TFTP server is available, the images can be easily updated.

  Just copy the u-boot-spl.bin and u-boot.bin to the TFTP public directory,

  and run the following command at the U-Boot command line:

  To update the images in NAND:

      => run nandupdate

  To update the images in eMMC:

      => run emmcupdate

  Booting 64bit SoC boards
  ------------------------

  The build command will generate the following:
  - u-boot.bin

  However, U-Boot is not the first stage loader for UniPhier 64bit SoC boards.
  U-Boot serves as a non-secure boot loader loaded by [ARM Trusted Firmware],
  so you need to provide the `u-boot.bin` to the build command of ARM Trusted
  Firmware.

  [ARM Trusted Firmware]: https://github.com/ARM-software/arm-trusted-firmware

  Verified Boot
  -------------
  
  U-Boot supports an image verification method called "Verified Boot".
  This is a brief tutorial to utilize this feature for the UniPhier platform.
  You will find details documents in the doc/uImage.FIT directory.
  
  Here, we take LD20 reference board for example, but it should work for any
  other boards including 32 bit SoCs.
  
  1. Generate key to sign with
  
    $ mkdir keys
    $ openssl genpkey -algorithm RSA -out keys/dev.key \
      -pkeyopt rsa_keygen_bits:2048 -pkeyopt rsa_keygen_pubexp:65537
    $ openssl req -batch -new -x509 -key keys/dev.key -out keys/dev.crt
  
  Two files "dev.key" and "dev.crt" will be created.  The base name is arbitrary,
  but need to match to the "key-name-hint" property described below.
  
  2. Describe FIT source
  
  You need to write an FIT (Flattened Image Tree) source file to describe the
  structure of the image container.
  
  The following is an example for a simple usecase:
  
  ---------------------------------------->8----------------------------------------
  /dts-v1/;
  
  / {
  	description = "Kernel, DTB and Ramdisk for UniPhier LD20 Reference Board";
  	#address-cells = <1>;
  
  	images {

  		kernel {

  			description = "linux";
  			data = /incbin/("PATH/TO/YOUR/LINUX/DIR/arch/arm64/boot/Image.gz");
  			type = "kernel";
  			arch = "arm64";
  			os = "linux";
  			compression = "gzip";
  			load = <0x82080000>;
  			entry = <0x82080000>;

  			hash-1 {

  				algo = "sha256";
  			};
  		};

  		fdt-1 {

  			description = "fdt";
  			data = /incbin/("PATH/TO/YOUR/LINUX/DIR/arch/arm64/boot/dts/socionext/uniphier-ld20-ref.dtb");
  			type = "flat_dt";
  			arch = "arm64";
  			compression = "none";

  			hash-1 {

  				algo = "sha256";
  			};
  		};

  		ramdisk {

  			description = "ramdisk";
  			data = /incbin/("PATH/TO/YOUR/ROOTFS/DIR/rootfs.cpio");
  			type = "ramdisk";
  			arch = "arm64";
  			os = "linux";
  			compression = "none";

  			hash-1 {

  				algo = "sha256";
  			};
  		};
  	};
  
  	configurations {

  		default = "config-1";

  		config-1 {

  			description = "Configuration0";

  			kernel = "kernel";
  			fdt = "fdt-1";
  			ramdisk = "ramdisk";
  			signature-1 {

  				algo = "sha256,rsa2048";
  				key-name-hint = "dev";
  				sign-images = "kernel", "fdt", "ramdisk";
  			};
  		};
  	};
  };
  ---------------------------------------->8----------------------------------------
  
  You need to change the three '/incbin/' lines, depending on the location of
  your kernel image, device tree blob, and init ramdisk.  The "load" and "entry"
  properties also need to be adjusted if you want to change the physical placement
  of the kernel.
  
  The "key-name-hint" must specify the key name you have created in the step 1.
  
  The FIT file name is arbitrary.  Let's say you saved it into "fit.its".
  
  3. Compile U-Boot with FIT and signature enabled
  
  To use the Verified Boot, you need to enable the following two options:
    CONFIG_FIT
    CONFIG_FIT_SIGNATURE
  
  They are disabled by default for UniPhier defconfig files.  So, you need to
  tweak the configuration from "make menuconfig" or friends.
  
    $ make uniphier_v8_defconfig
    $ make menuconfig
        [ enable CONFIG_FIT and CONFIG_FIT_SIGNATURE ]
    $ make CROSS_COMPILE=aarch64-linux-gnu-
  
  4. Build the image tree blob
  
  After building U-Boot, you will see tools/mkimage.  With this tool, you can
  create an image tree blob as follows:
  
    $ tools/mkimage -f fit.its -k keys -K dts/dt.dtb -r -F fitImage
  
  The -k option must specify the key directory you have created in step 1.
  
  A file "fitImage" will be created.  This includes kernel, DTB, Init-ramdisk,
  hash data for each of the three, and signature data.
  
  The public key needed for the run-time verification is stored in "dts/dt.dtb".
  
  5. Compile U-Boot again
  
  Since the "dt.dtb" has been updated in step 4, you need to re-compile the
  U-Boot.
  
    $ make CROSS_COMPILE=aarch64-linux-gnu-
  
  The re-compiled "u-boot.bin" is appended with DTB that contains the public key.
  
  6. Flash the image
  
  Flash the "fitImage" to a storage device (NAND, eMMC, or whatever) on your
  board.
  
  Please note the "u-boot.bin" must be signed, and verified by someone when it is
  loaded.  For ARMv8 SoCs, the "someone" is generally ARM Trusted Firmware BL2.
  ARM Trusted Firmware supports an image authentication mechanism called Trusted
  Board Boot (TBB).  The verification process must be chained from the moment of
  the system reset.  If the Chain of Trust has a breakage somewhere, the verified
  boot process is entirely pointless.
  
  7. Boot verified kernel
  
  Load the fitImage to memory and run the following from the U-Boot command line.
  
    > bootm <addr>
  
  Here, <addr> is the base address of the fitImage.
  
  If it is successful, you will see messages like follows:
  
  ---------------------------------------->8----------------------------------------
  ## Loading kernel from FIT Image at 84100000 ...

     Using 'config-1' configuration

     Verifying Hash Integrity ... sha256,rsa2048:dev+ OK

     Trying 'kernel' kernel subimage

       Description:  linux
       Created:      2017-10-20  14:32:29 UTC
       Type:         Kernel Image
       Compression:  gzip compressed
       Data Start:   0x841000c8
       Data Size:    6957818 Bytes = 6.6 MiB
       Architecture: AArch64
       OS:           Linux
       Load Address: 0x82080000
       Entry Point:  0x82080000
       Hash algo:    sha256
       Hash value:   82a37b7f11ae55f4e07aa25bf77e4067cb9dc1014d52d6cd4d588f92eee3aaad
     Verifying Hash Integrity ... sha256+ OK
  ## Loading ramdisk from FIT Image at 84100000 ...

     Using 'config-1' configuration
     Trying 'ramdisk' ramdisk subimage

       Description:  ramdisk
       Created:      2017-10-20  14:32:29 UTC
       Type:         RAMDisk Image
       Compression:  uncompressed
       Data Start:   0x847a5cc0
       Data Size:    5264365 Bytes = 5 MiB
       Architecture: AArch64
       OS:           Linux
       Load Address: unavailable
       Entry Point:  unavailable
       Hash algo:    sha256
       Hash value:   44980a2874154a2e31ed59222c9f8ea968867637f35c81e4107a984de7014deb
     Verifying Hash Integrity ... sha256+ OK
  ## Loading fdt from FIT Image at 84100000 ...

     Using 'config-1' configuration
     Trying 'fdt-1' fdt subimage

       Description:  fdt
       Created:      2017-10-20  14:32:29 UTC
       Type:         Flat Device Tree
       Compression:  uncompressed
       Data Start:   0x847a2cb0
       Data Size:    12111 Bytes = 11.8 KiB
       Architecture: AArch64
       Hash algo:    sha256
       Hash value:   c517099db537f6d325e6be46b25c871a41331ad5af0283883fd29d40bfc14e1d
     Verifying Hash Integrity ... sha256+ OK
     Booting using the fdt blob at 0x847a2cb0
     Uncompressing Kernel Image ... OK
     reserving fdt memory region: addr=80000000 size=2000000
     Loading Device Tree to 000000009fffa000, end 000000009fffff4e ... OK
  
  Starting kernel ...
  ---------------------------------------->8----------------------------------------
  
  Please pay attention to the lines that start with "Verifying Hash Integrity".
  
  "Verifying Hash Integrity ... sha256,rsa2048:dev+ OK" means the signature check
  passed.
  
  "Verifying Hash Integrity ... sha256+ OK" (3 times) means the hash check passed
  for kernel, DTB, and Init ramdisk.
  
  If they are not displayed, the Verified Boot is not working.

  Deployment for Distro Boot
  --------------------------
  
  UniPhier SoC family boot the kernel in a generic manner as described in
  doc/README.distro .
  
  To boot the kernel, you need to deploy necesssary components to a file
  system on one of your block devices (eMMC, NAND, USB drive, etc.).
  
  The components depend on the kernel image format.
  
  [1] Bare images
  
    - kernel
    - init ramdisk
    - device tree blob
    - boot configuration file (extlinux.conf)
  
  Here is an exmple of the configuration file.
  
  -------------------->8--------------------
  menu title UniPhier Boot Options.
  
  timeout 50
  default UniPhier
  
  label UniPhier
        kernel ../Image
        initrd ../rootfs.cpio.gz
        fdtdir ..
  -------------------->8--------------------
  
  Then, write 'Image', 'rootfs.cpio.gz', 'uniphier-ld20-ref.dtb' (DTB depends on
  your board), and 'extlinux/extlinux.conf' to the file system.
  
  [2] FIT
  
    - FIT blob
    - boot configuration file (extlinux.conf)
  
  -------------------->8--------------------
  menu title UniPhier Boot Options.
  
  timeout 50
  default UniPhier
  
  label UniPhier
        kernel ../fitImage
  -------------------->8--------------------
  
  Since the init ramdisk and DTB are contained in the FIT blob,
  you do not need to describe them in the configuration file.
  Write 'fitImage' and 'extlinux/extlinux.conf' to the file system.

  UniPhier specific commands
  --------------------------
  
   - pinmon (enabled by CONFIG_CMD_PINMON)
       shows the boot mode pins that has been latched at the power-on reset
  
   - ddrphy (enabled by CONFIG_CMD_DDRPHY_DUMP)
       shows the DDR PHY parameters set by the PHY training

   - ddrmphy (enabled by CONFIG_CMD_DDRMPHY_DUMP)
       shows the DDR Multi PHY parameters set by the PHY training

  
  Supported devices
  -----------------
  
   - UART (on-chip)
   - NAND

   - SD/eMMC

   - USB 2.0 (EHCI)
   - USB 3.0 (xHCI)

   - GPIO

   - LAN (on-board SMSC9118)
   - I2C
   - EEPROM (connected to the on-board I2C bus)
   - Support card (SRAM, NOR flash, some peripherals)

  Micro Support Card
  ------------------
  
  The recommended bit switch settings are as follows:
  
   SW2    OFF(1)/ON(0)   Description
   ------------------------------------------
   bit 1   <----         BKSZ[0]
   bit 2   ---->         BKSZ[1]
   bit 3   <----         SoC Bus Width 16/32
   bit 4   <----         SERIAL_SEL[0]
   bit 5   ---->         SERIAL_SEL[1]
   bit 6   ---->         BOOTSWAP_EN
   bit 7   <----         CS1/CS5
   bit 8   <----         SOC_SERIAL_DISABLE
  
   SW8    OFF(1)/ON(0)   Description
   ------------------------------------------

   bit 1    <----        CS1_SPLIT

   bit 2    <----        CASE9_ON
   bit 3    <----        CASE10_ON
   bit 4  Don't Care     Reserve
   bit 5  Don't Care     Reserve
   bit 6  Don't Care     Reserve
   bit 7    ---->        BURST_EN
   bit 8    ---->        FLASHBUS32_16
  
  The BKSZ[1:0] specifies the address range of memory slot and peripherals
  as follows:
  
   BKSZ    Description              RAM slot            Peripherals
   --------------------------------------------------------------------

   0b00   15MB RAM / 1MB Peri    00000000-00efffff    00f00000-00ffffff
   0b01   31MB RAM / 1MB Peri    00000000-01efffff    01f00000-01ffffff
   0b10   64MB RAM / 1MB Peri    00000000-03efffff    03f00000-03ffffff
   0b11  127MB RAM / 1MB Peri    00000000-07efffff    07f00000-07ffffff

  
  Set BSKZ[1:0] to 0b01 for U-Boot.
  This mode is the most handy because EA[24] is always supported by the save pin
  mode of the system bus.  On the other hand, EA[25] is not supported for some
  newer SoCs.  Even if it is, EA[25] is not connected on most of the boards.

  --

  Masahiro Yamada <yamada.masahiro@socionext.com>

  Oct. 2017