Boot Linux with U-Boot Payload

SBL can boot Linux by using U-Boot Payload.

This page provides a step-by-step how to build SBL with U-Boot Payload.

Build Instruction for U-Boot

Build U-Boot and obtain u-boot-dtb.bin:

$ git clone https://gitlab.denx.de/u-boot/u-boot.git && cd u-boot
$ make distclean
$ make slimbootloader_defconfig
$ make all

Prepare Slim Bootloader

  1. Create PayloadBins directory in PayloadPkg:

    $ mkdir -p <Slim Bootloader Dir>/PayloadPkg/PayloadBins/

  2. Copy u-boot-dtb.bin to PayloadBins directory:

    $ cp <U-Boot Dir>/u-boot-dtb.bin <Slim Bootloader Dir>/PayloadPkg/PayloadBins/u-boot-dtb.bin

Build Instruction for QEMU target

Slim Bootloader supports multiple payloads, and a board of Slim Bootloader detects its target payload by PayloadId in board configuration. The PayloadId can be any 4 Bytes value.

  1. Update PayloadId. Let’s use ‘U-BT’ as an example:

    $ vi Platform/QemuBoardPkg/CfgData/CfgDataExt_Brd1.dlt
-GEN_CFG_DATA.PayloadId                     | 'AUTO'
+GEN_CFG_DATA.PayloadId                     | 'U-BT'

  2. Update payload text base. PAYLOAD_EXE_BASE must be the same as U-Boot CONFIG_SYS_TEXT_BASE in board/intel/slimbootloader/Kconfig. PAYLOAD_LOAD_HIGH must be 0:

    $ vi Platform/QemuBoardPkg/BoardConfig.py
+               self.PAYLOAD_LOAD_HIGH    = 0
+               self.PAYLOAD_EXE_BASE     = 0x00100000

  3. Build QEMU target. Make sure u-boot-dtb.bin and U-BT PayloadId in build command. The output is Outputs/qemu/SlimBootloader.bin:

    $ python BuildLoader.py build qemu -p "OsLoader.efi:LLDR:Lz4;u-boot-dtb.bin:U-BT:Lzma"

  4. Launch Slim Bootloader on QEMU. You should reach at U-Boot serial console:

    $ qemu-system-x86_64 -machine q35 -nographic -serial mon:stdio -pflash Outputs/qemu/SlimBootloader.bin

Test Linux booting on QEMU target

Let’s use LeafHill (APL) Yocto image for testing. Download it from http://downloads.yoctoproject.org/releases/yocto/yocto-2.0/machines/leafhill/.

  1. Prepare Yocto hard disk image:

    $ wget http://downloads.yoctoproject.org/releases/yocto/yocto-2.0/machines/leafhill/leafhill-4.0-jethro-2.0.tar.bz2
$ tar -xvf leafhill-4.0-jethro-2.0.tar.bz2
$ ls -l leafhill-4.0-jethro-2.0/binary/core-image-sato-intel-corei7-64.hddimg

  2. Launch Slim Bootloader on QEMU with disk image:

    $ qemu-system-x86_64 -machine q35 -nographic -serial mon:stdio -pflash Outputs/qemu/SlimBootloader.bin -drive id=mydrive,if=none,file=/path/to/core-image-sato-intel-corei7-64.hddimg,format=raw -device ide-hd,drive=mydrive

  3. Update boot environment values on shell:

    => setenv bootfile vmlinuz
=> setenv bootdev scsi
=> boot

Build Instruction for LeafHill (APL) target

LeafHill is using PCI UART2 device as a serial port. For MEM32 serial port, CONFIG_SYS_NS16550_MEM32 needs to be enabled in U-Boot.

  1. Enable CONFIG_SYS_NS16550_MEM32 in U-Boot:

    $ vi include/configs/slimbootloader.h
+#define CONFIG_SYS_NS16550_MEM32
 #ifdef CONFIG_SYS_NS16550_MEM3

  2. Build U-Boot:

    $ make disclean
$ make slimbootloader_defconfig
$ make all

  3. Copy u-boot-dtb.bin to Slim Bootloader. Slim Bootloader looks for a payload from the specific location. Copy the build u-boot-dtb.bin to the expected location:

    $ mkdir -p <Slim Bootloader Dir>/PayloadPkg/PayloadBins/
$ cp <U-Boot Dir>/u-boot-dtb.bin <Slim Bootloader Dir>/PayloadPkg/PayloadBins/u-boot-dtb.bin

  4. Update PayloadId. Let’s use ‘U-BT’ as an example:

    $ vi Platform/ApollolakeBoardPkg/CfgData/CfgData_Int_LeafHill.dlt
-GEN_CFG_DATA.PayloadId                     | 'AUTO
+GEN_CFG_DATA.PayloadId                     | 'U-BT'

  5. Update payload text base.

  • PAYLOAD_EXE_BASE must be the same as U-Boot CONFIG_SYS_TEXT_BASE in board/intel/slimbootloader/Kconfig.

  • PAYLOAD_LOAD_HIGH must be 0:

    $ vi Platform/ApollolakeBoardPkg/BoardConfig.py
+               self.PAYLOAD_LOAD_HIGH    = 0
+               self.PAYLOAD_EXE_BASE     = 0x00100000

  1. Build APL target. Make sure u-boot-dtb.bin and U-BT PayloadId in build command. The output is Outputs/apl/Stitch_Components.zip:

    $ python BuildLoader.py build apl -p "OsLoader.efi:LLDR:Lz4;u-boot-dtb.bin:U-BT:Lzma"

  2. Stitch IFWI.

    Refer to Apollolake page in Slim Bootloader document site:

    $ python Platform/ApollolakeBoardPkg/Script/StitchLoader.py -i <Existing IFWI> -s Outputs/apl/Stitch_Components.zip -o <Output IFWI>

  3. Flash IFWI.

    Use DediProg to flash IFWI. You should reach at U-Boot serial console.

Build Instruction to use ELF U-Boot

  1. Enable CONFIG_OF_EMBED:

    $ vi configs/slimbootloader_defconfig
+CONFIG_OF_EMBED=y

  2. Build U-Boot:

    $ make disclean
$ make slimbootloader_defconfig
$ make all
$ strip u-boot (removing symbol for reduced size)

  3. Do same steps as above

  • Copy u-boot (ELF) to PayloadBins directory

  • Update PayloadId ‘U-BT’ as above.

  • No need to set PAYLOAD_LOAD_HIGH and PAYLOAD_EXE_BASE.

  • Build Slim Bootloader. Use u-boot instead of u-boot-dtb.bin:

    $ python BuildLoader.py build <qemu or apl> -p "OsLoader.efi:LLDR:Lz4;u-boot:U-BT:Lzma"