Add instructions to build U-Boot for the Milk-V Mars board
Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com --- v3: no change v2: describe how to preset fdtfile --- doc/board/starfive/index.rst | 1 + doc/board/starfive/milk-v_mars.rst | 111 +++++++++++++++++++++++++++++ 2 files changed, 112 insertions(+) create mode 100644 doc/board/starfive/milk-v_mars.rst
diff --git a/doc/board/starfive/index.rst b/doc/board/starfive/index.rst index 0c52dc7b095..2762bf74c11 100644 --- a/doc/board/starfive/index.rst +++ b/doc/board/starfive/index.rst @@ -6,4 +6,5 @@ StarFive .. toctree:: :maxdepth: 1
+ milk-v_mars.rst visionfive2 diff --git a/doc/board/starfive/milk-v_mars.rst b/doc/board/starfive/milk-v_mars.rst new file mode 100644 index 00000000000..554932ecfd4 --- /dev/null +++ b/doc/board/starfive/milk-v_mars.rst @@ -0,0 +1,111 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +Milk-V Mars +=========== + +U-Boot for the Milk-V Mars uses the same U-Boot binaries as the VisionFive 2 +board. In U-Boot SPL the actual board is detected and the device-tree patched +accordingly. + +Building +~~~~~~~~ + +1. Add the RISC-V toolchain to your PATH. +2. Setup ARCH & cross compilation environment variable: + +.. code-block:: none + + export CROSS_COMPILE=<riscv64 toolchain prefix> + +The M-mode software OpenSBI provides the supervisor binary interface (SBI) and +is responsible for the switch to S-Mode. It is a prerequisite to build U-Boot. +Support for the JH7110 was introduced in OpenSBI 1.2. It is recommended to use +a current release. + +.. code-block:: console + + git clone https://github.com/riscv/opensbi.git + cd opensbi + make PLATFORM=generic FW_TEXT_START=0x40000000 FW_OPTIONS=0 + +Now build the U-Boot SPL and U-Boot proper. + +.. code-block:: console + + cd <U-Boot-dir> + make starfive_visionfive2_defconfig + make OPENSBI=$(opensbi_dir)/build/platform/generic/firmware/fw_dynamic.bin + +This will generate the U-Boot SPL image (spl/u-boot-spl.bin.normal.out) as well +as the FIT image (u-boot.itb) with OpenSBI and U-Boot. + +Device-tree selection +~~~~~~~~~~~~~~~~~~~~~ + +Depending on the board version U-Boot set variable $fdtfile to either +starfive/jh7110-starfive-visionfive-2-v1.2a.dtb or +starfive/jh7110-starfive-visionfive-2-v1.3b.dtb. + +To overrule this selection the variable can be set manually and saved in the +environment + +:: + + setenv fdtfile my_device-tree.dtb + env save + +or the configuration variable CONFIG_DEFAULT_FDT_FILE can be used to set to +provide a default value. + +Boot source selection +~~~~~~~~~~~~~~~~~~~~~ + +The board provides the DIP switches MSEL[1:0] to select the boot device out of +SPI flash, eMMC, SD-card, UART. To select booting from SD-card set the DIP +switches MSEL[1:0] to 10. + +Preparing the SD-Card +~~~~~~~~~~~~~~~~~~~~~ + +The device firmware loads U-Boot SPL (u-boot-spl.bin.normal.out) from the +partition with type GUID 2E54B353-1271-4842-806F-E436D6AF6985. You are free +to choose any partition number. + +With the default configuration U-Boot SPL loads the U-Boot FIT image +(u-boot.itb) from partition 2 (CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=0x2). +When formatting it is recommended to use GUID +BC13C2FF-59E6-4262-A352-B275FD6F7172 for this partition. + +The FIT image (u-boot.itb) is a combination of OpenSBI's fw_dynamic.bin, +u-boot-nodtb.bin and the device tree blob. + +Format the SD card (make sure the disk has GPT, otherwise use gdisk to switch) + +.. code-block:: bash + + sudo sgdisk --clear \ + --set-alignment=2 \ + --new=1:4096:8191 --change-name=1:spl --typecode=1:2E54B353-1271-4842-806F-E436D6AF6985\ + --new=2:8192:16383 --change-name=2:uboot --typecode=2:BC13C2FF-59E6-4262-A352-B275FD6F7172 \ + --new=3:16384:1654784 --change-name=3:system --typecode=3:EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 \ + /dev/sdb + +Copy U-Boot to the SD card + +.. code-block:: bash + + sudo dd if=u-boot-spl.bin.normal.out of=/dev/sdb1 + sudo dd if=u-boot.itb of=/dev/sdb2 + + sudo mount /dev/sdb3 /mnt/ + sudo cp u-boot-spl.bin.normal.out /mnt/ + sudo cp u-boot.itb /mnt/ + sudo cp Image.gz /mnt/ + sudo cp initramfs.cpio.gz /mnt/ + sudo cp jh7110-starfive-visionfive-2.dtb /mnt/ + sudo umount /mnt + +Booting +~~~~~~~ + +Once you plugin the sdcard and power up, you should see the U-Boot prompt.