On 8/17/20 6:35 AM, Heinrich Schuchardt wrote:

Provide a defconfig that can be used to build U-Boot for the Maix boards running upon OpenSBI.

Update the documentation.

Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de

v2: adjust MAINTAINERS

---

board/sipeed/maix/MAINTAINERS | 2 +- configs/sipeed_maix_smode_defconfig | 10 ++++++ doc/board/sipeed/maix.rst | 49 +++++++++++++++++++++++++++++ 3 files changed, 60 insertions(+), 1 deletion(-) create mode 100644 configs/sipeed_maix_smode_defconfig

diff --git a/board/sipeed/maix/MAINTAINERS b/board/sipeed/maix/MAINTAINERS index e7bb9ec433..969a0afbad 100644 --- a/board/sipeed/maix/MAINTAINERS +++ b/board/sipeed/maix/MAINTAINERS @@ -4,7 +4,7 @@ S: Maintained F: arch/riscv/dts/k210.dtsi F: arch/riscv/dts/k210-maix-bit.dts F: board/sipeed/maix/ -F: configs/sipeed_maix_bitm_defconfig +F: configs/sipeed_maix*_defconfig F: doc/board/sipeed/ F: include/configs/sipeed-maix.h F: include/dt-bindings/*/k210-sysctl.h diff --git a/configs/sipeed_maix_smode_defconfig b/configs/sipeed_maix_smode_defconfig new file mode 100644 index 0000000000..2516bb7258 --- /dev/null +++ b/configs/sipeed_maix_smode_defconfig @@ -0,0 +1,10 @@ +CONFIG_RISCV=y +CONFIG_SYS_TEXT_BASE=0x80020000 +CONFIG_TARGET_SIPEED_MAIX=y +CONFIG_ARCH_RV64I=y +CONFIG_RISCV_SMODE=y +CONFIG_STACK_SIZE=0x100000 +# CONFIG_NET is not set +# CONFIG_INPUT is not set +# CONFIG_DM_ETH is not set +# CONFIG_EFI_UNICODE_CAPITALIZATION is not set diff --git a/doc/board/sipeed/maix.rst b/doc/board/sipeed/maix.rst index b1894f3a6f..efcde9aebf 100644 --- a/doc/board/sipeed/maix.rst +++ b/doc/board/sipeed/maix.rst @@ -75,6 +75,49 @@ console shall be opened immediately. Boot output should look like the following: Err: serial@38000000 =>

+OpenSBI +^^^^^^^

+OpenSBI is an open source supervisor execution environment implementing the +RISC-V Supervisor Binary Interface Specification [1]. One of its features is +to intercept run-time exceptions, e.g. for unaligned access or illegal +instructions, and to emulate the failing instructions.

+The OpenSBI source can be downloaded via:

+.. code-block:: bash

• git clone https://github.com/riscv/opensbi

+As OpenSBI will be loaded at 0x80000000 we have to adjust the U-Boot text base. +Furthermore we have to enable building U-Boot for S-mode::

• CONFIG_SYS_TEXT_BASE=0x80020000
• CONFIG_RISCV_SMODE=y

+Both settings are contained in sipeed_maix_smode_defconfig so we can build +U-Boot with:

+.. code-block:: bash

• make sipeed_maix_smode_defconfig
• make

+To build OpenSBI with U-Boot as a payload:

+.. code-block:: bash

• cd opensbi
• make \
• PLATFORM=kendryte/k210 \
• FW_PAYLOAD=y \
• FW_PAYLOAD_OFFSET=0x20000 \
• FW_PAYLOAD_PATH=<path to U-Boot>/u-boot-dtb.bin

+The value of FW_PAYLOAD_OFFSET must match CONFIG_SYS_TEXT_BASE - 0x80000000.

+The file to flash is build/platform/kendryte/k210/firmware/fw_payload.bin.

Loading Images ^^^^^^^^^^^^^^

@@ -363,3 +406,9 @@ Address Size Description interrupts) 0x8801f000 0x1000 credits ========== ========= ===========

+Links +-----

+[1] https://github.com/riscv/riscv-sbi-doc

• RISC-V Supervisor Binary Interface Specification

-- 2.28.0

Reviewed-by: Sean Anderson seanga2@gmail.com