configs: defconfig for Sipeed Maix in S-mode

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>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
This commit is contained in:
Heinrich Schuchardt 2020-08-17 12:35:39 +02:00 committed by Andes
parent 092f15aee5
commit 27cef4e4a3
3 changed files with 60 additions and 1 deletions

View file

@ -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

View file

@ -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

View file

@ -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