[PATCH 0/5] Convert Lichee Pi 4A to use S-Mode proper U-Boot

[Ricardo B. Marlière]

On Fri May 30, 2025 at 6:48 AM -03, Yao Zi wrote:
> RISC-V software usually expects that HARTs are running under S mode when
> leaving the firmware, for example, the UEFI specification explicitly
> states requirements for S mode.
>
> This series separates M-mode-only code for TH1520 port out, and
> configures binman to pack the OpenSBI firmware to initialize the S-mode
> environment. Then S-mode proper U-Boot is enabled on our Lichee Pi 4A
> port.
>
> Note that booting on Lichee Pi 4A is broken between PATCH 3 and 4,
> affecting bisectability. Considering TH1520 port is still in an early
> stage and separating the changes make the commit cleaner, I personally
> consider it's acceptable.
>
> Yao Zi (5):
>   riscv: cpu: th1520: Build spl.c for SPL only
>   riscv: cpu: th1520: Support cache enabling/disabling in M mode only
>   riscv: dts: th1520: Prepare binman configuration for loading OpenSBI
>   board: thead: licheepi4a: Run proper U-Boot in S-Mode
>   doc: thead: lpi4a: Update for S-Mode proper U-Boot support
>
>  arch/riscv/cpu/th1520/Makefile          |   2 +-
>  arch/riscv/cpu/th1520/cache.c           |   2 +
>  arch/riscv/dts/thead-th1520-binman.dtsi |  32 +++++-
>  configs/th1520_lpi4a_defconfig          |   1 +
>  doc/board/thead/lpi4a.rst               | 125 +++++++-----------------
>  5 files changed, 68 insertions(+), 94 deletions(-)

I also tested with OpenSBI 1.6 on a Lichee Pi 4A 8GB.

Tested-by: Ricardo B. Marlière <ricardo at marliere.net>