Re: [PATCH v3 0/3] serial: Add RISC-V support to the earlycon semihost driver

From: Sergey Matyukevich
Date: Thu Dec 22 2022 - 15:06:35 EST


Hi Bin,

> RISC-V semihosting spec [1] is built on top of the existing Arm one;
> we can add RISC-V earlycon semihost driver easily.
>
> This series refactors the existing driver a little bit, to move smh_putc()
> variants in respective arch's semihost.h, then we can implement RISC-V's
> version in the riscv arch directory.
>
> Link: https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc [1]
>
> Changes in v3:
> - add #ifdef in the header to prevent from multiple inclusion
> - add forward-declare struct uart_port
> - add a Link tag in the commit message
>
> Changes in v2:
> - new patch: "serial: earlycon-arm-semihost: Move smh_putc() variants in respective arch's semihost.h"
> - Move the RISC-V implementation to semihost.h
>
> Bin Meng (3):
> serial: earlycon-arm-semihost: Move smh_putc() variants in respective
> arch's semihost.h
> riscv: Implement semihost.h for earlycon semihost driver
> serial: Rename earlycon semihost driver
>
> arch/arm/include/asm/semihost.h | 30 +++++++++++++++++++
> arch/arm64/include/asm/semihost.h | 24 +++++++++++++++
> arch/riscv/include/asm/semihost.h | 26 ++++++++++++++++
> drivers/tty/serial/Kconfig | 14 ++++-----
> drivers/tty/serial/Makefile | 2 +-
> ...con-arm-semihost.c => earlycon-semihost.c} | 25 +---------------
> 6 files changed, 89 insertions(+), 32 deletions(-)
> create mode 100644 arch/arm/include/asm/semihost.h
> create mode 100644 arch/arm64/include/asm/semihost.h
> create mode 100644 arch/riscv/include/asm/semihost.h
> rename drivers/tty/serial/{earlycon-arm-semihost.c => earlycon-semihost.c} (57%)

Tested-by: Sergey Matyukevich <sergey.matyukevich@xxxxxxxxxxxxx>

Applied the patches on top of Linux 6.1 and tested earlycon logs from
RISC-V target in OpenOCD.

Regards,
Sergey