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

[Sergey Matyukevich]

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 at syntacore.com>

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

Regards,
Sergey