Re: [PATCH v1 6/8] xen/riscv: introduce early_printk basic stuff

[Julien Grall <julien@xxxxxxx>]

Hi,

On 06/01/2023 13:14, Oleksii Kurochko wrote:
> The patch introduces a basic stuff of early_printk functionality
> which will be enough to print 'hello from C environment"
>
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> ---
>   xen/arch/riscv/Kconfig.debug              |  7 ++++++
>   xen/arch/riscv/Makefile                   |  1 +
>   xen/arch/riscv/early_printk.c             | 27 +++++++++++++++++++++++
>   xen/arch/riscv/include/asm/early_printk.h | 12 ++++++++++
>   4 files changed, 47 insertions(+)
>   create mode 100644 xen/arch/riscv/early_printk.c
>   create mode 100644 xen/arch/riscv/include/asm/early_printk.h
>
> diff --git a/xen/arch/riscv/Kconfig.debug b/xen/arch/riscv/Kconfig.debug
> index e69de29bb2..940630fd62 100644
> --- a/xen/arch/riscv/Kconfig.debug
> +++ b/xen/arch/riscv/Kconfig.debug
> @@ -0,0 +1,7 @@
> +config EARLY_PRINTK
> +    bool "Enable early printk config"
> +    default DEBUG
> +    depends on RISCV_64
OOI, why can't this be used for RISCV_32?

> +    help
> +
> +      Enables early printk debug messages
> diff --git a/xen/arch/riscv/Makefile b/xen/arch/riscv/Makefile
> index 60db415654..e8630fe68d 100644
> --- a/xen/arch/riscv/Makefile
> +++ b/xen/arch/riscv/Makefile
> @@ -1,6 +1,7 @@
>   obj-$(CONFIG_RISCV_64) += riscv64/
>   obj-y += setup.o
>   obj-y += sbi.o
> +obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
Please order the files alphabetically.

>   
>   $(TARGET): $(TARGET)-syms
>         $(OBJCOPY) -O binary -S $< $@
> diff --git a/xen/arch/riscv/early_printk.c b/xen/arch/riscv/early_printk.c
> new file mode 100644
> index 0000000000..f357f3220b
> --- /dev/null
> +++ b/xen/arch/riscv/early_printk.c
> @@ -0,0 +1,27 @@
Please add an SPDX license (the default for Xen is GPLv2).

> +/*
> + * RISC-V early printk using SBI
> + *
> + * Copyright (C) 2021 Bobby Eshleman <bobbyeshleman@xxxxxxxxx>
So the copyright here is from Bobby. But I don't see any mention in the 
commit message. Where is this coming from?
> + */
> +#include <asm/sbi.h>
> +#include <asm/early_printk.h>
Please order the files alphabetically.

> +
> +void early_puts(const char *s, size_t nr)
> +{
> +    while ( nr-- > 0 )
> +    {
> +        if (*s == '\n')
> +            sbi_console_putchar('\r');
> +        sbi_console_putchar(*s);
> +        s++;
> +    }
> +}
> +
> +void early_printk(const char *str)
> +{
> +    while (*str)
> +    {
> +        early_puts(str, 1);
> +        str++;
> +    }
> +}
> diff --git a/xen/arch/riscv/include/asm/early_printk.h 
> b/xen/arch/riscv/include/asm/early_printk.h
> new file mode 100644
> index 0000000000..05106e160d
> --- /dev/null
> +++ b/xen/arch/riscv/include/asm/early_printk.h
> @@ -0,0 +1,12 @@
> +#ifndef __EARLY_PRINTK_H__
> +#define __EARLY_PRINTK_H__
> +
> +#include <xen/early_printk.h>
> +
> +#ifdef CONFIG_EARLY_PRINTK
> +void early_printk(const char *str);
> +#else
> +static inline void early_printk(const char *s) {};
> +#endif
> +
> +#endif /* __EARLY_PRINTK_H__ */
--
Julien Grall