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

[Oleksii <oleksii.kurochko@gmail.com>]

Hi,

On Fri, 2023-01-06 at 13:51 +0000, Julien Grall wrote:
> 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@gmail.com>
> > ---
> >   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?
> 
We can. It's my fault we wanted to start from RISCV_64 support so I
totally forgot about 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@gmail.com>
> 
> So the copyright here is from Bobby. But I don't see any mention in
> the 
> commit message. Where is this coming from?
> 
Could you please share with me an example how it should be look like?
Signed-off: ... ? Or "this file was taken from patch series ..."?
> > + */
> > +#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__ */
>