Re: [PATCH v1 4/8] xen/riscv: introduce sbi call to putchar to console

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

Hi,

On Fri, 2023-01-06 at 13:40 +0000, Julien Grall wrote:
> Hi,
> 
> On 06/01/2023 13:14, Oleksii Kurochko wrote:
> > The patch introduce sbi_putchar() SBI call which is necessary
> > to implement initial early_printk
> > 
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> > ---
> >   xen/arch/riscv/Makefile          |  1 +
> >   xen/arch/riscv/include/asm/sbi.h | 34 ++++++++++++++++++++++++
> >   xen/arch/riscv/sbi.c             | 44
> > ++++++++++++++++++++++++++++++++
> 
> IMHO, it would be better to implement sbi.c in assembly so you can
> use 
> print in the console before you jump to C world.
> 
I thought that we can live with C version as we set up stack from the
start and then we can call early_printk() from assembly code too.
Is it bad approach?

> >   3 files changed, 79 insertions(+)
> >   create mode 100644 xen/arch/riscv/include/asm/sbi.h
> >   create mode 100644 xen/arch/riscv/sbi.c
> > 
> > diff --git a/xen/arch/riscv/Makefile b/xen/arch/riscv/Makefile
> > index 5a67a3f493..60db415654 100644
> > --- a/xen/arch/riscv/Makefile
> > +++ b/xen/arch/riscv/Makefile
> > @@ -1,5 +1,6 @@
> >   obj-$(CONFIG_RISCV_64) += riscv64/
> >   obj-y += setup.o
> > +obj-y += sbi.o
> 
> Please order the filename alphabetically.
> 
> Cheers,
>