From: Andrew Cooper <Andrew.Cooper3@citrix.com>
To: Julien Grall <julien@xen.org>,
Oleksii Kurochko <oleksii.kurochko@gmail.com>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>,
Gianluca Guida <gianluca@rivosinc.com>,
Bob Eshleman <bobbyeshleman@gmail.com>,
Alistair Francis <alistair.francis@wdc.com>,
Connor Davis <connojdavis@gmail.com>
Subject: Re: [PATCH v1 4/8] xen/riscv: introduce sbi call to putchar to console
Date: Fri, 6 Jan 2023 15:19:07 +0000 [thread overview]
Message-ID: <8b6a9927-8a56-6fab-6658-deb4083d2c45@citrix.com> (raw)
In-Reply-To: <d77e7617-5263-0072-4786-ba6144247a4b@xen.org>
On 06/01/2023 1:40 pm, 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@gmail.com>
>> ---
>> 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.
That was already requested not to happen. Frankly, if I was an arm
maintainer I'd object to the how it's used there too, but RISCV is
massively more simple still.
Not even the pagetable setup, or the physical relocation (if even
necessary) needs doing in ASM.
I'm not completely ruling it out in the future, but someone is going to
have to come up with a very convincing argument for why they can't do
this piece of critical setup in C.
~Andrew
next prev parent reply other threads:[~2023-01-06 15:19 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-06 13:14 [PATCH v1 0/8] Basic early_printk and smoke test implementation Oleksii Kurochko
2023-01-06 13:14 ` [PATCH v1 1/8] xen/riscv: introduce dummy asm/init.h Oleksii Kurochko
2023-01-06 13:42 ` Julien Grall
2023-01-09 8:53 ` Oleksii
2023-01-06 13:14 ` [PATCH v1 2/8] xen/riscv: introduce asm/types.h header file Oleksii Kurochko
2023-01-06 14:12 ` Jan Beulich
2023-01-09 8:55 ` Oleksii
2023-01-06 13:14 ` [PATCH v1 3/8] xen/riscv: introduce stack stuff Oleksii Kurochko
2023-01-06 13:54 ` Julien Grall
2023-01-09 9:00 ` Oleksii
2023-01-06 14:15 ` Jan Beulich
2023-01-09 8:57 ` Oleksii
2023-01-06 14:55 ` Andrew Cooper
2023-01-06 13:14 ` [PATCH v1 4/8] xen/riscv: introduce sbi call to putchar to console Oleksii Kurochko
2022-12-20 6:23 ` Bobby Eshleman
2023-01-06 17:16 ` Andrew Cooper
2022-12-20 6:50 ` Bobby Eshleman
2023-01-09 13:01 ` Oleksii
2023-01-06 13:40 ` Julien Grall
2023-01-06 15:19 ` Andrew Cooper [this message]
2023-01-06 15:39 ` Julien Grall
2023-01-09 9:04 ` Oleksii
2023-01-09 11:11 ` Julien Grall
2023-01-06 15:19 ` Michal Orzel
2023-01-09 9:06 ` Oleksii
2023-01-06 13:14 ` [PATCH v1 5/8] xen/include: include <asm/types.h> in <xen/early_printk.h> Oleksii Kurochko
2023-01-06 13:45 ` Julien Grall
2023-01-06 13:14 ` [PATCH v1 6/8] xen/riscv: introduce early_printk basic stuff Oleksii Kurochko
2023-01-06 13:51 ` Julien Grall
2023-01-09 9:10 ` Oleksii
2023-01-09 11:14 ` Julien Grall
2023-01-06 13:14 ` [PATCH v1 7/8] xen/riscv: print hello message from C env Oleksii Kurochko
2023-01-06 13:14 ` [PATCH v1 8/8] automation: add RISC-V smoke test Oleksii Kurochko
2023-01-06 15:05 ` Andrew Cooper
2023-01-09 9:11 ` Oleksii
2023-01-06 13:51 ` [PATCH v1 0/8] Basic early_printk and smoke test implementation Andrew Cooper
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