public inbox for binutils@sourceware.org
 help / color / mirror / Atom feed
From: Nelson Chu <nelson@rivosinc.com>
To: Tsukasa OI <research_trasio@irq.a4lg.com>
Cc: Kito Cheng <kito.cheng@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	 Andrew Waterman <andrew@sifive.com>,
	binutils@sourceware.org
Subject: Re: [RFC PATCH 1/1] RISC-V: Add privileged extensions without instructions/CSRs
Date: Thu, 22 Sep 2022 16:48:22 +0800	[thread overview]
Message-ID: <CAPpQWtDAzB=_H1k895aFotZVwO0vKJ0-9t5pnfYeEYJ6CopwGg@mail.gmail.com> (raw)
In-Reply-To: <bd924e6658fa255b6d5bb5ee4bf21863f00ab5af.1663833488.git.research_trasio@irq.a4lg.com>

On Thu, Sep 22, 2022 at 3:59 PM Tsukasa OI <research_trasio@irq.a4lg.com> wrote:
>
> Currently, GNU Binutils does not support following privileged extensions:
>
> -   'Smepmp'
> -   'Svnapot'
> -   'Svpbmt'
>
> as they do not provide new CSRs or new instructions ('Smepmp' extends the
> privileged architecture CSRs but does not define the CSR itself).  However,
> adding them might be useful as we no longer have to "filter" ISA strings
> just for toolchains (if full ISA string is given by a vendor, we can
> straightly use it).

OKay.

Nelson

> And there's a fact that supports this theory: there's already an
> (unprivileged) extension which does not provide CSRs or instructions (but
> only an architectural guarantee): 'Zkt' (constant timing guarantee for
> certain subset of RISC-V instructions).
>
> This simple patchset simply adds three privileged extensions listed above.
>
> bfd/ChangeLog:
>
>         * elfxx-riscv.c (riscv_supported_std_s_ext): Add 'Smepmp',
>         'Svnapot' and 'Svpbmt' extensions.
> ---
>  bfd/elfxx-riscv.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
> index 7eda177bd6e..bbc30c9afc2 100644
> --- a/bfd/elfxx-riscv.c
> +++ b/bfd/elfxx-riscv.c
> @@ -1210,10 +1210,13 @@ static struct riscv_supported_ext riscv_supported_std_z_ext[] =
>
>  static struct riscv_supported_ext riscv_supported_std_s_ext[] =
>  {
> +  {"smepmp",           ISA_SPEC_CLASS_DRAFT,           1, 0, 0 },
>    {"smstateen",                ISA_SPEC_CLASS_DRAFT,           1, 0, 0 },
>    {"sscofpmf",         ISA_SPEC_CLASS_DRAFT,           1, 0, 0 },
>    {"sstc",             ISA_SPEC_CLASS_DRAFT,           1, 0, 0 },
>    {"svinval",          ISA_SPEC_CLASS_DRAFT,           1, 0, 0 },
> +  {"svnapot",          ISA_SPEC_CLASS_DRAFT,           1, 0, 0 },
> +  {"svpbmt",           ISA_SPEC_CLASS_DRAFT,           1, 0, 0 },
>    {NULL, 0, 0, 0, 0}
>  };
>
> --
> 2.34.1
>

  reply	other threads:[~2022-09-22  8:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-22  7:58 [RFC PATCH 0/1] " Tsukasa OI
2022-09-22  7:58 ` [RFC PATCH 1/1] " Tsukasa OI
2022-09-22  8:48   ` Nelson Chu [this message]
2022-09-22  9:44     ` Tsukasa OI
2022-09-30 15:44       ` Tsukasa OI

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAPpQWtDAzB=_H1k895aFotZVwO0vKJ0-9t5pnfYeEYJ6CopwGg@mail.gmail.com' \
    --to=nelson@rivosinc.com \
    --cc=andrew@sifive.com \
    --cc=binutils@sourceware.org \
    --cc=kito.cheng@sifive.com \
    --cc=palmer@dabbelt.com \
    --cc=research_trasio@irq.a4lg.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).