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From:   Huacai Chen <chenhuacai@kernel.org>
Date:   Mon, 10 Jul 2023 15:53:22 +0800
Message-ID: <CAAhV-H7ihMnYD3LZi4kfJ1SQHxpX=j8D39Riinbvbb0AMo2oDg@mail.gmail.com>
Subject: Re: [PATCH] loongarch: Make CONFIG_CMDLINE work with
 CONFIG_CMDLINE_EXTEND and CONFIG_CMDLINE_BOOTLOADER
To:     donmor <donmor3000@hotmail.com>
Cc:     "loongarch@lists.linux.dev" <loongarch@lists.linux.dev>,
        "kernel@xen0n.name" <kernel@xen0n.name>,
        "yangtiezhu@loongson.cn" <yangtiezhu@loongson.cn>,
        "zhoubinbin@loongson.cn" <zhoubinbin@loongson.cn>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "ardb@kernel.org" <ardb@kernel.org>,
        "tangyouling@loongson.cn" <tangyouling@loongson.cn>
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On Mon, Jul 10, 2023 at 1:35=E2=80=AFAM =E2=80=8E donmor <donmor3000@hotmai=
l.com> wrote:
>
> =E5=9C=A8 2023-07-09=E6=98=9F=E6=9C=9F=E6=97=A5=E7=9A=84 23:30 +0800=EF=
=BC=8CHuacai Chen=E5=86=99=E9=81=93=EF=BC=9A
> > How to reproduce? If you use UEFI firmware, this is handled in
> > drivers/firmware/efi/libstub/efi-stub.c; if you use non-UEFI firmware,
> > this is handled in drivers/of/fdt.c.
>
> In fact it 's not command line retrieved from efi or fdt, but the built-i=
n
> command line to be concerned. CONFIG_CMDLINE was never been touched durin=
g
> boot on loongarch, unless CONFIG_CMDLINE_FORCE is set because there is co=
de
> handling this. There should be code handling CONFIG_CMDLINE_FORCE and
> CONFIG_CMDLINE_EXTEND as well but is absent by now.

I mean the code in drivers/of/fdt.c already handles
CONFIG_CMDLINE_EXTEND and CONFIG_CMDLINE_FORCE, understand?

On the other hand, I found that for non-FDT system
CONFIG_CMDLINE_FORCE indeed doesn't work, but
CONFIG_CMDLINE_BOOTLOADER works, so you needn't fix
CONFIG_CMDLINE_BOOTLOADER, and you need add "goto out" in the "if
(initial_boot_params)" condition.

Huacai