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Date:   Tue, 30 Mar 2021 10:27:14 -0700
From:   Daniel Walker <danielwa@cisco.com>
To:     Christophe Leroy <christophe.leroy@csgroup.eu>
Cc:     will@kernel.org, robh@kernel.org,
        daniel@gimpelevich.san-francisco.ca.us, linux-arch@vger.kernel.org,
        devicetree@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        microblaze <monstr@monstr.eu>, linux-mips@vger.kernel.org,
        nios2 <ley.foon.tan@intel.com>, openrisc@lists.librecores.org,
        linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org,
        x86@kernel.org, linux-xtensa@linux-xtensa.org,
        linux-sh@vger.kernel.org, sparclinux@vger.kernel.org
Subject: Re: [PATCH v3 01/17] cmdline: Add generic function to build command
 line.
Message-ID: <20210330172714.GR109100@zorba>
References: <cover.1616765869.git.christophe.leroy@csgroup.eu>
 <878228ad88df38f8914c7aa25dede3ed05c50f48.1616765869.git.christophe.leroy@csgroup.eu>
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In-Reply-To: <878228ad88df38f8914c7aa25dede3ed05c50f48.1616765869.git.christophe.leroy@csgroup.eu>
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On Fri, Mar 26, 2021 at 01:44:48PM +0000, Christophe Leroy wrote:
> This code provides architectures with a way to build command line
> based on what is built in the kernel and what is handed over by the
> bootloader, based on selected compile-time options.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> v3:
> - Addressed comments from Will
> - Added capability to have src == dst
> ---
>  include/linux/cmdline.h | 57 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 57 insertions(+)
>  create mode 100644 include/linux/cmdline.h
> 
> diff --git a/include/linux/cmdline.h b/include/linux/cmdline.h
> new file mode 100644
> index 000000000000..dea87edd41be
> --- /dev/null
> +++ b/include/linux/cmdline.h
> @@ -0,0 +1,57 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LINUX_CMDLINE_H
> +#define _LINUX_CMDLINE_H
> +
> +#include <linux/string.h>
> +
> +/* Allow architectures to override strlcat, powerpc can't use strings so early */
> +#ifndef cmdline_strlcat
> +#define cmdline_strlcat strlcat
> +#endif
> +
> +/*
> + * This function will append or prepend a builtin command line to the command
> + * line provided by the bootloader. Kconfig options can be used to alter
> + * the behavior of this builtin command line.
> + * @dst: The destination of the final appended/prepended string.
> + * @src: The starting string or NULL if there isn't one.
> + * @len: the length of dest buffer.
> + */

Append or prepend ? Cisco requires both at the same time. This is why my
implementation provides both. I can't use this with both at once.

Daniel